James has posted his mixture so it's not a totally huge secret.
The key is getting the right quality chemicals. To the purist, you want to use the most pure chemicals you can get. But that's not always cost effective.
I buy my Methlyene Chloride from Midland Scientific. I get the 99.5% pure stuff, that's good enough for just about any hobbyist level build, if you were serious you might go for 99.9% purity. Mine might be actually. I buy it in the 4 or 5L jug.
The next ingredient is Glacial Acetic Acid. This is ultra-pure (99.99%+) so it's not vinegar but it still smells like it, only a whole lot stronger (don't take a whiff). AA causes the MC to run a bit slower and increases working time. Running slower means less propensity to from bubbles in the seam because you can control it more. The catch is that AA indices crazing if you allow too long of a soak time or use too much. Generally speaking, absolutely no more than 10% in the mix, I use between 5-7%.
The third ingredient is Ethylene Dichloride. This is nasty, dangerous stuff. Also it's like $150+/gallon. Is has the same effect as AA except no crazing. It also eliminates the susceptibility of the joint to turn "foggy" if you bond in poor conditions like high humidity and/or temperature. 15% to the mixture.
So the mixture that's been recommended to me (posted by James) is 80% MC, 15% EDC, 5% AA. I'm sure there are tweaks to that and potentially other ingredients that make for an ever better mixture. Hope posting that doesn't irk you other fabricators...like I said, it's posted elsewhere so that above formulation is publicly available if you took the time to dig through a 10 year long thread.
I use straight MC and 5-7% AA. I mix 4oz up at a time in an 8oz large-mouth Amber glass jar with a Teflon-lined kid. The MC evaporates but the AA does not, so if I let it sit on the shelf long enough, I just add a little bit of MC to thin it back out - better to have too much MC than AA. I've found that the jar I use makes for a very long shelf life (especially without the junk fillers)
I've never used EDC myself, for that reason, I have to make sure my garage is temperature and himumidity controlled whenever I'm doing bonding: 68-74F and low humidity. Being in Iowa, that means a beefy heater in the winter, and in the summer I have to keep the garage door closed and open the door to the house and out a fan in the doorway overnight before I do any bonding to make sure the air and the material and the solvent is all at the same temp. If the humidity is too high, when the solvent dries (the fillet) it turns white. This doesn't necessarily affect joint strength, but to looks pretty shoddy.
Thanks for all the fabricators chiming in, at this rate the thread is starting to write itself lol. But I'm not gonna let that stop me from totally avoiding work during the day by writing up more good stuff...
that's what I have available locally . Thanks for this post and all the help btw!
