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Hey everybody,

For my first build the most daunting job is bending the sides. I have five peices, 3mm thick, just in case there's trouble. The wood i am using is Tasmanian, Breackheart Sassafrass, fairly straight grained. The wood has similar attributes to mahogany.

Would one of the electric bending irons from Stew Mac or LMI be the way to go? I see some have sucess with the torch and alloy pipe.

I have read up about the bending process and it seams like its a feel thing. Also the wood type and amount of figure in your wood makes a difference to the degree of difficulty in the bending process. My first build is a weissenborn type copy. What thickness do you all suggest?

I intend getting some practise peices of ply to try first.

Any bending technique advice or things to watch out for will be greatly received!!!

Thank you all for your attention.

Cheers

Alan

  

Electric bending irons provide better heat control for the novice but a pipe and torch will work fine be sure to use some stainless of spring steel to back up the out side of your bending. Learn to feel the wood give. Keep a spritz bottle of distilled water handy. you want your side thickness more like 2.0-2.3mm 3mm is way thick in my books.

Hi Allan --

I, too, am new to the fine art of side bending, having begun my first two "scratch-built" guitars, both OM's, and semi-successfully hand-bending the sides. I have gotten some good practice, however, since I ruined my first two sets of sides in the radiusing process. That's another thread, though. The wounds are still a bit too fresh to discuss... 

Anyway, one big point I can share is that it's very easy to put creases in the waist bend of mahogany -- I've done it on both sets now. I think the cause was just trying to get that tight bend in there too quickly, sort of all at once, rather than getting a radius started across a small area, then slowly tightening the radius, until its where you want it. I'm really hoping I can sand out the creases without thinning the waist too much. On the other set, which is Granadillo (similar to rosewood), I had a different problem at the waist -- starting at the center of the waist radius, and again, trying to get the bend in there quickly, I got sharp bends on either side of the point actually touching the bending iron, while that point remained relatively straight, almost as though the heat had burnished the wood to the point that it refused to bend at that point. That was very frustrating, though I was eventually able to sweet talk it into place using a steel strap to back up the bend.

I'd told myself that I should gain some experience with hand bending, as that's the way it's been done for many years, and I'm glad I did, but I can honestly say that I'm now saving up for a Blues Creek Universal bender.

I hope I'm not discouraging you, but just thought it pertinent to share my recent experience. Good luck with it.

Ken

_________________
Mountain Song Guitars www.mountainsongguitars.com

One thing (since others have more experience): thin them more. 3mm is thick. Personally, I shoot for between 2.2 and 2.0mm on sides.

Beyond that, I'll say that building a side bending mold (Fox-style) and investing in a heat blanket is worth every penny. Consistent, symmetrical results from the get-go, and not breaking even one set of moderately expensive wood (say, cocobolo) already saves you money.

Well thanks everybody for your help and advice. I know bending wood won't be easy. But, hey i'm up to the challange.

Cheers

Alan 

Alan -as Ken said becareful not to force the bend to much!
The crease he talked about is called a compression ;caused by either bending to fast or the wood being to thick.
Have your shop quiet so you can hear what's going on (wood will give a small click) when it's ready to break!
Unless you have highly figured wood which may give no warning.
The electric bender is my favorite!
I still use a small diameter pipe for cutaways!
Practice on some scrap first.
Mike
www.collinsguitars.com

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Mike Collins

Hi Alan,

I’m new at this too, and if this is of any help, I just built my hot pipe jig 2 weeks ago. The first
time I tried it out, was last weekend, and had great success with one of the sides.
I still need to bend the other side for the cutaway. I already had a set of pre-bent mahogany sides for a
dreadnought. So, I decided to try and re-bend them to fit a OM mold. So far, so good! Of course
the real challenge, is when I try to do the cutaway side. However, I feel confident that it will work.

I got my information from the book William Cumpiano wrote “Tradition & Technology”.
I soaked the mahogany side in hot tap water, weighted it down in the bath tub for 10 minutes.
I had the pipe already going, so it was good and hot. I don’t want to say that it was easy, but, It
wasn’t very hard either. Like Hesh says, keep it moving, rock it back and forth, and you will feel
the wood relax. I kept my mold right next to me, and when I was satisfied with the fit, I held it
there for, maybe less than a minute. It holds its shape pretty quickly. I think the soaking was what
made it work so well, IMHO. But, when I was all done, I don’t think there was a drop of moisture
in that piece of wood.

The pics below show the jig, and the set of sides. The parts laying above the sides are what I used
to control the heat inside the pipe. Just a old sink drain, and a pipe cap served well as a baffle. The
side on the bottom is the side I bent to fit the OM mold.

