Official Luthiers Forum!

Hi

I have seen conflicting configurations of heating blankets and slats for bending sides. Such as

slat - wood - blanket - slat

slat - wood - slat - blanket

slat - wood -slat - blanket - slat

Which is correct, number three is out as I only have two slats

J

I use number two, from the inside out.

#2 for me.

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Jimmy Caldwell
http://www.caldwellguitars.com

blanket/slat/wood in paper/slat/blanket

another vote for #2.

I too use 3 slats

Slat / Blanket / Slat / Wood / Slat

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John Ressler

number 1 for me.

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Peter M.
Cornerstone Guitars
http://www.cornerstoneukes.com

#1

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"Try to be the person your dog thinks you are."

http://sites.google.com/site/bertsguitarshop/

#2...but I also use 3 light bulbs to heat the opposite side.

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JJ
Napa, CA
http://www.DonohueGuitars.com

I use #2 but add a strip of 6" aluminum flashing material to protect the blanket from abrasion caused by the ram and the spring loaded bending pieces.

Fred

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Fred Tellier
http://www.fetellierguitars.com
Facebook page http://www.facebook.com/pages/FE-Tellier-Guitars/163451547003866

I use the steel wood steel blanket. I have yet to rub through a blanket. In most cases , as I bend about 250 sets a year , that is over 500 cycles and I use 2 benders . I have replaced 1 blanket that was about 4 years old and was my first prototype. I actually wore through the cord as that came off at the side of the blanket near the waist cawl. The 2 blankets I now use are about 3 years old and still work very well.
Protherm is a true industrial product. We used their equipment when I worked as a machinist in a plastics extrusion division. The silicone took quite a beating and we have very few failures as compared to other heaters. That is why I use them. They are a bit more but they are a quality item.
I agree there isn't a problem if you want to use the 3rd slat but it isn't needed . Still I know how some builders are , so I do think Alum flasing would be just fine for the top friction slat.
john

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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

HI all

Thanks for your input, I'll try slat - wood - slat - blanket.

The blanket instructions do say do not use in an open environment, resting on the top slat is rherfore not cosidered to be an open environment then ?

John

spring steel/blanket/slat/wood in craft paper/slat/blanket/spring steel
for me.

I'd really like to pick up another blanket and use the same method as Christoph.

Most common method for me has been slat/wood/slat/blanket/slat
until I lightly scortched a side of Koa on the outside surface and spent way too much time sanding. For the 2nd side I
switched over to slat/blanket/slat/wood/slat to compensate for that problem and it worked fine.

Tim

putting the blanket under the slat is a good way to scortch . I place them on the top. The key is to use the blanket to heat the slat . Check out the bending video on youtube http://www.youtube.com/results?search_q ... ues+creek+
The one thing you will see that there are many ways to do this. Wood is an idiot and doesn't care how many blankets you use. In most cases , the people that need 2 blankets are using a 2 1/2 watt per inch blanket that cannot handle the thermal load. A 5 watt per inch is what you should use. It has enough power to handle the load.
If you feel you need 2 blankets than use 2 but after 10 years of bending , I can do it fine with one. I bend 250 sets a year. A good process will give you repeatable results.

_________________
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