Official Luthiers Forum!
http://www.luthiersforum.com/forum/

Brazilian Woes - Cracks
http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=19298
Page 1 of 1

Author:  rich altieri [ Thu Oct 23, 2008 8:13 pm ]
Post subject:  Brazilian Woes - Cracks

Have been working on a Brazilian 000 model for the past several months in spare time. Was really coming out sweet. Did French Polish job and that came out really well - all in all, my best effort to date with 25 builds under the belt over the last several years. Anyway, it sat in the workshop untouched for weeks as I was working on the neck and fingerboard and then one day I noticed some fine hairline cracks on the back.

Very fine, about 6 of them. I wicked some thin cyano and then scraped with a razor blade and now started reapplying French Polish. Then it occurred to me, wonder if I should have stripped before wicking in the cyano. It actually looks good and cracks seem to be gone but concerned about long term - return.

I had this one promised to a friend who was paying a pretty good sum of money for it. Now I am thinking of backing out of the deal and keeping it for myself. At least for several months until I see if it is stable.

Any thoughts? Do you think the cracks will come back?

I had the room humidified at 50% for weeks before starting and all the way through. Also, this is wood that has been in the workshop for several months, stickered. Humidity is now around 45%.

I think I have read before that Brazilian is prone to such.

Author:  Bruce Dickey [ Thu Oct 23, 2008 10:33 pm ]
Post subject:  Re: Brazilian Woes - Cracks

Where is Woolson when you need him?

I don't know a thing about Brazilian.

Sorry for your troubles Rich.

You may just have a great idea keeping it.

Just slip in a nice set of high grade Indian, he'll never notice. gaah

Author:  SimonF [ Thu Oct 23, 2008 10:49 pm ]
Post subject:  Re: Brazilian Woes - Cracks

I have some advice that I think is extremely important for any builder that sells their instruments. Many of the more exotic woods we use are prone to cracking. I think it is extremely important to have back/side sets for at least a couple YEARS. And when you go to build with them - make sure to comb thru the entire set and flex the set just a little bit and look for cracks and hairline fractures. You really don't have to worry too much about stuff like Mahogany, Maple, Walnut, and Indian. But I think it is wisdom to hold onto the Ebonies, many of the Rosewoods, and certainly Ziricote for at least a year or two before building.

This is also one of the reasons I like building with laminate or "double" sides. You can completely eliminate cracking issues with the sides and also eliminate warping problems from bending.

Know getting back on topic. I would definitely hold onto it for a short while before you sell it or just keep it for a personal guitar

Author:  Jody [ Fri Oct 24, 2008 6:24 am ]
Post subject:  Re: Brazilian Woes - Cracks

I remember what Charles Fox said at the GAL convention " the reason you charge so much to build with Brazilian Rosewood is, IT WILL CRACK , and there will be warrantee issues ." Jody

Author:  Hesh [ Fri Oct 24, 2008 7:50 am ]
Post subject:  Re: Brazilian Woes - Cracks

Hi Rich!

There is a great article in Fretboard Journal this quarter where they interview Jeff Traugott.

Jeff uses BRW often and described his technique which was VERY interesting.

First, like Wayne Henderson Jeff will soak the sides in water for 6-7 hours prior to bending. He does not say how he avoids cupping.

And second he takes the sides (prior to bending and soaking) and plates at slightly thicker than final thickness and squeegees in a thin epoxy, possibly West Systems, into both sides of the boards. His goal is to impregnate the wood with epoxy and stabilize any wanna-be cracks and splits. Then he works it as usual and thickness sands the epoxy off the surfaces. Not sure but I think that he heats the plates too prior to applying the epoxy to open up the pores more.

I know this won't help you Rich bro but maybe next time. I plan on trying the epoxy trick on my next BRW project.

Author:  Brad Goodman [ Fri Oct 24, 2008 8:24 am ]
Post subject:  Re: Brazilian Woes - Cracks

Hi Rich,
I built a brazilian rosewood (flatsawn) guitar about 6 years ago. The body was done (no finish on it yet) and it was in the dead of the winter (very low humidity) and I noticed several cracks in the back.I filled them with cyano.
6 years later- no sign of them.
I figure that the wood was as dry as it was going to get (in this region-NY) so all it was going to do was expand from that point-unless somone brings it Arizona!

Author:  rich altieri [ Fri Oct 24, 2008 4:33 pm ]
Post subject:  Re: Brazilian Woes - Cracks

Thanks to all of you for your feedback. Think what I am gonna do is strip the back down to bare wood. Apply some cyano to the entire back, and then sand back to wood, and then apply epoxy, and then re-do the finish. Dont think it is as much work as it sounds. And then, i think I will add it to the personal collection for 6 months or more and see if it is stable, and then sell it with full disclosure to my friend. Now the good news has been, having used FP as finish, repairs are not as painful as when i have had to do something with lacquer or poly.

I have been at this obsessive hobby now for around 7 years and not the first disappointment or the last - I think as we age we call these learning opportunities!!! :lol:

Thanks again for all your responses

Hesh - Im gonna check out that information, I like the concept - makes sense.

Author:  Mike Collins [ Sat Oct 25, 2008 4:15 pm ]
Post subject:  Re: Brazilian Woes - Cracks

Rich-was this a slab sawn back?
Or a 1/4-slab-1/4 back ?
I've worked with Braz. for along time-over 30 years !
I've never had this problem with it!
As stated by Simon the need to let it acclamate- mine is stickered for years in my shop at 45% humidity!
I've had newly arrived sets come with a crack-yours may have but you were not looking for that!
I always check all sets (tops & backs) for checking when they arrive-
some are hard to find -tap the wood-if there is a rattle there is a crack !

Good luck-use maple ! [clap]

Mike

Page 1 of 1 All times are UTC - 5 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/