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Author Topic:   Repairing Hull Damage the Whaler Way
jimh posted 11-17-2002 09:15 AM ET (US)   Profile for jimh   Send Email to jimh  
Please use this message thread for questions and comments on the REFERENCE article, "Repairing Hull Damage the Whaler Way," written and photographed by Taylor Clark.


GAwhale posted 11-17-2002 09:56 AM ET (US)     Profile for GAwhale  Send Email to GAwhale     
Amazing site.
Amazing people.
Amazing boat.
Barnett Childress posted 11-17-2002 10:04 AM ET (US)     Profile for Barnett Childress  Send Email to Barnett Childress     
Great article and pictures! Makes it much easier to imagine taking on a project like that yourself. Great job.
acassidy posted 11-17-2002 10:26 AM ET (US)     Profile for acassidy  Send Email to acassidy     
That's just a great addition to this site. Thank you so much for adding it. Super awesome!!!!!!!!!!!!!!
Whaler Proud posted 11-17-2002 10:39 AM ET (US)     Profile for Whaler Proud  Send Email to Whaler Proud     
Obviously Tom is a very gifted craftsman in any medium. Excellent article and work.

Did Tom include the fiberglas repair instructions in his CD?

Jimm posted 11-17-2002 11:07 AM ET (US)     Profile for Jimm  Send Email to Jimm     
What a feeling of accomplishment you both must have had when the project was complete. My hat is off to two skilled craftsmen...Jim
Marlin posted 11-17-2002 12:46 PM ET (US)     Profile for Marlin  Send Email to Marlin     
Wow. When I saw your initial picture, I just groaned. By the time I got to the end, I was simply amazed. I never would have believed you could get results like that.

Now I look back on my previous glass repairs, and think "geez, I'm a ham-fisted klutz". Thanks a lot, guys...


lae posted 11-17-2002 01:05 PM ET (US)     Profile for lae  Send Email to lae     
Nice looking repair. Taylor, only things left to do are send flowers to Christina (never know when you will be attacked by another dock) and list the beer tally so that we know what to budget when it happens to us. Nice job Tom.
David Jenkins posted 11-17-2002 01:21 PM ET (US)     Profile for David Jenkins  Send Email to David Jenkins     
Excellent work, Taylor and Tom. Can we make the official Boston Whaler repair instructions part of this site by either scanning them or re-typing them? If not, could you tell me how do you know how much chopped glass to add to the resin as filler. And when you said "one-inch strips" do you mean one-inch squares? Also, could you elaborate a bit more about how you created and used wooden blocks to re-do the chine line? Thanks!
dscew posted 11-17-2002 03:49 PM ET (US)     Profile for dscew  Send Email to dscew     
Can you really tow a Montauk with a 325? Really?
11 footer posted 11-17-2002 04:26 PM ET (US)     Profile for 11 footer  Send Email to 11 footer     
Sure looks that way. :0


weekendwarrior posted 11-17-2002 06:34 PM ET (US)     Profile for weekendwarrior  Send Email to weekendwarrior     
Stellar work! Thankfully I haven't had to do this yet but I have filed this in the back of my head and I know where to go if I ever need to do this. Great article!

DaveNJ posted 11-18-2002 07:10 AM ET (US)     Profile for DaveNJ  Send Email to DaveNJ     
Great article and photos! WOW! I am about to start some similar repairs and I am glad I was able to read this before starting.

Thanks for taking the time and effort to document so thoroughly. I really love this website and it is the people that make it great. First class all the way.


jimh posted 11-18-2002 09:13 AM ET (US)     Profile for jimh  Send Email to jimh     
In the photograph with the caption "Painting Gel Coat", I notice that the gel coat being applied by Tom is noticeably lighter in shade than the hull.

Does the gel coat color darken slightly as it dries?

The match seems excellent in later pictures.

Jerry Townsend posted 11-18-2002 11:51 AM ET (US)     Profile for Jerry Townsend  Send Email to Jerry Townsend     
Taylor, Tom and Jim - very good reference article - Thanks. The pictures are very beneficial in showing how the repair was expertly done. Thanks again ---- Jerry/Idaho
Arch Autenreith posted 11-18-2002 12:09 PM ET (US)     Profile for Arch Autenreith  Send Email to Arch Autenreith     
Very nice article and account Taylor and Tom.

I had a similar major repair and see the similarities. You brought back those painful memories I had of "Good gosh. Now what?" to "Whew!! That job turned out better than I ever expected."

I didn't gelcoat to hide the repair but after seeing what you did I think I will.

Again, thanks to both. And jimh for publishing.


Taylor posted 11-18-2002 01:30 PM ET (US)     Profile for Taylor  Send Email to Taylor     
David - good questions.

Regarding the instructions, they contain some hand drawings describing the process, so we really need a scan. lhg is mailing me a clean copy to scan since Tom's looked pretty bad by the time I finished pawing it with dirty hands.

The purpose of the 1" strips is just to make it easier to pull the individual fibers to pieces. The fiberglass used in the mash layer are individual short fibers mostly less than 1 1/2" long, organized like "pick up sticks", in other words, random loose fibers.

