Poly or epoxy, not sure what to go with?

[Lou C]

Agreed I’ll pay the price for epoxy

 

[jeffrey.bean]

I used a polyester repair kit on a 45 HP Chrysler cowling.-----The reek of that stuff is just awful.----Just epoxy for me now.

That’s what is steering me towards epoxy. I’ll be fiberglassing in the garage over the winter

 

[jeffrey.bean]

Spent the morning getting the bulk out of the transom, still have more to go.
The area where the motor mounts, it’s getting pretty thin, but I still have exposed CSM (pic) keep going till it’s pink or day light comes through, lol?
I plan on putting two layers of 1708 on the inside, before I place the core, and possibly one on the outside. Does that sound good?

 

[racerone]

I think you are grinding too much material away.

 

[Lou C]

However, with epoxy keep in mind some people can develop a sensitivity to it, make sure to always wear personal protection equipment. That can be like an allergic reaction where the person would get hives any time they were exposed to it. I used it numerous times, never had that happen but was always careful.

 

[zool]

However, with epoxy keep in mind some people can develop a sensitivity to it, make sure to always wear personal protection equipment. That can be like an allergic reaction where the person would get hives any time they were exposed to it. I used it numerous times, never had that happen but was always careful.

Ive been using epoxy exclusively for years and years, then one day I got sensitized out of the blue. Its the uncured hardener that get you. Now, even with long gloves, my hands look like a lizard with prolonged sessions.

I still use it or vinyl ester as opposed to poly tho, but thats just me.

 

[88 Capri (2022 SOTY)]

Spent the morning getting the bulk out of the transom, still have more to go.
The area where the motor mounts, it’s getting pretty thin, but I still have exposed CSM (pic) keep going till it’s pink or day light comes through, lol?
I plan on putting two layers of 1708 on the inside, before I place the core, and possibly one on the outside. Does that sound good?

I think you are grinding too much material away.

Some of that isn't CSM, that is the actual sprayed layup fiberglass I believe. I think you may be pretty good in some areas.
There may be areas that aren't going to be as pink as others like in the picture I shared, I just prepped with extra acetone and I didn't have an issue.
All gelcoat must be removed at the bare minimum where you will be glassing.
I wouldn't grind in that closeup picture anymore.

 

[jeffrey.bean]

Some of that isn't CSM, that is the actual sprayed layup fiberglass I believe. I think you may be pretty good in some areas.
There may be areas that aren't going to be as pink as others like in the picture I shared, I just prepped with extra acetone and I didn't have an issue.
All gelcoat must be removed at the bare minimum where you will be glassing.
I wouldn't grind in that closeup picture anymore.

Thanks for the info, will do.
Yeah, I still have gelcoat in the bilge area, and the sides of the hull to clean up.

However, with epoxy keep in mind some people can develop a sensitivity to it, make sure to always wear personal protection equipment. That can be like an allergic reaction where the person would get hives any time they were exposed to it. I used it numerous times, never had that happen but was always careful.

I’ll keep an eye out for that, thanks

 

[TheLostOne]

I used a polyester repair kit on a 45 HP Chrysler cowling.-----The reek of that stuff is just awful.----Just epoxy for me now.

think poly is bad...try vinyl ester. That stuff smells like a school bus on fire.
I ended up on VE for my rebuild (87 Ski Centurion, gutted to the hull and complete update/rebuild) as it is stronger than PE and easier on the wallet than epoxy. Just layout and prep everything, wet your glass out, wet out were your glass will go then lay it up, roll it down with a paint roller dipped in resin. After fully saturated and rolled down, use a bubble breaker roller to work all the air out.
Defiantly practice on some scrap pieces.
After geeking out and analyzing price of glass and resin between several vendors, US Composites was hands down the best price on everything for me.

 

[Baylinerchuck]

Just grind enough to get the dirt or grime out of it. No need to go deep. Get rid of any imbedded wood, like in the chines. Sand any gel or paint out. Use acetone to clean everything up. I used MEK to clean mine as it’s a little stronger and helps the mechanical bond when using poly. I really enjoyed working with poly to be honest. Once it kicks, which is as quick as you want it, the smell is gone. To each their own tho.

 

[froggy1150]

Poly shouldn't smell if you are wearing respirator correctly with good cartridges. I will stink your house though

 

[Drivewayboater2]

For what it’s worth, if you‘re going to use epoxy resin you need to use 1700 fiberglass not 1708 CSM. CSM is chopped strand mat that needs the styrene from polyester resin to help bind the strands. Ask me how I know?? I was set straight by the folks on here. Very knowledgeable people they are

you mentioned in post 43 about doing 2 layers of 1708. Just want to be sure you get the right material if your using epoxy resin.

 

[jeffrey.bean]

think poly is bad...try vinyl ester. That stuff smells like a school bus on fire.
I ended up on VE for my rebuild (87 Ski Centurion, gutted to the hull and complete update/rebuild) as it is stronger than PE and easier on the wallet than epoxy. Just layout and prep everything, wet your glass out, wet out were your glass will go then lay it up, roll it down with a paint roller dipped in resin. After fully saturated and rolled down, use a bubble breaker roller to work all the air out.
Defiantly practice on some scrap pieces.
After geeking out and analyzing price of glass and resin between several vendors, US Composites was hands down the best price on everything for me.

Wow, best prices I’ve seen,thanks

 

[jeffrey.bean]

For what it’s worth, if you‘re going to use epoxy resin you need to use 1700 fiberglass not 1708 CSM. CSM is chopped strand mat that needs the styrene from polyester resin to help bind the strands. Ask me how I know?? I was set straight by the folks on here. Very knowledgeable people they are

you mentioned in post 43 about doing 2 layers of 1708. Just want to be sure you get the right material if your using epoxy resin.

The vendor I bought it from, says the fibers are bonded with powder, so styrene based product isn’t needed.
Thanks

 

[Scott Danforth]

The vendor I bought it from, says the fibers are bonded with powder, so styrene based product isn’t needed.
Thanks

May want to verify since 1708 of an industry standard requiring styrene

 

[froggy1150]

If you are in Europe from what I gather they use a non styrene based binder but in the Americas I think it's all styrene based but I would not bet real money on that. I would say to get documentation on what the binder is at least. Would suck to do all that work and have it fail. And it would fail In Rough seas..... ask murhpy

 

[jbcurt00]

CSM on 1708 can be considered unnecessary bulk, but can be used w epoxy. Plenty here have used 1708 w epoxy.

 

[zool]

You can use any cloth with epoxy, but the backing doesnt dissolve, and becomes a resin sponge. I used 10-08 IIRC on the checkmate transom to build up thickness, but that was on top of multiple layers of 1700 for strength. Multiple thin single layers is stronger than less thicker layers as a rule of thumb. Think 7 layers of 3/4 plywood vs 4 layers of 3/4.

2-3 staggered layers of 17oz cloth with epoxy is more than enough for any boat tabbing or laminating.