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Author Topic:   Basic Water Infiltration Repair
k2163 posted 03-31-2004 01:51 PM ET (US)   Profile for k2163   Send Email to k2163  
Has anybody done the "Basic Water Infiltration Repair" described at the OFFICIAL Whaler website here?

If you have, can you tell me a few things about it?

How hard was it?

What brand name products did you use?

Where did you get the pump?

Did you put glass over the top or just gel coat?

How has the repair performed?

Anything else I should know?

I have copied the repair instructions.



Q. I think that my older Whaler has water in the hull. How is that possible?

A. Boston Whaler uses a closed cell foam. It does not absorb water.

The only way water can enter between the hulls is through a break in the fiberglass or through an improperly sealed thru-hull drain or attachment. Make it a regular practice to inspect your thru-hull fittings and apply sealant as appropriate.

If water is allowed to enter the hull under pressure, it could cause the foam to separate from the fiberglass. This would form a void where water could sit.

Note: It is very important to keep your boat’s drains properly sealed, along with keeping up with any hull damage, to prevent water infiltration.

Basic Water Infiltration Repair (This is a complex process and should be completed by an authorized Boston Whaler dealer to guard against future problems.)
· Tap the damaged area with a hard plastic tap hammer.
· A dull thud will indicate a void, or separation of the foam from the fiberglass.
· Mark the outside of the entire voided area with a marker.
· Drill from one to several 1/8” holes (depending on the size of the void) near the bottom of the void. This will allow the water to drain.
· Void must be dry before proceeding to the next step.
· Hint: A heat lamp or heat gun may help draw the water out faster, don’t hold the heat too close; it may cause more damage.
· After the void is dry, drill from one to several 1/8" holes at the top of the void (again, depending on the size).
· Proceed to pump polyester resin with a pump gun (available at most marine suppliers) from the bottom holes until it comes out the top holes.
· Plug the bottom holes to prevent the resin from leaking out.
· Allow the resin to cure.
· Repair any damage that caused the water infiltration and re-gelcoat.
· Remember: Keep a lookout for hull damage and maintain your drains.

BillVT posted 04-01-2004 09:25 PM ET (US)     Profile for BillVT  Send Email to BillVT     
Yes, back in my old Whaler dealer service shop days. I would want to drill some fairly large holes and leave this open to the atmosphere for quite a while. Try to get things really dry. Injecting alcohol or acetone (w/syringe) will help to dry it out also, mixing with the water and flashing off. If it's serious, open 'er up and carve that bad foam out and replace using the tips in this Forum.

In the history of Whalers, we've all carried around a little water (fiberglass laminates are not completely watertight if cracked or scratched through the gelcoat) but long term we would like to get rid of it. -Bill

jimh posted 04-02-2004 09:53 AM ET (US)     Profile for jimh  Send Email to jimh     
[Deleted uninformative comments]
k2163 posted 04-02-2004 11:55 AM ET (US)     Profile for k2163  Send Email to k2163     
Thanks Bill,

The instructions say to dril 1/8" holes. Did you drill larger ones? Also, what brand product did you use? What kind of pump are they speaking about?


jimh posted 04-02-2004 07:38 PM ET (US)     Profile for jimh  Send Email to jimh     

Do you find that the instructions and information regarding water entrapped in the hull provided by Boston Whaler is significantly different or significantly MORE SPECIFIC than the information contained in the FAQ provided here on the web site?

k2163 posted 04-02-2004 08:43 PM ET (US)     Profile for k2163  Send Email to k2163     

I'm sorry, but I did not see where this website talks about drilling holes, and filling them with polyester resin with a pump.

Maybe I missed something.

k2163 posted 04-02-2004 08:46 PM ET (US)     Profile for k2163  Send Email to k2163     
I also wanted to speak directly to someone who has done the repair firsthand.

I guess that's what I see as the purpose of this board.


jimh posted 04-02-2004 11:44 PM ET (US)     Profile for jimh  Send Email to jimh     

Thanks for your comments. I try to improve the quality of the information available here, and your situation has provided an opportunity to see how well the FAQ has worked.

Regarding the drilling of holes, the FAQ says:

"If you suspect trapped water, the most straightforward approach for further examination is to drill a hole in the boat in the region suspected and see what comes out! Orient the boat so that gravity will cause water to drain into the area. Drill a small hole (1/4-inch diameter) and check for outflow of water. If none appears immediately, you can cover the area with a plastic bag tightly taped to the hull. Moisture that escapes will show up in the bag as condensation or droplets--or even water!"

Regarding the repair of these holes, the FAQ says:

"A test hole can be easily repaired, another article in the Reference section provides the details. If the hole is in the transom area and enters wood backing, you may fill the hole partially with a wooden plug, topping with epoxy and then gelcoat finish."

A hyperlink to an extensive article with illustrations and diagrams of repair techniques is included.