On reforming the chine, the outer surface is easier, you carry the plane of the relatively flat side of the boat down, sanding with large flat blocks. The harder part is the shaping the underside of the chine. The outside angle of the chine (between the upper side of the boat and the under side of the chine) is close to a right angle. But the angle formed by the underside of the chine and the lower hull is greater than 90 degrees, more like 115. That's where Tom made a block to match the angle. We ended up covering just the top face of the block with sandpaper, because it was the underside of the chine that needed the forming, but running the other face of the block along the lower hull enabled us to get the underside of the chine at the correct angle.

Actually, the angle of the chine to the lower hull varies from place to place, so a couple of different angled blocks would help. One for forward, one futher aft.

The curve of the chine faired smooth by eye. Tom was much better at this. The one one little wow that was left was a result of my over sanding one spot with the tail of my block. Ironically this was a part of the chine that had not been damaged. Long strokes key.

Tom W Clark posted 11-18-2002 01:37 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
Taylor had already asked me if I had scanned copies of the repair instructions. Jim then asked us the same thing. I think we can get Jim to help us get something posted soon.

We produced chopped fibers by cutting up some glass cloth (at a 45 degree angle to the fibers) into c. 1” strips and then simply pulling the fibers apart with our fingers. This produced a nice fluffy pile of fibers about 1” to 1.5” long.

The instructions call for adding fibers to the catalyzed resin to produce a “stiff mash” and that’s what we did. Taylor catalyzed some resin in a paper cup and then we just added fibers and mixed them up until we thought we had what we needed. It was a pretty intuitive process.

The wood sanding blocks that Taylor described were used to sand the under side of the chine where it meets the lower hull. These two planes meet at an angle greater than 90 degrees, maybe something like 120 degrees. The two planes do not meet in a sharp corner of course, so the block needed to be rounded over as well.

I just used a piece of 1” or 1.25” material and ran one edge over my jointer until I had the desired angle then I radiused the edge until it fit up in there just right. By doing this we were able to use the intersection of chine and hull as a guide to run this sand paper covered block back and forth and maintain the shape and get the repair really fair in a spot that would otherwise be difficult to deal with.

jimh, I’m looking at that photo and I do not see the gelcoat as lighter than the rest of the hull. In fact it looks darker but that is mostly because it is shiny and is reflecting the light differently that the roughed up gelcoat of the hull.

In fact, the gelcoat we used was a tiny bit lighter than the hull. We too wondered if it would dry darker but it does not. Gelcoat maintains its color from liquid to solid.

I had anticipated that the gelcoat from Spectrum would be a bit darker, not lighter, because these hulls typically get a bit bleached by UV rays over time (at least that has been my experience with my boats) but Taylor's boat is fairly new (1988) and has been very well cared for.

In the end, the difference in color was very hard for me to perceive and Taylor decided not to mess with it though he did purchase some black and white coloring to adjust the color up or down.

The only place where the two colors (new and old) meet on a flat plane is on the right side of the repair. It helps that the registration numbers go over this area. There is no way you will be able to see the difference in a photo. You really need to get your face right it too it in a good light to see any evidence of the patch.

Taylor posted 11-18-2002 01:42 PM ET (US)     Profile for Taylor  Send Email to Taylor     
Jim - I'm not sure I recall the before and after hardening color of the gelcoat. Tom?

Larry - Angel and I took Tom and Christina to dinner at Bruke's Creole Cafe in Ballard, it was the least we could do. . Great place.

How much beer? That would depend. The deal was that anytime we needed more, Tom would just walk me and my wallet over to the nearby convenience store. I'm not sure I was keeping a careful tally.

Towing with a 325? Well, it handles really really well. Its certainly not recommended by the manufactuer (I asked) but we went almost 600 miles on the round trip. I think its the transmission that may be the weakest link. Time will tell. Tom has in several posts tried to make the point that it does not take a big truck or SUV to pull a Montauk. Boat, engine and trailer I would estimate at just shy of 2000#, and lots of cars have [i]rated[i/] towing capacity to handle that. Things like the Subaru Imprezza WRX, and the Audi S4 Avant, and the Volco V70 XC, the Saab 9-5 Aero Wagan. Yeah (yeah, I like those little performance wagons)

Taylor posted 11-18-2002 01:58 PM ET (US)     Profile for Taylor  Send Email to Taylor     
Tom and I are playing tag team posting here...

Bob - 'ham-fisted klutz'? I think not. While Tom is certainly a craftsman (he is a professional contractor, and from what I can tell, pretty good at it) and I'm what you might call a dedicated amateur, this was some new ground for both of us. I think in the end if you allocate enough time, and work carefully, a reasonably handy boat owner should be able to get good results. I think we sometimes tend to hurry our projects. Nice thing about the Whaler instructions, is that it gives you a chance to take the job step by step.

Dr T posted 11-18-2002 03:24 PM ET (US)     Profile for Dr T  Send Email to Dr T     
This a tremendous addition to the web site.

Since my so-called repairs look closer to where you started than where you finished, I can honestly say that I aspire to be a Ham-Fisted Klutz.

