Author Topic: Repairing Cracks In Crotch Mahogany  (Read 3490 times)

briyon

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Repairing Cracks In Crotch Mahogany
« on: March 11, 2011, 10:39:28 AM »
Can anyone share their tricks for repairing cracks in a crotch?  I have heard of using epoxy.  What type?  2-part?  Or are there other ways to seal the cracks and ensure they don't expand.  I would appreciate any information anyone can provide.

Thanks,

Brian
Brian Harding
Atlanta,GA

Parttime/Hobbyist Woodworker (20 Years). Recently (last 6 years) concentrating on period furniture.

albreed

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Re: Repairing Cracks In Crotch Mahogany
« Reply #1 on: March 11, 2011, 12:39:56 PM »
Brian- In veneer, the ones that don't close up by themselves I fill with sawdust and hide glue. Mound up the filler and warm before applying. In a few days the hide glue will shrink, then flatten the fill. I use a file to flatten-Al
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mikemcgrail

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Re: Repairing Cracks In Crotch Mahogany
« Reply #2 on: March 11, 2011, 12:40:58 PM »
I have filled small voids in solid crotch with the west system epoxy. It is pretty well clear. I think it is less noticeablylike this- clear- some other epoxies are translucent rather than transparent when mixed so be careful.
I cannot really comment on this as anything but a filler. I don't really think of it as a repair-
I have several chests made of crotch walnut and finished in shellac. Over timein my house, 15+ years, the crotch surfaces have expanded and contracted so many times due to fluctuations in humidity that what was once a perfectly flat planed surface, will feel ever so slightly rippled. This is only after 10 or 15 years. on 18th century examples, this is often more pronounced(and it is a texture that I like). I tend to think this coming and going of the crotch will tend to eventually cause any cracked crotch to recrack- just my guess.

awleonard

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Re: Repairing Cracks In Crotch Mahogany
« Reply #3 on: March 11, 2011, 01:45:56 PM »
That makes me feel a little better.  The cortch on this top has cracks in it and it is only a few years old.  I used MDF and Unibond.  The cracks are very fine though and they don't show up beyond a few feet (at least not with my less than perfect eyes!). 

Tony

Jeff L Headley

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Re: Repairing Cracks In Crotch Mahogany
« Reply #4 on: March 11, 2011, 07:07:37 PM »
Mdf as a substrate is EXTREMLY susceptible to moisture fluctuations. Once cracks appear then that leads to more moisture exposure which can cause more problems. Now I am talking over many years of exposure. I do like your table.

albreed

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Re: Repairing Cracks In Crotch Mahogany
« Reply #5 on: March 12, 2011, 01:28:06 PM »
I have a feeling, unproven, that new crotch cracks because of the way it's sliced, as I don't see the cracking often in old sawn crotch. The old stuff will crack, but usually because of exposure to some extreme conditions, I think.-Al
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mikemcgrail

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Re: Repairing Cracks In Crotch Mahogany
« Reply #6 on: March 12, 2011, 05:43:43 PM »
I wonder if the logging itself is different also, as I seem to recall timber cutters only cutting when the trees were dormant(sap down, they used to say), and I wonder if there is as much concern for that in the world today. And the old veneer was generally thicker. 1/28 in the late 60's, 1/42 to 1/64 is common now. I used to haunt a few veneer mills about here(always on the lookoout for fine stuff), and they were often known to brag that even there 1/64 wasn't a true thickness.
I really think some of the old sawn I have seen was closer to 1/12 or so.