Epoxy question

[jeffyjeep]

Can epoxy be thinned? Has anyone done it, and if so, what with? Thanks.

[snuggles]

I've used rubbing alcohol to thin epoxy in the past, makes it easier to pour.
Doesn't take much.
My 2 cents
Mark

[GregGleason]

Some epoxies (emphasis on some) can be made to be more runny by the application of heat. However, care should be taken in that a little can go along way. The application of heat typically also reduces the working time before it begins to set, so that is another thing to watch for.

Also laminating epoxies, such as WEST Systems and Aeropoxy, are thin by nature and can have amendments added to them (such as fumed silica or milled glass) to get them to the desired viscosity. However, you see these applications more in use in the HPR arena than the LPR side.

Greg

[snuggles]

My initial response was for the store bought 15, 30 minute epoxies.
Mark

[jeffyjeep]

I've used rubbing alcohol to thin epoxy in the past, makes it easier to pour.
Doesn't take much.
My 2 cents
Mark
Thanks Mark. Do you thin the components separately before mixing them or thin the mix? Jeff

[snuggles]

I take the resin and hardener bottles and set them in a pan of hot tap water for a few minutes, the epoxy flows much smoother.
I use those little portion cups for condiments.
I mix resin and hardener together first, then add a small amount of alcohol, stir it to a runny maple syrupy consistency and pour it for fillets.
I tilt the filleted area fwd and aft till the epoxy sets up..
YMMV
Mark

[jeffyjeep]

THANKS!! I'm going to try that on the two (2) TLP Nike Ajaxes that I'm building as we speak. Jeff

[pantherjon]

Best to use DENATURED Alcohol and not Rubbing Alcohol..And it doesn't take much to thin the epoxy down..1/2 to 3/4 of a cap of alcohol is all I generally use..If you use the Rubbing Alcohol it will tend to make the epoxy turn a milky color..

[jeffyjeep]

Hi Jon. If discoloring the adhesive is the only detriment the rubbing alchohol causes, I can probably live with it since it will be painted anyway. I'll probably use a graduated eyedropper or syringe to measure. I'm not sure where to get denatured achohol. We used to get it in the Navy for cleaning the compensator plate on the SONAR gear, but the chiefs would find it and drink it so we were always running out.

Now I'm REALLY excited about thinning my epoxy! Yes, this is as interesting as my life gets now.

Thanks again.

p.s. The chiefs did eventually get their sight back, but it was "touch-n-go" for a while.

[pantherjon]

You can probably find the denatured stuff at Lowes or Home Depot in the paint department, and I think Wally World may have it in their paint dept as well. Thinning does degrade the strength of the epoxy, not sure by how much though, but I don't think by much unless too much alcohol is used.

[mn-rocketry]

Of course, "snuggles" has also been known to mistake epoxy for shampoo... ;)

I take the resin and hardener bottles and set them in a pan of hot tap water for a few minutes, the epoxy flows much smoother.
I use those little portion cups for condiments.
I mix resin and hardener together first, then add a small amount of alcohol, stir it to a runny maple syrupy consistency and pour it for fillets.
I tilt the filleted area fwd and aft till the epoxy sets up..
YMMV
Mark

[jeffyjeep]

You can probably find the denatured stuff at Lowes or Home Depot in the paint department, and I think Wally World may have it in their paint dept as well. Thinning does degrade the strength of the epoxy, not sure by how much though, but I don't think by much unless too much alcohol is used.

No wonder I can never find it! I keep looking in the liquor department.

[jeffyjeep]

Of course, "snuggles" has also been known to mistake epoxy for shampoo... ;)

I'm sure there's nothing better for maintaining a mohawk or cowlick. Maybe Alfalfa used it.

[ghrocketman]

Denatured Alcohol can be found in any hardware store.
When thinning epoxy, mix it first then add the thinner.
DO NOT USE rubbing alcohol to thin epoxy; the 30% water content not only turns it milky, it also WEAKENS the epoxy by introducing a water element to the glue that will remain trapped.
Best solvents to thin epoxy are Acetone, MEK (methyl ethyl ketone), or MIBK (methyl isobutyl ketone). They are listed in order of evaporation from fastest to slowest. All will evaporate prior to a full-cure of 15 or 30 min epoxy. Alcohol is a bit slower to evaporate and while not a first choice to thin epoxy, it will work. If thinning 5-min epoxy, I would not use anything but Acetone. Keep in mind that all thinners tend to slow the cure of epoxy by a bit.
Acetone, MEK, and MIBK can be mixed together to vary the thinner drying properties in any proportion.

[jeffyjeep]

Thanks. I think I'll go with acetone for 5 minute epoxy and denatured for longer cure times. I never knew that rubbing alcohol contained water!