crack repair question

farmerdude · #1 07-09-2006, 05:50 PM

My luthier is repairing some cracks in my bass. He is using a patch method with 3" wide or so strips of a thin veneer the length of the crack. These cracks are on the top-G side upper bout. There are two cracks within this patch area.

Is this a proper method or should I insist on traditional cleats?

Thanks

toman · #2 07-09-2006, 08:32 PM

Seems to me like cleats would be stronger, but maybe that's not a good thing... If it's an area that is likely to move (and thus crack) again, maybe it's better to have a thin veneer type patch that will crack first, instead of the top cracking again in another place. Obviously I'm no luthier though, so let's see what the pros have to say.

farmerdude · #3 07-09-2006, 09:21 PM

The grain of the veneer is 90 deg from the top grain. It may even be a thin plywood of some kind. I have no doubt that this patch will hold the bass together forever but I'm concerned that it will drastically change the tone. (this is my good bass) It seems to me like a lot of surface area will be affected by the glue/added wood. There will be four of these patches when all is complete. Two in the G side upper, and one on each side of the lower bouts, plus a sound post patch.... I can hardly sleep at night thinking about it...

toman · #4 07-09-2006, 09:36 PM

Oh yeah, I hadn't even considered the grain. Duh.

I suppose it just depends on how thick/heavy the stuff is, and if he perhaps removes wood to compensate or something? I don't know, I see a lot of old basses that have had tons of cleats and patches put in, and obviously they still sound great. Maybe you should have another luthier check it out and give an opinion, or get your guy to explain it a little better.

arnoldschnitzer · #5 07-10-2006, 07:25 AM

Quote:

Originally Posted by farmerdude

My luthier is repairing some cracks in my bass. He is using a patch method with 3" wide or so strips of a thin veneer the length of the crack. These cracks are on the top-G side upper bout. There are two cracks within this patch area.

Is this a proper method or should I insist on traditional cleats?

Thanks

I'm not sure I follow the method. Are you saying he's going to apply a 3" wide strip of veneer to the entire crack? Is it just going to be squashed to fit the contours? If this is true, you should be worried.

KSB - Ken Smith · #6 07-10-2006, 07:42 AM

Quote:

Originally Posted by arnoldschnitzer

I'm not sure I follow the method. Are you saying he's going to apply a 3" wide strip of veneer to the entire crack? Is it just going to be squashed to fit the contours? If this is true, you should be worried.

Arnold, if you ever do this to one of my Basses, I will hunt you down like a Dog...

....Grrrrrrrrrr......

......... lol

farmerdude · #7 07-10-2006, 08:35 AM

Quote:

Originally Posted by arnoldschnitzer

I'm not sure I follow the method. Are you saying he's going to apply a 3" wide strip of veneer to the entire crack? Is it just going to be squashed to fit the contours? If this is true, you should be worried.

That is what he is doing. Should I have them removed?

reedo35 · #8 07-10-2006, 07:29 PM

Oh, I thought you meant he was going to do an inlay to repair the cracks! I have never heard of anyone slapping down
some veneer to cover a crack, and no, I don't think that's a good idea.

uptonbass · #9 07-11-2006, 07:46 PM

Nice diamond cleats will do the trick, if a veneer of some sort best used is a "crate paper" similar to brown paper bag material, drenched in hide glue, it will at least meet the contour of the bass

The cleats: http://www.stringrepair.com/images/d...Hunter_095.JPG and at the top SMALL strips of the paper.

drurb · #10 07-11-2006, 08:03 PM

Quote:

Originally Posted by uptonbass

Nice diamond cleats will do the trick, if a veneer of some sort best used is a "crate paper" similar to brown paper bag material, drenched in hide glue, it will at least meet the contour of the bass

The cleats: http://www.stringrepair.com/images/d...Hunter_095.JPG and at the top SMALL strips of the paper.

For what type of repair does one use the paper rather than cleats?

uptonbass · #11 07-11-2006, 09:11 PM

Well on that bass we didn't quite need the strength of more cleats due to the doubling on the top at the neck block area, also we didn't want a cleats edge touching (and possibly buzzing) on the neck block. Leaving the cracks un-supported was not an option!

