Monday, May 25, 2009

Can't Beat Humidity

After cutting out the guitar top, I wasn't really done for the day. It was just time to eat lunch.

My plan for the rest of the day was to cut out all the braces, shower, run some errands with Pam, then go to a cookout with her rescue squad team. (Monday is her squad night). Then I would come home and at least get the X-braces glued onto the top.

Got all the braces cut, but it took a few hours. Measure twice, cut once works great, but all that measuring takes time. The braces are made out of quarter-sawn Sitka spruce; quarter-sawn means that all the grain runs vertical with no run-out so that the braces have the strength they are designed to provide. Each brace needs to be cut to length, height, and width, and that's a lot of measuring, setting up the tablesaw and/or bandsaw, and cutting.

But I got it done, took a shower, and Pam and I headed out around 4 p.m. It was then I noticed the overcast sky. Felt like rain. Pam said, yeah, we're supposed to get some rain.

If rain is coming, that means that the humidity is up. And if the humidity is up, I can't glue any braces. They lock the top up, preventing or at least severely limiting it from expanding or contracting.

Like would happen when wood goes from high humidity to normal humidity. As it dries, in contracts. If the braces are glued in high humidity, then if the guitar is ever in an extremely low humidity environment, there is a very good chance it will crack. Likewise if they are glued under extremely dry conditions.

Wood likes it in the middle. 45% is optimum. Nothing less than 40% or higher than 60% is acceptable.

When I get home from the cookout, the humidity in the garage is 67%.

And it's 8:30 p.m.

I turn off the lights. Live to fight another day.

But that day may be a few off. It's supposed to rain the next two days, with 50% chance of thunderstorms on Thursday. It may be Saturday before I can glue any braces.

Oh well. There's other things to do.

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