Hot knife

I've had good luck with ham radio battery packs for handhelds by freezing them and then hitting them on a stone step. The welds crack open.

Geoff.

Squash, long ways first, in a carpenters vice usually splits enough in the middle of the run, to make a start, and then blades. If nothing seems to be happening , before you chicken out, try diagonally or short ways. Sometimes will make a small tear into the cosmetic area but I've never had a full tear into the fare surfaces. Somtimes distorts internal heatsink if up against the case

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

In the same vein, I try the freezing and then use an old wood chisel and a light mallet along the seam. Sometimes it takes several passes around the weld. The last bit is usually done with a thin, wide knife blade. The corners -- if any -- can be the toughest...

GL Jonesy

That's what I do. It works best with plastic that has been glued as the glue becomes brittle when cold. The plastic will bend somewhat while the glue will crack. It doesn't work so well when the enclosure has been solvent welded properly. Fortunately, few toys, battery packs, and devices are properly solvent welded.

For real butchery, there's the ultrasonic knife. For example:

Think of it as a miniature Milwaukee Sawzall. I don't own one but have used one to tear apart a reluctant battery pack that was filled with RTV. It worked quite well, but I can't claim that it was cosmetically acceptable when I was done. Like all such reciprocating power tools, it will cut when sharp, but burn when dull. I also tried to make one out of an electric tooth brush and a razor blade, which didn't work.

Hmmm.... I was just about to tackle a small UHF transceiver. I'll try that (if it doesn't work, I can always trash the thing :< )

Ouch! This seems more likely to yield a *mess*...

I tried freezing and then wacking with a hammer (i.e., as if trying to dislocate one side of the weld from the other). No good.

I'll try a sharp wood chisel on the seam next.

Then, resort to the heated knife. :<