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Author Topic:   Can I use Epoxy or is fiberglass needed?
billh1963 posted 01-25-2004 11:21 AM ET (US)   Profile for billh1963   Send Email to billh1963  
What would be the best way to fix this damage? I've read the instruction on hull repair but I wonder if some Marine-Tex or West epoxy wouldn't fix this just as easily. It only needs to last a season since I intend to either re-gelcoat or paint the hull next winter. Any opinions?

I'll try to post the pics but I don't think I'm authorized for image UBB code....


jimh posted 01-25-2004 12:50 PM ET (US)     Profile for jimh  Send Email to jimh     
Bill--In-line images are not allowed in the forum. You are welcome to post URIs to your images.

Opinions about which adhesive to use for repairs are mixed, so to speak. Some like the greater strength and better small-batch mixing of special marine formulated epoxy resins, like those from WEST Systems.

Others are catalysts for use of polyester resins, which are similar to the resins originally used when a Boston Whaler boat was constructed. The folks at Boston Whaler have never disclosed exactly what brand or formulation of resins they use in making their boats, so there is no way to know if the polyester resin you might use will match the original formulation.

Secondary bonds between polyester resins are not as strong as the secondary bond that results with epoxy.

One consideration is the hardness of the repair area when sanding and smoothing. Raw epoxy tends to be (in my experience) much harder to sand and fair than polyester resins. This may make the process of fairing a repair area more difficult. For this reason, epoxy is often mixed with various fillers to help make it more easily sanded and faired.

My personal choice is to use epoxy because of these reasons:

--cures reliably with simple mixing ratios
--higher strength
--better water proofing
--longer shelf life

I don't like polyester resins because:

--mix ratio is very small (1:1000) and hard to get right
--getting hard surface cure is problematic without additives, etc.
--shelf life is limited (end up throwing out most of the quart can)

For a final top coat I recommend a gel coat grade polyester resin because of the better UV protection and color fast tint.

This topic has been discussed at length before, so you may find more information if you make a search of the website.

billh1963 posted 01-25-2004 01:29 PM ET (US)     Profile for billh1963  Send Email to billh1963     
Thanks, Jim, for the information and clarification.

I did a search but without pictures couldn't really visualize if any of the repairs mentioned matched my requirements. I'm leaning toward the epoxy as well. I'm just looking for a sanity check.

jimh posted 01-25-2004 02:37 PM ET (US)     Profile for jimh  Send Email to jimh     
It looks like the damage is in an area that has bottom paint. If so, you will have to remove the bottom paint to get a good repair.

If the area is not in a prominent spot so that the cosmetics are most important, I'd just repair it as I described in my fairly long and detailed narrative:

The Epoxy Cure

dburton posted 01-26-2004 12:58 AM ET (US)     Profile for dburton  Send Email to dburton     

Jimh, as always, has written a very clear article on his use of epoxy. I will add a few thoughts of my own.

I used West System epoxy to fix similar damage to the keel on my 13’ sport. I am quite happy with the results. I would recommend that you buy and read the booklet “Fiberglass Boat Repair & Maintenance” published by the West System. You can get/order the booklet and other West System products from most any marine store such as West Marine, etc. The booklet doesn’t actually cover the exact situation that you have but does give a good background in the use of epoxy on boats. I used the book to develop the method outlined below.

I drilled holes through the fiberglass about one half inch (and about 1” apart) from the damage and along both sides of damage. I tried to compact the foam some so that a shallow pocket would form along the entire damaged area. I injected epoxy into each hole and into the damaged area. I filled the whole pocket with epoxy. The idea is to get the epoxy well under the undamaged fiberglass. Try to fair the epoxy the best you can while it is still wet but don’t take it down too much.

Three points to consider. The first is how warm the air and hull is going to be when you do your repair. I would recommend that you use a slow setting hardener. I sets up just as well but doesn’t get as hot. Epoxy, especially in a confined area, will get quite hot when it is setting up. However, if you are doing the repair in an unheated garage, say 50 degrees then the regular will be fine. Using epoxy at above 80 degrees definitely calls for the slow hardener.

