acrylic cracking?

[fred sanchez]

why am i geting cracking after i vector cut acrylic ? any tips

[Doug Griffith]

If you are gluing the parts together, it could be the solvent in the glue causing the crazing.

[fred sanchez]

no gluing its cut from one piece of mirrored acrylic

[Bob Tate]

I don't know if it will help your situation or not but it did the trick for me. I was doing flight simulator instrument and radio panels. Lots of cuts in small panels. The cracking happened over night. My solution was annealing.

http://www.polyfab.biz/annealing-acrylic.htm

My kitchen oven worked just fine. People said you have to have a special oven that is more precise. The kitchen oven was close enough. It worked.
Bob

[Rodne Gold]

Its stress cracking due to the heat the laser puts into the acrylic when its being cut. The problem is most likely cos the acrylic you are using is extruded rather than cast - extruded tends to stress crack more.
Any solvents nearbye , any solvent vapours and often paints used with a sovent base will cause this. Looks to me in the pics that you are painting the plates - try a paint that is not solvent but rather water based.

[carl stevenson]

Yes I had exactly the same thing happen this morning, Its the paint.

The remaining edges on the sheet I cut from were fine but the cut out pieces I had painted all had cracked edges.

The paint solvents seeped between the mirror backing and the acrylic. I think its the backing that actually cracks rather than the acrylic.

I now use non solvent based paint form a craft shop

[fred sanchez]

right on thanks guys for your help

[Lee DeRaud]

I think its the backing that actually cracks rather than the acrylic.Actually, it is the acrylic. I've seen this any number of times with plain clear.