Thinning w/Acetone

[dude11]

Maybe I over looked it-but when applying poly resin on new wood(ply) I've read somewhere you could or should cut it w/acetone abit for a better soak-in,prior to layup.My question is how much can or should you cut it?As you know--it's fairly thick straight out of the can,even though it's in the low 90's here.One would think-the thinner the easier to apply.Thax in advance

 

[JAFO1]

Re: Thinning w/Acetone

Maybe I over looked it-but when applying poly resin on new wood(ply) I've read somewhere you could or should cut it w/acetone abit for a better soak-in,prior to layup.My question is how much can or should you cut it?As you know--it's fairly thick straight out of the can,even though it's in the low 90's here.One would think-the thinner the easier to apply.Thax in advance

In my thread, I asked this same question. I got several answers. I ended up not thinning my poly. Thinning poly resin will weaken it. Thank you to Ondrvr for this information. Set your plywood in the sun to warm it up, and then seal it with your resin. But, don't resin in direct sunlight, it will set to fast. Keep coating until the wood doesn't take in any more resin. Don't over do it. Resin with no glass is very weak. When you are ready to glass, just do a 'buff and scuff' or light sanding with 36 grit, just enough to give the resin some 'tooth'.

 

[JAFO1]

Re: Thinning w/Acetone

Maybe I over looked it-but when applying poly resin on new wood(ply) I've read somewhere you could or should cut it w/acetone abit for a better soak-in,prior to layup.My question is how much can or should you cut it?As you know--it's fairly thick straight out of the can,even though it's in the low 90's here.One would think-the thinner the easier to apply.Thax in advance

Also, I just noticed you said "out of the can." Are you using waxed resin? The kind from the hardware store? If so, that changes the way you apply the resin, and I have no experience with waxed resin. But, I think you can not let it dry between coats. If you do, you will have to remove the wax layer that forms before you can move on to the next step. I'm sure someone will chime in on this.

 

[jonesg]

Re: Thinning w/Acetone

retail home store resin is quite thick, i don't like using it, especially as it contains wax. Unwaxed boatyard polyester is much easier to work with.

 

[dude11]

Re: Thinning w/Acetone

Thax fellows-I'm using unwaxed resin,I was just thinking that uncut resin would be quite thick and also wouldn't go as far in coverage as thinned would.I hadn't planned on glassing the bottom of it-this is just to help waterproof the underside.I don't think strength is an issue on this coat--might be wrong--I'm not above it!!:redface:

 

[Bondo]

Re: Thinning w/Acetone

Ayuh,... I believe Styrene, rather than acetone is a Better thinner for the task you're doin'...
Styrene don't lower the strength of the resin as much as acetone...

 

[Yacht Dr.]

Re: Thinning w/Acetone

Hello Dude..

IMHO "weaker" resin is still better then no resin. I thin my resins for saturation coatings.

Either acetone or styrene .. again IMO..

% will vary depending on how thick the resin is in the first place.

Before I get slammed for recommending thinning.. I just have to say that I have resin coated ply before without thinning but It was too thick to absorb into the wood.

If you do decide to thin ( or not to thin ) just make sure you are ready for nonstop coating untill the glass is ON. Dont coat..comeback..sand..coat and glass.. Do It All At Once.

YD.

 

[oops!]

Re: Thinning w/Acetone

If you do decide to thin ( or not to thin ) just make sure you are ready for nonstop coating untill the glass is ON. Dont coat..comeback..sand..coat and glass.. Do It All At Once.

YD.

ill leave the thinning alone...i dont beleive in it....but the trick to coating wood...is to coat it with un waxed resin...let it START to tack....then start your wetout and glass as normal with waxed resin. (just add airdry).
(only use waxed resin if it is the final barrier between water and the glass...if you are going to gellcoat the glass, then use unwaxed)

at 90 deg outside the resin will be as thin as you need it

 

[ondarvr]

Re: Thinning w/Acetone

Read the sticky at the top of this forum page it has a section on thinning epoxy, it does about the same thing to polyester. Read and then decide.

 

[dude11]

Re: Thinning w/Acetone

Thax again fellows;I guess I do as I normally do--didn't give enough info at the begining.I am talking about the bottom side of the deck flooring,that faces the floatation.So I can't, as Yacht Dr.suggested, do it in one motion.It's going to be the same game with the transom,before gluing it in.with some PL.

 

[JAFO1]

Re: Thinning w/Acetone

Thax again fellows;I guess I do as I normally do--didn't give enough info at the begining.I am talking about the bottom side of the deck flooring,that faces the floatation.So I can't, as Yacht Dr.suggested, do it in one motion.It's going to be the same game with the transom,before gluing it in.with some PL.

