Official Luthiers Forum!

There is quite a bit of effort involved in bending on a bending rig with a blanket, admittedly most of the time is spent making forms.

I watched this Video posted by Robbie O'Brian recently

http://www.youtube.com/watch?v=8fEhicNLgxo

It does not seem that bad, when I bend in the rig I don't seem to get that perfect fit in the mold, I like the ideas of bend and check. I just bent some Cherry and Its in the mold but there is some tension in there to get it to fit.

Ideally I would like an iron to fine tune, which got me thinking about using an iron for the whole process.

Any thoughts ?

J

John,

I'm not the best person to respond, but I'm interested in your question and hopefully you'll get something better than this.
I built a bending machine according to plan but went with light bulbs as the heat source, hoping to avoid the expense of a blanket if I could. Anyway, the machine was not getting hot enough for me, so I thought I would try the bending iron, and I made one similar to that described at the site below, using a 3" outside diameter pipe and a charcoal lighter as the heat source. Didn't really like the idea of an open flame in my garage, so I avoided the propane torch. Anyway the bending iron exceeded my expectations. I think the charcoal ligher was about $12.00 and the dimmer switch was under $10. I actually was able, after some trial and error to get the sides to fit in the mold fairly well; takes a little practice, but you can correct the bend by re-heating. I turn the dimmer switch to about 2/3 power (if you believe the info with the lighter it can get up to 1000F); tried checking temperature with my wife's meat thermometer, but don't think it works too well. Just adjusted so that water droplets sprayed on the iron jumped and vaporized right off. I'm keeping the bending iron, but I did just order a silicon blanket and will be giving the bending machine another go since it looks so lonely sitting on the floor in my garage. Others on the site have mentioned that they use the iron to touch up their sides when they come out of the bending machine. In any case, John, I think you can make an iron pretty cheaply and see how you like it without taking too big a risk. I'm more comfortable with the iron, than I thought I would be.

http://soundsalon.com/Make_a_Bending_Iron.html

FWIW I do all my bending on a hot pipe. I like it because I am more in touch with the work, and when I do multiple sets I think it is quicker.

_________________
Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

I prefer a bending iron. I actually owned a bending mold system and I Ebayed it after trying it out. I found you still have to sometimes touch the sides up after the mold with the iron because of spring back. I decided to just stick with the iron. I built my iron just using a piece of 2 1/2" by 12" black threaded pipe a flange and an electric barbecue charcoal barbecue starter. I use a router speed control from harbor freight to vary the temperature. I got this idea from somewhere on the web. I used a propane torch before that. Just seems a little safer with the barbecue starter as longs as you remember to turn it off....Mike

_________________
Another day, another dollar.

I have blankets and a form, but I still use the bending iron for my sides. Not saying it's better, but I do like the process. Might change my mind if the wood is difficult.

_________________
Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

BBQ starters are not that common in the UK, I have found a source of pipe heaters which could be adapted and would probably be safer.

There are mixed reviews on the Ibex heater, some say it does not get hot enough.

J

can you send pics of your bending pattern issue. Often it is more technique or the pattern wasn't compensated for the wood that can cause a mismatch.
I agree a iron will help you tweak for irregularities. It is a good skill to have. If you have industrial tooling outlets in your area check out there for heat elements. They are not that expensive.

_________________
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

I have a fox type bending form with blanket and an Ibex bending iron. I use the bending iron cause I like to do it. If I was trying to make more guitars I would probably use the bending form.

_________________
Steve Smith
"Music is what feelings sound like"

I started with a bending blanket but moved to a hot pipe. I'm just a hobby builder and rarely do the same body shape twice so building bending forms isn't worth it. I get great results with the pipe and it only takes about 20min per side. If you're building many of the same body shape then building forms would probably make sense.
My hot pipe is just a section of iron pipe and a heat gun. Pretty cheap and easy. The nozzle on the Wagner heat gun fits in a 1-1/4" pipe coupling perfectly

I bent these sides on Saturday and just about managed to shoe horn them into the mold hence the reference to tension, I clamped the neck and tail blocks just to keep it all together (no glue). I then spritzed it with water for most of the afternoon and left it in the sun to dry. Every time it dried out I spritzed it again, I didn't have a plan it just seemed like a good idea at the time.

I just removed all the clamps to show you how badly my side fit my mold , guess what .............................

Thanks I am now looking into building a bending iron, heating bands seem like the ideal solution to heat the pipe

http://www.resistanceheaters.co.uk/www. ... fo.php?p=2

These retail for $15.00 so it would not be too expensive to make a couple of diameters

J

your fit looks pretty good. One thing is that you want to keep the sides a tad long so you can use the waist spreader to help get the sides dead tight to the sides. Often it is that people trim sides short. There is a technique for that perfect fit and you soon will master that
jh

_________________
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

I used blankets and forms for many years. I recently switched to a bending iron for my current archtop build, so my only experience so far with the iron is with maple.

My experience with the bending machine is that the blankets often produced excellent results, but sometimes gave me flat spots, uneven curves, and ripples. I occasionally got cracking in cutaways. Invariably, I got more springback than I would have liked.

With the iron, I did several test pieces of maple (mostly flatsawn curly maple), and then I did the "real" pieces (quartersawn and highly flamed). Every piece bent perfectly. No flat spots, the curves were even, and no ripples or cracking. Absolutely no grain lift on the figure. No springback. The only problems I encountered was on (a) on my first test piece, I didn't use enough water and the wood case hardened before I finished the bend, and (b) on one test piece I got very light scorching (so light I hesitate to call it scorching), but it sanded out very quickly and easily.

The cutaway was pretty tight with the iron, and it took a little while to bend the cutaway side (probably 25-30 minutes to get it perfect). I'm sure it will go faster as I get more experience. The non-cutaway side went pretty fast (10 minutes).

With the bending machine, it always takes longer than what it took me to bend with the iron. The bending itself is faster with the bending machine, but setting up the machine, wrapping the sides in foil, and getting the sides perfectly aligned in the bender all takes time. Not to mention the fact that, once you bend, you have to let it sit there a while to cool before you can use the machine again. Also, I have never been thrilled with the results I get from the machine on cutaways, and it is a pain in the neck to sand defects out of the cutaway.

I'll defer final judgment until I have more experience with the iron. Perhaps I will get less favorable results bending sides for flattops (which are wider than archtop sides), or bending species other than maple. But unless I have a radically different experience on future builds, I'll eventually put the bender up for sale.

Hi You are echoing my sentiments exactly, I don't have that much experience and I have invested quite a bit of time end effort in to building a fox bender. You are correct, you never quite know what you are going to get until it comes out the bender and by then it is too late to correct any mistakes.

J