Epoxy/alcohol questions....

Re: Epoxy/alcohol questions....

John in NM

Yes, you should be able to clean up uncured epoxy with alcohol. There may be better solvents to use, but it seems to work (I'm usually using isopropanol for this since I'm usually at work when using epoxy and isopropyl is what we have around).

It won't clean up cured epoxy in my experience.

It might thin epoxy, but I've never tried it. I have added transtint dye to 5 minute epoxy by mixing it with a little acetone. Works, and makes it a little thinner, but it also tends to make the epoxy rubbery.

Yes, No, Don't

Mark Mandell - Gone Round In New Jersey

Cleans uncured but not cured.

Used as a thinner you're asking for trouble. Epoxy is thermosetting. It creates heat in the cure reaction, and, depending on the thickness, enough heat to boil water (212°) and cause scald-like burns. With that amount of heat and the alcohol in the mix, the thickening epoxy will boil the alcohol (180°) causing the mix to foam which then expands and sets up looking like a stiff sponge giving you a real mess to clean up. DTDT

If you need thinner epoxy for penetration into cracks or punky wood, use the stuff that is specially formulated for such use.

a bit of chemistry

Bill Tindall, E.Tn.

"Epoxy" is short for epoxy resin, which is short for a mix of an epoxy resin and an amine that when brought together crosslinks the molecules into a net work of molecules that makes a good adhesive.

Crosslinked stuff of any kind-rubber, cured varnish, for example- is insoluble in everything. Period, no exceptions.

The "epoxy" part of epoxy adhesive is highly reactive. It will react with water and alcohols. If it reacts with alcohol and water it won't be left to react with the amine part of the epoxy system to cross link and make an adhesive.

Alcohol per say would be a lousy solvent for the stuff in the "epoxy" bottle. But the reaction product with alcohols will dissolve in alcohol.

As a general rule if some commonly available aspect of chemistry is not practiced, like thinning epoxy with alcohol, there is probably a good reason.

Thanks, I need all the help I can get

Re: Safe and never sorry solvent...

TomD

I have thinned epoxy with alcohol and applied it to wood to see if it would allow the epoxy to better penetrate wood, which I did not expect. At first it looked successful, and the resultant epoxy was hard, but really all that was happening was that the alcohol was wetting the wood deeply and leaving the epoxy pretty much on the surface, I put that down to the large epoxy molecules being suspended in the alcohol. This was wood penetrating epoxy, designed for wood, though not the rot doctor, which I haven't tried. My aim was to come up with a product that would penetrated the first layer of ply into the underlying glue, which would have been a game changer for me. We are talking about .6mm of luan, rotary cut. Almost open pore to start with. No luck.

If you want to remove epoxy from your hands (should it get around your gloves, they break; or get on forearms, though I use tyvek sleeves), by far the best product I have ever used is home made soap out of oils and soap. If I get a tiny bit on my skin from say a small repair of 5 min, or some penetration by say WEST through my gloves. I just get some butter or margarine, a pea to a lima worth, and I rub it on and wash with the butter thoroughly. Then I use liquid soap to wash the grease off. Leaves your hands clean and moisturized. The real formula if you choose to use it in bulk, which I do when I have a boat building job on is:

https://www.dixdesign.com/epoxsoap.htm

As you can see in the article, vinegar is a good product for some cleaning. Though I don't use it.

When working with fiberglass, I use a lot of chip brushes and they get better with use, the hair fall stabilizes. I use a 1 pound coffee container and put about 1/2" of acetone in the bottom of it. When I get the brush "dirty" I wipe it off, and it can be useful to have a list of things that would benefit from a wipe of epoxy. Then I dip the brush in the acetone, and wipe it on some paper, then I drop it into the can and leave it. Being acetone the brush hardly takes any drying to be ready next time. I can get dozens of uses out of the brush and acetone in the can. I cut the brushes short, just below the hole in the handle, and round the edges on a concrete block so they don't damage my gloves. Some kind of glass bottle is better, (I get masons from the dollar store), so long as you don't drop the bottle.

I use variants of this process when using other brushes. I find I can clean out an artist's brush of high quality that I have for little repairs, with a similar process and just a half cap of acetone. I let the brush dry.

