bending machines vs bending iron?

[Simon Magennis]

I watched a demo on uTube of the updated lmii bender. (Fox style). As far as I can see the only benefit of a bending machine is consistency. It looks to be to be slower than hand bending on an iron.

The model in question seemed did one side at a time. I can easily understand using a bending machine if you could pop in (say) four sides at a time and bend them in the time it takes to do one on a bending iron and have superb consistency. All the more so if it was automated so you did not have to work with springs - just go away and leave it to do the work. However, I reckon a pro with experience is pretty consistent with a bending iron too. (As an amateur it doesn't matter much anyway.) A further attraction I can see is getting binding bent all in one go and also consistent.

Why do you choose one or the other?

[Clay Schaeffer]

Hi Simon,
I have chosen an "in between" approach. I use a blanket and a block form. The block form is simple to construct and is usually made with the off fall from the building mold. What I like about using the blanket, is the entire side is evenly heated at one time, and so I feel less inclined to kink or twist while being bent. Since it is bent over a form the shape is fairly consistent.
I have bent sides using an hot pipe and in the right hands it would probably be about as quick and accurate, but for the amateur I don't think this is the case. The bending "machine" looks like it would work well but is a bit more complex to make than a block form. Some people love simplicity, some love complexity, and some just want to "get 'er done".

[Ron Belanger]

Also, once the side is in the bender you are free to to other tasks. It allows me to use my time more efficiently.

[Bob Gramann]

I use the pipe. For me, bending by hand is both satisfying and fun. It took me a couple of guitars to get it down but I wouldn't even consider a machine. Depending on the wood (and cutaway vs none), it takes me from 30 to 60 minutes to bend a set.

[Randy Roberts]

I'm with Clay,
A bending form is already half made for you when you cut out your mold pieces. Less chance of broken sides, and as a 1 or 2 a year builder, I won,t ever aquire the facile touch for me to trust sides to an iron.

[Waddy Thomson]

I have all the stuff, blankets, controller, form, slats, but for the life of me, I can't seem to justify the set-up time. I can bend on a pipe and be done - no springback - and in the mold (though I don't use a mold) in a couple of hours, from the time I decide to do it till everything is put away. I don't have a "bending machine", and don't have a place to keep one, so if I did it with a blanket, etc., I'd have to do it like Mario, on a form, with clamps etc. Are my bends perfect? Probably not, but no one has complained yet.

[David Malicky]

Some builders do bend 2 sides at a time (e.g., Trevor Gore). My current bender does 1-per but I'll go to 2 for my next one. More than 2 has some issues: the heating watts are more than a wall outlet can put out, and if you have 1 troublesome side, the other 3 would have to go along. Here's a semi-automated 2-per machine:
http://www.youtube.com/watch?v=dWS2yUN7xcI

For 1 at at time, it's hard to imagine being much faster, simpler, and more efficient (lengths are pre-trimmed) than Mario:
http://www.youtube.com/watch?v=sUJbB0pa7Zs

I've never tried bending with an iron -- it does sound satisfying, though.

[Jason Rodgers]

I just bent my second set of sides last night (hooray!). It took me about 90 minutes, and I will need to touch-up (sigh). About an hour into it, I said to myself, "Maybe I should look into heat blankets..." On the one hand, I agree with Randy that I'm not exactly racking up experience time on the iron (it was my second set in 4 years), so a bender setup would probably give me better results; but on the other hand, I'm not building enough instruments frequently enough to justify the cost. That, and this second set of sides is the second body style, with a third coming up in the next project, and at least two more in the following projects, which means I would need to build an annex to my tiny shop to keep all the moulds!

I can say personally, though, like Bob, that I find bending on a pipe tactilely satisfying, and it makes me want to practice on scrap and get better.

[Bryan Bear]

I am set up to do both but have found that I like the pipe much better. There is just nothing like bending on the pipe. On my current project, I did a quick rough bend on the pipe, then put the bent side in the bender to cook and even out any lazy bends. I think I liked that approach but the timing was a bit off since the second side was done well before the first was cool in the bender. . . Personally I think learning to use the pipe is an important skill to acquire even if intend to use a bender. The time will come when you want to alter a cutaway, touch-up linings or other things that are just easier and faster to do free hand.

[Rodger Knox]

I don't have a blanket, so I do a bit of both. I bend the waist on the pipe, and then put it in my bender to finish it up. My bender is not much more than a form with 3 100watt bulbs inside. I also use a regular clothes iron to heat the outside while I'm bending the upper and lower bouts on the bender. It's not quick, but it's pretty easy, and I get more uniform results.

