Warped Tops And Fingerboards.

[Gilbert Fredrickson]

I went on vaction and didn't leave enough water in my wood cabinet. When I returned to 8% humidity in the shop. I had some bowed fingerboards and 2 fully braced tops that had gone concave. Should I put them back in sealed plastic bags and add a wet sponge? I cant seem to get the fingerboard blanks to lay back down. What to do?

[Alan Carruth]

I would not try anything extreme to get things re-hydrated. Trying to introduce miosture too fast could well set up more stresses than you've already got. Get your R.H. back to normal, or a little above, and have patience. Lots of patience....

[Gilbert Fredrickson]

Thanks, Allen. They're in big zip-lock bags with damp sponges. I've sparingly twice applied steam from a boiling kettle to aid some of the more pronounced curl on the faces. They are nearly there.

The fingerboards are now bowed only a millimeter and a millimeter and a half. I'll wipe the convex faces and clap them with caul to a flat surface. Thanks, again.

[Gilbert Fredrickson]

Time to buy a humidifier. I'm in the desert with an outside daytime temp of 100°F and 8° humidity. Inside, it's 85°F with 30° humidity and 40° inside the wood cabinet.

[Clay Schaeffer]

If they will be living in the desert, building at a lower humidity might not be a bad idea.

[Dave Meyrick]

It's a bit ironic - I am bracing a soundboard, based in the UK, desperately trying to get the RH down below 50%. Doors tightly shut, dehumidifier going full blast, while you are trying to get water back into your boards!

I guess this is what makes these international forums so useful; that we get so many viewpoints with different slants on the build process.

Dave from a pretty damp Somerset.

[Randy Roberts]

Dave,
Could you perhaps wall off a smaller area with plastic sheeting (Visqueen to you over there?)? If you can do a smaller area than your whole shop and vent the dehumidifier into the "plastic room" that may help control the humidity where you are gluing up better. I have often used very large ziplock bags made for clothing storage for storing parts (tops, braces, etc.) and throw in a handful of dessicant packets for long term storage. Has worked well, as my garage shop leaks air like a fishnet.

[Dave Meyrick]

Randy good suggestions. I am lucky enough to have a well sealed workshop. The problem is mainly that due to the grass growing and gardening season I have been taking a break from building, so have not been running the dehumidifier. It then takes some days to dry everything out again.

However I am using Trevor Gore's falcate bracing system and have finally got all the carbon fibre overlays on today so we should be pretty stable, and hope to get the top on the box over the next couple of days which will be a great relief.

Cheers Dave

[Gilbert Fredrickson]

I've used a little steam from the teapot and placed them with a moist sponge in a big plastic bag. They're back to normal. I monitored there progress through this process, making adjustments when needed. The fingerboard is cut such that it finds it's equilibrium slightly bowed by 1/16". N9 big deal, it's thick.

Thanks.