Thinning epoxy

See our FAQ and tutorials before posting.
User avatar
Jerry In Maine
Active Poster
Active Poster
Posts: 350
Joined: Wed Aug 18, 2010 11:56 am
Location: Down-East Maine

Thinning epoxy

Post by Jerry In Maine »

Can epoxy be thinned by adding a solvent?


_______________________________________________________
I'm just a number in a great design.

User avatar
Cracker Larry
* Bateau Builder - Expert *
* Bateau Builder - Expert *
Posts: 22491
Joined: Fri Mar 11, 2005 3:39 pm
Location: Savannah, GA

Re: Thinning epoxy

Post by Cracker Larry »

No
Completed GF12 X 2, GF16, OD18, FS18, GF5, GF18, CL6
"Ships are the nearest things to dreams that hands have ever made." -Robert N. Rose

Woods Designs
Frequent Poster
Frequent Poster
Posts: 162
Joined: Mon Nov 10, 2014 8:20 am
Location: UK and PNW

Re: Thinning epoxy

Post by Woods Designs »

Agreed - no. Instead try warming it up to make it runnier. Do it before mixing (of course!) but remember you also have a shorter potlife

Richard Woods

User avatar
Corto Maltese
Frequent Poster
Frequent Poster
Posts: 147
Joined: Tue Jul 12, 2011 5:20 pm
Location: Adriatic Sea

Re: Thinning epoxy

Post by Corto Maltese »

I have a hardener to mix with normal 25 min hardener and to prolong this time. This hardener is like water but needs whole day for epoxy to become hard. The epoxy mix is thin like varnish. German stuff but I believe you can get something similar in US.
Image

jacquesmm
Site Admin
Site Admin
Posts: 28165
Joined: Wed Aug 14, 2002 1:00 am
Location: Florida USA
Contact:

Re: Thinning epoxy

Post by jacquesmm »

Thinned epoxies exist but they are not adequate for boat building. They are fine for a protection coat like on furniture but don't have the mechanical properties we need.
Here in the US, there are some cheap epoxy brands that are thinned.
I don't know the German resin you use, it may be excellent.

Many years ago, I was guilty of specifying a thinned epoxy for a priming coat.
At that time, it was common use, it was mentioned in the Gougeon book but also, the resins were much thicker. I stated that you could add 5% of lacquer thinner. With today's thinner epoxies, I would not do it.
And that was only for a coat to prime the plywood, never for any fiberglass or glue work.
Jacques Mertens - Designer
http://boatbuildercentral.com

User avatar
Jerry In Maine
Active Poster
Active Poster
Posts: 350
Joined: Wed Aug 18, 2010 11:56 am
Location: Down-East Maine

Re: Thinning epoxy

Post by Jerry In Maine »

Thanks!

In order to get a decent coat of resin/graphite applied I'll have to warm it up. I'll also run the heat in the shop the night before in order to get the hull warmed up a bit too. Heating the shop is expensive but warranted in this case in order to do a good job.

As I mentioned in another thread I've done the graphite thing before a couple years ago. That came out fine so maybe it was a bit warmer then than now.
_______________________________________________________
I'm just a number in a great design.

ks8
* Bateau Builder *
* Bateau Builder *
Posts: 8403
Joined: Mon Nov 24, 2003 1:00 am
Location: NC USA
Location: Now a much longer sail to Tampa Florida! Back to NC, Youngsville FM05tw

Re: Thinning epoxy

Post by ks8 »

If thin epoxy is desired, then a thinner epoxy product should be purchased, already tested and formulated as such by the manufacturer, and approved for these designs. There are too many potential chemistry quirks to try to homebrew a good and safe result. Leave it to the pro formulaters. :) The designers at Bateau review the physical characteristics of the cured epoxy products they spec and sell for the designs here. Its best to stay within that building envelope. :D

Pictures Jerry? Progress? :)

[edit -- oopps. Too slow. I'm still only typing with one finger at a time, but slower than usual today. One wing in a sling. This doesn't let you off posting pictures soon. :) ]

User avatar
Jerry In Maine
Active Poster
Active Poster
Posts: 350
Joined: Wed Aug 18, 2010 11:56 am
Location: Down-East Maine

Re: Thinning epoxy

Post by Jerry In Maine »

No pictures. The hull is currently in the corner of a dark basement so you wouldn't see much anyway. Anyone is welcomed to drive up and take a look though. Be advised you'll need a good 4WD vehicle to get up my drive.

Once it's flipped I'll try to move it toward the outside doors. Might be able to get a decent pic there.

...and bring beer.
_______________________________________________________
I'm just a number in a great design.

ks8
* Bateau Builder *
* Bateau Builder *
Posts: 8403
Joined: Mon Nov 24, 2003 1:00 am
Location: NC USA
Location: Now a much longer sail to Tampa Florida! Back to NC, Youngsville FM05tw

Re: Thinning epoxy

Post by ks8 »

So, right now it looks something like this?

Image

:lol:

User avatar
Jerry In Maine
Active Poster
Active Poster
Posts: 350
Joined: Wed Aug 18, 2010 11:56 am
Location: Down-East Maine

Re: Thinning epoxy

Post by Jerry In Maine »

Got the first coat of epoxy/resin sanded. Figured it would make more of a mess than it did....

The plan for the next coat is to:

Warm the shop up to about 60F or so.
Throw a drop cloth over the hull with an oil filled space heater underneath to warm the surface overnight.
Set the epoxy/hardener jugs by the wood stove overnight to warm them prior to mixing.

Any other tips that might be helpful?
_______________________________________________________
I'm just a number in a great design.

Post Reply

Who is online

Users browsing this forum: Bing [Bot] and 1 guest