posted 02-28-2015 11:31 AM ET (US)        

I have this contribution to the subject of wet foam: my boat is 51-years-old, and I bought it about 30 years ago. At that time it had been used and abused with some sketchy looking repairs to several areas. I continued to use it hard and take only basic care of the hull, repairing gouges with simple resin and cloth patches. When I decided to re-power three years ago the dealer that sold me the motor refused to mount it as they said the transom looked suspect. I got the stripped boat and after removing all hardware and console ground all the bottom paint and alligator-looking gelcoat down to good gel or glass.

My plan was to fair the hull with epoxy resin and then epoxy a layer of this cloth on the bottom. Fairing went fine and then two times the epoxy on top of the cloth failed to harden. Ten hours each time with acetone and a floor scraper. I am sure I did not really get all the bad epoxy off but thought the new layer (different brand) would adhere. I put three coats of epoxy barrier coat on the top and then flipped the hull.

I added woven roving and epoxy to splash well to satisfy the motor people. Then decided to paint interior with Interlux Perfection. First I wanted to fill holes in deck and sides so I took a tapered air fitting attached to my compressor and blew into each hole to clear moisture--bad idea. The compressed air caused separation of the glass skin and the foam. I could hear it happen. [The hull] still sounded the same when tapped so I let some resin drip in the holes and kept going. Within three months of re-splashing the boat, parts of the epoxy and cloth were starting to peel at the bow area. I could remove letter-sized pieces with a putty knife. Two years passed with no real problems until the major de-lam mentioned above. I am sure the cause was the peeling cloth at the area where the water hits the hull caught water like a scoop and the force caused the cloth and epoxy to overcome the bond of the original hull to the foam inside. This happened two miles from home in a coastal bay with three of us on board. We circled back and picked up pieces, some 2-feet by 4-feet and rode in with no problem.

About the foam: even after all this the foam was bone dry, as it has been anywhere I ever drilled a hole in this boat. The foam is yellowish in color. My plan now is to pour new foam, create a template from the non de-laminated side of the keel to recreate the hull shape, and then re-glass the damaged area and grind the other side to get back to below the bad repair.

The boat has lived on a trailer or a lift since I've had it, so those who keep in the water may have other [repairs or problems or concerns].

posted 03-01-2015 12:39 PM ET (US)            

The fact that you had two unsuccessful epoxy pours tells me that either you're doing something wrong or that there is a contaminant or environmental factor at work that needs to be addressed. It could also be moisture in the hull. Whaler foam will feel dry to the touch but can still have moisture.

I think you need to consider the value of time and materials (mostly time) in your evaluation about whether to keep or scrap this hull. The 16'7" hulls can be had for short money. The only justification to spending big dollars on a repair is if the boat has sentimental value to you or if you want the intrinsic value of the experience in making the repair yourself.

posted 03-01-2015 11:17 PM ET (US)            

A good friend asked if I would inspect a Montauk 17 that had been rode hard and put-out very wet. It was a rental boat that remained in the water at all times. The boat was rented for the day and on the return trip to the harbor had actually started to dramatically come apart. This all stemmed from a poorly done fiberglass repair on the underside of the boat near the bow. Once that fiberglass patch opened up it behaved like an inverted air scoop. When underway the water pressure was separating the outer fiberglass skin from the foam like a relentless chisel.

The water passed between the fiberglass and foam all the way to the stern of the boat and then forced it's under the transom and up through the deck. This compromised all of the foam in the Port side of the Montauk. The problem was not detected until the water broke through the deck and started spraying up threw large cracks like a high pressure fire hydrant. The two people that rented the Montauk left a trail of foam chunks across the Santa Barbara channel and returned to the dock in shambles but still afloat.

posted 03-01-2015 11:50 PM ET (US)            

quote:

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...two times the epoxy...failed to harden...

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Poor cure of epoxy might be from mixing the resin and hardener in the wrong ratio. You must have the stoichiometry correct to get a strong and properly cured outcome. You are creating a chemical reaction where two reagents combine to make a new compound. It's not like adding catalyst to a reaction already underway to just increase the speed. If the reagents are not in the correct proportion, there will be a portion of one reagent that is not used in the reaction. This left over reagent then contaminates the desired compound being created.

posted 03-08-2015 11:46 AM ET (US)            

Polyester resins do not form secondary bonds that are as strong as the secondary bonds of epoxy resins. When a laminated hull is being laid up, a new layer of polyester resin laminates is usually added before the previous layer has cured, and in that way the polyester resin forms a primary bond with the underlying layer. When the laminate has been completely built up, the resins all cure together.