Hope this helps,

Robert

_________________
Everything has beauty, But, not everyone see's it!

I had problems with my heat blanket bending all the way. I did 2 sets of wood, and it came out of my bender like the TOP wood shown above. So I had to rework my fox style bender.

So Bluesman here is my $2.00 advice. If you use a foxbender, build the Positive blanket mold first, bend the wood see where it goes adjust if neccessary. THEN build the negative holding mold to fit the guitar sides. It will avoid this:

 

That will be $2.00 please!

 

The most important thing with bending Weissenborn sides is to get the neck/upper bout curve perfectly symmetrical. The Fox system comes in handy here, but I've bent about a dozen Weissenborn sets by hand and it's definitely doable. Be forewarned though that it's a lot more frustrating than your average acoustic side bending, due to the fact that there's no neck block to pull the two sides together perfectly should you be out by a few millimetres. Whereas a regular set of sides might take an hour to do, you can realistically expect to spend 3-4 times that long getting a Weissenborn set perfect.

Try bending the upper bout and neck area together, taping the two sides together. That should make the process of getting uniform sides a bit easier.

_________________
Richard
http://www.guitarmaker.com

Al,

My adventures in side bending:

1. started bending on an electric iron with fairly good results. Hard work but I enjoy being in tactile contact with the wood right through the bending process. My first attempts were on a practise side set from Stewmac.

2. Built myself a fox based bending jig powered by light bulbs but have never used the thing.

3. have just bought myself one of John Halls thermal blankets and a mother of all stepdown transformers (1500watt/22Kg) and will be using same for my next build.

Campiano's book has useful information on side bending but like riding a bike you cant read about it and suddenly become an expert at it.

If your wood came out of the fox bender not set to the form shape. My guess is that you one or two things happened and more than just a little likely both.

You did not cook for 10 min or so after the bend to set the shape and or you did not allow the wood to cool over night before removing.

Both these steps are important to setting the bend into the wood.

The blanket is not the culprit here.

There are times I have need to remove a side while warm. I avoid this 90% of the time. When I do this I clamp the side to a double depth rim mold to allow it to cool and set. However I prefer to allow the sides to set over night clamped in the bender.

I am not knocking pipe bending at all. I use the pipe a lot to do binding fillets for fretboards bindings and other tasks, However blanket bending has no more spring back than pipe bending. Also unless you have good experience level with the pipe bender, the process of pipe bending often causes case hardening of the sides more than blanket bending because the blanket heats consistently and then cools ones. Pipe bending you are constantly heating, cooling and reheating individual areas which leads to case hardening. Just my personal opinion.

[QUOTE=MichaelP]If your wood came out of the fox bender not set to the form shape. My guess is that you one or two things happened and more than just a little likely both.

You did not cook for 10 min or so after the bend to set the shape and or you did not allow the wood to cool over night before removing.

Both these steps are important to setting the bend into the wood.

The blanket is not the culprit here.

There are times I have need to remove a side while warm. I avoid this 90% of the time. When I do this I clamp the side to a double depth rim mold to allow it to cool and set. However I prefer to allow the sides to set over night clamped in the bender......

[/QUOTE]

 

What I ended up doing was taking out around an inch on the backside, and half inch on the front of the guitar mold.So it would technically be distorted if it stayed that way out of the mold.

My Paduk and mahogany sets both did the same thing, identical. It got very hot, was left over night etc etc.

 

I had to redo the mold as descibed above, and this was after like 5 attempts with the heat blanket, and yea, I did everything recomended at least 2X. Blues creek blanket I believe, off ebay.

 

I no longer use the temp control   I just heat er up for 5 and cook it, turn it off when it get too hot,spreay, wet rages, steametc etc. turn back on. etc. 10 minutes let sit overnight. I think I still get a little spring back and I have to redo the mold again to make it a tight fit. 

It finally worked, that is why I say do this step first, then make the holding mold. That is worth $ 2 dolla!

 

Also, my bender is way more simple than the early design fox monstrosity shown above, that will scare a newby fast! I use screw eye bolts and on one half have a hand crank for the threaded bolt.

It works fine, its a pain, you have to be careful but I dont mind not using the rheostat. It takes too long to heat up with that.

 

Hey can we get email replies on this forum?

 

 

 

So I gather you are using a bender some what like the Mike Doolin showes on his site. Not that that should matter. I have to say a 1" of overcompensation is a lot.

I have bent a lot of different woods including High Quilt Mahogany and many other tough to bend woods. I have never had spring back issues like that unless I took it out hot and just set on the bench over night. all woods will spring back some. The fibers want to return to their natural state. I am not sure why you are having this problem. I still do not believe that the blanket or the temp controller are the culprits. To many of us bend very successfully with them every day.

Wished I could help