Can you thin expoxy and what would you thin it with.

I am using a 20 minute clear epoxy and was wondering if I could thin it down to make it more workable.

Reply to
ghelf
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Isopropyl alcohol, 99%. Some drug stores (in the US) have 99%; that's more than good enough. 90% has too much water.

That assumes that you're doing something easy, like fuel-proofing the inside of a cowl. If you're going to be using it in a thick enough layer that the alcohol can't flash off before the epoxy starts to set then bite the bullet and get some epoxy resin. Epoxy glue has fillers in it that are there to make it thick enough to work well as glue. Epoxy resin has a different mix of fillers, to make it workable as, well, resin.

Reply to
Tim Wescott

Or you can thin it with acetone. Acetone is Epoxy glue and resin thinner. It will however evaporate out of the epoxy faster than the alcohol.

Reply to
Vance Howard

The best way to thin it is with a heat gun. It will then be like water but it will set faster.

Reply to
M-M

I bought some Everclear for that purpose. A few drops will do. Totally not worth it but I have a bunch. If you want some just stop by my shop. :) mk

Reply to
MJKolodziej

My first question is why do you want to thin it. What are you doing that calls for a thin epoxy?

I have used 20 minute laminating epoxy which is like pancake syrup. Brushes well. Stuff like this is what I use for small fiberglass jobs. Brushes will, wets out the cloth and you can blot it up pretty well to keep the weight down. I would use this over any kind of major thinning.

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I have thinned epoxy with 90% isoprop alcohol. Not the best choice but I have only done it when I will be using very thin layer. Also good for cleaning epoxy off stuff before it sets.

So, why do you need thin epoxy?

Ed

Reply to
Ed Anderson

My stuff is pretty old and has thickened over time; especially the one in the red container. I preferred not to throw it out.

Reply to
ghelf

When a thermoset* resin like epoxy starts getting hard it's often not because solvent is evaporating -- it's often because the resin itself is becoming partially polymerized. The strength of the bond, and/or of the glue itself, is likely not going to be as good (possibly not nearly as good) as when it was new.

Use at your own risk. I wouldn't use it for anything really critical, if I were flush I'd just toss it and buy new, and I wouldn't use it at all without mixing up a test batch and seeing how it does.

If you thin it with anything volatile and it hardens up before the volatiles evaporate, then the result won't be like regular epoxy glue -- it'll be epoxy glue (not too good, because it was old to start with) that's full of micro-sized holes.

  • "Thermoset" is a bit of a misnomer -- the original thermoset plastics needed to be heated to set up, but the name has stuck to just about any two-part plastic.
Reply to
Tim Wescott

I don't know how old it is or what you are using it for, but if you are working in a basement or some area that gets cool, say below 60 degrees you may find that 10 seconds in a micro wave ( with the cap off) will turn it back to liquid. I have this issue sometimes in the winter in my basement. Seems to work fine but it will set up very fast as it is now warm and will be quite reactive. It will also be quite thin.

Ed

Reply to
Ed Anderson

What he said.....but a safer way is to put the epoxy container under the hot water tap for a while.

Tom

I don't know how old it is or what you are using it for, but if you are working in a basement or some area that gets cool, say below 60 degrees you may find that 10 seconds in a micro wave ( with the cap off) will turn it back to liquid. I have this issue sometimes in the winter in my basement. Seems to work fine but it will set up very fast as it is now warm and will be quite reactive. It will also be quite thin.

Ed

Reply to
Tom Minger

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