When I was working at Wooden Boat School they had a 5 gallon bucket of some powder dissolved in water, and you just stuck your brush in, or gloves, and the epoxy was just gone. I don't know what it was, but it was useful.

With rollers I use the short ones, and hit the frame crook on the edge of the garbage can to cause the sleeve to jump off the frame of the roller. Not worth cleaning, but I do work out and use as much of the epoxy in them as possible, before chucking. When I talk of a list I am referring to secondary uses around the property. Say on the bottom of a wooden chair leg for the garden, to slop water wicking up, or for rust protection, or minor repairs.

Curiosity question OT

ebd

[quote]Crosslinked stuff of any kind-rubber, cured varnish, for example- is insoluble in everything. Period, no exceptions. [/quote]

Someone told me once that oil and gasoline degrades rubber. He was working on an old MG and was obsessive about drips. From what you've said it seems he was wrong. Correct?

degrade vs insoluble

Henry (Raleigh NC)

Your friend may not be wrong - there is a difference between degradation and dissolving.

Degraded belts may stiffen, crack, and fail - but still not dissolve in a solvent.

I have no specific knowledge of the effects of oil and gas on rubber, or the mechanisms, but it would not surprise me that they would degrade it. That may involve oil or gas components absorbing into the rubber, or some oxidation mechanism may be enhanced in the presence of the compounds in gas or oil. Lots of possibilties.

Hope that helps.

Henry

Re: Curiosity question OT

Bill Howatt

This is something I've wondered about over the years. My father had a garage business in the 50's and keeping oil off rubber was definitely what everybody said.

My thought now is that it was indeed true for early rubber products made with a lot of natural rubber but it is much less so now for the compounds used today. As always, I may be wrong.

I've spilled a lot of gasoline on my snowblower's tires to no ill effect that I can see but gas does evaporate much quicker than spilled oil.

Bill

Re: Rubber Oil & Fuel resistance

Ron in Sterling, CT

There has been a tremendous amount of improvement in fuel resistance to "rubber" over the last 60 plus years. Saying rubber is like saying wood. There are so many different polymers and then each is compounded for a specific application. While not a rubber chemist, I did work in the rubber molding industry for 30 years and can say that polymers of today have much improved fuel and oil resistance.

what happens

Bill Tindall, E.Tn.

Hydrocarbons will dissolve in some kinds of rubber and soften it. It will not dissolve, but as rubber is typically used, softening it will compromise its performance. Expose a latex glove to mineral spirits for a demonstration of the effect.

There are synthetic rubber polymers that are resistant to hydrocarbons.

Re: Curiosity question OT

AZ in Colorado Springs

Gas lines are made of rubber. On the cars I had with carburetors, it was 3/8" ID hose. There was a specific hose for fuel lines, but it's 100% exposure in that case.

Your post also called to mind the oily drips on roads and driveways. Lots of contamination for tires there.

How about water?

Tony - Memphis

I just replaced a toilet. Those "rubber" seals for the tank bolts are some really nasty things. Takes weeks to get that black washed off! I have no idea what they are really made of though. The new ones have a different feel, but that just might be because they are new. Now, the drain hole seal seems to be something a little more exotic. Wish they had used that on the bolt hole seals!

Warning - when the new flapper fails to stop the leak into the bowl....don't tighten the bolts! Just get a kit, remove the tank, and replace all the seals. I swear I turned the nuts about a quarter turn and that's all! Cracked the darn tank. And this model is 20 years old and they don't sell replacement tanks. Bummer. Hurts my feelings to send 100lbs of ceramic to the dump for nothing. So long old friend!

Re: How about water?

Bill Tindall, E.Tn.

Takes weeks to get that black washed off! ...the black is carbon black used as a filler and stabilizer.

All polymers, which includes rubber compounds of the vast variety, eventually succumb to ozone, oxygen, light in some combination. Don't forget there is oxygen in water. Had the toilet company sprung for silicone seals, adding $1 to the cost, they would have lasted forever.

don't tighten the bolts! Just get a kit, remove the tank, and replace all the seals. ....

the first sign of polymer degradation is loss of flexibility. Your seals became brittle- no give and force got transferred to ceramic which has little tensile strength.

Flapper "fix"

Jason Roehl in Lafayette, IN

I've fixed quite a few leaky flappers by simply running my finger over the flapper seat and the flapper where it contacts the seat.

Jason