The laser stresses the Acrylic very badly, any process that puts heat into it does. (sawing , routing , bending)
Solvents will promote and cause stress cracking , thus dont use any paint with a sovent in it near or on lasered acrylic.
What makes it worse is that the clear acrylic best used for reverse engraving is extruded (engraves clear and not frosted) which is stressed more by lasering , its a short polymer chain acrylic and thus will stress crack way before cast will.
Dont think that time will stop the problem either , the stresses are there permanently and even worse is the fact that the stress cracks might not appear immediately when solvent is introduced , they can happen weeks later.
There is a fix tho , you can put the pex in an oven at 70-80c for 1 hr per mm thickness and let it air cool , this will stress relieve the pex and then you can use solvent based paints. |