Bongo restoration question - HELP!!! Split in Hembra wood

[Mike]

Hi,
I bought Supercussion bongos @ ebay (price OK, 46 Euros). But unfortunately it has got a long crack from the bottom (there it is deepest) all through the shell.
Otherwise the bongo is fine, but I really would like to have a DECENT, i.e. intact second set. I wonder if it´s possible???
Supercussion is a Dutch brand they do not make any longer. The bongó is very light-weight (wood type? Dunno..) and sounds alright.
Even if the wood is NOT COMPLETELY split, I wonder:

Can it be repaired?
How? Epoxy or something?

Will it stand tuning tension?

Please, any quick help is greatly appreciated!

Thanks in advance by Mike aka Miguel El Desperado



Edited By Mike on 1194365294

Attachment: http://mycongaplace.com/forum/eng/uploa ... u_riss.JPG

[burke]

I'm a big fan (and in no way associated with the company) of this stuff - first encountered it re: boat building.
http://www.stickwithpl.com/Products.aspx?ID=PL-PREMIUM-POLYURETHANE
I just posted a little repair job I used it for on a cheap requinto.

If you can open up the crack that helps, if not then use a needle and syringe and inject it into the crack.

ps.

It will expand as it dries and show but the lumpy bits are easily cut off with a sharp exacto knife

[Mike]

Thanks for the quick reply, Darrell,
I am trying to figure the mending process out.
I´ll keep you posted.
Edit: On second thoughts: Just wonder if or why Epoxy wouldn´t do the job?

Mike



Edited By Mike on 1194374096

[bongosnotbombs]

I would suggest a wood glue, not a product called Gorilla Glue,

wood glue is made for wood. I wonder what is available in Germany, your in Germany right Mike?

Some glues expand or something else, they all behave differently, best to get some advice from a local carpenter.
Part of the reason wood specific glue is better is at it expands it fills into the grain/ cells of the wood itself making it stronger, some epoxies would just adhere to the surface.

Then fill the crack with glue and use some kind of strap to tighten around that shell really really tight.

Theres a lot of good advice in the conga section, bongos would basically be the same, probably easier.



Edited By bongosnotbombs on 1194379147

[Mike]

OK, BnB, yes, I´ll stick to the wood glues, that makes perfect sense. A friend of mine is a carpenter, so I´ll ask him about the best/hardest wood glue.
Thanks for your input.
I´m in Germany, yes.

use some kind of strap to tighten around that shell really really tight.

I only wonder if you can still pull the wood cleaving together when it does not run through the whole shell. I´m certainly not breaking up the shell first and then fix it
But of course a tight strap will keep the wood in place.
Thanks again
G´night to good ol´ Frisco
Mike

[yambu321]

HELLO MIKE,

IF YOUR BONGO HAS CRACKED THROUGH, IT HAS ALSO SHRUNK A TAD, BECAUSE OF IT. IF YOU'LL GIVE WHAT I AM ABOUT TO SAY SOME THOUGHT, I'M SURE YOU WILL AGREE. YES, THE BASIC COMMON APPROACH ON REPAIRING A CRACKED DRUM IS TO OPEN UP THE CRACK SO THAT THE GLUE CAN BETTER PENETRATE THE AREA, AND THEN USE RACHETING STRAPS TO KEEP IT ALL TOGETHER. YES THIS WILL WORK. AND MAY LAST YOU A FEW YEARS IF YOU ARE LUCKY.

WHEN A DRUM HAS CRACKED, AND YOU GLUE AND STRAP IT BACK TOGETHER, THE SHELL WILL BE UNDER MORE PRESSURE BECAUSE THERE IS LESS WOOD SURFACE. SO THE BEST WAY FOR A PERMANENT FIX, IF YOU ARE HANDY. IS TO CONVERT THE CRACKED AREA, INTO A COMPLETELY CLEAN CHANNEL AND SHAPE A COMPARABLE PIECE OF WOOD TO FIT IN THE CHANNEL VOID AS EXACTLY AS POSSIBLE INORDER TO AVOID ANY SHELL PRESSURE. APPLY AN EXCELLENT WOOD GLUE, TO ALL THE MATING SURFACES, AND THEN STRAP IT ALL TOGETHER. AFTER IT'S ALL CURED YOU'LL BE ABLE TO FINE FINISH THE SHELL, AND IT WILL BE A PERMANENT FIX WHICH IF DONE RIGHT WILL OUTLAST THE REST OF THE DRUM. :;):

CHARLIE "EL COQUI" VERDEJO (YAMBU321)



Edited By yambu321 on 1198416874

[Mike]

