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Drying time for lumber


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I have a friend who is clearing a nineteenth century hotel grounds for redevelopment, I already snagged some Purple Heart, mahogany and various species that made up the only two remaining window frames after a fire took out most of the building in the mid 1980s but he is now begining to fell what is best described as a small Forrest of very large trees. He's got an Alaskan mill and has told me that he would happily cut me some boards of the various types. Yew, beech, walnut and others like oak and holly (which I've never seen so big) all in 2" boards more than guitar body in width and effectivly quarter sawn.

My question is, what's a ball park figure for time in drying it? Is it worth even getting from him in that raw state or am I barking up the wrong tree ?

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Thanks Scott. Inch a year sounds plausible and possible. Will just stash it all in my loft and forget about it if it's only a couple of years, it's free so why not. Will do some more research. Could always ask the wood place to stick it in his kiln next time it's on. Not sure if he'd be up for that but no harm in asking eh ?

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I've got slabs that are several years old and still not at a moisture content where they are usable.

It really depends on the timber, the way it's cut, the way it's stored.

Best bet is to buy a moisture content reader. I use two different sorts and then estimate an average. Even a moisture content reader is not 100% accurate but it can help you with your guesstimate and can be used as a rough guide if you don't know how to tell any other way

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The "1 year for each inch" rule is the standard to dry timber suitable for furniture grade, which is 12% moisture content (generally).

However, the local conditions also play a part in determining if this moisture content is suitable. So, for Texas, which is dry, the moisture content would be lower than let's say, Indonesia (which can be as hot, but higher humidity).

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  • 3 weeks later...

First of us having a dry enough day to get stuck in about these logs was Sunday there. Boarded out a few different looking pieces. Couple of them were very plain but some are very pretty including some figure and colouring. Here's the few pieces I lifted, all are 2 1/4" thick slabs. The purple/brown is defo yew. Not sure what the lighter stuff is tbh, we think beech but I'm not sure. Probly around 100 large logs/trunks still to cut up and sort, think I need to build a kiln lol. Thanks for the advice on drying.

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The only way to know is to use a meter. I'll talk later about drying wood, however if you're air-drying then "it's ready when it's ready". It just needs to have good airflow around all four faces of the board plus the end should be waxed or otherwise sealed. Endgrain loses moisture far faster than the facing grain which can exacerbate losses from checking. Pretty standard stuff.

The year-per-inch thing is a reasonable rule of thumb, but not for all woods or end uses. We aim for about 7-12%. Some might say as low as 5% and as high as 15%. As long as the wood is stable and acclimated at whatever moisture content then that's better than forcing it to be dry and expecting it to stay there. Air dry is good. Kiln dried should still be allowed to stabilise out "in the real world".

Sorry I didn't have time to read the thread better. Just throwing information out after a quick skim.

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Just had time to re-read the thread. All sound advice. There's no use in describing the process of how wood loses water from the cells and between them, however suffice it to say that you need to confirm it's below 15% first of all (meter) and then consider dressing the material into stock sizes. There will still be dimensional change, however at this stage the material should be simply stored for another few months in the conditions where it will be used, eg. the workshop or dry wood store, by which point the moisture content will be acceptable. Anything above 15% with bad airflow and you've got conditions for mould. Ensure that each piece is separated from the one above and below using a couple of sticks of wood to create an air gap. You might get limited staining from where the sticks contact each piece (dependant on moisture) so figure this loss into your dressing.

Slabs sound great. The best slab to yoink from the pile is the one with the heartwood (pith). You can usually talk the seller into a better price because of that "unusable" bit of the material, however you're guaranteed to get a lot of quartersawn stock either side of that....especially on the bigger slabs.

If there's any danger of hidden metal such as nails (we get WWII bullets and shrapnel in trees around here) then grab a metal detector. Easier than shattering planer blades or sending teeth flying off the saw.

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There are a few high figures getting thrown around here and I highly recommend not building with anything over 8%.

I tend to stick with 6 percent as a preferred percentage but will go up to 8%.

I did a "test" body lamination a couple of years ago and sat it on a shelf to see how it would age. The back was kiln dried @ 6%, I put a top on it that was air dried @ 10%.

For the first six months, no sign of movement. I was starting to think I didn't need to be as fussy as I am about sticking to 6-8%.

After 12 months you could see some separation in the top join, but the body was still rock solid. It supported my habit of sticking with the lower contents. The test was a failure, but a success in the way it has shown that those extra few percent can effect shrinkage in the final stages of drying.

I happened to look at it the other day as I was moving things and the top join was wide enough to put a screw driver inside, it had lifted very slightly at the edge, however the rear which was 6% to begin with is still a perfect join and straight as a die. Imagine if you built and sold a guitar like that. Play it safe and stick to the low contents.

Also, be careful about testing even if your supplier tells you it's dry, as "dry" means anything under 18%. If you're talking firewood that is, but some sellers tend to use 18% as their benchmark. So test and test again to be safe.

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Just to touch on testers, I use two. The first is the pin type that you shove into the timber, the second is a non evasive kind where it has a pad on the back which you hold onto a surfaced part of the timber.