Epoxy resins are generally better adhesives than polyester resins, and can form good secondary bonds to previously cured laminates. Epoxy has demonstrated outstanding properties as an adhesive resin in making repairs to boat hulls laminated with polyester resins. Epoxy resins have been used in those applications for 45-years and have a consistent history of good results.

I have used epoxy resin formulated by WEST SYSTEMS to make repairs to my Boston Whaler boat hull, and I have never seen any results with poor cures or poor adhesion. On the basis of the 45-year history of WEST SYSTEMS epoxy and on my own experience, I have no reservations about using epoxy resin to make repairs to a Boston Whaler boat hull.

I recommend you listen to the two-part recorded interview with Jim Watson of WEST SYSTEMS that I conducted fifteen years ago. The interview goes into the specifics of using epoxy to repair Boston Whaler boats. It can be found in the listing of several similar interviews at

posted 05-12-2015 04:51 PM ET (US)            

Flipped the hull and started to asses what to do. Two members of this site have many pics of the condition of the hull and the progress through yesterday. If they care to share tat is fine. Thanks for the great help so far.

I did some basic prep and used the 2 part foam to re-create the shape of the bottom as best I could. Using plastic bags and thin plywood bent from good hull points I was able to allow compression of the foam and waste almost none of it to over expansion.

Then I used a knife to trim to foam to a more exact shape and put on my first layer of epoxy resin to seal and harden the foam.

At this point I have re-attached the torn off piece at the rear/side and also re-attached the piece cut off by the other repair guy. I am confident in their structural integrity. I am at the point where I have faired the initial laminations I added and tomorrow hope to apply a possibly final layer of cloth and resin.

Lots will remain to be done after that. I will be happy to share pics for anyone interested. I do not have a place to store them.

posted 05-28-2015 05:37 PM ET (US)            

The plywood was forced downward by wood braces to the roof of my carport. I also used a plastic trash bag to keep the foam from sticking to the plywood.

The foam was coated with epoxy resin and then ground to shape. I then used 6 oz cloth in pre-cut pieces and did 3 layers of that set in epoxy.

Just yesterday I started with an epoxy fairing compound [wet/dry 700] from progressive epoxy. I am on the third coat and it is a very easy 1:1 product to work with.

I have drilled about 30 1/2" holes through the bottom and poured and injected a low viscosity epoxy in them until it finds it's way out. This has re-bonded any foam to existing glass. I have spent a lot of time sounding with a hammer to assure no hollow spots.

My boat was no beauty when I bought her almost 30 years ago and she will not be when I am done, but I probably have $500 in material and will spend another $100 on Interlux 2000E epoxy barrier coat.

posted 06-14-2015 10:22 AM ET (US)            

Epoxy is an excellent material for making repairs to a laminated fiberglass resin boat. Epoxy is a stronger adhesive than the usual polyester resins used when laminating the boat in its original construction. Epoxy is very water resistant. It is a superior repair resin.

I have never had any problems with the epoxy resin failing to cure. I use WEST System epoxy. For small repairs I use the small foil packets. The packets have the proper ratio of ingredients, so the resulting resin is always good for a complete and strong cure. For larger areas I use the WEST System metering pumps. They dispense the resins and hardener in the proper ratio. WEST System epoxy is a good product to use for repair of Boston Whaler Unbond hulls.

There may be alternative products to WEST System epoxy, but, considering the convenience of the packaging, the extremely wide distribution and availability of the product, and the generally modest amount of resin that will be used, I do not see any compelling reason to choose another brand.

I have made many minor repairs to holes in my Boston Whaler boat that are below the water line. I have ever experienced any problems with the repaired areas coming loose. All the repairs I have made with epoxy have shown no sign of any problems, even after many years.

Epoxy resin does have one drawback: its color tends to yellow when exposed to ultra-violet light (from sunlight). This problem is not particularly significant for repairs made below the waterline, particularly on boats which have anti-fouling bottom paint.

Again, for a very informative interview with Jim Watson, see

http://continuouswave.com/whaler/radio/

I highly recommend listening to the interview. Jim Watson has decades of experience in making repairs to Boston Whaler boats using WEST System epoxy. You can certainly benefit from his knowledge.

posted 06-15-2015 05:00 AM ET (US)            

West System recommends a minimum 12 to 1 bevel angle in order to achieve the best bond between the old fiberglass and new. I recall reading somewhere that in the aircraft industry, the recommended angle was in the neighborhood of 50:1. That's a lot of grinding!

posted 06-15-2015 02:37 PM ET (US)            

Gel coat resin is usually only applied to a thickness of 0.020-inch, and most of it will be ground away when making a repair. Gel coat resin is extremely well bonded to the polyester resin of a laminated boat hull. I have never heard of any instance in which gel coat resin delaminated or unbonds with the polyester resin of adjacent layers in a laminated boat hull.