Official Luthiers Forum!

I just acquired some back and side sets and when they arrived, they were almost all slightly wavy. It's all warped in the same spot so I'm guessing it was stored improperly. The last owner had it for 30 years.

Do I need to flatten it? If so, how?
Can I just build with it how it is and let the braces and everything else hold it straight?

If they will conform to the desired shape easily you might be O.K.. You could possibly flatten them with a clothes iron (with or without steam depending on species). Soaking them in hot water to make them more pliable and clamping them flat to dry might also work.
Wet wood moves more easily than dry wood - steam boxes are used to bend wood, but could also unbend wood.

I've had some luck (Zircote back plate) with SS2, wrapping in alufoil and an iron, then clamping them flat between stickers.
I have some brazilian sides which are warped and will need to flatten them before thickessing as they are 3-3.5mm, and will probably try with the same method.

_________________
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.

I had good luck on a few pieces with buying a couple pieces of large slate tile from Home Depot. Then, spritzing the wood and sandwich between the tiles with a heating blanket. IIRC, the blanket was set to 200 for like 20 mins or so. I then left it sandwiched for a few days.


Sent from my iPhone using Tapatalk Pro

_________________
Insta - https://www.instagram.com/cbcguitars/
Facebook - https://www.facebook.com/cbcguitars

Thanks for the replies. I hadn’t considered thicknessing so I’ll need to flatten them.

The species is Brazilian Rosewood. I have some super soft 2, but I’ve never tried it. I’ll try that with some clamps first.

Using hot water and steam on oily woods can sometimes move the surface oil around and muddy the grain. A light sanding usually restores the surface.

And my perennial comment:

Do not heat wood with wax on it. The wax will flow like water into the wood and never come out. Glue joints will gradually be compromised over time.

Absolutely!

_________________
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.

I sell sets and often have to flatten them after I dampen them to show the color for photo purposes. Been doing it with many hundred for sets for 40+years. What works for me is to spray both sides with water, and dead stack them on cement, with a weight on them, over night. I find that no more than 5 or 6 sets at a time works best. They will all be flat in the morning and then you can sticker them. If they don't flatten, or don't stay flat after being stickered for a day or 2, then the wood has issues and I don't use it for sets or sell it. It gets repurposed into things like head plates, binding, etc. Good luck!-Bob

_________________
“ The meaning of life is to find your gift and the purpose of life is to give it away” Pablo Picasso

Or you could force and torture them into straightening up like this. I use stainless or galvanized bolts 10-12" ones and bailing wire. Tighten up and put out in the 100deg sun with the cup side down, spray with the hose, go back in an hour and rinse and repeat, tightening the wires each time until they promise to stay straight.
These planks are over 1/4" thick also.