Apparently this did not convey the same information to you as the article on the Boston Whaler company website. As you cited above, it says:

"Drill from one to several 1/8” holes (depending on the size of the void) near the bottom of the void. This will allow the water to drain."

And for repair instructions, it recommends:

"Repair any damage that caused the water infiltration and re-gelcoat."

In particular, with regard to offering specifics, I don't know if that sentence provides as much information as the entire illustrated article in the Reference section.

I am going to try to re-read the FAQ with a fresh mind to making it more clear. Apparently the Boston Whaler instruction were more clear and comprehensible. This is what I would hope I could achieve with the FAQ and the illustrated article on repairs. I'll give it another look.

Regarding the use of resins as fillers, I have been thinking about the use of epoxy versus polyester resins. Previously I have been a proponent of epoxy, but I do want to add a special caveat. When filling voids with raw epoxy resin one must be careful that the volume of epoxy does not become too large. A large reservoir of epoxy injected into a void or hole in the hull will have a tendency to generate heat while curing. This could lead to a run away exothermic reaction. Even a surprisingly small amount of fast-cure epoxy can run away like this. Because of this, I think that one ought to use a slow-cure hardener in the epoxy and also thicken it somewhat with a filler. This will reduce the tendency of the epoxy to achieve critical heat mass and run away in an exothermic reaction.

That said, if you do have a large void, you ought to be filling it with something other than just resin, anyways.

I do think it is perfectly fine to get first hand repair results. I don't know if anyone has posted extensive information about making these types of repairs. In part, that may be due to the lack of success in making them--it is hard to say.

I would suggest that if you do undertake a repair as described above, you consider giving some detailed feedback on how it worked.

Also, if you ever find out what a polyester resin pump gun (available at your marine store) turns out to be, please let me know, too.

WEST System sells a syringe for injecting their resins. I think it will work with polyester resins as well.

Also, for some more information on drilling holes in a hull to dry it out, you ought to look at Cetacea Page 67. (Hyperlink below) This article shows a Boston Whaler sail boat hull being restored after many years of service as a mailbox post.

k2163 posted 04-04-2004 01:58 PM ET (US)     Profile for k2163  Send Email to k2163     

Thanks for the response. I appreciate the info. I guess what I think the FAQ is missing for me is the goal of it. To me, the Official Whaler FAQ is dealing with a separated foam/hull situation. They are essentially telling to you to glue the hull back to the foam. I see your FAQ as draining water and then filling the holes.

That's all. No offense to you Jim. I'm just trying to figure this whole thing out before I start.



BillVT posted 04-04-2004 11:14 PM ET (US)     Profile for BillVT  Send Email to BillVT     
Whew! Youse guys are intense! Important to remember that despite the plethora of good information on this site, we should not let fear of only knowing 97% of what we should, cause us to hesitate.

I dunno about any fancy resin pumps and don't know why one would need one. Just any old plastic syringe works pretty well. I think lots of places have them. And you need to not be too concerned about just "getting into it" when doing repairs, esp. on the bottom where nobody at the yacht club will notice. When you're carving out a little more outside skin, or drilling larger holes, you just have to make a bit more involved patch to that skin when you are finishing up. You really don't want to be injecting a large amount of resin into a big void--place some foam in there instead. 3 cheers to the guys who grind out the poor previous repairs and do it right!

Like all repairs, you're going to grind back the edges of the laminate, feathering it out and and lay in some mat, or sandwich some cloth in between mat layers. The argument can always be made for the superiority of epoxy resins, but unless the area can't be dried out well, they really are overkill. Polyester resin is perfectly okay.

Now-- does a post fr. the moderator (in this thread, 'bout certain "deletions") right after yours mean that it applies to your comments? Hmm? -Bill VT

k2163 posted 04-05-2004 06:45 PM ET (US)     Profile for k2163  Send Email to k2163     
Thanks for your help Bill.

The deletions had to do with someone telling me to use the seach function and my response that I did before I made my post.

"Whatever" as they say.

I want to do this repair once, do it right, and never again, so I'm trying to find out as much as possible up front. I also want to do it as efficiently as possible.

Here is another thing that is starting to bug me and maybe you guys can help...

How do I get to the bottom of the boat?

It's sitting on a trailer right now and I think the trailer is what has caused most of the damage. I can see the boat sag where it rests on the trailer boards (I know it should be supported by the hull, that's another matter) and the hull lines are damaged here.

It's an 18 foot outrage 1985. I would like to flip it over one I get it dry but I think I would need to take the motor off, maybe the console and drain the tanks. And flipping something that big seems a little hairy. Anyone ever try this?

Is there a safe way to jack it up off the trailer? I will have to work under it once I get it up so I'm obviously a little shy about that.

Any suggestions would be a big help.