Craftwmanship like this is an inspiration. I may even go grind out some old repairs and do it again properly.


lhg posted 11-18-2002 04:15 PM ET (US)     Profile for lhg    
I am very happy to see this excellently produced reference article on ContinuousWave. I have always thought that Classic Whalers required special techniques of repair since seeing the offical Whaler process detailed on these "Repair Kit" instruction sheets. Fixing a Whaler is not the same as fixing a single skinned hull.

The West people, with their own highly regarded repair manual, have unwittingly added confusion to the Whaler hull repair process, while at the same time doing a great job marketing their material. But their manual does not apply specifically to repair of Whaler hulls, and is some case could actually promote further damage or delamination of the hull. Their main purpose in publishing their Fiberglass repair publication, of course, is to sell West material for the huge majority of boats in the world, those with single skin hulls. For these purposes everyone seems to indicate it is an excellent material, although somewhat difficult to work with.

I have examined both the West manual and Whaler's instructions, and the repair process required by Whaler is simply not in the West manual. West has never indicated that their methods are for Boston Whalers.

So hopefully, Tom and Taylor's work will be a great benefit to those needing to do hull repair on their Whalers.

The one thing that has always impressed me with Boston Whaler, particularly during the "Classic" days, was an obsession with outfitting and detailing the boat, and components, for the bad days of boating, when weather and other conditions unexpectedly turn against the boater, and things get serious. Everything, including the little details, is designed to protect the occupants from disaster when the going gets bad. Safety rails, firmly attached, Mills canvas that REALLY protects, battery boxes and straps that hold, hull drains that work on their own rather than a reliance on $15 pumps, kickers firmly attached to the hull rather than on brackets that can fail, and, hull repair instructions like these that won't fail when you need them most. Almost all boats are safe for the fair weather days, but what appears to be Whaler "overdesign" on those same days is what you need to survive on the bad days.

Never rig or repair your Whaler based on what is required for fair weather conditions. Always assume the worst, and plan your rigging work for that day.

David Jenkins posted 11-18-2002 06:47 PM ET (US)     Profile for David Jenkins  Send Email to David Jenkins     
Are there really a lot of differences between the West System method and the official Whaler instructions? The Whaler way emphasizes digging out the foam so that the bond can be made to both sides of the existing fiberglass, but I don't see how this contradicts anything in the West instructions--it just makes sense when you have a foam-filled hull. As far as using polyester or epoxy resin, I find Jim Watson's explanation of primary and secondary bonds (in the radio section of this website) to be convincing. Whaler used polyester resin when making the boat because it makes a good primary bond and it is two-to-four times cheaper than epoxy resin. Polyester resin makes a satisfactory secondary bond, but it is my understanding from reading Allan H Vaitses, The Fiberglass Boat Repair Manual (page 28)that epoxy makes a stronger secondary bond and is more water resistant than a bond made with polyester resin. Neither type of resin will damage the foam. The only disadvantages I see to using West System's epoxy are that it is more expensive and you have to wash it with soap and water before top coating with gelcoat. Or am I missing something?
Arch Autenreith posted 11-18-2002 11:27 PM ET (US)     Profile for Arch Autenreith  Send Email to Arch Autenreith     
Whenever we have a discussion on Whaler hull repair there seems to be two different camps: The 'Whaler way' and 'anything else'.

There are numerous other posts relating to hull repair here and I still respectfully disagree that every repair is to be done as the way Taylor and Tom did it. (I noted earlier that it is a beautiful job.)

There simply will never be only one way to repair anything. Never has. New materials and methods are always being developed.

Just me thoughts.


Matthew posted 11-18-2002 11:38 PM ET (US)     Profile for Matthew  Send Email to Matthew     
Taylor and Tom,

Fantastic article and a great repair!

I cringed when you explained the damage to me at Hale's. I shouted an expletive when I saw the pictures on the Site (which my two year old promptly shouted right).

That away to jump in and pull an oar Tom.

I'm lucky to know the two newest owners of my local Boston Whaler repair shop!


JM325iX posted 11-19-2002 02:17 AM ET (US)     Profile for JM325iX  Send Email to JM325iX     
Taylor and Tom, great article! I too damaged my 13' Whaler (at the Swinomish launch) and Ihg sent me those very same instructions. It worked really well.

Taylor...I drive a BMW 325iX, similar to yours but never even thought of towing my Whaler with it. I might now give it a try.

I am in Bellingham, work in Anacortes, we should get together sometime!

JM325iX posted 11-19-2002 02:19 AM ET (US)     Profile for JM325iX  Send Email to JM325iX     
Taylor and Tom, great article! I too damaged my 13' Whaler (at the Swinomish launch) and Ihg sent me those very same instructions. It worked really well.

Taylor...I drive a BMW 325iX, similar to yours but never even thought of towing my Whaler with it. I might now give it a try.

I am in Bellingham, work in Anacortes, we should get together sometime!

