Thinning epoxy

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Jerry In Maine
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Thinning epoxy

Post by Jerry In Maine »

Can epoxy be thinned by adding a solvent?
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Cracker Larry
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Re: Thinning epoxy

Post by Cracker Larry »

No
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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

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Corto Maltese
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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.
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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.
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Jerry In Maine
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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.
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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. :) ]

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Jerry In Maine
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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.
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Re: Thinning epoxy

Post by ks8 »

So, right now it looks something like this?

Image

:lol:

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Jerry In Maine
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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?
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