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Jan 22, 2021 - 8:23:38 AM
165 posts since 3/19/2018
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Looking at the LMI or StewMac bending iron, and the LMI product is cheaper and appears very similar. Anyone else have experience with these?

Really wanting to try my hand at backstraps, which to date I've not done. I steam bend my own rims so I have a steam box, but my understanding is that the heat transfer necessary for bending say ebony or rosewood really necessitates something like this.

Thanks ya'll.

Jan 22, 2021 - 9:18:17 AM
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beegee

USA

22179 posts since 7/6/2005

i used a metal pipe and propane torch for years. I recently bought a Chinese-made bender on ebay, which is entirely adequate for my uses and more affordable.

Jan 22, 2021 - 9:34:06 AM
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3011 posts since 2/18/2009

I use a copper pipe and propane torch too, and for my first mandolin and fiddles I used a heat gun in the end of the pipe instead of a torch. My first little bottle of propane ran out a couple of months ago after being used to bend the sides for about 20 fiddles, 15 guitars, a few mandolins and several banjos worth of rim veneers. The flame is really low to heat the pipe the right amount. I use a 3" pipe about 6" long for most bending, but a 1-1/2" pipe for fiddle and mandolin sides that need a tighter curve. I've never tried an electric bending iron, I'm too cheap for that.

Jan 23, 2021 - 4:19:12 AM
Players Union Member

Helix

USA

13410 posts since 8/30/2006

An elder here in my town uses TIME and GRAVITY to bend his Rosewood sides gradually. He hangs weights with string, very simple really.
Two scoops of patience.  Therefore his method does nothing to force the wood to do anything. All my trees are female, so I'm going to write some fancy sentence: He coaxes her to bend just a little to make a guitar side and then go to sleep for a century.  No cell  is harmed in the making of the audio, therefore the logic would be that his guitars sound better.  I've heard them and they do.  He built his wife a little bitty bass.  How loving. 

I use my Wagner wallpaper steamer with the trigger when I need dry steam.  steam iron for wet steam, like getting a perfect fit for the binding going around the 5th string jog, I have a jig for that.  Maple and Cherry have a patience factor, then they give gradually so you don't split stuff.  

I repaired 22 fret slots one time because of too dry Ebony, so the "Exotics" that we bring out of the jungle are worth way more care and respect. 
And I hope this information is helpful. I hope this hope is not for naught. Put Input in. Put Output out.

I'm not lecturing, or saying you should do this, just giving more info to budding garagistas. 

Edited by - Helix on 01/23/2021 04:37:05

Jan 23, 2021 - 5:17:53 AM

2280 posts since 2/7/2008

I would have no concerns about buying anything from Luthiers Mercantile. The cost of shipping may even things up.

Jan 23, 2021 - 5:25:21 AM
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13383 posts since 6/29/2005

I don't think you'd need one for a backstrap—I would use a couple layers of material 1/16 or less laminated in a wooden form that's exactly the bend you want for the backstrap.

In terms of bending irons, I made a very workable one from a pipe nipple stuffed with aluminum foil in one end and an electric heat gun.

I used galvanized pipe, but people have told me that the zinc fumes will cause me to die or turn into a lizard, so I'd recommend either black pipe or copper pipe to avoid that—green scales are already starting to grow on my skin.

Jan 23, 2021 - 9:34:52 AM

165 posts since 3/19/2018
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Ooooh -- this is cool. I was hoping to bend ebony and was told you needed to get it pretty dang hot. this is great, thanks!

Jan 23, 2021 - 9:37:29 AM

165 posts since 3/19/2018
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quote:
Originally posted by Helix

An elder here in my town uses TIME and GRAVITY to bend his Rosewood sides gradually. He hangs weights with string, very simple really.
Two scoops of patience.  Therefore his method does nothing to force the wood to do anything. All my trees are female, so I'm going to write some fancy sentence: He coaxes her to bend just a little to make a guitar side and then go to sleep for a century.  No cell  is harmed in the making of the audio, therefore the logic would be that his guitars sound better.  I've heard them and they do.  He built his wife a little bitty bass.  How loving. 

I use my Wagner wallpaper steamer with the trigger when I need dry steam.  steam iron for wet steam, like getting a perfect fit for the binding going around the 5th string jog, I have a jig for that.  Maple and Cherry have a patience factor, then they give gradually so you don't split stuff.  

I repaired 22 fret slots one time because of too dry Ebony, so the "Exotics" that we bring out of the jungle are worth way more care and respect. 
And I hope this information is helpful. I hope this hope is not for naught. Put Input in. Put Output out.

