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Where do you like to place your thermometers in the side bending sandwich?
I have a significant discrepancy in temperature readings when I place the thermometer next to the heating blanket or on the side of the metal slat away from the heating blanket.

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Formerly know as Mandodiddle.

I put my thermocouple between the wood and the paper and foil layers under the top slat.
But bear in mind your "bending temperature" will vary to other's with the position of the temperature sensor.
I kind of follow John Hall's bending method/temperatures, but use lower temperatures than him because I understand he places his directly under the blanket where it is hotter.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

you don't want to be on the wood. That will often leave a mark.. I place it between the top slat and the blanket. If you place it on the wood you have water coming out in steam so you will have different temp reading. Use the blanket and rely on the heat coming from the blanket.

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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

I had marks that looked like charring on some Narra sides with the thermometer next to the wood. There were two dark lines on either side of a lighter line where the therm was. They wouldn't sand out so I had to shade the lacquer on the sides to cover it. Now the therm goes outside the blanket under a third slat over the blanket. Haven't had the problem again.
I also use John's suggestion of Windex D for the wetting agent.

Top slat and blanket as well. Just behind the waist caul. Personally I’d stay away from the wood. Do it the same every time and note the temp when steam is really rolling off. That’s a good time to start bending. For me it is around 250-260.

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It's not what you don't know that hurts you, it's what you do know that's wrong.