Seal the wood, thinned or un-thinned, your choice, then glass. Yes, glass the underside of the deck. I wasn't able to do all my laminations at one time either. Also, I was told that PL must cure about 72 hours before glassing over it.

 

[ondarvr]

Re: Thinning w/Acetone

Thax again fellows;I guess I do as I normally do--didn't give enough info at the begining.I am talking about the bottom side of the deck flooring,that faces the floatation.So I can't, as Yacht Dr.suggested, do it in one motion.It's going to be the same game with the transom,before gluing it in.with some PL.

I'm not sure what you mean by this, but the recommendations don't change.

 

[dude11]

Re: Thinning w/Acetone

Under the pressure of all this new-to-me boat redoing;I guess I have over looked or misread some info.I didn't think I was to glass the underside of the deck,just resin, then once installed,glass it in!! That said-there's no good reason to cut the resin,as I see it.I'm just glad I'm in no hurry.Looks like I need some more supplies.Is there something else to fill in cracks around where ply meets sides,rather than "peanut butter"? I am looking at the labor it takes to smooth up inside corners & such.Folks that knock all the grinding & sanding out over the weekend amazes me!! OR is it not that bad to work with?This "little project" has already caused my liquor bill to damn near double.

 

[dude11]

Re: Thinning w/Acetone

I'm not sure what you mean by this, but the recommendations don't change.

Ah, come on there big fellow--I'm from Ga.--We talk real slow--not that hard to understand.:

 

[Yacht Dr.]

Re: Thinning w/Acetone

Thax again fellows;I guess I do as I normally do--didn't give enough info at the begining.I am talking about the bottom side of the deck flooring,that faces the floatation.So I can't, as Yacht Dr.suggested, do it in one motion.It's going to be the same game with the transom,before gluing it in.with some PL.

Why cant you do this in one motion ? its the underfloor.. Thin resin..resincoat with glass ( one layer of 1.5oz mat would do fine as long as the wood does not drink your resin up before lams ).

You know..funny .. I suggested you thin your resin out..to treat the wood so the "topcoat of resin" does not absorb into the wood..therefore keeping your mat wet while curing ( though you say you dont want or need to mat your underside of your floor )

Look m8... Im not trying to be .. diplomatic...

I can tell you that just a resin coat..unthinned ply Will "drink" some resin.. so If you do plan on just a resincoat..then glass..you will most likely have a dry layup when you put glass on the wood.

My suggestion isnt for how well your resin holds in the wood..its for Bonding Only.. Its for Lessons learned that you cant just start laminating glass on bare ( or one coat of just resin ) ply.

Plywood should be softcoated..then coated .. then put lams ( chemically bound ) for the most durability.

You should be able to do this .. and all/most glass repairs in one motion..

I have done this..many have done this..Please dont say it cant be done.. ( unless you have some HD crap resin that kicks off in 5 min )

YD.

 

[dude11]

Re: Thinning w/Acetone

Why cant you do this in one motion ? its the underfloor.. Thin resin..resincoat with glass ( one layer of 1.5oz mat would do fine as long as the wood does not drink your resin up before lams ).

You know..funny .. I suggested you thin your resin out..to treat the wood so the "topcoat of resin" does not absorb into the wood..therefore keeping your mat wet while curing ( though you say you dont want or need to mat your underside of your floor )

Look m8... Im not trying to be .. diplomatic...

I can tell you that just a resin coat..unthinned ply Will "drink" some resin.. so If you do plan on just a resincoat..then glass..you will most likely have a dry layup when you put glass on the wood.

My suggestion isnt for how well your resin holds in the wood..its for Bonding Only.. Its for Lessons learned that you cant just start laminating glass on bare ( or one coat of just resin ) ply.

Plywood should be softcoated..then coated .. then put lams ( chemically bound ) for the most durability.

You should be able to do this .. and all/most glass repairs in one motion..

I have done this..many have done this..Please dont say it cant be done.. ( unless you have some HD crap resin that kicks off in 5 min )

YD.

Oh no--your right as rain.I was completely off tract.I was thinking you meant one coat of resin is all I needed on the underside.Then flip that boy over and screw'er down and glass the top. As I posted-I need some more supplies,more resin,and glass.I made a virgin run today in the front casting deck with some csm--Boy was I surprised!! That stuff don't take much dealing with,it starts coming apart.I was also thinking just two layers on the deck.I can see now that it will need cloth or something of substance over the mat.So I plan on one layer of mat on the bottom side,maybe two on top then cloth.I asked before-is "PB" the right stuff for cracks,where new ply lines up to side,and to give inside corners a smoother feel?Is it EASIER to sand & finish? Bout had it with the grinding ordeal.BTW--glued up the new transom ply today--boy that PL comes off your hands easy,don't it It laughed at acetone!! And yes I got the good stuff,not the HD repair kit.I only regret I didn't order enough stuff in the begining.Live and learn.