bending iron advice

**Matthew Tucker** · #1 05-11-2006, 06:24 PM

Soon I’ll need to think about a bending iron. Correction – I’m already thinking about it, soon I’ll need one.

I don’t seem to find commercially made bass-size electric irons with generic curves, and i probably wouldn't want to shell out huge $$ anyway. Chandlers book (and others) suggest a simple piece of steel pipe heated with a gas flame – I tried that but not very satisfactory, because the heat seems too localised.

The local luthier (makes violins, cellos, doubles basses and lots of other instruments) I spoke to the other day said that the ONLY way to go is to cast one – built for the C-bout of the model in mind - at a foundry. He uses a wide tin strap attached to the bottom of the iron, (pictured below) heats the metal up to just right and pulls the soaked ribs around the iron using the strap. Works great, but i'm wondering if making up my own bespoke iron is a lot of work for my first bass. But maybe it would be worth it?

Any suggestions or advice for me?

mcnaire2004 · #2 05-11-2006, 08:19 PM

Not the place to ask about this.

**Matthew Tucker** · #3 05-11-2006, 08:26 PM

Quote:

Originally Posted by mcnaire2004

Not the place to ask about this.

Really??

Anon2962 · #4 05-11-2006, 11:05 PM

Quote:

Originally Posted by mcnaire2004

Not the place to ask about this.

Yes, this is quite obviously more suited to the 'Recordings' forum.

JansenW · #5 05-11-2006, 11:11 PM

Quote:

Originally Posted by Conor MacCarthy

Yes, this is quite obviously more suited to the 'Recordings' forum.

LOL. I don't know what you think Matthew was referring to. I think Matthew is asking about a heated bending iron used for bending the sides of a double bass.

Anon2962 · #6 05-11-2006, 11:18 PM

Quote:

Originally Posted by JansenW

LOL. I don't know what you think Matthew was referring to. I think Matthew is asking about a heated bending iron used for bending the sides of a double bass.

Sarcasm:
1. A cutting, often ironic remark intended to wound.

2. A form of wit that is marked by the use of sarcastic language and is intended to make its victim the butt of contempt or ridicule.

arnoldschnitzer · #7 05-12-2006, 06:27 AM

I'd either buy the bender from GEWA (about $400-500 US) or make forms using plywood, sheet metal and heated silicone blankets. I have a few homemade irons that cost me handily and work like %@#*.

Ben Joella · #8 05-12-2006, 09:41 AM

Arnold,

Would you mind elaborating on "GEWA". That led me to a German wholesaler of everything musical. Is this correct or is GEWA an acronym for something else?

Heifetzbass · #9 05-12-2006, 01:23 PM

Check in on www.mimf.com- it's an instrument makers forum. There are plenty of side bending threads and pipe benders over there. Pics and how to's, etc...

Also links to other suppliers. Unfortunately, some of them are more for guitar and violins, but you will get a good idea. Also, some really great tips about bending in general.

FWIW
Brian

PS- Mcnaire- we're not talking about ab exercises...

Heifetzbass · #10 05-12-2006, 01:26 PM

Quote:

Originally Posted by mcnaire2004

Not the place to ask about this.

BTW... when did you become a moderator?

**Matthew Tucker** · #11 05-12-2006, 03:23 PM

you can do a lot of things when you turn 16 ...

Thanks to all who pointed me at those resouces. Hmmm ... its all a matter of asking the right people in the right places!

nicklloyd · #12 05-12-2006, 04:40 PM

I built one out of poplar, took it to a foundry, and had them cast it in solid aluminum. Then over to a machinists, and had a long 1/2"x8" hole drilled for a heating cartridge. The heating cartridge is rated at 400 watts. I regulate the heat with a 500 watt dimmer switch. The bending iron works great with relatively even heat.

This iron is a knock-off of the GEWA iron... they are nice but overpriced, especially with the U.S. dollar becoming cheaper. Parts cost around $70, foundry/machinist charge was around $125. It was enjoyable to make this iron, but other luthiers would probably spend the money for the GEWA.

**Matthew Tucker** · #13 05-13-2006, 06:48 AM

Did you cast a shape to follow roughly the curve of the entire C bout?

nicklloyd · #14 05-13-2006, 12:23 PM

The oval profile is not as long as a c-bout, and there is a tighter radiused end and a slightly shallow radiused end.

