Polyester Resin is working great but...

[Intermediate Mariner]

Morning Gents,
Have two questions, one about resin and the other about model of boat.
I am working on a Red Fish. Does anyone know the model? I am thinking a 61 shark or inland or baylap... ayone know (notice how is has only 3 slats on the sides).

Also I am kinda worried about this resin issue. Having never worked with fiberglass before I was naive when I picked up the 3M fiberglass polyester resin from wally world (wondering now why in the heck they don't have epoxy on the shelf).

I have seen that you do not want to use polyester resin. I am seeing MANY people prefer epoxy.

Here is what I did. After removing transom I heavily sanded the transom area along the bottom and sides and they coated with a couple layers of fiberglass cloth and polyester resin. I am wondering if that was used in it's original construction because despite people saying that poly does not stick to epoxy is has bonded wonderfully.

I am now ready to install transom. As you probably know, after the original transom they caked up layers of some sort of resin connecting the transom to the sides, it's built up pretty good.

Should I use epoxy resin when installing transom? Will they fact that I coated everything in the polyester make a difference?

Also, for some reason the transom is smaller. I traced it off the old one and cut it out and its smaller, go figure. I guess the sanding along the sides did it. I had planned to pour some resin down the side gap and fill it up. Will epoxy pour good and will it be ok that I coated the surfaces in polyester.

I am hoping that if I build it up heavy I should be good.

Any ideas?

Thanks
Shawn T
Wichita KS

 

[Doug N.]

Re: Polyester Resin is working great but...

I haven't used poly resin, but I used epoxy to build a couple of wood boats. You could get in touch with Raka.com or 3M. Raka is where I bought my epoxy and they were very helpful and inexpensive. They could probably advise you on the bonding issue. Obviously, 3M are also the experts in all things related to materials and adhesives. What may seem to be a good bond now could delaminate later, so you could be saving yourself alot of work by getting good advice before you proceed. 3M makes a good marine adhesive that comes in a blue and white caulk gun tube (I think it is 7600). Best of luck to you.

 

[109jb]

Re: Polyester Resin is working great but...

Epoxy over poly is fine. Poly over epoxy isn't fine.

I personally did my whole boat including transom replacement with poly resin. Mine was poly from the factory. Most smaller boats were poly.

 

[Intermediate Mariner]

Re: Polyester Resin is working great but...

Thanks for the replys guys.

Hmmm, anyojne know if Red Fish used poly or epoxy?? Will poly INITALLY stick to epoxy (?) because whatever was used in this boat, the poly is sticking and seems to have become very well bonded... for now?

People say poly will delaminate... would this be because of poor surface prep? I have used 40grit die grinder followed by lots of acetone before all resin work.

I'll tell ya, that poly really seems heavy-duty... it seems to become one with the existing resin.

I DID NOTICE THIS: In preparing transom area, I did chip away some loose "resin" of some sort, looked like clear glass, was pretty brittle. I am thinking that this may be poly. But yet the heavy duty build-up around the sides that held the transom to the side seems much different (not brittle, not clear, sort of yellow). Is it possible they used poly to fill the space on the transom edges but used epoxy to hold it in?

 

[tdrudd87]

Re: Polyester Resin is working great but...

I can't guarantee it, but I don't think anyone on this forum has found that the factory used epoxy. Especially that size, that old.

Most of us rebuild with poly too. Sounds like you did good prep, so I would carry on. Poly is plenty good.

Terry

 

[Intermediate Mariner]

Re: Polyester Resin is working great but...

Trudd that is one heck of a project. I got lucky with this red fish at least in that there are no stringers and it's pretty little. Hope to get into something bigger like yours on the next one... those old rotted boats are pretty cheap but that fiberglass work (sanding) is a pain- you would indeed need a good respirator.

I see alot of people talking about epoxy vs poly and the opinions seem to be 50/50. I also see that you do not use fiberglass cloth with epoxy resin. I just do not want any delamination since this is transom. Plus I'm hanging a little bigger motor back on (was 35 hp- going with 40).

In my red fish I see some sort of cloth imbedded from original design - sort of a wide weave cloth.. It's probably fiberglass.

I included a couple photos below. Thats fiberglass cloth in there isn't it? That build-up that held in the transom: was that probably poly then? I would have figured epoxy in the 60's!

 

[tdrudd87]

Re: Polyester Resin is working great but...

Looks like a heavy woven roving in your pics there, common material for glass boats.

The issue is that you cannot seal wood with only poly, it is too brittle. It requires some form of glass to tie it together, so it does not crack. Epoxy, being more flexible, can be used on its own for sealing purposes. When adding strength though, it is still used with glass, be it mat, weave, or cloth.

I would keep working with poly, it is very cost effective. Get some CSM, otherwise know as mat, for building up strength, and for a binder layer when you poly the transom in. You can also get some cloth to give it more strength on the surface, and for tabbing it into the hull.

I'm probably crazy for doing what I am on my boat, but it is fun to learn! Good luck with your project!

Terry

 

[Intermediate Mariner]

Re: Polyester Resin is working great but...

Thanks Terry,
"Tabbing to the hull" - that's the word I was looking for for build-up.

I know what you mean about brittle. Straigt resin snaps like plastic but resin-saturated cloth can barely be bent.