Taylor posted 11-19-2002 12:53 PM ET (US)     Profile for Taylor  Send Email to Taylor     
I certainly did not mean to imply from the title that there was only one way to go. In my case, I've worked with polyester resins a few times before, and my epoxy experience is more limited. and we had a complete set of instructions in front of use, so we followed them. As we got into the repair, I began to realize, based on the evidence in front of me, that there are some differences in repairing a whaler hull. The skin is thinner, it is all multidirectional fibers, and there is no access to the back of the repair. I think the instructions that we had dealt with those problems well.

But there is certainly more than one way to skin a cat. Arch is right. Its tough when you have two or more methods to choose from, its easy to think that one is right, and the others wrong. I don't know about the other ways, but this way worked just great.

Gep posted 11-19-2002 04:06 PM ET (US)     Profile for Gep  Send Email to Gep     
Taylor and Tom,
Great article and great job on the restoration!
Can you use West system epoxy and do the repair per the Whaler instructions or do you have to use resin?
Arch Autenreith posted 11-19-2002 05:51 PM ET (US)     Profile for Arch Autenreith  Send Email to Arch Autenreith     
Taylor (and Tom).
Please don't think for a moment that I thought you were referring to only one way to repair. I didn't mean it and I'm sorry for the confusion.
Your job is truly spectacular.
David Jenkins posted 11-19-2002 07:33 PM ET (US)     Profile for David Jenkins  Send Email to David Jenkins     
I completely agree with Arch. Thank you, Taylor and Tom and lhg. These are the kind of articles and threads and discussions that make this web site a pleasure to visit.
Tom W Clark posted 11-20-2002 12:45 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
Thank you all for the kind words, but I have to disagree with a few of the themes here. This repair turned out well NOT because of any special talent of Taylor's or mine. It worked out well because we had a plan and stuck with it until we got it where we wanted it. I am sure that any Whaler owner could have gotten the same results if only they were patient and methodical.

This is the beauty of fiberglass and Boston Whalers. They are simple. Whaler's do have a unique hull construction method and thus require different approaches to the repair of them.

I agree that there is more than one way to skin a cat. I am also sure that this repair could have been accomplished with epoxy, I'm just not sure why one would choose to do so.

In order to convince me that I should use epoxy resin to repair a Whaler hull you need to convince me there is an advantage to using epoxy. I do not think there is an advantage and there may be some disadvantages, thus I recommend using polyester resin for the repair.

If you tell me that epoxy resin is stronger than polyester resin, I will not disagree with you. Epoxy is both stronger and more flexible than polyester resin. But the notion that epoxy will stick and polyester resin won't is false. If you tell me epoxy will stick better than polyester resin and that the bond of polyester resin is not sufficient then I have to say that's utter nonsense.

If you go to your local boat yard and ask them to repair your Whaler (or other fiberglass boat) they're going to use polyester resin. Ask them to use epoxy and they'll likely laugh you right out the door.

If you do make a repair using epoxy you will spend a bit more money buying the materials and you might have a harder time finding the stuff. Once the patch is in place you will have a more difficult time grinding and fairing the patch down as epoxy is typically harder that polyester. This is going to make it difficult to fair the repair with the rest of the hull.

And then you are going to have to deal with the incompatibility of gelcoat and epoxy. This can be overcome by removal of the blush with soap and water but I have heard too many reports of gelcoat no sticking well to epoxy for me to want to risk it.

I guarantee you that Taylor’s patch is not going to fall out nor will it delaminate because we used polyester resin. If Taylor will just give me the keys, I will take his boat up to Neah Bay and give his boat a thorough abuse test and see if I can get the patch to pop out. Then we’ll know. What do you say Taylor?

No really, do you think that a Whaler, which is made of polyester resin, is going to fail somehow because a small (or large) repair was made of polyester resin?

Regarding epoxy: West System epoxy may be as good as any on the market. It certainly is the best marketed epoxy, but there are many other brands of epoxy out there. There seems to be this cult of “West System” here on continuousWave which would have you believe that West System is the stuff to use.

I love epoxy. I use it all the time in my business. I have far more epoxy in my shop that polyester resin. For my part I prefer to use System Three Resins . I like System Three because it is a local manufacturer (their warehouse used to be just down the road from me in Ballard, though they are now in Auburn near Spectrum Color). They have a repair book (downloadable from their site) just as West System does. I have had great success with their products and always have some of their five minute epoxy on hand. It’s also sold just about everywhere in Seattle including my primary lumberyard.

If you really want the Rolls Royce of epoxy then you want to get some from Industrial Formulators of Canada. They are the makers of the famous “Cold Cure” epoxy.

Epoxy is great stuff and can be used for many, many different things where polyester resin would not be satisfactory to me. But for a boat repair like this I would use polyester resin.

lhg posted 11-20-2002 05:16 PM ET (US)     Profile for lhg    
Well said, Tom, and a great repair job on Taylor's boat, also. We are all very frotunate to have your participation on this site. Now, if you'd only get back into a Whaler!! I may know of a mint, one owner 1973 19' Classic Outrage, with twin OMC's (what could be better) on it, coming up for sale in the Spring, that you may not be able to resist. Garage kept, fresh water, no bottom paint, not used for 23 years except for annual fogging and test of engines.
jimh posted 11-23-2002 01:12 PM ET (US)     Profile for jimh  Send Email to jimh     
The follow-up comments from Tom Clark are really very much appreciated, and they raise a point that is seldom mentioned: the difference in abrasion resistance between epoxy and polyester resin.

