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Hey, i am new to guitar building and last week after weeks of researching and reading I decided to dive in and get started, I bought most of the wood and started on the top. I had quite an interesting time getting the joint for my top square. I ended up finally getting very close last night with a combination of planing and sanding, I glued the top together overnight using the method in Jonathan Kinkead book. This morning when I took the weight and clamps off I noticed that my top now has a bow in it at the ends, im guessing one of the plates...or both cupped while sitting around and I didn't notice; I say that because I HAVE noticed my back plates cluuping and twisting for some reason. Is there any way of flattening the top so I can plane it to thickness and get the braces on.

Thanks for the help, I think I really need it, hahaha

Hi Michael,
Welcome to the OLF!
Are you building in a humidity controlled environment?

I suspect your top is reacting the RH your working in.

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Let it dry out a bit , keep flipping it for a few days. I don't think you are in any trouble. The cupped side is the dry side so lay it hump up .

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John Hall
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unfortunatly I am not in a humidity controlled enviroment, i rent a basement apt. which has a small room i more or less turned into a shop so my workspace is currently that small room and my kitchen. i don't know if that means im dedicated or just crazy but thats what I got to work with. I'll try resting it on its hump and see what it does. i'll also try running a dehumidifier to try and regulate the room a bit better

Michael, welcome to the forum, trying to build in a room ( especialy a basement, if it is below grade )that is not at least humidity monitored is asking for a disaster. I have one dedicated room,I run a dehumidifier when needed and have a hygrometer to monitor the RH. Jody

Michael, I had the same thing happen last week. We had two days in a row where the temperature spiked and the humidity dropped over 45%. I had a top curl up like a potatoe chip. I have gotten the humidity back under control and the top is flat again. Bluescreek is right, just keep flipping it. You'll be fine.

I share your pain of building in a small residential space (becoming an expert in the silent operation of a Stanley #4).

To control humidity I take the top drawer out of my workbench/Ikea desk and bolt the face of the drawer back in place (to get more space in the cabinet), store the wood I'm working on in the cabinet, and put my desk lamp inside to warm it up. It's a little leaky and pretty low-tech as far as drying boxes go, but I'm able to hold it around 45% with a little maintenance. A downside is you'd have to cut your sides in half to get them to fit, so I have to wait until I get a decent stretch of stable humidity to work those.

The next step is to thread some rods into the surface above the cabinet to make a go bar deck.

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Evan McCartney

Thanks for all the suggestions, its nice to know im not the only guy who's building his guitar using his apt. as a shop im going to get a hygrometer this weekend and I got the dehumidifier running now and the top curve down to start

You did not say how long you had the wood prior to working with it. Even in a non environmentally controlled shop if the wood is properly acclimated it will react far less. it still will react to sudden changes but a 5% change will affect you far less if the wood has be acclimated. When I buy a set of tonewood, I sticker it for at least a month before I work it in anyway. I try to have wood on hand for a year but that is not always possible.

When working in an environmentally uncontrolled shop, Spring is the worst time to build. Typically across the North America sudden and sever RH changes happen frequently and often un expectedly. Summer and fall the changes tend to be less frequent and not as sever of changes. Winters typically are more on the extreme dry side but changes aren’t rapid very often. In spring on the other hand the RH can go from 30%-90% in a mater of and hour and the other way as well. I worked in with out humidity control for the first four years of building. I just did not work from Feb till mid May with a few exceptions.

i've had both my back and sides as well as my top, bracing, fretboard and kerfing for about a week. I was told by a few wood shop employees that also build guitars that I could use the wood immediately and that no adjusting period was necessary once I got the wood home. was this incorrect? its a little late now for this build but for future reference

I usually like to put up the wood for a week or two -- to let it settle down a bit.

On the warping/cupping after gluing.....

You have added glue to 1 small part of the board -- that glue contains water. It may cup a little. Lay it up on top of something so it can lean at an angle -- so air can circulate behind and infront freely. Let it sit a couple days or a week.... and things should be OK.

I am building in an apartment -- so I lay glued soundboards up on top of a spare dresses against a wall. The air can circulate around.... and they don't get stepped on....

Oh.... a little advise for when building in a small place...

Get a couple of those plastic table cloths to cover your kitchen table with... Those plastic table cloths are pretty glue resistant.... Then, when you are done, you just wipe the mess off into the trash, fold up the table cloth, and the table is good as new..... and the Wife's stuff doesn't get trashed or covered with shavings.

Good luck

John

Once jointed prop the top up near vertical against something that stick out from the wall a bit like a power point or whatever, this exposes both sides of the wood to the same moisture levels and it will flatten out when it reaches equilibrium. You will still need to address the RH issue of course but at least the top will be flat when the RH is right to go.

Cheers

Kim