They both read/measure in a different manner, so when they return a similar figure I feel confident they are "close", as you can never rely on the readers alone.

One example, a guy I know who owns a tonewood milling business was describing to me how their $3000.00 reader was suggesting a chunk of Gidgee was 20%, yet when he weighed the piece it was closer to 6%. So, even if you have testers, speculation is still involved somewhat.

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Imagine if you built and sold a guitar like that. Play it safe and stick to the low contents.

But if you build that guitar, and sealed it with lacquer, it would not have the ability to move. Strip back a gibson, fender, etc, and check what they use as "standard. You'll be surprised.

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Air drying just needs patience. A nice low percentage will always be reached, whatever that value is. The inch-year "rule" of thumb is fine if your conditions are good and you add additional time on top. Kiln drying requires a specific schedule, otherwise the risk of cell collapse or other faults might be on the cards.

Testing and time. Just like brewing beer.

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Imagine if you built and sold a guitar like that. Play it safe and stick to the low contents.

But if you build that guitar, and sealed it with lacquer, it would not have the ability to move. Strip back a gibson, fender, etc, and check what they use as "standard. You'll be surprised.

Last year I did a repair to a guitar for a bloke that thought he'd try strip back and refurb his treasured ax.

When he stripped the extremely thick paint off, the timber started falling apart on him after it sat around for a while in between his spurts of motivation.

When it came to me there were massive crater splits all over it as the grain started opening up and splitting. It had been sealed in Japan in 1981, obviously a little bit still not dry enough and then stripped a couple years ago in Australia in the middle of our drought!

I filled it all with epoxy, did some other repairs and then sprayed it all with no warranty and he understood what had happened and what it was up against. To my knowledge it's still all good and hasn't moved since being sealed.

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Imagine if you built and sold a guitar like that. Play it safe and stick to the low contents.

But if you build that guitar, and sealed it with lacquer, it would not have the ability to move. Strip back a gibson, fender, etc, and check what they use as "standard. You'll be surprised.

Last year I did a repair to a guitar for a bloke that thought he'd try strip back and refurb his treasured ax.

When he stripped the extremely thick paint off, the timber started falling apart on him after it sat around for a while in between his spurts of motivation.

When it came to me there were massive crater splits all over it as the grain started opening up and splitting. It had been sealed in Japan in 1981, obviously a little bit still not dry enough and then stripped a couple years ago in Australia in the middle of our drought!

I filled it all with epoxy, did some other repairs and then sprayed it all with no warranty and he understood what had happened and what it was up against. To my knowledge it's still all good and hasn't moved since being sealed.

Yep. Ive had to refinish only the fronts, or backs of numerous guitars. I learnt pretty quickly not to leave them overnight, or they will cup :(

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I wonder if this would happen on a modern Gibson since they claim to kiln dry all their timber to under 6% before use?

Anyone got a brand new Gibson they don't mind stripping back to raw wood just to find out??!!

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Ive posted photos on my page about 12 months ago of a couple gibsons that cupped 8-12mm WITHOUT removing the lacquer.

How can you trust a company's specs for building, when the 2015 Les Paul lineup lists the dimensions of the bobbins (under covers) but not the output of the pickups? Or the WEIGHT of the strap buttons?

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Thanks again for all the info guys. I've ordered pin and pad testers and it'll be interesting to see what various pieces of stock I have collected from different sources actually are. So 6-8% is perfect 15+ is bad and unusable.

On Saturday im taking a trip up to a guy who sells exotic hardwoods and has a kiln. Obviously my friend has a huge amount so he is hoping to strike a deal to dry it all in exchange for a percentage of the lumber. Looks like I've been nominated to go ask the guy so we will see haha. Don't know if he'll go for it but if he does I'll get first pick at the usable stuff for guitars in exchange for a tele built out of the woods for my friend. If the kiln guy doesn't want to do it I'll be air drying maybe 20-30 choice slabs for myself, enough to keep me in tonewood for years and his tele will just have to wait till its dry.

Scotland is inline with Alaska on the globe, it's not a dry arrid place exactly. As I look out my window I see grey skies and that fine rain that gets you wet in seconds, we call it scotch mist but really it's just frickin rain lol. Bout 8*C and this is suppose to be the end of spring really. I've looked into possibly building something at the bottom of the garden, sorry yard ?, but I don't know if it's worth the time effort and expense of it all for a one time use.

I understand density of the individual wood etc will all have an effect on the time it takes to dry but how long does it take to dry in a kiln?

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Good news guys. The very friendly and helpful man at the hardwoods place has agreed to test a new steam kiln he has recently installed. He's putting my slabs in with the first run as a bit of a test. Have agreed to take up some slabs from all the species we have and dry them to 6-8% moisture content. I guess it's a good first test for him, my friend gets some lumber dried and I get some really nice local wood with a bit of a story for the cost of a couple tanks of fuel ? .

Also found out the nice lighter coloured stuff in the pics is figured sycamore. Is it any good for necks or tele/strat bodies maybe?