After a repair has been made, if the surface needs to be sanded and faired, you will find that unthickened epoxy will be removed at a much slower rate than gel coat or polyester resins. This may create additional problems in obtained a smooth surface.

However, it is typical for the surface layers of an epoxy repair to be thickended with low-density fillers, precisely to improve the ability of the epoxy to be faired.

When I initially began to use WEST System products, their widespread availability was the primary reason I chose them. Walk into most any marine store and there is a West Systems product section. (Perhaps that is due to high margins!)

The SYSTEM THREE products are also well-known. The founder of that company, Kern Hendricks, used to be very active in the USENET forum and posted much great information.

Taylor posted 11-23-2002 02:35 PM ET (US)     Profile for Taylor  Send Email to Taylor     
One reason that that I had for working on this article (other than fact that Tom needled me to do it :) was that after the repair work was complete, I gave the leftover materials to my friend Peggy and she asked me exactly how to use them to repair some smaller holes and cracks in her Montauk. All I could do is jot down some inadequate notes. Tom as now scanned the pictures of the whaler instructions, and they will probably appear in due course as a link within the article. I hope that others will be able to fix their own boats with more confidence after seeing how someone else did it.

So if you are getting ready to tackle a job, feel free to ask questions on the forum (here perhaps) and then let us know how it goes. I'd love to see some other repair efforts and results, if only to know that that I'm not the only one to screw up their boat.

And Peggy... best use that leftover gelcoat as soon as the weather warms up, but before it goes bad in the can.

Taylor posted 12-17-2002 03:13 PM ET (US)     Profile for Taylor  Send Email to Taylor     
Chesapeake asked in another thread:

"How did you feather the gelcoat in the repair on Taylor's boat? It noted that you masked the area, but did you feather inside the masked area or go full fan through the mask and then feather with sandpaper. Would appreciate your techniques."

The masking was just to prevent overspray onto other parts of the boat, such as the deck, the trailer, Tom's New Zealand Flax plants, etc. We did not use the masking as a hard stop for the new gelcoat. We left some old gelcoat unmasked and then spayed the new gelcoat over the repair, feathering by letting off the spray button as we came off the repair and over the old gelcoat. When we wet sanded all this extra spray over the old gelcoat came off, which is not too difficult.

It turned out that the transition is ends up being just about where we sanded down the old gelcoat before we started spraying.

"It was mentioned in the reference article that there was a color difference between the patched area and the original gelcoat, but that you were able to minimize this, I thought by either the way you feathered it or by where you applied the new gelcoat on the hull."

Buffing a hull tends to bring it back closer to the original color, so in the transition zone, we had a slight color difference between the new gelcoat and the old, but buffing down into the old gelcoat a little tends to minimize that, spreading the transition over a wider area. Also, the color match between the spectrum product and my boat was pretty close. I'd just buffed the boat at the start of the season too.

We did try to minimize transition zones. At the front of the repair, we had a transition zone on the smirk, but right in the corner of the bow where it curves sharply. On the top, we tried to get it in the shadow of the rail. On the bottom of the repair we went right down to the bottom of the sponson (the port keel line). Which left the aft side of the repair, where the transition is a line down from the green Washington state sticker into the bottom paint.

Waxing after the repair helped to hide color differences in the relections off the surface.

Tom W Clark posted 12-17-2002 08:59 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     

No need to be afraid of this thread.

With a properly prepared surface, the sprayed on gelcoat becomes one with the existing gelcoat. The adhesion and blending is really good. I suppose if you were to spray some gel coat onto a surface that was not roughed up at all or still had some residual wax on it then adhesion might be a problem, but that was not the case here.

My impression of the color was that what we got from Spectrum was a tiny bit lighter than Taylor's boat, but that may or may not be accurate given that color perception is not my forte. Taylor and I also noted that as we sanded the existing gel coat down it appeared that the color underneath was lighter than the existing surface. This is contrary to what we had expected as in my experience with my boats the gelcoat would lighten with age as the result of exposure to the elements.

It may also be that the changing textures of roughing the gelcoat up with sand paper and then smoothing it back out and ultimately buffing it out caused the colors to seem more different than they actually were. I have not seen the finished hull in person, only in the photos but it looks good there! As Taylor notes, the placement of any transitions helps to disguise any variation.

If there were a scratch in the side of a Whaler that was not broad, I would be tempted to just use Spectrum's gel coat patch paste kit. Open up and clean out the scratch or gouge and then trowel in the paste and buff to match.

