What causes crazing?

chemman1 · #1 01/04/2008, 09:54 PM

Im working on some small acrylic projects and using weld-on to join 2 pieces of acrylic. I am seeing some crazing at some parts of the joints. The joints are a surface of one piece of acrylic being glued to the edge of another piece. It seems like the crazing is on the piece of acrylic with the surface in the joint.

Any explaination for what causes it or how to prevent it?

Thanks.

checkinhawk · #2 01/05/2008, 10:03 AM

what weld on are you useing?if you used WO 3 it is super fast drying and can craze the acrylic.for the averge DIY guy WO 4 is best,it dries a little slower but less chance of crazing.

Acrylics · #3 01/05/2008, 10:11 AM

Solvent can be a part of it, but also how was the material cut and machined? If the material was heated up too much (esp extruded) it can get stressed and craze when another stressor hits the affected area, solvent in this case.

James

chemman1 · #4 01/05/2008, 11:32 AM

I am using weld-on 4. I dont know how the material was manufactured. The crazing is not bad, and it is not along the whole joint. After wicking solvent into the joint should i let it set for any time before applying pressure to the joint? If so how long?

Thanks.

Acrylics · #5 01/05/2008, 11:44 AM

Quote:

Originally posted by chemman1
I am using weld-on 4. I dont know how the material was manufactured. The crazing is not bad, and it is not along the whole joint.

This would lead me to believe there was an area that got heated up too much and that area got stressed.

Quote:

After wicking solvent into the joint should i let it set for any time before applying pressure to the joint? If so how long?

What kind of pressure are we talking about? Like weights on top of the piece? If so, *maybe* some light weight and possibly some shims under the joint if necessary but I *rarely* put anything on top of the piece, maybe 5% of the time is this necessary. And once you get used to the signs, you'll know it immediately. No good way of explaining the signs of this, and pics don't help. It's more in how the solvent flows through the joint.

James

ETA: what is the brand name/masking of the acrylic?