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Hi, I’m about to bend sides for a couple of 00 sized guitars. I used the hot pipe with heat gun method for my initial attempts with no issues but built a Fox bender to use for this batch. Back and sides on these will be Osage orange for one and walnut for the other. I’m wondering how much water, how saturated the paper in the slat/paper/wood/paper/slat/blanket/slat sandwich should be for each species? Also use super soft 2 or no?
Thanks,
David


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David,

I'm an amateur at this (13 guitars so far). Remembering my 3rd grade science class, water only gets to 212 degrees f before changing to vaper/steam; and that's if you are at sea level (I am at 5000 ft). Yes, I spritz the side with water, but only to dampen it. I also wrap the side in paper and then aluminum foil. My bending blanket thermometer says I start bending at around 230 degrees or so, but there's still steam coming out. I know that steam CAN be hotter than 212, but my thermometer isn't inside the paper/aluminum, so I'm measuring between the outside of the package and the blanket. I'm not doing this on a pipe but on a Fox-style bender from Mr. Hall of Bluescreek. When I did a venetian cutaway, I used super-soft and thinned that section of the side.

Now that I'm thinking about this, why would there still be steam at 250 degrees f? My only guess is that my paper/aluminum foil wrap is keeping the water/steam in, maybe increasing the pressure a bit? I'm curious.

I've had 100% success using this method, though I'll admit I only have a limited amount of experience and nothing more exotic than EIR. I've also bent walnut, white oak, and mahogany.

I hope this helps,

Steve

I hope this helps,

Steve

Just as an FYI water and steam under pressure can be over 1000 degrees fahrenheit. The temperature of water in a pressure cooker is about 250 F so it may not reach much above 212 F in a bending jig.

Don’t over think itZ sprits it good... I’ve also been doing what JHall does with winded and it seams to help.
So moisten it.., then wrap in foil, then from the bottom up/- slat, side, sale, blanket. Or in your case just a sandwich between the slats


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Really I’m after information specifically about these two woods , Osage orange and walnut. Whether they bend with better results with more or less moisture. Everything I’ve read, has expressed that different woods and figure do better with varying amounts of moisture, some respond better fully soaked and some with very little if any moisture.
Also trying to get an idea by those who use super soft or the like when it’s best to use or not use those aids.


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You won’t need a ton of water for walnut, just spritz the paper or spritz the side directly if you are using foil only. You won’t need SS with walnut.

This is all assuming a 0.070 - 0.075 thickness, which is where I have experience with it.

No experience with Osage Orange.


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Walnut is pretty easy to bend so don’t stress too much about that. The only Osage I have bent was bindings on the hot pipe. But I don’t remember how much heat and ware I ended up having success with. Sorry I can’t be more help.

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Bryan Bear PMoMC

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

both bend well
thickness should be about .075 in. Bend 250F for walnut 275F for the osage

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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

Pressure would not build up in the sandwich to any measurable degree. However, the water may evaporate more slowly just because it can't escape as quickly as if it was sitting out in the open.