If there was damage that had some significant width, then filling and then spraying on gel coat might be in order. If, hypothetically speaking, there was a small area of damage that had been previously filled with something like MarineTex (an epoxy putty) or Bondo (a polyester putty) then I would simply sand the area down a bit to get the surface clean and rough and the use the Preval to spray on a couple coats of gel coat. Buff it out and it will look like new.

skookum point posted 12-17-2002 10:59 PM ET (US)     Profile for skookum point  Send Email to skookum point     
Really outstanding contibution to the site, Tom and Taylor. However, it left me wanting to know more about Taylors vacation to BC. How about a trip report? Posted in the appropriate section of course. I would like to make a similar trip, possibly next summer, and would love to have the benefit of your experience.
Al_A_Buy posted 12-20-2002 11:49 PM ET (US)     Profile for Al_A_Buy  Send Email to Al_A_Buy     
This question might have been answered before but I can not find the info I need.

I need to repair a divit in the keel. WHen the glass repair is complete do I need to gel coat if I am going to reapply the bottom paint?



tazman632000 posted 01-07-2003 09:45 PM ET (US)     Profile for tazman632000  Send Email to tazman632000     
this repair seem fine but i dont see any possible way to do that repair on a large area
Tom W Clark posted 01-07-2003 10:15 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     

If you are going to bottom paint it anyway, there's no need to apply gelcoat.



Taylor posted 01-08-2003 12:52 PM ET (US)     Profile for Taylor  Send Email to Taylor     
I suppose that depends on your definition of big, and your prespective. It looked plenty big to me.
No, 'tis not so deep as a well, nor so wide as a church-door; but 'tis enough,'twill serve: ask for me to-morrow, and you shall find me a grave man.
The whaler instructions specifically address repairs that are larger, and where the foam has been damaged or is missing. Luckily for me, we did not have to use that part of the directions. But the same sorts of problems that we encountered with a repair along the chine would show up in a larger repair too. Basically, how do you form and fair the repaired section of hull? A bigger repair section would just have less existing hull to index off of. I'm sure Tom could do it. But maybe I could now too. But the approach would be the same. Perhaps someone who has repaired some (more) catastrophic damage would like to provide input on this.
DIVE 1 posted 01-08-2003 08:36 PM ET (US)     Profile for DIVE 1    
We applied the same basic process on DIVE 1. The hull had a 6'x 1' gash in the bottom of the hull that had been repaired in the field. The entire repair had to be cut out and redone properly. We substituted vinylester resin for polyester and used biaxial matting for the last few layers of the lay-up. The damage was in the stern of the boat and wrapped up the chine about 8-12 inches. This is a very high stress area when the boat is underway and we did not want any problems. We also used the same process to repair the bow area including the smirk(2'x 2' area). There were hours and hours of block sanding to get the smirk area perfect. There are no signs of a repair and no stress cracks near any repairs. This process would not have worked with West Systems epoxy because the shrinkage rates of epoxy and polyester resin are different(stress cracks). I do not mind using epoxy for small nicks and dings, but for large repairs I prefer to stay with the original type of material.
DaveNJ posted 02-19-2003 10:53 AM ET (US)     Profile for DaveNJ  Send Email to DaveNJ     
One thing I found that should corrected in Taylor Clark fine article:

In the Preval Sprayer paragraph: He mentioned thinning the Spectrum gelcoat with 25% Acetone then adding the surfacing agent wax.

Caution: On Boston Whaler's maintenance page they caution against using acetone as a thinner as it will discolor and yellow the gelcoat over time. SpectrumColor also advises to not use Acetone.

Instead, use a reducer such as Patch Aid. Spectrum sells it as well as Mini-Craft. If you use Patch Aid, it acts as the surfacing agent and then you do not want to mix the wax with it according to Spectrum.

flyguy posted 02-20-2003 04:58 PM ET (US)     Profile for flyguy  Send Email to flyguy     
great job and great article. so how is that repair holding up? any problems with the gel coat?
Taylor posted 02-24-2003 01:23 PM ET (US)     Profile for Taylor  Send Email to Taylor     
Dave, I'm not sure where Spectrum recommends against Acetone as a thinner. In their onlne instructions they say "Gel coat may be thinned for use in a siphon pot gun or preval sprayer with Acetone or Styrene Monomer. Do not use more than 20% by volume of thinner..." (see ) I believe those are the same instructions they ship with the gelcoat quart. I agree they say 20% and I incorrectly say 25%. When you are actually standing there doing the mixing, the difference between 20% and 25% is pretty hard to measure. But you got me thinking about it, so I've sent an email to Spectrum's customer service department to see what they say on the subject.

Also - Tom did a great job of scanning the pictures and getting the Whaler repair instructions ready to go online. See if you have not already.

Taylor posted 02-24-2003 05:43 PM ET (US)     Profile for Taylor  Send Email to Taylor     
Dave, you are absolutely correct. Spectrum Customer Service sent this reply:
We don't recommend using Acetone with the new-type gel coats of today. They are formulated with regard to California EPA regulations and may change color when Acetone is used. Therefore, we suggest using Styrene or
Patch-Aid instead.

I've suggested they update their instructions. Flyguy, I'll keep an eye on it.

John O posted 03-23-2004 11:10 PM ET (US)     Profile for John O    
Spectrum Color is now stating NOT to use Acetone to thin their gel coat for spraying in a Preval Sprayer. They suggest Styrene Monomer. Which is what?

This contradicts what Tom is suggesting.

What is the correct way?