The second point is to learn about the West System fillers. I would recommend using the 406 Colloidal Silica filler. Epoxy without fillers is incredibly hard and will be difficult to fair (sand to be the same shape as the original hull). The 406 filler will be relatively easy to sand but is made for gap filling and bonding and cures to an off white. The epoxy with fillers will be very strong and will make a good repair. Another good reason to use fillers is so you can change the consistency of the epoxy. Unless you can turn your boat upside down, you will want the epoxy to be the consistency of peanut butter. Fillers will help you achieve a thick consistency while the epoxy is still “wet.”

The third point is to understand the various cure stages. If you have to mix more than one batch, you will want to do it fast enough that it gets a chemical bond with the first batch.

If you want to gel coat the repair so you will need to consider that the repair will need to be slightly lower that the rest of the hull. You will end up an area 2 – 3 inches bigger than current damaged area to gel coat. It may be possible to use a Dremel tool to fair the repair but others will have to advise you of that. Also, learn about Amine blush and its removal before you attempt to gel coat the repair.

All in all, West system epoxy is pretty easy to use but you need to read a lot before you use it. I’m sure that many on this forum have much more experience than I have.

Good Luck,


whalerajm posted 01-26-2004 12:39 PM ET (US)     Profile for whalerajm  Send Email to whalerajm     

In your post you refer to "injecting" a 2-part epoxy...What do you use to inject the mixed epoxy? I'm assuming whatever you use is throw away and not reuseable.

I'd like to use an epoxy to fill multiple holes in my deck but still trying to figure out how to get epoxy into 1/4 in holes...any ideas would be appreciated.


dburton posted 01-26-2004 02:44 PM ET (US)     Profile for dburton  Send Email to dburton     

The West System folks are willing and able to sell you everything that you need. They sell syringes that are designed just for injecting epoxy. I was able to get 2-3 uses out of each syringe. The syringe is made from plastic (polypropylene - ?). Some epoxy would remain in the syringe after use but it would not bond to the plastic. You could ream out the syringe from the small end and push out the hardened plug. After about 2 -3 of these reamings the syringe would be too beat up to use again.

The syringes don't really hold very much epoxy, maybe a dime in diameter and 3 inches long. So, be sure to think about the size of your project, the "pot life" of your batch and the time you have to get a "chemical bond" using multiple batches. I could use two syringes per batch before I started to run out of pot life. Syringes come in packs of 3. If you had a buddy to help, you could mix a good size batch and use two syringes and just keep moving. Trying to work within the "chemical bond" window can create problems. However, if you mix a bunch of epoxy and fill up a large hole or void it is going to get very hot and will expand and will become a mess. The heat could also cause some problems. If you are just filling some small fastener holes most of this should not be a problem unless it is very hot outside when you do it.

The problems outlined above are why I prefer using the slow setting hardener. Since the chemical reaction is happening much slower, there is more pot life, a wider chemical bond window and less heat. It seems to work better for a hack like me. If I was using the epoxy as a wood preservative and basically painting it on the wood then I think that I would prefer the regular hardener so I could do more coats in a day.

West systems also sell little bowls to mix the epoxy in, stir sticks to mix it with and various types of cloth if you need it. The bowls and sticks can also be cleaned after the epoxy hardens. If you are going to use much of the stuff at all it may be cheaper to buy the larger cans of the resin and hardener. If you go that route be sure to buy the pumps that automatically pump the correct ratio of resin and hardener. You can also use the stuff to fix all sorts of broken things around the house.


Taylor posted 01-26-2004 04:06 PM ET (US)     Profile for Taylor  Send Email to Taylor     
I don't see any structural damage, and it does not look like you are through to the foam. Marine-Tex should work fine, or for a better match, this looks like a candidate for Spectrum gelcoat paste to me.
BEACHPANDA posted 01-26-2004 05:45 PM ET (US)     Profile for BEACHPANDA  Send Email to BEACHPANDA     
I've got a similar, but larger & deeper problem. Also, my ding/hole is at the Bow's Port Side Rub Rail. The actual hole is 4" x 1 1/2".

