Hi,
I have been really concern about the crack problem so, as I was working into the plant today, I run some test with my acrylic offcut. I drilled holes on side of acrylic and fulled them with four different solvant + some stain color. Toluene, acetone, Industrial lacquer thinner and regular household thinner (Varsol)…

The results are clear as water…

Those pics have been taken 6 hours after the beginning of the test, I’m really sorry for the poor quality cam isnt home. Varsol is super agresive onto my acrylic… A big crack in 45 minutes.

Paul and Soybomb ---I have read somewhere that some product were a mix of toluene and varsol would you check if your product is pure toluene cause toluene seem to be the least agressive onto my acrylic.

Thank
Chris

The toluene that I used was from Ace hardware store.  It says Toluol and then toluene under that.  On the back it says that it’s 100% pure, and I saw no mention of Varsol.  I think it’s the same stuff in one of Adam’s pictures.

Hi
ARRRRRRRRRRRRRRR! No conclusion..... Hi hate what I cant explain!!!!! I really like to understand.... Maybe Plexiglass from different provider dont have the same chemical properties..... After two days inside my acrylic toluene made a little crack and varsol reaction seem to be stable… I’ll try to take A high res pic to show my result would be interesting if anyone could do the same test as me and then send the result......

Something sure, its Sorta clear will never lead to those as its water based.... None tried to thin sorta clear with water or methyl hydrate????? AS the product seem not to be catalysed it could be more complicated......

Chris

Christopher,
Did you origonally come up with the toulene/clear caulk mix to be sprayed
onto the acrylic ?
I too had this problem of the cracking when i first attempted to thin my caulk to the point
where it would POUR onto the surface and level it self out. Even with pure toulene.
In testing what might have gone wrong, I tried a couple different thickness and manner of application.
My end result was the assumption that thinning the caulk to the consistantcy thin enough to run thru
a spraygun, infuses alot of the toulene. But in the process of spraying it on the surface, a large amount of the
toulene is expelled into the air and the result is a much thinner layer of product/toulene on the surface.
But the process being modified to be able to POUR the mixture onto the acrylic, Causes there to be a much larger
amount of the chemical in the mix and thus causing a longer cure time . The longer the toulene remains liquid the
more damage it does to the acrylic. 
I.e....  When you clean the surface of acrylic with the toulene and wipe it dry, there is no damage . But try placing a
piece acrylic into some toulene for an extended amount of time and your left with trashed acrylic.

Yeah it seems like not every plexi or toluene are similar.... I’ve drilled a hole into my acrylic and filled it with pure toluene now for two days and the acrylic have only alittle crack. I will make some more tests to be really sure but toluene seems to attack a little my acrylic but after 2 days inside of it..... Maybe thats an additive into toluene or plexi that change all results. Something sure with the spray method I would be really surprise to see the plexi crack. I’ve never tried pooring method and I dont understand people not to buy a 15$ spraygun onto ebay. Its a lot more simpler to get an even layer and you have no bubbles problem or things like that… and with a large surface it most be extremely difficult to achieve good result. And wave into rubber are from my results the things that kill sensibility. Your system have to be the darkest possible and waves in rubber set the ftir effect.....

Chris

Add me to the list of members with a very expensive acrylic 8 piece jigsaw puzzle lol

I found this when doing a google search on acrylics and toulene:

Acrylic resin may be eroded its surface by solvents, which may result in crazing (microcracking on surface). In particular, toluene and aromatic hydrocarbons solvents which contain many of various quick-drying thinners easily cause crazing, and may generate big cracks. Since those solvents are contained in most of paints, coating agents, adhesives and other various types of primers, special attention is necessary so that solvents do not directly touch acrylic resin. Vapor from those solvents may also cause crazing if acrylic resin is exposed to it for long time.

Seem like my solution is a lot more tricky… I feel like you should not use the pooring method and let it dry in a well ventilated place. When I have time I’ll try to update my tutorial with this information. The toluene is totally dissolved into my test acrylic after 2 days. Varsol dont dissolve the acrylic but make it crack really fast. Acetone and lacquer thinner also dissolve the acrilyc. Sorta clear is water base but some ‘’water based glue’’ at our plant are toluene base....

Seem like the best way is to do small layers with a lot of ventilation..... My layers were dry in 2 minutes just to let people understand wath I say...... But it was spray in a profesionnal paint shop with a 24 inch evacuator fan....

Chris