Official Luthiers Forum!

AUSTRALIAN TONEWOODS
Greetings all my fellow luthiers!

I thought that it would be prudent and timely to bring to your attention some guidelines that I have found from experience will help those who have purchased some Tasmanian Blackwood as part of the group buy.

If you are anticipating a billet(s)delivery from Shane then you would do well to read my comments that I posted when the Tasmanian Blackwood was initially offered. http://www.luthiersforum.com/forum/forum_posts.asp?TID=5874& KW=blackwood&PN=0&TPN=2#forumTop

I hope that you will never end up with sets like these but this is what can happen when the blackwood has been exposed to one or more of the following conditions.

1. Resawn unseasoned and left without sufficient strapping and stickering.

2. Exposed to a dramatic moisture reduction with or without stickering.

Blackwood from my experience in the resawing process benefits from some initial racking out before being resawn into sets. There is also some tension present in most boards with the highly figured material being most prone to movement if not restrained. Following the seasoning process Blackwood is very stable and a joy to work.







RESAWING:

As Kim (LARKIM) will attest Blackwood which is partially seasoned is difficult to resaw if your bandsaw blade is slighty dull, teeth tpi greater then 2 and your resaw fence is not set up dead square in both axis. It has a tendency to follow its own path if given the chance!!!

kind regards

Tim


AUSTRALIAN TONEWOODS

Tim, many thanks for the tip. I plan on using my billet for making an archtop. Any advice for storing blackwood in billet form?

If by chance change my mind and decide to resaw for flattops -- how long should the billets be air dryed before resawing?

Take heed brother OLFers take heed.

I have watched in horror with my own eyes as veneers sliced from this 15" deep board of unseasoned blackwood cupped and buckle dramatically as they sliced from the billet.

Not only did the veneers themselves move like a worms as they came from the new blade, also to did the 1 1/4" thick billet cup against the fence with such force that it was beyond mere mortal to control...

Beauty does cometh at a price my friends. Beware he who should be tempted to claim her too early less she fly from thy hands to be lost forever.

Cheers

Kim larkim38963.5419328704

YIKES!! I guess the big question is how long does this stuff need to season before resawing?

Thanks,
Greg

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Gwaltney Guitars

Perhaps foolishly, I bought a couple of sets of Brazilian Rosewood from one
of the ebay sellers that... how should I say it... has a bit of a problem with
the English language. Anyhow, spent nearly as much on shipping as the sets
cost so I wasn't expecting great things. Well, after a few days in my humidity
controlled basement (45-50%) they looked like the potato chips you have
pictured here. Won't do THAT again!

Is there anything that can be done at this point? I think I've read about using
a steam iron...

Cameron Reddy

YIKES is right!!
What do we do then?

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Peter M.
Cornerstone Guitars
http://www.cornerstoneukes.com

Cameron, do you have a heat blanket? If so, lay the heat blanket on your BRW with a piece of scrap ply over top ....heat and and clamp.

Cameron, I had a similar problem with a side of walnut too! I wetted the side and wrapped it in parchment paper, layed it on a piede of ply wood and ironed it with a wet rag and heat blanket. after nice and hot a placed another piece of plywood on top and clamped pretty tight (without the rag ) for a few days, tightning the clamps a bit every time I walked by or remembered.... after a week the side was straight as can be!

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Peter M.
Cornerstone Guitars
http://www.cornerstoneukes.com

Hmmm.... sounds like I better get a heat blanket. Thanks!

Maybe my very exquisite $60 and $80 BRZ sets were not a total waste
afterall!

[QUOTE=GregG] YIKES!! I guess the big question is how long does this stuff need to season before resawing?

Thanks,
Greg[/QUOTE]
A broad rule of thumb is that you need to air dry wood 1 year for each inch of thickness. The ends should be waxed, or sealed somehow, when the billet is first cut to prevent rapid water loss and the associated checking that can occur from that loss. Keep the ends sealed throughout the drying process. If, as you resaw, you run into wet areas deeper in the wood, stop and put the billet away for more curing. Do sticker the sets you have cut and let them acclimate to your shop for at least 6 months.
Remember, this is just a guideline and YMMV.