I had definitely planned on using cloth with the wood. I have 2 transom pieces. My plan is to make a cloth resin sandwich and then cover w/ more cloth on both outer sides. This way I would have a layer of cloth with each layer of resin.

I have been using cloth everywhere I have used resin, even if it meant cutting a little piece. Even when I coated the transom area I used little strips of cloth. There is no strait resin anywhere... yet.

Do I sound like I am headed in the right direction.

Before I tabbed in the transom I was going to cover interior transom wood with more cloth to get it good and covered. Then I was going to layer the tabs with 5 or more layers of cloth & resin to get it good and solid. After seeing people's opinions of poly I was sort of afraid of the tabs separating. There is about a good 1/2" of build-up from original and it seems pretty solid. can I just tab over the build-up? Am I safe from tab separation if I build it up good and thick?

Back to the straight resin.. As I mentioned earlier in the thread, I somehow ended up with a smaller transom than the original. Anyways it's a small 1/8" gap on the side but still critical I was thinking. My plan was to get the transom installed and the tabs done. Then I was going to pur resin in the gap and fill er up tot he top and I figured that would be good and solid... I did not think it would be practical to try to stuff fiberglass pieces down in there. As an alternative can I go epoxy resin for just this and be ok with poly on the tabs?

Thanks so much to all you guys that have done this and experienced trial, error and success and sharing your knowledge.. this is my first one and I hope to share my trial and error - and there is usually plenty of error!

 

[Doug N.]

Re: Polyester Resin is working great but...

When I built a cajun pirogue, I covered the outside with a polyester cloth and epoxy for strength. It worked out pretty well, but added alot more weight than I wanted. The cloth looks like cotton gauze and it really eats up the resin. The finish at the end is rough from the cloth, so it provides good traction if needed. Once again, I got the stuff from Raka.com. I tried to get a couple of pictures, but i can't figure out how to get them attached

 

[Doug N.]

Re: Polyester Resin is working great but...

Here is a picture of the poly cloth that I put on the deck of the jon boat i built. You can see where I used less resin because I wanted a rougher surface for traction. At the left edge I filled in the pores with resin.

When i have tried to use resin for filler, it just runs out all over. You could stiffen up the mix with a filler material. You can get maple sawdust or poly beads, etc. If the gap is too wide you won't get much strength in the joint. You may be able to fill the gap by laminating a thin strip on, and make the joint from there.

Best of luck.

 

[archbuilder]

Re: Polyester Resin is working great but...

Poly works great as long as you clean and sand the surface. I would also use a laminating resin. The typically wally world stuff is usually a waxed resin, made for topcoats. You should sand and de-wax it if you are doing more than one layer. Here is a link with a lot of good info on this topic.

http://www.fiberglasssite.com/servlet/the-68/Fiberglass-Information%2C-and-How/Detail

 

[jonesg]

Re: Polyester Resin is working great but...

Yeh you got the wrong type resin, wally world poly is waxed but..
you need the unwaxed to avoid a ton of sanding between coats.
Unwaxed polyester will fix that boat fine.

 

[Intermediate Mariner]

Re: Polyester Resin is working great but...

Arch, thanks for those links.. VERY informative and answers most of my questions.

Jones, I have been using the Wally world resin but have been sanding and applying acetone between each coats (hmmm they never mention waxy on the can- thats nice of them). Can I get by or should I swith now? I still need to tab the transom to the hull.

Thanks guys

Shawn T
Wichita, KS

 

[archbuilder]

Re: Polyester Resin is working great but...

I would switch it makes life a lot easier! The people who run that site are also good about answering questions if you have any more. Good luck with your project!

 

[ondarvr]

Re: Polyester Resin is working great but...

Before you go any further stop and read a bit of this thread, it will give you a much better idea of what you need to do and a better understand of the products you're using.

http://forums.iboats.com/showthread.php?t=234392

 

[Intermediate Mariner]

Re: Polyester Resin is working great but...

Man that thread was something. Thanks for the link.

 

[redfury]

Re: Polyester Resin is working great but...

you can add milled fibers or microballoons( cabosil ) to poly and it will increase the strength of it, Oops calls it "peanut butter", because of the consistency. that's probably what you are seeing from the factory build., they used a similar thing to fair out the deck of my hull where the tri hull intrudes into the main deck space.

 

[jonesg]

Re: Polyester Resin is working great but...

Save yourself a bunch of sweat and get the unwaxed resin, almost all retail poly resin is waxed unless you buy it from a marine shop, I like boatyard resin but I usually order the premium poly resin from fiberglassite.com
they pack the wax in a little bottle in case you want to add it.
If you get some milled glass fiber and cabosil , that will make rock hard glass putty when added to resin. Boatyard terminology is peanut butter, I call it mud.

 

[andgott]

Re: Polyester Resin is working great but...

That looks like an Inland to me- Sans windshield. You can check out the brochures here-
http://www.fiberglassics.com/library/Red_Fish

She'll be a nice boat when you're done!

-Andrew

 

[Intermediate Mariner]

Can you buy the unwaxed resin local?

Can you buy the unwaxed resin local?

Thanks all so much. Man I thought I was doing good with the wally world stuff... I mean heck it was 3M at least!

I see lots of places online but can one typically buy the unwaxed poly resin locally? True most places carry the same general purpose product.