[Brian Dyskin]

... I use a blanket and a block form. The block form is simple to construct and is usually made with the off fall from the building mold. What I like about using the blanket, is the entire side is evenly heated at one time, and so I feel less inclined to kink or twist while being bent. Since it is bent over a form the shape is fairly consistent.

Hi Clay,

Could you please give more info on how you use the block form? Do you bend the side by hand over the form? Do you clamp the sides to the form once they're bent? If so, how? Any instructions on how to use this techinque would be greatly appreciated.

TIA

[Randy Roberts]

When you cut out the pieces to form your outer mold for the body, the part that is cut away ( in the shape of half a guitar body) can be used to make your "inside mold" or block form to bend the sides on. If you trace out the outside mold exactly the size of the body, draw a parallel outline 1/4 inch inside this this line, and cut in between the lines. Then sand the inside piece and the outside piece down to their respective lines, and you get both the outside and inside shapes to make the outside building mold, and the inside bending form.

The inside mold will be 1/4th inch small, but the sandwich (of heating blanket, slats, side wood being bent, etc.) you will be bending over it just about exactly takes this gap up and gives a slight overbend that will help counteract any springback in the wood. You don't need the rigamaroll of the screws etc. of the Fox style bender, you can just clamp with cauls and regular
clamps.

[Kelly Moran]

I'm a new builder on a learning curve using a diy iron. I bought a set of practice sides from Stew Mac and, of course, split the first one within a couple of minutes. The second side turned out much better, a couple of scorches but good enough for me to try my technique on my real Rosewood sides. It took me well over two hours per side to complete the set and I did walk away a couple of times when my lack of patience got the better of me. All in all I learned a lot and I got good results. I'd like to try a blanket and bender to see how well they work but at my rate of production the iron is all I need.

[Bryan Bear]

. . I did walk away a couple of times when my lack of patience got the better of me. All in all I learned a lot and I got good results.

I just might make this into a sign and hang it over my bench!

[Clay Schaeffer]

Hi Brian,
I use a piece of bendable plywood or kerf kore material in conjunction with the block form. I use formica strips in lieu of the steel slats most people use for the bending "sandwich". The bending ply is the top layer of the sandwich and spreads the pressure of the clamps that are used to pull the sandwich against the block form when the wood has come up to temperature. The sandwich from top to bottom is bending ply, formica strip, wood, heat blanket, formica strip, block form. I use F body (Bessey )clamps to pull the sandwich to the form, starting at the waist and working to the ends.

[Eddie McRae]

This is the bender that I built. Took a couple of hours or so to build with a cost of around $35 (not including blanket or controller). It takes less than 5 minutes to set it up and I can have a side bent in 3 or 4 minutes. I honestly can't imagine trying to fight with a bending pipe now. I still use a pipe sometimes for small quick bends...binding, etc. But that's about it. I'd highly recommend building yourself a good bender.....it's well worth the trouble IMO. Clay, in regard to your statement above about using formica for slats......does that work well? and have you tried using formica for a cutaway bend?

[Clay Schaeffer]

Hi Eddie,
Formica (or any other brand phenolic based laminate) does work in place of the spring steel slats. The material will take a "set" from the heat but can be reused several times before this becomes a problem. the blanket could probably be used to flatten them back out but since it is scrap material I just cut new strips when changing models or as needed. I have not tried using it for a cutaway bend, but the material does come in a thinner grade (vertical grade) that can be bent with heat to a 1" radius.

[Simon Magennis]

I would be interested to see how many people would change their minds in either direction after carrying out the following experiment. Grab 5 or 10 pairs of sides (in Europa Madinter supplies so-called "practice" sides, and I am sure every tonewood supplier will do it, for for about $4 a set ex-tax) and get them down to your preferred thickness and shape. Then on a nice hot bending iron work your way through the pile. I suspect that the first 2-4 sides would take over 10 mins each. By about about number 8 I'd guess you would be down to about 3 mins a side. I am assuming a cooperative material such as mahagony or a thin maple.

[Clay Schaeffer]

Hi Simon,
Did you do that "experiment"? Is that how it worked out for you? Do you prefer the hot pipe method over the blanket and form method?

[Jason Rodgers]

I can see that exercise working. It's practice, after all. Don't know if those times would hold true for everyone, though. I certainly felt more confident about bending - duration of wood/pipe contact, pressure, etc. - after the first side on this last set. If I had a stack of sides, for practice or a run of instruments, I'd be very disappointed if my efficiency didn't go up.