using epoxy

[Tailwalker 0]

could someone tell me how you thin epoxy so you get a nice thin application.Often it's to thick and makes my chronies too bulky!thanks for the help.TW

[Guest]

You can thin epoxy with the judicious addition of a small amount of a solvent such as acetone or MEK (methylethylketone). Some people advocate using ethanol, but I've never used that. I rarely thin my epoxy, but on the few occasion I needed to do so I used MEK. If you add solvent, DO NOT apply heat with a heat gun, hair drier or other heating device...the solvent will bubble and ruin your coating (opposite effect of what you really wanted).

 

boiling point ethanol = 78 C (172 F)

boiling point MEK = 80 C (176 F)

boiling point acetone = 56 C (133 F)

 

Mark Delaney

[Buzzby 0]

Hey guys don't forget that MEK is very toxic, both to your skin and lungs. The MSDS sheets on that stuff are scary. Have you tried soaking the epoxy bottles in hot water for a while and then mixing them.

[Guest]

I'm sorry to disagree with you, but MEK isn'y really so toxic (although it is toxic, not as bad as most MSDS sheets make it out to be). it is quite flammable, and has toxicity similar to acetone. Unfortunately most current MSDS sheets have gotten the lawyers involved. A couple of years ago I ordered a chemical for my lab at work. I said I had to wear safety glasses, gloves, respirator, and basically an environmental suit....the chemical: cleaned and ignited beach sand!! In other words this was written by a lawyer, with no regard for true hazards but making sure his company could say not all recommended safety precautions were taken in case anything ever happened. This MSDS wasx useless. And it had NO toxicity data.

 

If you are looking for toxicity data, you should compare LD50s (usually mg/kg) which is the dose that kills 50% of the lab rats.

 

MEK oral LD50 (rat) oral is 2.737 mg (2.737 g) per kg (estimating to my mass thats over 400 g!!!

MEK inhalation LD50 (rat) 23,500 mg/cu. meter/8hrs

MEK LD50 skin (rabbit) 6340 mg/kg

 

For comparison purposes here's the LD50 for some other materials:

 

aspirin: oral LD50 (rat) 200 mg/kg

oral LD50 (rat) hardener for 5-minute epoxy: 1300 mg mg/kg (rat)

oral LD50 (rat) resin for 5-minute epoxy: 20000 mg (20 g)/kg

oral LD50 (rat) toluene 636 mg (0.636 g)/kg

oral LD50 (rat) ethanol 7060 mg (7.060g)/kg

oral LD50 (rat) acetone 5680 mg (5.68 g)/kg

 

So MEK is more toxic than acetone, but is less tha half as toxic as the hardener used for five minute epoxy!! If you notice, all the compounds here are less toxic than aspirin. I take much more aspirin than ant of these, and you'd have a hard time getting past the smell of the compounds...Both acetone and MEK can go through the skin and tend to carry whatever is dissolved in them through the skin as well...solvent-resistant gloves are a good idea.

 

One thing you should remember: the mantra of all toxicologists is: Everything is toxic, it is all a matter of dose!

 

For example, pure water is toxic if consumed (drunk) in large enough quantities (water perfuses into the lungs, so you'd essentially drown on dry ground)

[Twofingerz 0]

AAAAAAAGHHHHHH

FLASHBACKS FROM MY PESTICIDES CLASSES!!!!!!

 

[Tailwalker 0]

Thanks chemprof.I'll try acetone,You wuoldn't happen to know why 5minute epoxy whitens after some abuse and its been wet (fished).I hope acetone doesn't somehow impart this attribute to regular epoxy. thanks again go get em TW

[Guest]

Had a student extracting gecko tails to see if they were absorbing any pesticides in several different locations. Never found any pesticides in any of them by GC-MS (gas chromatography-mass spectrometry). However, we got a couple of interesting results from a couple of geckos from the country club golf course: one had methamphetamine residues in it, and the second had methamphetamine and benzidrine resideus in it.

 

Geckos on speed!! Just what those little buggers need!! the second one apparently needed to slow down some so managed to find some benzidrine (downers). More likely, theres a meth lab near the country club...

 

Mark Delaney

[camoham 0]

chemprof,

 

see what happens when that chap from the automobile insurance commercial becomes famous? either pressure or stardom must of led that poor lizard down the wrong path.

 

its a sad day.

 

camoham

 

 

[cutbow 0]

I have used denatured alcohol to thin epoxy. It works fine. Use 50/50 epox /ETOH. One advantage is it doesn't evaporate as fast as acetone giving you longer work time. Once you get it on your application ,however it seems to dry just as fast as using acetone.

 

Hope this helps;

 

Dave

[Twofingerz 0]

Chemprof

 

that's exactly wht I was taking those classes. did ten years as a golf course superintendent.

 

cool story.

[Guest]

If you are wondering, I'm the guy who maintains the GC-MS here at McNeese Sate University, so I get to train all the students who need to use it for their research. My interests in GC-MS for research are actually much simpler than detection of pesticides or drugs...I do kinetics of polymerization and analyze my quenched samples using the GC-MS.

 

At least the thing is working now...took 13 months after hurricane Rita to get it back up and running...

 

Mark Delaney

[Gran8Rocks68 0]

tailwaker,

 

I keep my epoxy in a warm room around 80 degrees or so... just remember with any 2 part epoxy the warmer it is the quicker it will set off.... 30 minute works better for me

 

I use loon hard head as much as I can....

[Guest]

Whitening of epoxies is usually due to loss of bond between the epoxy and substrate and then water seeps into tghe microscopic fissure between the epoxy and substrate. This can happen with any type if surfaces haven't been adequately prepared (i.e. not enough "tooth" to provide decent bond),

 

Mark Delaney

[Buzzby 0]

Webster's defines toxic as; "of, relating to, or caused by poison, or a toxin: poisonous" and toxin as; "a poisonous substance produced by metabolic activities of a living organism that is usually unstable , very toxic when introduced into the tissues, and usually capable of producing antibodies."

 

For clarity's sake, how does this relate to pure water ?

 

 

[nthrngrayling 0]

I've used quite a bit of epoxy and this is my experience.

I mix only as much as I need for one fly on a piece of paper with a tooth pick. Then I warm it with a desk lamp. Contnue mixing as it is warming and it will start to thin out.

 

As others have mentioned, the warmer it becomes the shorter time you have to work with it. A bit of trial and (in my case a lot of) error, you'll find it's fairly simple.

 

Good luck,

ng