Strap length for steam bending?

[sailorbenjamin]

I've got the box just about ready, I've got the wood just about ready, I've got a metal strap.
Now, when I clamp end blocks to the clamp, should I fit them up snug against my stock prior to bending or should I expect some lengthwise expansion to happen in the steambox?

 

[Andy Hutyera]

Wood only expands very minimally along the grain so you shouldn't need to leave much of a gap if any. The purpose of the strap is to put lengthwise compression on the wood and surface pressure to discourage split outs. You can make cheap metal straps from perforated cross brace stock sold in most hardware stores.

Good Luck!