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More than likely, yes. If it is a reasonably stiff and resilient hardwood (think, better than soft crap like Aspen or Poplar) then you're in business. Generally woods for guitars are suitable for tops, bodies, fingerboards and necks in rough order of appropriateness. Necks should tick all of the boxes. What you've got there may well work for bodies, however it might be a little fractious in moving on you during climatic shifts and the seasons. Tops, certainly.

My first thoughts were about the cancerous nature of European Beech wood dust. No idea whether that applies here, but you should treat it like it does. All woods are a potential hazard when in fine dust form, some worse than others. I avoid Beech like the plague. Mostly because it is just like the plague. Good extraction if you're sanding, otherwise stick to planing.

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Thanks for the tip P. I'm working with Purple Heart just now which is the same apparently and my extraction isn't great, so Ive just been wearing a good mask. I'll treat the beech with the same caution .

Tops eh! That's good. Will make some beautiful tops, one piece and bookmatched. There's still loads to cut up but id like to do a build entirely of of the woods from these trees. This will be for my friend who owns the ground we are clearing. As for a neck material would sycamore work?

There is Oak, Yew, Sycamore and Beech so far. I think that's what all of it is apart from one unidentified tree. Assuming that's not maple or something you see as a neck material would it be possible to do a whole build using only those woods?

Sycamore neck? Would it need to be laminated with one of the others?, oak is pretty hard so... fret board? Yew back with a Beech top for the body maybe? I'll cross my fingers and hope this other stuff is maple lol.

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Sycamore is in the same family as Maple, but obviously not all Acers are the same. Generally so, but dig up some numbers. If the quality of the wood and seasoning are of a high standard the end product should also be like that too. Crap Maple of a bad cut and inappropriate drying schedule is far worse than excellent Sycamore for example.

I suppose I should qualify my statement earlier about the "appropriateness" of woods. Right at the top of the pile are the neck woods; woods that should be straight-grained and stable under tension and through environment changes. That the materials transfer acoustic energy around the "physical guitar system" in a pleasing manner is useful too. The neck is the thinnest piece under the most tension by mass, so this is where the quality of the materials win out. Crap wood will just shoot all your fine fret levelling to hell in use and at worst pretzel on you.

In my personal opinion, Oak is an underused wood. I can't comment on "non-European white Oak", however it's a really attractive material with excellent strength properties. Coarse, but that is not necessarily a negative. Oak has a nice tap tone. So much so, I made a wooden bridge the other week for a bass. We'll see how that works out when if I finish it. Burns like crazy if you cut too fast or hesitate during procedures, but silky as anything with a little wax after fine sanding. An Oak neck would be heavy as hell, however I'm a little unsure as to whether it is stable enough on its own. Certainly not "unstable", but for necks you want the wood to do as little possible of its own accord. Quartersawn white Oak laminations would add significant stiffness to a neck, interesting acoustic properties and visual interest from the ray flecking off the quarter. Fingerboard material, sure. I just think the coarseness needs taking into consideration as chips out of the ends can ruin an otherwise perfect board. Not entirely unlike Wengé in that regard.

Bodies are next down the list, more or less for the same reason as necks. Cupping from radial movement is undesirable. This will be a common problem with woods that are dried inappropriately, insufficiently or simply not allowed to acclimate to their local environment after drying. Straight from the kiln is bad bad bad. Cupping can also occur after the first dressing of your stock down from raw lumber. Taking a 50-55mm Birch board to the jointer and producing a 40-45mm four-side square piece of stock won't always stay that way. Anything from a few hours to a few weeks down the line, the wood can cup as internal tensions are released. This is a recommendation to take any raw stock you have dried, cut it into rough stock with minimal dressing and store it appropriately. As long as it takes for that wood to get into its thick head that it is going to be a guitar and not a tree. When it comes to putting it into actual use, you'll more than likely find your 40-45mm will lose a few more mm bringing it back into square.

Tops have minimal effect, but that isn't to say "none". A nicely prepped body which is sitting happily, jointed and square might be pulled a little out of line once even a thin top is added. I think RestorationAD had an issue with this a while back. A recidivist top that wouldn't get with the program. Tops in general don't have to deal with anything in terms of the heavy mechanics of an instrument. Bridges mostly screw right through into the body, same as posts or whatever. Have a look over on curtisa's current multiscale sixer build thread for what he's doing to stabilise some less-than-ideal top woods. That Beech looks nowhere near like it needs that level of stabilisation, however if you want to incorporate wood that has bark inclusions or the arse end of knots then follow the same sort of procedure. Unlike parts of the instrument that need real strength and reliability, tops can be made from stuff that is almost junk if damage mitigation is carried out. That second pic looks great. I can see a bit of a potential bark inclusion around the larger lower whorl. That's usable, but do check out how much heartwood is included. You'll get virtual quartersawn wood either side of the cut, but mad radial inclusion either side!

Yew. Isn't that a softwood? I used some for chisel handles a while back. Sweet off the lathe, but probably not good for instruments....maybe soundboards....

Sorry for the long post. I hope somebody else can chime in to balance off what I've written since it contains a lot of subjective opinion from experience. I couldn't underline more how important dust mitigation is though. A dust mask is better than none, but stopping dust getting to the working atmosphere is far superior. Simple masks just slow the problem down a little.

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