Being a novice, at all of this, and still fairly new to the CW boards I'd like to learn first what to do, and how to do it properly.

How do I remove the rubrail where the hole needs patching? How do I put securely put the rubrail back?
The Rubrail runs from stern to stern as a solid piece, so I'm concerned about putting everthing together again.

Many years ago, I used Marine Tex, it was great stuff. From reading the comments on the forum, Glass is the way to go, with Spectrum to finish up the aescitics.

Advice on the rubrail would be greatly appreciated.



BEACHPANDA posted 01-26-2004 05:48 PM ET (US)     Profile for BEACHPANDA  Send Email to BEACHPANDA     
By the way, if you look at the "forward storage" link, on the Port Side you can sort of see the area at the Rub Rail Line, about +/- 3' back from the Port side bow light.

Beach Panda

lhg posted 01-26-2004 06:23 PM ET (US)     Profile for lhg    
Regarding bill's damage, I think you guys are "overkilling" the necessary fix. I have repaired several gelcoat chips like that, where the underlying blue fiberglass/resin hull is showing, but intact (not missing). All that is necessary is to use Spectrum Desert Tan gelcoat to re-apply the gelcoat lost and chipped away. It may take two coats, 2nd one applied 24 hours later. Rough sand the area before application of gelcoat. Sand & fair flush, beginning with #240 wet sanding, and work up to grade #2000, using all available grades in between. Hull will look like new. I just did a similar sized reapir on the keel of my 25 Outrage (hit a submerged marker), all with gelcoat (which is pure polyester resin anyway). If in doubt, see Boston Whaler's recommended repairs, reproduced on this site.

I have done repairs like this, even on the keel where it sits on the rollers, and they have been permanent, some as many as ten years old.

billh1963 posted 01-26-2004 07:51 PM ET (US)     Profile for billh1963  Send Email to billh1963     
I like all the suggestions....but lhg's sounds the "easiest" :-) I contacted Spectrum a couple of months ago but they stated that they don't carry the color to match my hull. Is it my understanding from reading the forum postings that West Marine now carries the matching gelcoat? Maybe I misunderstood them.
BEACHPANDA posted 01-26-2004 08:04 PM ET (US)     Profile for BEACHPANDA  Send Email to BEACHPANDA     
Interesting fix, but in my case, the "foam" IS exposed. I want to seal this up before water gets into the hull.

As for the spider cracks, there are more than there's hair on a dog. I plan on using Spectrum's products once I patch/repair the hole, but first need to get to the area by removing the rub rail.

How do I remove the rubrail, and re-install, it without breaking it? My rub rail has a "rope" inlay, and I like the look. It would be a shame to remove the rubrail only to have to discard it and replace w/ a plain black job.



rayl posted 01-30-2004 01:38 PM ET (US)     Profile for rayl    

Looking at your pictures I see that the console is just like the one on my 86 18OR. That isn't the original console based on what I have found through research. Did you put it on? Do you know how that console got on the boat?


Taylor posted 01-30-2004 03:39 PM ET (US)     Profile for Taylor  Send Email to Taylor     

If you have not already, look at these:

I can't tell from your picture, but it may be that your repair is going to be under the rubrail, which would make things more complicated. So, is that where the damage is... do you want to provide a closeup picture?

Taylor posted 01-30-2004 03:40 PM ET (US)     Profile for Taylor  Send Email to Taylor     
Sorry, that last post should be addressed to Allen (BEACHPANDA)
Taylor posted 01-30-2004 03:43 PM ET (US)     Profile for Taylor  Send Email to Taylor     
Gosh, my reading skills suck today. I see now you you already know that the rub rail is going to have to come off. There is an article in the reference section on that process also.

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