Ken McKay · #15 05-16-2006, 09:58 PM

Matthew, I think I would go with a silicone blanket over a wooden form. You can get the silicone blanket for around fifty bucks from Omega and make the form by bandsawing oval shapes from 3/4 plywood. Then rout them with a pattern bit in a router to get them all the exact same shape. After drilling a couple holes in each slice, stack them together and run a rod through them to bolt them together.

You don't really need a temp regulator for the blanket I have found, but you could regulate temp with a controller similar to a dimmer switch only it should be able to handle the wattage of the blanket which is 1000 watts approximately.

I think you can even get the blanket made with a adhesive already on it so you can just stick it down to the wood.

I used 2 inch pipe with a squashed electric charcoal lighter inside to bend many sides including double bass.

**Matthew Tucker** · #16 05-16-2006, 11:38 PM

Yeah I have been researching silicone blankets.

An interesting variation I found is ...

Make a mould of the shape of the bout and cover with this sheet matal. Lay the silicone blanket flat on a bench. Sandwich the wet rib material between 2 sheets of aluminium and place flat on the heat blanket. Clamp one end of the rib to the mould. Heat the rib then *roll* the mould over the rib and clamp where necessary. Kind of like doing it upside down.

The advantage of this strategy appears to be the large contact of heat blanket with the wood; ie: you're not just heating one point at a time, but softening the whole rib at once. No idea if its practical for double bass, but the theory sounds good so I'm considering it quite seriously. The disadvantage is I suppose, more patternmaking.

Do Omega make heat blankets wide enough for DB ribs? The ones that are made by Watford only come 125mm wide, unless you pay for a bespoke one made to size. What size do you use? What do you use to stop the blanket burning the wooden form?

Ken McKay · #17 05-17-2006, 06:36 AM

Matt,

That method of bending is the way I made my first violin years ago. I read about it in Harry Wakes book.

I wouldn't think all the tooling up and mold making would be necessary for a bass violin. Lots of work for not much gain, unless you plan to set up a factory and then there are better ways.

Here is the info on the Omega blanket: Go here and look for the SRMU051018. That is the 5 watt, 10 inch wide and 18 long, (see how they code it?).

www.omega.com/ppt/pptsc.asp?ref=SRMU_HEATER.

Less than 50 bucks.

Now, for a safety message. Never leave the heating blanket turned on without direct supervision and a timer switch is a good idea. Have a fire extinguisher nearby.

Good luck, and make sure your rib stock is thin enough or you will surely have a hard time with any bending iron.

Now get to work!

arnoldschnitzer · #18 05-17-2006, 11:09 AM

Personally I think learning to bend ribs the traditional way is important if you are trying to develop as a luthier. It always makes sense to learn the old-timers' methods before reinventing the process (in any craft). I still bend ribs the old-fashioned way because I feel like I have control over the process and can touch-up minor imperfections. But if I was making the same model over and over in a production environment, then I would certainly invest in heated molds.

basswraith · #19 05-17-2006, 09:01 PM

I was recently faced with replacing a rib on a Chinese bass. I used a non-orthodox method. I wet the wood and sandwiched each end of the rib between 2, 9-inch pieces of steel bar stock to minimize twisting. I set the rib under a heating lamp. The red one they use to keep the French fries warm. I flexed the wood with a bungee chord connected to each end. I let it sit under the heating lamp for 30 min. After it was warm and flexible. I clamped the rib on to the bass and let it cool. Later that day when I took he clamps off the wood had stayed it the form I need with very little bend back.
Just my 2 cents.

**Matthew Tucker** · #20 05-17-2006, 09:48 PM

yes I have seen quite a few guitar bending systems (Fox benders) that use 300W lightbulbs for heating, however for some reason I thought that the 2.5mm for DB ribs would be much harder to bend using that heat source as opposed to a regular contact heat source. But what you're saying is food for thought.

And I do understand what Arnold said, but because whatever i do involves expense, time, and non-off-the-shelf items, I have to decide which way is going to work best for me. If someone gave me or lent me a bass-sized torch-fired bending iron I'd use that, but as they haven't yet ... I want to know whether getting one cast a la Nick Lloyd is going to be the best option.

Harry Vatiliotis (our local luthier) says making a separate mold sized to the C -bout for each model is the only way to go. But he's got a little violin factory going there, and he doesn't make basses that often. For my first bass I don't necessarily need to go that far.