Sun plastics - test-drb@ccmp.vtda.org

10 Jan 2007

...
   I've used
a product called plastic epoxy which includes a solvent to 
 eat
 into the items being bonded for a better bond. I've had the best luck
 placing a small piece of metal (paperclip) across the break and 
 spreading
 an 1/8" thick layer over that. 
 For plastics that it will disolve (if you see what I mean), I've had
 great success using a liquid called 'Plastic Weld' available from good
 model shops. It's basically dicholoromethane (methylene chloride).

 What you do is put the plastic parts together and run a brush dipped in
 the solvent along the crack. For a stronger join, I cut a piece of 
 cotton
 frabric to fit over the hack of the repair, put it in place and 'paint'
 it with the solvent. Then push the cotton into the softened plastic.

 -tony 
Sun seems to use some odd plastic compound or alloy with two different 
types. I usually use MEK (methyl ethyl ketone) for welding plastics, 
and usually it either has no effect or works well, but with the 
Sun-type (I've seen it elsewhere, but first on Suns) plastics it 
dissolves one component but not the other, and the plastic turns into 
this yucky granular stuff with no strength to speak of (the bond will 
hold, but only until you move it). The epoxy kind of worked (it was one 
of the trim pieces off of a SPARCstation 20 (one of the $1 Boeing 
specials- thanks for the heads-up) it holds together O.K., but it's a 
little loose now (epoxy is much slower than MEK, and stuff moved).