Wood Drying

[Farrell]

Thanks for the response Ron. A very hectic two days on my end. Received 346 bd.-ft. of Sitka Monday morning while I was still asleep. Inventoried wood, and found that approximately 1/3 of it had grain angles less than 60 degrees (90 degrees being perfectly quarter sawn). Moved, stacked, stickered wood. Cut panel pieces and rib material (yes, I will be laminated ribs) for first soundboard. Being that the first board will be for my M&H upright, I tried to use the worst wood - stuff that had grain angles from 45 to 60 degrees. I did a bunch of angled resawing to produce panel pieces with grain angles between 80 and 90 degrees. It is simply not the easiest thing to cut big boards at high angles like that. What a b$&ch! It didn't help that the wood was so wet either. I had to switch to a blade with 2TPI - and even that was loading up with a stringy mess at times. I found that when I slice a board on an angle, I usually end up with about 1/3 waste (although, I will use what I can of that also for rib laminates!). 

Another thing I have learned is that the price of expensive Sitka Spruce is almost negated after you realize how much time you can spend coating ends, stacking, monitoring, RESAWING at odd angles, selecting optimal wood for the application, etc., etc. I would gladly pay twice the price if the wood was 9% MC and all between 75 and 90 degrees grain angles.

Regarding drying rate. I checked my hot box this morning (no heat applied) - 70 degrees F and 85% RH! I feel really good about these environmental conditions for the wood - don't really know what the heck it should be, but I have gentle air circulation in the box and I figure that this will dry the wood at an acceptable rate, and minimize MC gradients within the wood pieces (the wood is around 40% MC, and the hot box environment targets about 20% RH). I think I need to get a wood moisture meter - never bought one, because I had not intended on getting wood this wet. 

Also, the remaining 320 bd.-ft. of uncut spruce is stacked and stickered in my garage (2"-thick, 10' long and 6, 8, and 10-inch widths). The RH in there is often in the 60 to 70% range. On Monday, right after I first stacked the wood, I also put a fan on it to get the long drying process going. After seeing initial indications of how fast wood in my shop appeared to be drying, and after determining how wet the wood was, I got a bit concerned about too-rapid drying, so I turned the fan off. Then, late yesterday after see some small scraps of wood in the shop starting to check badly, I decided to go a step further and put a piece of thick plastic over the wood to keep some moisture in and further slow drying. I stuck my RH meter up in the bundle this morning and it was 80% RH. This makes me feel much better. I was getting paranoid of $2,000 worth of wood turning into worthless splinters. I think I am OK now.

Geezzzzzzz, talk about a rushed introduction to wood technology! Ah well, all in the day of a piano tuner!   ;-)

Terry Farrell
  
----- Original Message ----- 
From: "Ron Overs" <sec@overspianos.com.au>
To: "Pianotech" <pianotech@ptg.org>
Sent: Tuesday, March 25, 2003 4:49 PM
Subject: Re: Wood Drying


>Terry,
>
>Your most immediate danger is too rapid drying through the end grain.  THe
>dimensioinal change from differential drying through the end can create
>checking that will make large sections of wood unusable.  Don't waste a
>second getting some form of moisture-impervious sealant into the end of
>every piece.  Melted parafin wax works best, IMHO.

Or, if you have any wood glue (out of date Titebond or rubbish PVA) 
lying about, that works very well also. When sourcing local logs, we 
specify that the log is end-sealed as soon as it is cut.

Your idea of breaking the log down into 1/2" boards is a good one. 
Such boards will be ready to use in one year with just air drying 
(ie. for the panel, rib stock will take at least two years, unless 
you plan to make laminated ribs out of the 1/2" boards).

SNIP

Best,
Ron O.
-- 
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