Acoustic Guitar Construction

When I am anticipating a glue-up operation I think of two catagories, humidity sensitive and non humidity sensitive. for example I think of glueing braces to the top/back and closing the box as probably the most humidity sensitive operations in the guitar building process. Some things that I would consider non humidity sensitive would be glueing the neck and tail blocks to the sides and glueing the lining to the sides, however I'm beginning to question my assessment of this. Obviously I would like to perform the entire building process at optimum humidity conditions but due to my geographical location this is hardly a realistic expectation and that is OK as I have come to accept this and exercise patience. Living on the Gulf coast our RH is almost always high. I would like to know how others (with experience and knowledge) feel about this. Are there some glueing operations that you will do when the humidity is not at the ideal level? If so, what specifically are those ops and how far out of range will you "cheat"?

Thanks!

David L

My shop is heated/conditioned. Humidity is always 65%, spring summer, winter, fall. I don't know if this is good or bad. It's supposedly a bit on the high side.
What did luthiers do before the invention of humidifiers and de-humidifiers?

PiedmontSlim wrote:My shop is heated/conditioned. Humidity is always 65%, spring summer, winter, fall. I don't know if this is good or bad. It's supposedly a bit on the high side.
What did luthiers do before the invention of humidifiers and de-humidifiers?

They repaired their instruments a lot. All the old violins, guitars, cellos, and other stringed instruments have been repaired over and over and have even had wood components replaced.

Really, any time a gluing operation will fix the wood in place so that it cannot expand and contract, such as when the braces are glued or the box closed, you want your humidity to be 50%, if you plan on the guitar travelling out of your region, or expect it to be exposed to varying humidity levels, such as if your region is 30% in the winter and 70% in the summer, so that the humidity level is always within about 20% of the level that the wood was fixed into place in. I think you can join a top in pretty much any humidity level, but you want to brace the top in 50% humidity, after the wood has reached equilibrium at that level, for example.

Anyone have a recommendation on a dehumidifier?

Eric

We have an "LG" 32 pint unit trouble free three years -- nice controls. The shop is 1400 sq. ft. We clean regularly -- the smaller shop is air conditioned -- that keeps RH just where we want it on its own.

Ken:

Thanks - I'll look into it. The shop is heated and air conditioned. The heating system has an integrated humidifier which is why the humidity is always 65%. There's no control for the humidity. I'll ask my AC guy for one.

Eric