I'm not lecturing, or saying you should do this, just giving more info to budding garagistas. 


Lecture on!  i love hearing this stuff as I continue refining my own processes.  Really appreciate the thoughtful (and eloquent) response.

Jan 23, 2021 - 10:12:04 PM
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Players Union Member

Helix

USA

13410 posts since 8/30/2006

LMI  , they are not millionaire's from shipping charges. 

LMI has pro features that StewMac freely competes with, 


I used galvanized pipe, but people have told me that the zinc fumes will cause me to die or turn into a lizard, so I'd recommend either black pipe or copper pipe to avoid that—green scales are already starting to grow on my skin.

You are too valuable, young man, to risk your talents this way.   Humor:    Please, I can see the BORG is sprouting already out of your left wrist,  The fumes have already altered your understanding, no zinc, no copper nor black steel.  see,?  Just an observed recommendation, all of us garagistas use our noggins, not always wisely.  We still use 'em. 

Just simple tempered glass tubing.  Is all I ask.

  Sherry, this could seriously injure someone and has been discussed before. 

 

Tempered Glass tubing from Corning?  We have to be careful what we recommend, let's keep it fun and friendly to help people build and play better. 

 

Now, the task is bending Ebony, so advice and experience about that topic is what I would be interested in next.  Liquid Nitrogen, I suppose.  no kidding. 

Edited by - Helix on 01/23/2021 22:28:23

Jan 23, 2021 - 10:21:04 PM
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Players Union Member

Helix

USA

13410 posts since 8/30/2006

What happens when you raise you steam box temp?

A nice Ebony noodle is what you are after.

But I was hoping a backstrapper would chime in for you.  I'm too young. 

Edited by - Helix on 01/23/2021 22:26:50

Jan 24, 2021 - 8:59:52 AM

69 posts since 5/27/2019

I've looked for information about the safety of hot pipe bending with galvanized pipe, and it's a bit hard to find a straight answer. One source said that the hot-dipped galvanized metal is "safe" from a fumes standpoint below 392F, which is probably around the upper surface temperature most people would bend at. The inside of the pipe is presumably hotter than the outside, but I don't know what that delta would be. The melting temperature of zinc is much higher than anyone would ever bend with, and you would think it would need to get near the melting temperature to generate fumes in large quantities. But some materials can change in state from solid to vapor below melting temperature (ordinary ice being one of them - search on "sublimation"), so I wouldn't assume that galvanized pipe emits no fumes below the zinc melting point.

So if I had to guess, occasional bending with a galvanized pipe at reasonable temperatures (assuming good ventilation) is *probably* not going to harm anyone. To be on the safe side, if making a bending pipe from scratch, it might be a good idea to use copper pipe or black iron with the coating sanded off.

Jan 24, 2021 - 9:35:21 AM
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wtalley

USA

270 posts since 7/2/2010

My first backstraps were made using 1/16" thick black veneer from Constantine's. You do need to steam it to make the radius on the back of the neck. I just use the steam coming out the spout of a tea kettle. When shaping the neck, you cannot be aggressive as the veneer will shred around the edges. If you start with a rasp you'll get a good idea of the pullout, switch to files and move to a finer cut as you get close to where you want to be. Finish with a scraper for a nice fine line.

I've also used ebony for backstraps. A 1/16" thick piece of ebony will bend dry to a 10" radius, maybe even a bit smaller. Ebony won't shred like the veneer, but it will splinter. So, again, don't be too aggressive when shaping the neck.

In checking some of my ebony, it looks like 0.075" thick will bend to a 10" radius, but 0.090" won't make it. To go with a thicker ebony, you would have to experiment with different radii.

Jan 24, 2021 - 9:36:03 AM
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7897 posts since 1/7/2005

There is information on the net for building bending jigs heated with a 100 watt (or so) light bulb mounted inside an aluminum tube. I've never tried it, but I like the low-impact and simplicity of the idea. If the power is variable with a rheostat, you could dial in the heat needed for a variety of woods and thicknesses. Here's a web site with specifics on the process:

https://www.tysonguitars.com/build-blog/2017/01/20/the-bending-iron

DD

Edited by - Dan Drabek on 01/24/2021 09:48:48

Jan 25, 2021 - 1:03:27 PM
Players Union Member

Helix

USA

13410 posts since 8/30/2006

I agree Dan, aluminum and a bulb is a good start
Working simple is hard

i have clamp-ons with dimmers I use as heat lamps 

Edited by - Helix on 01/25/2021 13:04:51

Jan 26, 2021 - 11:01:08 AM

1594 posts since 7/2/2007

I started out bending fiddle and banjo parts with a couple pieces of pipe and tubing of different sizes. I simply locked them in a vice and heating with a propane torch.  For occasional bending any kind of pipe works as long as you keep it clean. An easy temperature check was a drop of water and when it sizzled a bit, I'd bend. For a few occasional bends it was all I needed. You can get a variety of exhaust pipe sizes at auto parts stores, even stainless fairly cheaply.