I have used Duratec High Gloss Additive for curing and it also thins the gelcoat as well.

Can some one clarify? I would like to spray some nicks with some leftover Spectrum Color gel coat.

John O posted 03-23-2004 11:15 PM ET (US)     Profile for John O    
PS I did try to reach Spectrum Color today as well as Hawkeye industries (Duratec). No answer from Spectrum and phone tag with Hawkeye
jimh posted 03-24-2004 12:36 AM ET (US)     Profile for jimh  Send Email to jimh     
When the acetone/styrene thinner question is resolved, I would appreciate being notified by email and I will make any changes necessary in the article.
Tom W Clark posted 03-24-2004 12:43 AM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
John O,

I'm no expert. I only know I have used acetone before and Taylor and I used it on his boat for his repair.

Now that some time has passed, maybe Taylor can report as to whether or not any adverse effects were suffered by using acetone as a thinner. I doubt it.

John O posted 03-24-2004 01:15 AM ET (US)     Profile for John O    
Tom, I agree that the Acetone should not be problem. I think my best bet is to contact Spectrum and determine the batch of gel coat I have.I think my purchase was around the time they changed formula if I am reading the info correct.

While it is 18 months old and the shelf life claims to be 8 months it appears to have not broken down. I sprayed some on a piece of wood with Duratec. I want to see if the gel coat is still good before attempting to repair any nicks. After 2 hours in my basement with a temp of low 50's it was setting up. My wife is mad enough about the smell from the basement. Good idea that I did not bring it up to the kitchen to cure in a warmer enviroment.

When I opened the can today I discovered a layer of cured gel coat underneath the lid at the top of the can. The layer was almost 1/4 inch thick and had seperated into a smooth layer of the colored gel coat on top with a layer of clear rubberized materiel below. The top layer was about 10% of the total 1/4 inch thickness. The clear layer looked very much like cured clear silicone. It was very flexable.

I have about 6 ounces of gel coat out of the can and I poured it into two 3 ounce glass steril baby food jars. I knew that baby would pay off soon.

If my test on the wood sets up I will attempt the nicks once the weather brings mid 60 degrees.

jimh posted 03-24-2004 07:11 AM ET (US)     Profile for jimh  Send Email to jimh     
If the shelf life is only 8 months, I bet that $20 jar of gel coat I bought four years ago is not going to be very good. Darn, I was going to get around to using it this spring.

Not to start a holy war, but the long shelf life is one of the things I like about using epoxy. With epoxy, the two component appear to be able to sit around for the better part of one glacial epoch without going bad. The chemical reaction that cures the epoxy does not proceed until they are mixed.

With polyester resins, my impression is the chemical reaction is going on in the can, just very slowly. You add the catalyst ("hardener") to speed up the reaction rate. But if you give it enough time, it cures right in the can.

JayR posted 03-24-2004 08:47 AM ET (US)     Profile for JayR  Send Email to JayR     
I bought 5 gallons of Glidden Gel Coat 10 years ago. I used about 3 gallons of it and the remainder sat for 5 years.

It was a solid mess when I opened the container. I concur with your assessment Jim...

Epoxy is a much better product. I am considering having a quart colored at the local home improvement center. I found a color chip that is a perfect match to the blue interior of my 1967 hull. If they can get close to the correct shade, I may give it a shot.

The only problem is that the formulas are designed to be used with a white base not a clear one.... Hmmmmm!!!

What are my chances of matching it?

Colored West System Epoxy.... I like the thought of that. That's about as hard a product I have ever worked with. Wear would be minimal and water absorption mot an issue....

k2163 posted 03-25-2004 12:38 PM ET (US)     Profile for k2163  Send Email to k2163     
Thanks for the detailed analysis. It will really help me!

Do you have any recommendations for repairs on the bottom of the hull? It seems gravity could be an issue here. Would you allow the filler to set up more before applying it? Would you keep it in while it sets with a form? I was considering duct tape over wax paper.

Any ideas you have would be greatly appreciated.


John O posted 07-07-2004 09:49 PM ET (US)     Profile for John O    
I was just wondering how the repair has held up over time.
Taylor posted 08-31-2004 05:50 PM ET (US)     Profile for Taylor  Send Email to Taylor     
Update.... its been two years now, and my repair is holding up perfectly. I can't see it at all. No change in gelcoat color, no sign of delamination, and lord knows I've given it every opportunity to fail. The only thing I can see is a little wow in the chine line where I got lazy and did not make it perfect. On re-reading the article today, I noticed that it still says 'thin gel coat with acetone' and I've sent Jim a correction in light of the recommendations of Spectrum customer service to thin with Styrene or Patch Aid. But as I said, I've not noticed any problems, so don't panic if you used Acetone to thin.

One other thing I noticed is that I'm sorry I did not include a picture between the first mash layer and the second layer photo. The text describes the process, but a picture would have been nice, the photos skip through a couple of steps. I think I must have been trying to keep resin off the camera. It would have been nice to see the matt applied over the top before sanding, and a close up of the fiberglass putty we used to fill low parts after we applied the second layer.