Jerry Brown posted 04-06-2004 08:07 AM ET (US)     Profile for Jerry Brown  Send Email to Jerry Brown     
Has anyone ever tried expandable foam for this problem? I'm wondering if that might work as well as a resin for filling the air gap. My 13 is in need of this repair and I'm contemplating trying it. Any feedback? Thanks JB.
k2163 posted 04-06-2004 12:12 PM ET (US)     Profile for k2163  Send Email to k2163     

I've been wondering that as well.

It certainly would make repairs that much easier.

I guess it would have to bond to the fiberglass and the old foam, and maintain it's strength under operating conditions.

I used some of that stuff as insulation around some retro windows in my house (I should have used the soft, white DOW type but Home Depot was out).

It expanded everywhere and bonded to the vinyl, the glass, the wall, the paint and the window shade. I still can't get it off the vinyl.

I'm going to do a search on it.

Maybe we could test it on some hull material to see if it bonds well.


Jerry Brown posted 04-06-2004 12:43 PM ET (US)     Profile for Jerry Brown  Send Email to Jerry Brown     
Ken, Thanks for your reply. I'll try some on part of the hull that's getting fixed anyway, and we'll see how it adheres. I'll let you know how I make out. JB.
Jerry Brown posted 04-07-2004 07:33 AM ET (US)     Profile for Jerry Brown  Send Email to Jerry Brown     
Ok, Last night I drilled 1/4" holes every five or six inches within the affected area and pumped in the expandable foam. It expanded and came out the adjacent holes nicely. I checked it again today and found the area to be solid now and the foam was sticking to everything it touches. I'm going to clean the holes out and west system the bottom next. I think this will work well because its quick, easy and the material repels water and doesn't add weight like resin will. We'll see how the bottom holds up after its in use. JB
John O posted 04-07-2004 09:38 AM ET (US)     Profile for John O    
I drilled several holes up to 1/4 inch in an area I suspected of having water on my 1988 Newtauk.A small area was damp for some time and appeared to have a drip coming through the hull.Also in the winter the area appeared to have a slight frost in the same area. I drilled six holes in the bollom off center from the keel about six to 12 inches in from the transom area. One of the holes had a small drip that lasted about two week once the Spring temperature moved up.

This is messy work as I did it while the boat was on the trailer. The key is to have double of everthing you need laid out under the boat before you began. I had no helper available and it wastes a lot of time pulling yourself from under the boat because you need another rubber glove or rag.

Once the hole was dry I squirted some acetone in the hole. I sanded an area around each hole about 4 inchs in diameter to remove bottom paint and feather slightly toward the hole.

Next I used a bent coat hanger and scraped out an area inside the hole creating a shelf if you will.

I used polyester resin and chopped up fiber glass matt and created a mash. I used a small wooden dowel and pushed the mash into the holes. I used rubber gloves and push the mash with my fingers as well. I continued this until it became difficult to pack anymore in and the resin oozed out. I had strips of duck tape handy to cover the holes to hold the mash in. in some areas I used a combination of duct tape and syran wrap.

The next day I removed the duct tape/Syran Wrap cover and found most of the holes had cured smootly reducing the amount of sanding to get fair.

Next I washed the areas with soap and water and sanded with 80-120 grit. I then applied bottem paint to the exposed areas.

The patches are solid. I do plan on sanding around the areas that I painted over last spring and check the work.I will use a fairing agent to create a smoother finish. I may add an epoxy barrier coat or uses some extra gel coat I have. I am a bit concerned that I should have used epoxy rather than polyester.

I used an ablative bottom paint. It wore off over one hole out of the several that I drilled and repaired. Tha area that is wore off also comes into contact with the trailer rollers.

The job was messy, but I am confident that the holes are water tight. I can not imagine the holes to open up as I did create a shelf on the inner skin and tapered the outside of the hole with a dremel so the mash would "bite" on both sides of the repair.

I choose not to lay any glass down due to the size of the holes which were 1/4 of an inch or less. Everything that I read indicated that holes smaller than the size of a dime do not require laying fiberglass.

k2163 posted 04-07-2004 01:41 PM ET (US)     Profile for k2163  Send Email to k2163     

Thanks for the very informative post!

Can I ask you if you workend on any areas hidden by your trailer? I think I have a problem in some of mine and I'm not sure how to access those covered by the trailer boards.

Any ideas you have would be greatly appreciated.

k2163 posted 04-07-2004 01:53 PM ET (US)     Profile for k2163  Send Email to k2163     

I'm really intrigued by that foam. I think it could work well for the spots in my hull that are loose but not damaged. I think this is where water has settled from another entry point.

Judging from the spread of the foam, how far apart do you think I could drill the holes?

Also, do you think I could get away with 1/8" holes rather than 1/4."