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Hank Mauel

One suggestion I can make is to cover the stickered and weighted sets loosely with clear plastic so that you can see the moisture accumulate on the inside. Leave like this for about 10 days to 2 weeks untill the moisture starts to dissapate. Then uncover so that air can circulate thru the stack. A small fan helps but don't place too close to you valuble stash.

_________________
Beautiful and unusual tone woods at a reasonable price.
http://www.rctonewoods.com/RCT_Store
The Zootman
1109 Military Rd.
Kenmore, NY 14217
(716) 874-1498

[QUOTE=Hank Mauel]A broad rule of thumb is that you need to air dry wood 1 year for each inch of thickness. The ends should be waxed, or sealed somehow, when the billet is first cut to prevent rapid water loss and the associated checking that can occur from that loss.
[/QUOTE]

Thanks Hank! At the speed I build -- waiting 2 years shouldn't be a problem

[QUOTE=Bobc] One suggestion I can make is to cover the stickered and weighted sets loosely with clear plastic so that you can see the moisture accumulate on the inside. Leave like this for about 10 days to 2 weeks untill the moisture starts to dissapate. Then uncover so that air can circulate thru the stack. A small fan helps but don't place too close to you valuble stash.[/QUOTE]

Bob what does this do to enhance the process? If moiature can't escape the plastic tent sounds like a good way to grow mold. I wouldn't recommend this for any predominate sap wood species like maple unless you like splotchy gray color.

Larry it slows down the drying process thus less tendency to warp. Notice I said loosely so that air flow is still present to avoid mold. I only do this on problematic woods.

_________________
Beautiful and unusual tone woods at a reasonable price.
http://www.rctonewoods.com/RCT_Store
The Zootman
1109 Military Rd.
Kenmore, NY 14217
(716) 874-1498

[QUOTE=Bobc] so that you can see the moisture accumulate on the inside. [/QUOTE]

Guess it was this part that threw me into confusion. If moisture is accumulating inside the plastic tent it's a green house :). Nothing wrong with covering wood if moisture is allowed to escape Storing stickered green wood away from air circulation (like walnut) will help prevent surface checks in problematic woods. This should be done in the initial air-drying phase prior to kilning. Good weight on top of the pile so the wood won't move (warp) is another way to prevent drying defects. I use straps that I can tighten as the wood drys and shrinks sometimes. Stretch wrap on the stack ends other times. Chunk of railroad iron other times or all of the above depending on the wood condition and purpose.

Frankly, there's a lot of stress and compression in stump wood (buttress wood in Australia and other countries I believe it's called) and it will not stay flat in use in many cases. Keep in mind a full mature tree weight was supported by that stump and compressing the grain. Moderate compressed stump wood has a fair chance of staying flat if dried properly. Wood cannot be made more stable or flat than how stable or flat it grew.


Larry Davis38964.0041319444

Just a final note which I received from my saw milling partner:

Most unseasoned blackwood can be sawn to 5-6mm and dried, however it benefits from partial air drying after resawing to 1"-2" thick. It will take approx 1" thickness per year to air dry, the main advantage of air drying is to stabilize any imperfections, or wild grain that may shrink if cut to 5mm.
If this method is used I would suggest 5 - 6 mm for backs and sides, stickered out with approx .25 thick and wide, very dry sticks spaced about 5" - 6" apart, with forced airflow at up to 40 degrees C.
This should dry within 4-6 weeks.

regards

Tim
Australian Tonewoods

Thanks for all of this. So the next question is, when was this wood sawn? It has been in transit for 2 months. For spruce (admittedly an entirely different animal) I am in the camp of "cut wet and dry in near finished dimension". I have read that some spruce guys do air dry their billets first, I have found that that can cause problems, so once I slice a block off a log I head for the re-saw and then dry them as we have previously discussed many times. Of particuar note though, is that the best spruce has no figure or wild grain to consider.

So Tim, I have to re-saw some sets and I will head your advice ad I note that you expressed most concern for the birdseye figure. Wodd this wood benefit from being sealed on all faces with a wax emulsion to restrict the loss of moisture? Or would the emulsion be absorbed too deeply into the wood making it difficult to properly remove which I am sure would result in problems getting your finish to stick. Anyway, any more details would be appreciated!

Thanks

Shane

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Canada