Thinning epoxy resin

Intlwaters

Help Support Intlwaters:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Ken Webb

Well-Known Member
Joined
Jun 14, 2007
Messages
921
I've read that some guys thin their resin with alcohol. How much thinner to epoxy. Using for sealing a wood radio box.
 
I usually add just enough to make it flow like paint, brush it on and then wipe off the excess with a cotton rag. Then I lightly sand it and apply another coat.

How much will depend on the epoxy you use and the amount...it may just take a few drops to get it to flow from a brush.

It seems that some Hobby grade epoxies may take up to a day to cure with just a little alcohol added. Your best bet is to test it out on a piece of scrap ply first.
 
Something else you need to be careful of is some brands tell you not do thin with anything but heat. I know this is the case with West Systems, per their website, it's not recommended as it adversely affects the post-cure characteristics
 
I've had good luck with putting a "cap full" of rubbing alcohol in a one pump batch of west systems using the calibrated mini pumps. A little goes a long way. It will definitely make the cure time longer but not too extreme. It works great for sealing wood as it will soak into the wood better and you wont end up with a bunch of excess.

I always wondered about heating west system to thin it but thought it would make it kick off a lot faster.

Brian
 
It does kick off faster but, if you use the 207 hardener, it will still flow out close to if not equally well to thinned epoxy
 
no no no. alcohol is water.thin only with paint thinner .i use acetone myself.for sealing wood/outriggers i normaly make it 50/50 then ad the hardener+10% or more,n dont touch it jus let it soak in.then repeat.if im not painting it at all ill add a 3rd thicker coat.whatever u use if u dont add extra hardener it may stay sticky and never fully dry but it depends what ur using.

i mean alcohol will eventually evaporate but the finish is cleaner with stuff that evaporates fast..acetone,lacquer thinner,xylene
 
Zpox finish epoxy is the way to go.

Mix 50/50 no muss no fuss. lt is as thin as water.

Takes 24 hours to set up hard.

It will soak into the wood and pickle it.

I do all my wood boats with this. Let it soak in for 30-45 min then scrap it with a card.

I then scrape it with a razor blade after 24 hours. Smooth as a babies you know what.

David
 
I have only tried both denatured alcohol and 91% Isopropyl and have good success with both for sealing. If you had to purchase something I would go with the denatured alcohol to be safe. I will say that Alcohol doesn't seam to have any ill effects to Z-Poxy Finishing Resin (what Greg uses in his video).

Yesterday, I layed up some 5 oz fiberglass cloth to repair a cowling using the 91% and Z-Poxy FINISHING RESIN. I think Greg uses a 1:1 ratio for the 1 oz cloth he uses in the video, but for thicker cloth I used the resin needs to be a bit thicker. Thinning this particular resin doesn't seem to make the cure time longer....about 3 to 4 hours.

I haven't tried acetone,lacquer thinner, or xylene but may try it in the future. Like I mentioned earlier, experiment with whatever you have first before you risk ruining your project!
 
System 3 Clear Coat epoxy is another excellent option, very low modulus thin viscosity without solvents, cures in 24 hours without amine blush. I've used it for many years for this purpose all good results and no problems.
 
Well, the final verdict is in. Since De-natured alcohol is not available in Canada readily I called MAS to get the scoop from them.

He said since I can't get de-natured alcohol that I can use Lacquer thinner or Acetone. Both are heavy on the vapors so I'll have to think of a way to build without choking myself out in my apt.

Thanks guys, I better get to work!
 
I have had great luck heating the object with a heat gun prior to applying epoxy and that helps it flow well.I use West systems and Mas as well as some devcon and others.

I would not heat the epoxy once it has been mixed as it will have bubbles and kick off to quickly.

Terry
 
well well well.. a company called raka industries makes some darn great epoxt resin .. located in florida I reduce w/ a 1/2 cap of acetone. they mix resin and hardner w/ u/v screeners for you if you wish. I strongly recommend this... if you are not painting the hull.. the finish is outstanding .cryystal clear w ultra-high gloss.finish. reducing does not effect the cure or finish at all. ...this product is used on high end surf boards.etc.etc. also this is a 2-1 ratio mix 2 part resin 1 hardner. follow the directions all is great!!!!
 
Ray, in Canada what do they sell for camping and sailboats alcohol stoves? Here it is the right stuff.
 
Back
Top