Uh-hah!
Charlie, you are a genius to explain construction matters to an unsavvy nerd like me :;):
So your basic idea

IS TO CONVERT THE CRACKED AREA, INTO A COMPLETELY CLEAN CHANNEL

You mean sanding it (probably with a file) or really opening the shell up and then making it smooth?
I´m really afraid to f%&! up the shell completely when breaking it up.
Your suggestion to spare the shell too much pressure makes sense though, especially because the bongó seems to be quite old and the wood very light (is it cedar, I wonder?)
Thanks a lot anyway!
Mike



Edited By Mike on 1194384402

Attachment: http://mycongaplace.com/forum/eng/uploa ... _bongo.JPG

[buckoh]

Mike, that crack looks like a glue joint failure. It appears to be very straight and possibly contrasting in color to the stave next to it. I would disassemble the drum and see if the crack will open up by itself. If not, then from the inside, try to open it with a knife. If it opens a little then get some glue inside. The strongest wood glue is Titebond II. Its a yellow PVA glue and it is the best. Any PVA glue, yellow, white or brown will work. You can clamp it, but just enough to squeeze a little of the glue out. Too much pressure will starve the glue joint. Epoxy is also a good choice. It will hold well and will fill gaps up to almost 1/8th inch. You can also add sawdust to the glue if you think it will help the acoustics. Good luck, Buck

[yambu321]

YES, WHAT I MEANT TO SAY IS TO EITHER FILE OR USE A CUTTING WHEEL TO CONVERT THE CRACK TO A NICELY STRAIGHT LINE VOID. THEN CUT AND SHAPE A PIECE OF SIMILAR WOOD TO FIT IT; A CLOSE FIT IS PREFERED. ENSURE GLUE IS APPLIED TO ALL THE MATING SURFACES BEFORE FINAL FITTING. THEN USE RACHETING STRAPS TO HOLD IT ALL TOGETHER. REMEMBER TO PLACE FOR EXAMPLE WAX PAPER SPRAYED WITH A NON-STICK SPRAY, OVER THE CRACK AND UNDER THE STRAPS, THAT WAY THE STRAPS WON'T WIND UP BEING GLUED TO THE DRUM.



Edited By yambu321 on 1198417089

[Whopbamboom]

A recent issue of Fine Woodworking magazine had a strength-test comparison of available wood glues, done in a lab with a press and PSI gauge to record the amount of holding strength the glues had before the joints broke loose. Titebond III came in first place, and Gorilla Glue came in last. I seem to recall that the wood itself sometimes broke before the top-ranked glues let loose. I'd give a look at Titebond III and see if it'll do the job.

[Mike]

Thanks everyone for the sound advice.
I´ll look for Titebond; that glue is even available in Europe - http://www.titebond.eu/product_info.php?language=en&products_id=15

So let´s hope it´ll work fine.

BTW do you guys have any idea concerning the wood type of the Supercussion bongo? (see photograph above)

Cheers
Mike



Edited By Mike on 1194418866

[buckoh]

Mike, I looked at the pic again to see the wood type and noticed that a glueline shows very clearly in the V cut grooves just to the left of the crack. My mistake! It is an actual split in the grain. Any of the advice posted so far has been good. I wouldn't try to close it very much. It will just split again, probably right next to it. I would say to cut a properly sized piece, taper the edge and gently tap it in from the inside. I forgot that there was Titebond III. I'm still using up my Titebond II.
The wood type looks to be some kind of pine/fir that probably grows in that part of the world. It doesn't look like cedar. I don't like to positively identify wood unless I have lots of info on it. Local names vs. scientific names can cloud the issue. There are folks who can tell you exactly what it is and where it came from. Buck

[Tonio]

buckoh,
what does open time refer to in glue specs?

T

[buckoh]

Tonio, I'm not quite sure. I think it is the amount of time you have to reposition the pieces or change your mind and pull the pieces apart. I'll see what I can find out. Buck

[Tonio]

Buckoh, here's a capture of description of Titebond III, if that helps:

Application Guidelines Application temperatureAbove 47°F.
Open assembly time10 minutes (70°F./50%RH)
Total assembly time20-25minutes (70°F./50%RH)
Minimum required spreadApproximately 6 mils or 250 square feet per gallon
Required clamping pressure Enough to bring joints tightly together (generally, 100-150 psi for softwoods, 125-175 psi for medium woods and 175-250 psi for hardwoods)
Methods of application Plastic bottles for fine applications; glue may also be spread with a roller spreader or brush.
Cleanup Damp cloth while glue is wet. Scrape off and sand dried excess.

Patent Pending

Bond Strength ASTM D-905
(On Hard Maple)
Temperature