I've been waiting four months for a compression strap (for steam bending) from Lee Valley and they just estimated the new delay will be another three months! Does anyone have a suggestion for an alternative supplier?
Mike
https://www.leevalley.com/en-us/shop...g?item=05F1101
Contributor
Mike,
You could build your own. Or possibly there is a woodworking club in your area, someone may loan you theirs.
Richard
Contributor
Mike, It looks like the strap itself is available, so it must be the end block that is unobtanium. Perhaps you could rig something up using a wood block and a turnbuckle or the like.
--I had my patience tested. I'm negative--
Contributor
If memory serves me correct, compression strap is the same a banding strapping material. Two problems with this, first, because it's steel, it can leave black staining on some woods. Second is drilling holes to attach clamping blocks. This is easily solved by heating area to be drill to red stage, and let it cool slowly. I've been know to use cut off nails in drill press, and let them spin against strapping till it creates a red spot, softening the steel.
Staining isn't an issue as the final shape is pattern shaped after steam bending. The issue is the end blocks to handle the force of bending 9/4 kiln dried cherry. Wood blocks will not stand up to the force. The Veritas stuff works well -- I've used it at Anderson Ranch bending both 9/4 cherry and walnut for the legs of my chairs. Unfortunately, Lee Valley is having significant issues with pandemic suppliers and it doesn't appear that anyone really supplies stuff for major steam bending besides them.
The last set of chairs were glue laminated, but that is very messy and wastes lots of material.
Mike
Contributor
Mike, I can't offer any suggestions, but it caught my eye you're using kiln dried cherry. I wasn't aware kiln dried woods could be steam bent.
Do they behave differently to air dried?
Yes, it is possible to steam bend kiln dried domestic hardwood, but it is much easier to steam bend air dried stock. Unfortunately, living in Colorado, it really is not easy to obtain high grade air dried cherry or walnut. There are two things that make it more difficult: our low relative humidity and the kiln drying process itself. What helps is to raise the moisture content of the stock prior to bending it. So I'll soak the stock for a day or two and wrap the stock in plastic wrap, then steam it for a longer period of time. The cherry (which was about 9/4 across the section bent) was in the steam box for 4 hours prior to bending. It took a lot of force to bend it. And it dried on the drying form with a clamp applying pressure across the chord of the bend for a week -- I'd probably have been better letting it dry even longer but ran out of time.
Mike
Contributor
Make the straps and instead of bolting on a block of wood, use a short piece of angle iron.
Protect the wood and strap with package tape.
Contributor
Some people use worn out sawmill bandsaw blades.
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