Eventually I got way more sophisticated with heating blankets and temperature controllers for guitar sides.

One of the nicest effects of back straps happens when you laminate thinner veneers and in many cases it can be done with thinner pieces that will bend without heat. Just make a form that will fit the back of the neck, Glue up the veneers and press into the form. I recommend some of the thinner epoxies for that since it doesn’t cause the veneers to tater chip.

A good backstrap takes some careful planning because it has to be glued to the neck shaft in the exact position to yield what you want  after profiling.

https://www.banjohangout.org/photo/270413

Could the hangout make it any more difficult to post pictures? It used to be easy, I gave up, follow the link.

Jan 27, 2021 - 6:29:23 AM

wtalley

USA

270 posts since 7/2/2010

OOPS! I forgot to point out in my post above that if you use a 10" radius on the back of the neck to blend the neck to the peghead you won't have to steam the ebony.

Jan 27, 2021 - 6:39:22 AM

165 posts since 3/19/2018
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quote:
Originally posted by wtalley

OOPS! I forgot to point out in my post above that if you use a 10" radius on the back of the neck to blend the neck to the peghead you won't have to steam the ebony.


William - Where do you get ebony that thin?  do you resaw it yourself?

Jan 27, 2021 - 1:51:10 PM

wtalley

USA

270 posts since 7/2/2010

quote:
Originally posted by QuailCreekBanjos
quote:
Originally posted by wtalley

OOPS! I forgot to point out in my post above that if you use a 10" radius on the back of the neck to blend the neck to the peghead you won't have to steam the ebony.


William - Where do you get ebony that thin?  do you resaw it yourself?


Yes, I do a lot of work restoring late 19th century banjos.  Fingerboards on these banjos are usually 1/8" thick or less.  With a 1/2" wide blade on your bandsaw it's quite easy to resaw ebony.  I don't have a thickness sander, but I do have a spindle sander with a homemade fence for thickness sanding.


 

Jan 27, 2021 - 2:03:31 PM

165 posts since 3/19/2018
Online Now

quote:
Originally posted by wtalley
quote:
Originally posted by QuailCreekBanjos
quote:
Originally posted by wtalley

OOPS! I forgot to point out in my post above that if you use a 10" radius on the back of the neck to blend the neck to the peghead you won't have to steam the ebony.


William - Where do you get ebony that thin?  do you resaw it yourself?


Yes, I do a lot of work restoring late 19th century banjos.  Fingerboards on these banjos are usually 1/8" thick or less.  With a 1/2" wide blade on your bandsaw it's quite easy to resaw ebony.  I don't have a thickness sander, but I do have a spindle sander with a homemade fence for thickness sanding.


i have a decent Grizzily extreme resaw bandsaw but I've never been pleased with my resawing probably because of the blades i use.  too much waste.  what types of teeth do you use for resawing?  appreciate your help!

Jan 27, 2021 - 3:11:36 PM

wtalley

USA

270 posts since 7/2/2010

quote:
Originally posted by QuailCreekBanjos
quote:
Originally posted by wtalley
quote:
Originally posted by QuailCreekBanjos
quote:
Originally posted by wtalley

OOPS! I forgot to point out in my post above that if you use a 10" radius on the back of the neck to blend the neck to the peghead you won't have to steam the ebony.


William - Where do you get ebony that thin?  do you resaw it yourself?


Yes, I do a lot of work restoring late 19th century banjos.  Fingerboards on these banjos are usually 1/8" thick or less.  With a 1/2" wide blade on your bandsaw it's quite easy to resaw ebony.  I don't have a thickness sander, but I do have a spindle sander with a homemade fence for thickness sanding.


i have a decent Grizzily extreme resaw bandsaw but I've never been pleased with my resawing probably because of the blades i use.  too much waste.  what types of teeth do you use for resawing?  appreciate your help!


I use a 1/2" wide, 4 TPI, raker tooth set.  In fact, that is all I use.  At one time I switched to a thinner blade for cutting out pegheads, but now I use the same blade.  You just made cuts perpendicular to the outline, about 1/16" apart, break away the waste wood, and let the spindle sander and files take care of the rest.  I'm a "hobby" builder and only work on one build at a time, so timewise, for me, it's quicker this way than changing out the blade.

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