Square stock keeps snapping

[Mysterion]

I've run into a problem I've never experienced before. I'm building a pair of suoerchargers. I want to add .040x.040 around the case to simulate the ribs. I can get them to bend around the case fine, but within a second of adding cement, the square stock snaps. .080 stock does the same thing.

Is there a reason it's doing this?

It's Evergreen stock, and I'm using MEK as a cement.

[colbart/colin]

Some evergreen stock I used seems to be brittle, i was never sure if it was because of age, or the material, when glue/cement is used seemed to make matters worse.

Look out for stress marks when bending stock, I found using a metal/copper pipe and slowly bending the stock around that, then using the liquid cement to weld the already rounded stock to the item. melting the corners may help take stress out of it.

Take your time and don't rush.

Tube bending copper pipe using that strange spring device and a big pipe when a mechanical tube bender broke!!!!!!


Col.

[rocketeer]

I've had this happen, too; very frustrating. I think bending the strip puts stress into the part, and when you add the solvent it weakens the plastic enough that it just snaps. You could try pre-bending the part, which might work, or you might try a non-solvent cement (like superglue) or a less aggressive cement (Testors tube glue). You might also try a non-plastic material, like lead foil or solder, with superglue.

Last time I had it happen I ended up heat-bending the strip (wrapped it around a piece of dowel and plunked it into a pot of boiling water) and that solved the problem.

[badroadahead]

Maybe try heating it first. That will soften it up to bend slowly.

Dave

[Paul B. Canney]

I did this with Ambroid Pro-Weld
canneysgarage.canney.net/cherrybomb/stage3/Index.html