Taylor posted 08-31-2004 05:58 PM ET (US)     Profile for Taylor  Send Email to Taylor     
Not sure when Ken posted his question about gravity, duct tape and wax paper to hold the glass against the repair, but I can address that now (8/2004). Sometimes vacuum bag material (or plastic wrap) is used with tape to hold resin against a repair and the main reason I've seen this done is to make the surface of the resin smooth. Its a neat trick. I can't see where it would hurt, but since we were going to be sanding the repair smooth this was a non-issue. The mat and resin ought to be tacky enough to stay stuck, and if not, just keep daubing at it with a brush till it does stick, which will happen as the resin starts to go off.
jimh posted 08-31-2004 08:46 PM ET (US)     Profile for jimh  Send Email to jimh     
[Added comment to use Styrene or Patch-Aid in place of acetone for thinning of gel coat resin prior to spraying as suggested by Taylor Clark.]
whalingVdub posted 09-01-2004 04:55 PM ET (US)     Profile for whalingVdub  Send Email to whalingVdub     
I had a similar repair and I have a small question about the gel coat. This is probably because my repair was done to the bottom of the boat and I wasn't concerned about using the original gel coat paint, but the directions called for me to put a physical barrier between the gel coat and the air so the gelcoat could dry propperly. I opted for wax paper and it worked rather well, but I know it could have been done better. Any suggestions for the future? or did the gel coat you wre using not require to keep the air off of it?
John O posted 09-01-2004 10:12 PM ET (US)     Profile for John O    

thank you for the follow up.Again, a most impressive post.

John O

jimh posted 09-01-2004 11:31 PM ET (US)     Profile for jimh  Send Email to jimh     
Details about the gel coat resin and additives mixed with it are included in the article. The manufacturer recommends certain additives to insure the hardening of the top layer.

For more information on applying gel coat, consult the instructions with your particular brand of resin. One common technique is to overcoat with polyvinyl-alcohol (PVA).

Repair Boy posted 11-25-2004 11:38 PM ET (US)     Profile for Repair Boy  Send Email to Repair Boy     
Outside repairs look alright. I'm currently rebuilding my second whaler. Same problems, leaking on chines or decking. Current project is a V-20 with a chine rip below water line. This repair requires removal of screwed down interior deck (Thank someone for this construction)because the foam is watered logged everywhere. Once the foam has absorbed water it is extremly hard to remove the absored water. The only solution is to remove all of the foam affected. The water content increases the overall weight (by alot) & performce of the boat. It becomes alot of labor to remove the old water logged foam pior to carring out repairs from the inside of hull.
Bow rails were very loose, solution was to cut-in 4" deck inspection plates on the vertical inside deck next to the rail connections & bolt.
sweet spot posted 11-29-2004 10:51 AM ET (US)     Profile for sweet spot  Send Email to sweet spot     
Thanks for the great information, I have just discovered a small crack w/some water leaking out from it in the keel. I began just wanting to prep to repaint the bottom. Oh well... Now I'll go and buy some poly resin and do the job right. I notice many of you folks live in my old neck of the woods, the Great Pacific North West, I've fished Neah Bay w/ my father and all over Puget sound. Also know the Stilly and those clean clear waters. Now live in NE Florida and am on the edge of the Timucuan Preserve off the St John's river, which by the way, is one of the few in the world that flows north. The water is tannic stained and not clear nor is it fast moving or cold but there are plenty of fish in it and beautiful low country scenery.

Thanks for the post, Chris

Captain13 posted 11-29-2004 02:47 PM ET (US)     Profile for Captain13  Send Email to Captain13     
OK, I have one for the experts? How do you repair a crack below the waterline when you can’t get all the water out…I’m trying to make a repair on the keel of my dads whaler and have drilled several holes and yes water is coming out slowly…the problem is I can’t keep this boat in my garage for a year letting it dry out…I can get the hull dry enough to stop dripping, but when I have tried marine-Tex or epoxy for the repair, both generate heat when curing and the water flow starts again and the repair won’t take….What can I use to make this repair without getting all the water out? I just want to seal the hull up thus keep more water from getting into the hull! HELP anyone please HELP…..
Repair Boy posted 12-07-2004 12:19 AM ET (US)     Profile for Repair Boy  Send Email to Repair Boy     
My vessel has a removable interior deck. That was the only way I could access the problem. Had to cut out the interior liner to reach the problem that many people had tried to repair from the outside. Once located I installed multiple layers of mat & roving including an interior stringer made from urethane foam.
Repair Boy posted 12-07-2004 12:31 AM ET (US)     Profile for Repair Boy  Send Email to Repair Boy     
Styrene yes, max 25%, mainly used with spray equipment. Epoxy & poly don't mix & shouldn't be used for a permanent repair. Best to check with your local fiberglass supplier for info.
BustedHull posted 01-23-2009 06:42 AM ET (US)     Profile for BustedHull  Send Email to BustedHull     
[Revived this older discussion for the purpose of completely changing the topic to a repair of a boat without a Boston Whaler Unibond Hull. This discussion is on the topic of proper repair techniques for Boston Whale Unibond hulls. Please do not change the topic. --jimh]

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