For example on this Westover bass the entire ribs were reinforced with the paper. Why...well the birds eye maple is not really a strong wood (its not cut on the quarter) and rather than a heavy complete doubling the paper was employed to strengthen the ribs BUT remain light and true to the basses original making. I feared just cleating the open cracks would result in other weak areas not being assisted and thus more issues once the top was back on.

http://www.stringrepair.com/DB_Westo...ass_repair.htm

uptonbass · #12 07-11-2006, 09:15 PM

Here is a good shot of the crate paper on the ribs: http://www.stringrepair.com/images/d...ST&DEL_010.JPG

Jeff Bollbach · #13 07-11-2006, 09:31 PM

Quote:

Originally Posted by uptonbass

Here is a good shot of the crate paper on the ribs: http://www.stringrepair.com/images/d...ST&DEL_010.JPG

Gary-
can you compare and contrast this paper with linen?

uptonbass · #14 07-11-2006, 09:52 PM

Jeff, first off I can say it looks a little more true to the bass, in function it is very similar to linen...strong light weight etc... I feel the glue saturates and becomes more ''part of'' the paper. Also its weight is probably a bit less and it's a little more true to wood in composition, when dry I also feel its a bit more ridgid and doesn't have any negative dampening tonal affect that linen can on a top. I have removed both and can say with time and warm water the paper is cleaner.

I am sure I have more

peasandhoney · #15 07-11-2006, 10:37 PM

I recently read a very old strad artical about using parchment in the same way (on the crushed ribs of a violin). Natural parchment (thinned lamb's skin) had the bonus of streching when soaked in hot glue and contracting as it cured. In the artical, they had to make a form to to clamp it in place. Is that what you do Gary, or is it more like applying tape?

Jeff Bollbach · #16 07-11-2006, 10:38 PM

Thanks Gary, but I was just curious. I am a linen guy-after all it was good enuf for Tony S.!

Eric Rene Roy · #17 07-12-2006, 05:01 AM

Quote:

Originally Posted by peasandhoney

I recently read a very old strad artical about using parchment in the same way (on the crushed ribs of a violin). Natural parchment (thinned lamb's skin) had the bonus of streching when soaked in hot glue and contracting as it cured. In the artical, they had to make a form to to clamp it in place. Is that what you do Gary, or is it more like applying tape?

That practice was proven to be not a good one. Parchment continues to shrinks with time (well past the glue drying)...and causes new cracks at the edges of the parchment where all the new stress is. Large sheets is very bad.

IF you are to use parchment safely (and I have used it in this application), it should be very sparingly and use a paper punch to make small little circles. At least this way the shrinking will be minimal and not much stress will be put on the wood...perhaps even shearing the glue before spliting a grain.

*edit* P&H, I just remembered there was a GREAT Lott bass in that issue! I can no longer find that issue...but I had those Lott bass pictures on my bench in violinmaking school as inspiration for what I really wanted to build!

uptonbass · #18 07-12-2006, 06:51 AM

Another thought on the crate paper is that it acts like paper mache (with a hide glue base) and does stretch a small amount. We have all seen how strong the paper mache kindergarten projects can be, thats pretty much just newspaper and a flour based glue.

**Matthew Tucker** · #19 07-12-2006, 08:15 AM

I have seen cracks repaired without taking the top off, by working glue into the crack then using a strip of brown paper glued along the crack on the outside of the bass. As the glue and the paper dries, it shrinks, supposedly pulling the crack tightly together in the process. Then when the repair is fully dry the brown paper and glue is sponged off. Seemed to work especially in the middle of the plate where cramps are harder to use.

farmerdude · #20 07-12-2006, 09:17 AM

I walked in on my bass in mid operation (bad thing to do) and saw a few things that scared me, but because I dont know a thing about repair-everything scares me when my bass in on the table...Since I could hardly eat or sleep from this experience, I went door to door around the shops in town and finally located the man I was looking for....(he had changed shops since I used him 3 years ago)...he gave me some "if thens" to check out and gave me hope that this is not such a bad thing, so ...I returned to my bass to see a closer-to-finish product and found that the 3" wide strips (I thought were being used) ended up being about 1" or so and the thickness of the top went from 6m +/-. to about 8 mm in the patch area...esthetically, the patch also blends in well (looks good)

I'm just a farmer so I have searched (what seem like to me) everywhere for info on material and methods of crack repair. Seems to be little info on the web (you guys dont talk about this

) but from discussions, I have found that luthiers have their own school of thought and top secret ingredients...it doesnt take long to get in an opinion war!!...the method above has apparently been used by some in Kansas City for years....so for now I'm gonna kick back-not worry and wait for the finish product (the tone). If we have a problem then....well I'm not thinking about that now

Thanks for the all the feedback, I appreciated you guys and the time you take to share you knowlege....