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Ok, I think there are a few guys that have use this wood? Was it John Kinnaird?
Anyways, this set has been warped (cupped) for over a year and it wont seem to flatten out.
What is a good fix for this? I'm starting to get my HGF batch together and Id like to add this set.

Thanks.

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Lance@LuthiersForum.com

Lance,

Have you tried wiping the concave side with a wet rag? Or put the concave side down on a concrete floor for the night?

Finally, (another of those Grant Goltz tricks), you can try a dry clothes iron, and iron it flat.

Dennis

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Dennis Leahy
Duluth, MN, USA
7th Sense Multimedia

Hi Lance,
When I had that problem with a curly maple set which was cupped at least a quarter of an inch per side,I followed Bruce Dickeys' advice. I misted the concave side until it was flat then quickly ran it through the thickness sander sanding only the former convex surface until I was near final thickness,flipped them over for a light pass on the bookmatched side and presto problem gone. Bruce said it was a case hardening problem and this was the way to fix it. I followed his advice and it worked like a charm. I don't know if it is a cure-all but that set stayed flat until I made it into a sweet little parlor.

I have used the mist one side trick, as well as the put it on the table saw with the blanket and some weight idea. Both can work out.

My number 1i s flamed euc .. makes a nice sounding guitar, even for my first effort.

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

[QUOTE=LanceK] Ok, I think there are a few guys that have use this wood? Was it John Kinnaird?
Anyways, this set has been warped (cupped) for over a year and it wont seem to flatten out.
What is a good fix for this? I'm starting to get my HGF batch together and Id like to add this set.

Thanks.[/QUOTE]

Lance, if you look back in the archives I have posted this cure before. This was taught to me by Harry Fleishman...Get two pieces of 1/4" aluminum and wet the wood both sides. Place the wet wood between the 1/4" aluminum pieces and bake in the oven around 350 deg (325-375 is what I usually do)for about 20-30 mins ( can go longer if you like) Remove from oven. Place some heavy weight on top. I have used the living room table. But now use cinder-blocks. Let sit for a few days. Check to make sure no mold or anything is happening. If still some warpage you can spray lightly and put weight back on or you can try re-heating. Usually one heat treatment is all that is needed for a perfectly flat result.

p.s. I have tried it also wrapped in alum foil...just like when bending. It helps, but you still need the thick aluminum to keep things flat. Also if you wrap in foil you need to bake longer because all the moisture won't evaporate and the mold possibility is greater.Dave-SKG38948.4286689815

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Dave Bland

remember...

"If it doesn't play in tune...it's just pretty wood"

Lance wet the cocave sides and place the convex sides together with stickers between. Put stickers to either side and add cable ties to the ends of the stickers gradually tighten the cable ties to flatten the wood, never failed. (famous last words!)



ColinColin S38948.4262962963

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I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

Thanks Guys! Plenty of solutions!
Ill let ya know how it turns out.

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Lance@LuthiersForum.com

I'm glad to hear these tips, I've got half of a back of cocobolo that is badly warped. After heating it with a blanket, I put it in clamps for about a month, and that didn't help at all.

I'll give this a shot, too.

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Eagles may soar, but weasels don't get sucked into jet engines.

Same here, good info. I have a nice, and expensive, set of Ebony that is in need of some help!

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Joe Beaver
Maker of Sawdust

I had the same problem when resawing some 1 1/4" cocobolo. My plan was to split it down the middle, then slice each piece again.The wood was badly casehardened, and developed a severe warp like this )( or mabe like this()immediatly upon resawing. I tried everything, then finally gave up and ran it through my planer. It made a nice electric guitar top when it should have made 2 acoustic backs. Some times You just have to resort to "Plan B".

Al

Thanks for the info, guys!

'Course there's always plan "C"--buy new wood! Feel the Crazy RITZ!!!

If the wood truly is "case hardened", then it was improperly dried in the first place. To remove (or greatly reduce) the effects of case hardening, you may need to basically start over on the drying process. The good news is that with thin wood, drying is much quicker than with thick boards. Give it a good soaking (maybe even for days if it is a resinous wood), and then sticker it with weight on top to dry. With lighter colored woods and any species prone to "sticker stain", move the sticks a couple of times over the first few days of drying (to cut down on trapped moisture between the sticks and the wood being stickered.) You can use small square sticker sticks, and rotate them 90° each day.

If the wood is completely or partially flatsawn, then you are also fighting the physics of wood's different shrinkage in radial and tangential orientations.

Dennis

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Dennis Leahy
Duluth, MN, USA
7th Sense Multimedia

When I built one of my walnut guitars, the back curled up like a potato chip. I was able to flatten it with much better results than with the cocobolo that I described earlier.However, I never did get it flat, but when I braced it, and installed it to the rims, you would have never known that it curled. It's been good for over a year. If it is flat enough, and flexible enough to go through the thickness sander I wouldn't worry about it.

Al