bending machines vs bending iron?

[Waddy Thomson]

I've bent 22 sides, and it takes me 5 minutes just to do the waist on each one to get it just right. I go slow, and attempt to get a perfect fit. I don't use a mold, and my side have to fit the perimeter of my top with minimal gapping, depending on the purfling pattern I'm going to use. The only sides I've had a problem with were, oddly enough, a set of Sycamore, which decided to keep bending after I was done. I set them aside, and was gluing in the neck and tail block, looked over and they had continued to bend over the 30 or so minutes they'd been sitting. When I was done with them, they fit this form.

[David Malicky]

A few factories use an iron, handled by some very skilled people:
Martin for some guitars, 4:30 in -- http://www.youtube.com/watch?v=SFNYxjlU_-0
Eastman, 0:38 in -- http://www.youtube.com/watch?v=mtBlGRmnmJE

[Simon Magennis]

@ Clay.

Not exactly as I suggested but close.

I did 5 sets - two cypress, two African mahogony (khaya) and one European maple the last time I did a batch. The whole lot took about 50 mins. I was really surprised and especially at how fast the last one went. The first set was about 20 mins and then it just got faster and faster. The last set of the batch (very thin maple for a small guitar) seemed to take only a few mins. I left them sit for months after than and I have just recently used three of the sets and didn't have to touch up anything. My previous experience was always bending one set at a time and I'd guess anything from 20 mins up.

A comment that Alan Carruth made here ages ago really stuck in mind then - it was to the effect that if you get the iron hot enough wood bends quickly and easily but that if you have it a bit too cool and it is slow, the wood seems to harden up and just gets even slower to bend and with a bigger risk of cracking. I can't remember the exact way he phrased it but the message for me was do it hot and quick and it will work, slow and cold will be a battle.

Next time I am in bending humour I will try and time it precisely and write it down. Memory is a fickle thing.

[Ryan Mazzocco]

this is the machine I built. I haven't had any problems with it. It's definitely not fancy, but it gets the job done. I can bend both sides at once with it.

it's heated by 6 120W bulbs separated into 3 zones, upper, waist and lower, each with it's own dimmer to try in an attempt to have better control of the heat distribution.

There is always some spring back with it, but once I put it in the form it's no problem.