Jerry Brown posted 04-07-2004 04:27 PM ET (US)     Profile for Jerry Brown  Send Email to Jerry Brown     
Ken, I used a product called triple expanding foam.There are others that expand at different rates so the distance between holes might need to be adjusted. I drilled holes about 5 inches from eachother. I used a 1/4" drillbit only because the foam applicator hose was the same diameter and fit snugly in the hole. By the way my boat has no water in it anymore as the previous owner managed to get it out and now the boat is light again.After expelling the water I think you should have the same success. Good luck. JB
John O posted 04-07-2004 06:16 PM ET (US)     Profile for John O    
I have dropped one of the bunks at a time to bottom paint. This is assuming that the trailer has keel rollers and bunks with the weight of the boat on the keel and the bunks as stabilizers.

I tied a strap on the gunnel opposite the side of the bunk dropped and attached to the trailer to shift the weight away from the side I was working on. Blocking would work as well, but the strap was quick.

I did repair a spot below a keel roller last spring with Marine Tex. I blocked the keel in front of the keel roller and then slid the roller down to work underneath it. I plan on taking a look at the job this spring and repair with West System Epoxy if the repair is faulty. I made the investment today in West System Epoxy, Hardener and Micro lite filler. I also bought the pumps to use. Expensive stuff, but in the long run I think the quality will be worth it.

k2163 posted 04-07-2004 06:43 PM ET (US)     Profile for k2163  Send Email to k2163     

Thanks for the info on trailer logistics.

I'll give mine a look and see if that might work.


k2163 posted 04-08-2004 12:24 PM ET (US)     Profile for k2163  Send Email to k2163     

I did some searching on this website and found that many folks have found that epoxy will melt spray foam.

Is this what you found?


Jerry Brown posted 04-08-2004 01:12 PM ET (US)     Profile for Jerry Brown  Send Email to Jerry Brown     
Ken, I didn't try aplying any epoxy yet, so I don't know if it'll melt the foam. I'll let you know as I make progress. JB.
k2163 posted 04-13-2004 12:06 PM ET (US)     Profile for k2163  Send Email to k2163     

Any word on how the spray foam reacted to the expoxy? I'm really interested. I was also thinking some small barrier between the foam and the epoxy might work. Like body filler.

What do you think?


Tom W Clark posted 04-13-2004 12:21 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
Epoxy WILL NOT melt the polyurethane foam used in Whalers.

As to a large volume of epoxy producing heat, polyester resin will do that as it cures too. Use neither to fill large voids.

jimh posted 04-14-2004 12:51 AM ET (US)     Profile for jimh  Send Email to jimh     
It would be greatly appreciated if articles in the archives which state that epoxy dissolves the foam in a Boston Whaler hull could be pointed out to me so that they could receive some review and editing. I would like to eliminate them. I really don't recall this being stated anywhere which was not followed with an immediate contradiction, as just happened here.

There are many half-truths passed out by 14-year olds on internet forums, but on this web site I try to diligently remove such garbage. Vague allusions to the half truths of 14-year-olds are also not encouraged.

k2163 posted 04-14-2004 12:32 PM ET (US)     Profile for k2163  Send Email to k2163     

Please re-read the posts. We are talking about SPRAY FOAM insulation as a repair for voids and areas where fiberglass has separated from the foam.

I realize this is a non-standard repair technique but one that is interesting.

The stuff does a great job of bonding to everything, is pretty strong, and expands everywhere.

Jerry Brown used it in his hull. But as of yet I have not heard how he covered the holes he drilled to drain the water. There are some threads on this website that have discussed SPRAY FOAM. Several people have commented in those threads that epoxy will melt it.

Jim, I think our discussion is clear on this and I hope you let us finish it.



k2163 posted 04-14-2004 12:38 PM ET (US)     Profile for k2163  Send Email to k2163     
Here is the thread on epoxy melting spray foam.

I believe these folks are genuine in their posts and I take them at their words.


jimh posted 04-15-2004 08:25 AM ET (US)     Profile for jimh  Send Email to jimh     

Thanks for the clarification regarding the concern about epoxy melting some other type of foam you are considering, not the foam in your Boston Whaler boat.

In as much as several of us read the comments and misinterpreted their meaning, a clarification was probably necessary.

I just searched the 194,557 articles that are available in the forum archives for possible occurrences of the words "melt" and "foam" and "epoxy." This search turned up about 25 message threads. I did find one article among those which contained a statement that epoxy melted the foam in a Whaler hull, to which I have appended an advisory.

In my opinion it is good advice and technique to test the reaction of materials with each other before combining them in the hull of your classic Boston Whaler boat. It will be much simpler to recover from a bad outcome of an experimental trial than to repair damage it might cause to a Boston Whaler hull.

k2163 posted 04-15-2004 02:16 PM ET (US)     Profile for k2163  Send Email to k2163     

That's good advice. That's why we need the board.


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