IS this POLY or EPOXY resin and does it matter ??

[Wishiniwuzfishin]

I recently purchased this 1974 15' Arrowglass Muskie in which the previous owner had replaced the plywood deck. First let me say I have never worked with any kind of resin or done any kind of fiberglassing work. The only knowledge I have on the subjects is from the many posts I have read on here. I am going to finish the interior and was wondering if there was any way I could tell if this is poly or epoxy resin or even something else. I am not sure what I am going to use to finish it but was thinking of a coating of gelcoat, Kiwigrip, or Durabak. I thought if i knew what kind of resin was used it might limit my choices or maybe not. But I don't want to ruin anything that has been done. To me it looks like the job was done fairly decent. The pics may not help but there appears to be some sort of cloth strips only along the seams and edges of the plywood and a thin coating of whatever it is on the rest of the plywood (although there does seem to be one bare spot where there is no resin). Do you think it would be ok to go ahead with my finish material, whatever I decide? I am leaning towards the gelcoat right now. Or should I put more resin or maybe even another layer of resin with fiberglass? The floor does feel pretty solid right now and seems to be sealed pretty good. Any help will be greatly appreciated. I could also add more pics but I am not sure they would be of any more help. Thanks

 

[ajgraz]

Re: IS this POLY or EPOXY resin and does it matter ??

I'd expect epoxy, even freshly done, to have a bit more of a yellow-ish cast than that. So I'd guess that's poly.

Any chance you've still got the PO's phone or email? Best bet would be to ask him.

If it is epoxy, AFAIK gel coat is out, as would be putting a layer of poly over top. Whether to epoxy glass in a layer of glass mat or cloth would be kinda optional, but advisable on a deck to add stiffness and water-"proof"-ness.

If it is poly, I'd definitely poly in a layer (or two) of mat or cloth before any kind of finish. Poly painted straight onto wood is going to crack with flexing, and won't shed water very well.

 

[Mark42]

Re: IS this POLY or EPOXY resin and does it matter ??

If you can put a power sander to it, check out the smell of the powder. Poly often has a bit of a sweet smell, epoxy smells kind of musky.

 

[Wishiniwuzfishin]

Re: IS this POLY or EPOXY resin and does it matter ??

I bought the boat about 4 months ago from someone who was selling it for the owner who had moved out of the area. The guy selling didn't know much about it and his main interest was getting the boat out of his garage so I don't think there would be much hope of getting any more info. If I had to guess I would have to guess poly also, just because of what I have read on here about the cost of epoxy. I only paid $350 for the boat and a nice trailer (no motor). The covering does have sort of a yellowish tint though. It doesn't show up in the pictures good. Just to make sure I am clear on this....epoxy is ok over epoxy or poly....but poly is a no go over epoxy but ok over poly? Do you have any idea how long it would take for a reaction if I were to do a small test area of poly resin or gelcoat over it as is and it is epoxy?

 

[ajgraz]

Re: IS this POLY or EPOXY resin and does it matter ??

Just to make sure I am clear on this....epoxy is ok over epoxy or poly....but poly is a no go over epoxy but ok over poly?

Correct.

Do you have any idea how long it would take for a reaction if I were to do a small test area of poly resin or gelcoat over it as is and it is epoxy?

Not so much a "reaction" as that if you put a small patch of poly resin or gelcoat on it, and the deck's epoxy, after the small patch hardens, it won't adhere well (probably could pry it off with your thumbnail). If it takes a chisel to get it off, you can bet the deck's poly.

For best test, sand the area of deck and wipe with some solvent (acetone, carb cleaner, etc.) first to make sure all waxes/greases/etc. are cleaned off.

EDIT: I have heard of "tie-coat" products that are supposed to allow you to put poly (or gelcoat) over epoxy, but you'd need someone with experience using those to chime in.

EDIT 2: if all else fails and you simply can't determine with sufficient certainty whether it's poly or epoxy on the deck now, "Plan Z" of doing a layer of mat glassed in with epoxy, finished with Durabak (or Kiwigrip, or polyurethane paint with grip texture added), will work no matter what. On a 15' boat, a layer of epoxied mat is really not going to be all that expensive.

 

[Wishiniwuzfishin]

Re: IS this POLY or EPOXY resin and does it matter ??

So if I play it safe and assume it is epoxy and either go as it is or add another layer of fiberglass/epoxy, then gelcoat is out right? I previously owned a boat with a factory gelcoat interior and really liked it. But if it won't work well then I'd be ok going with Kiwigrip or Durabak over epoxy correct? Thanks for all your help.
EDIT: Update...I just looked at the Durabak website and it says to contact them before using Durabak over a fully-cured two-part epoxy substrate???
Kiwigrip website specifically states it can be used over epoxy.

 

[Mark42]

Re: IS this POLY or EPOXY resin and does it matter ??

My experience has been poly has a yellow tint, epoxy is crystal clear. Poly is much, much softer than epoxy. If you can easily sand the surface with a piece of 80 grit sand paper, its probably poly. 80 grit won't affect epoxy much or at all without being on a power tool.

 

[Wishiniwuzfishin]

Re: IS this POLY or EPOXY resin and does it matter ??

I'm gonna try and hit it with a piece of sandpaper tomorrow and see what happens. I really think it is poly and would love to use gelcoat to finish it, especially after checking prices on Kiwigrip (Kiwigrip=$130 gallon....gelcoat=$50 gallon). As far as the smelling tip, I might try it but my sinuses are screwed up a lot of the time so my sense of smell is not always too good. Thanks again for the help.