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Yep, I did it. I bent two bass sides. I want to keep the bookmatch at the tail so I have to either get new sides or straighten and rebend one of them. The sides are cherry and bent really easily so I'm sure I can do this but not sure of the best approach.

Do I need to wait a wile for it to take on moisture again now that I have cooked it in the bender?

That is the best way to flatten it?

Should I really fuss about getting it perfectly flat before I bent the other direction or will the bender take care of wavy/close enough to flat?

I could use SS2, I didn't the first go round and it went easily. Should I bother with it for the flattening and/or rebending?

What else am I not considering?

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

I have never had any association with trying to do this. Having said that. is there a piece of scrap that OP can run through the bender experimentally? Might yield up some information. If no scrap, then perhaps trying to unbend a side with a pipe and seeing if OP winds up with more than 1 piece of wood. If that works, then maybe a return visit to the bender and see what happens. Sounds like there's no downside to experimenting, as the side being reworked is not useful in its present state. I have no idea as to how much fiber damage is done during bending. Maybe some veneer softener could help?

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Peter Havriluk

Sadly, I have no more cherry to resaw for sides. This side pretty much is the practice on scrap; if it doesn't work, I'll have to go out and buy more material to make some sides. So in that regard, there is no harm in trying. I'd just like figure out a method that offers the best chance of success.

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

This doesn't answer your questions directly, but the standard procedure that the builder I learned guitar building from used to make Venetian cutaways was to bend the side to the non-cutaway shape in his bending machine and then fully reverse the upper bout bend into the cutaway shape on a hot pipe. He did this immediately after the initial bending in the machine so no recovery time for taking on moisture and he didn't use SuperSoft. It worked fine on the guitar I built in his course which had highly figured Macassar ebony sides.

I would be inclined to flatten the side on a hot pipe and then decide based on how the wood behaved during that unbending whether to proceed to bend it to the correct shape on the hot pipe or in the bending machine.

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Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

get a cloths iron and paper towels
forget supersoft 2 windex works great the ammonia in it helps to get the cell to move
with the wet paper towels keep wet between the wood and iron just heat it and rebend .

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

Thanks, that is good to know. Right now, I am leaning towards getting it reasonably straight on the hot pipe and going directly to weighting it flat on the bench with the heat blanket. I got almost no springback the first time so I'm hoping that will get it flat enough that the bending machine won't leave any wiggles. If not, I'll do it all on the pipe. I guess I was just worried that you could overwork a side.

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

John, you posted while I was typing. A clothes iron is a wonderful idea!

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

Yup. An iron for getting it flat. Or in my case, a ski waxing iron. I had to do this on a mandolin with walnut sides. No problems. Just added moisture to the foil wrapped package before rebending. I think I did it the next day after cursing on day 1.

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Tony Thatcher
Bozeman, Montana

A steam iron works great for flattening bent sides.
A dedicated steam iron is a must for the shop. Dedicated, because the base will stain and those stains will transfer to clothes, and your spouse will .........(her favorite threat here)

Bob

Parenthetical question: Is worth a try to use a clothes iron + wet paper towels to flatten out some cupping?

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Peter Havriluk

Every stinky set of Zebra wood I have bent cupped and I used the trusty iron to flatten the cupping successfully.

Bob

I wanted to wait until you got good answers before posting... and this may need its own thread, but...

In the last three years of building guitars I’ve made about every possible mistake. For some reason I’ve never made this one (bending two of the same side).

I *think* this is because I turn the bender 180 between each side so that I always have the non tapered (top side) of the side wood pulled toward me. I do this to be sure to keep it square to the side of the bender and also so that the mark with the waist is toward me.

Anyone else do that? I don’t even know why I started doing it specifically, other than I wanted to be 100% sure the non tapered side was pulled firmly against the side of the bender.

Brad


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Sure wish I'd had the presence of mind (or the experience with bending) to use a clothes iron when I bent a set of 'Boire' sides. Cupped like crazy and a nightmare of a time with the side struts to flatten the sides enough to sand flat. Good experience, I guess. And a clothes iron was five feet away on a shelf. Learn something every day.

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Peter Havriluk

Some great info here, thanks guys!

Tony, that’s exactly what I wanted to hear!

Brad, in my case it was because I had a 5 year old little girl hanging out with me in the shop the entire holiday. It was a welcome distraction to be sure but I was feilding a million silly questions at the time I was marking out inside/outside, bass/treble. I marked it wrong and blindly followed my marks and he. Loading the bender. . .

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

We've done this a few times, including a very old set of Brazilian discarded by a builder after a 'spooned' set of sides. For rosewoods, water and a clothes iron until flat. For mahogany or other more challenging woods, SuperSoft 2 and 12 hours to dry, then work with clothes iron.

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For the times they are a changin'

- Bob Dylan

Well, it’s bent back the other way. I’m going to let it sit in the bender overnight. Running my gloved hands over the slats, I think I may be able to feel a slight hump where the bouts changed direction (I didn’t get it perfectly flat with the iron). Hopefully, I’ll be able to touch it up with the hot pipe.

I used the iron and the hot pipe to flatten it. As I was taking out the bend on the lower bout with the hot pipe, I had a flashback. I had done this before on some African mahogany for a woodtop banjo I made about 10 years ago. I can’t remeber why I had to unbend it though.

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

I’m happy to report that the side came out of the bender in great shape (pun intended). There were no waves at all like I feared. I did get a fair amount of springback; the previous bends had virtually none. I’m not sure if that means it didn’t bend as well after being bent, straightened and rebent, or if it was just because I didn’t cook it as long the second time (I was afraid of scorching).

The spring back is not bad at all. I can push it into the mold without much force on the spreaders; a little tough up with the hot pipe and it’ll be all set (pun not intended).

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

Well done!

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Tony Thatcher
Bozeman, Montana

Yep, nice save!


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I did that once. As John said, I just ironed it flat with a regular household steam iron. It went very well. Easy actually

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Joe Beaver
Maker of Sawdust