How to clean epoxy from brushes?

I have resorted to using cheap 55 cent brushes to apply epoxy and wet out cloth and just throwing them away after each use. reason is i cant prevent them from turning into hammers! i have tried soaing the brushes in acetone for like 5 hours and the brushes still go hard on me! whats a man to do?

 

Acetone doesn't clean epoxy, it just dilutes it. When the acetone flashes off (dries) it will leave a sticky epoxy residue where ever the acetone touched. That's because it doesn't stop the reaction. Any material that's particularly acidic will stop the reaction. Vinegar is the common material of choice and it's cheap. I had epoxy on my fingers when I brushed up against a newly glued part last year, I used the orange juice I was drinking to get it off my fingers and it worked well, though a lot more costly then vinegar, but also quite acidic.

I've long given up on trying to clean brushes, I buy chip brushes by the case from Harbor Freight for 3 or 4 bucks. I hit their sales and stock up. Try their web site.

 

The time you waste trying to clean the brushes cost more than buying new brushes. In the past I have used the Dollar general brushes (5 for a dollar) but they left fibers.So buy the cheap brushes but not to cheap.
Good luck
Ben

 

Clean the brush out as best you can and leave them in the acetone untill you need it next. A tall container with a lid is best.

 

Harbor freight chip brushes are the way to go. I buy the boxes of 2" brushes and end up paying like $.20 a brush when on sale.

 

Brushes

Make sure to use pure bristle brushes- nylon being cleaned in acetone is a formula for a big bang due to static electricity. Tolulene will clean brushes but I don't think it's worth it and its nasty on the skin-it burns. Acetone will take epoxy mostly off your hands(but don't get it on your hands in the first place) and then soap and water will finish the job. Haven't tried Pars idea but it's worth a try...

 

I heard something a while back about vinegar, but never tried it.

 

Why use a brush?

I will admit to being a novice on this subject. The one time I've wet out glass cloth with epoxy I was just a lowly helper on the project. We used what I believe are referred to as a squegee (or a bondo spreader if that is not the correct term) and I can not imagine that a brush would even be remotely as good a tool for doing this job. These spreaders were no problem to clean, just wipe them clean before the epoxy kicks.

 

squeegee

Those are good tools but in complicated molds like my model hulls and decks there is no substitue for a brush to apply the epoxy. But you still have to use a squeegee of some sort to remove excess resin in hand lay up.

 

I use brushes all the time, also squeegees, plastic spreaders, rollers, popsicle sticks, putty knives and a stray finger or two when necessary (gloved of course)

Brushes are handy when wetting out raw wood, working into joints, inside corners and areas that a squeegee (my favorite applicator) or other tool can't do.

Brushes can also be used to apply uniform thicknesses of thickened goo, but they need to be modified, by cutting 2/3's of the hair off the end. They then have the stiffness to spread thickened mixtures. I also will run each brush over the wire wheel on the bench grinder, to remove any loose hairs.

The Harbor Freight chip brushes are the way to go. As Jem has pointed out, they are a fraction of the hardware store prices (my local Ace wants 69 cents a piece for a 2") Check their web site, they place them on sale regularly. I buy several cases of them at a time, for less then 20 cents a piece. You can buy two for a $1.40 at Ace or seven for the same price at Harbor Freight, your choice.

 

While all of the answers that have been posted are valid, Denatured Alcohol, AKA stove fuel, will clean uncured epoxy from brushes and almost everything else.

 

40 - 50 mm foam brushes work well to tip off epoxy spread by a squeegee. Down side is they absorb resin and exotherm quickly.

I have been buying pvc garage door trim in 9 foot lengths for squeegee stock from Menards. It cuts easily with a chop saw or table saw. I round the corners of the blade with scissors to keep it from hooking the cloth. The flexible plastic blade that protrudes from the hard rectangular part "drags" flat across the glass/resin. It gives a good feel of the pressure being applied.

Wipe the blade off before the resin sets with a paper towel. A touch of MEK after that and it will last for many times.

 

thanks for the responses fellers. i guess i been wasting time and money trying to use nicer brushes.

on a side note - after i wet out the cloth and then go back over it with a bondo spreader, the epoxy that comes out is very white and super thick and slimey, thick like nasty snot or something. is this a problem?

 

Not a problem at all. It is white because you have worked a lot of air into it and created a foam. Just as soapsuds are not as runny as soapy water epoxy foam won't be as runny as clear fresh epoxy.

 

I use acetone. At $12.00 a gallon (use to be $8.00) I break even on cost ($0.50 brush) at around 24 cleanings out of a can. I'm sure I get many more than that. Then I brush the remaining fluid on my holding fixture to put a nice epoxy finish on that too. Then finally, I smack the bristles across a blunt edge (piece of plywood) that knocks most of the residual fluid out and flays out the fibers so that on reuse, I only need to massage them a bit to loosen them up. I can get 10 applications or more with a single brush. Eventually, they all go hard though. I'm going to have to find PAR's 20 cent brushes though. That's a hard deal to beat.