Split Repair: Stop that belt clamp from sliding - Rug Mate

[taikonoatama]

Split Repair: Stop that belt clamp from sliding

You know how when you're fixing splits or cracks on a conga with either belt-clamps or rope-tourniquets and they always want to slip up the drum (for splits in the top half) or down the drum (bottom half) toward the smaller circumference? I've tried all sorts of things (tack nails, two-sided sticky tape, counter-pull ropes, etc.), but nothing really seemed optimal.

I was talking to Tony (CB member blango) about this last week and he told me how he used a kind of thick rope netting or something, so I went to the hardware store today looking for something like this and stumbled across something else that looked like it might be worth a try and I have to tell you - it works amazingly well: Rug Mate. It's a thinnish non-slip foam rubber mesh that you put under a rug to stop it from slipping on hard slippery floors (wood, linoleum, etc.).

Check it out.

~Taiko

Update: Seems to have done the trick. The cracks needing to be closed here were not major, and the clamps I used worked fine. I'll try Tony's rope mesh for the next big project.

Gorilla glue is a bit messy and tends to not wipe off easily when wet and mar the existing finish on a drum when it dries, so be very careful or maybe use a different glue or something. The problem is that with clamps, ropes, netting, etc., it's nearly impossible to remove the excess glue whatever type you use. There's a bit of a Rug Mate pattern around the top of my drum where the glue was, but most of this will be hidden when I put the head on.



Edited By taikonoatama on 1183477206

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[taikonoatama]

Rug Mate

Attachment: http://mycongaplace.com/forum/eng/uploa ... ugmate.jpg

[Thomas]

Thats great, my wife has some of them, thanks for sharing, I'll try it soon on my solid wood quinto!
All the best, Tom!

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[blango]

Hello all,

I use a cargo net, like the one in the site below. It is a 1" thick, 12" mesh like PG-12.

It goes for about 4.25 per square foot, so its not cheap, but it works very nicely.

Belt clamps dont work well for me. they are weak straps and you cant get enough force, even with the heavy duty belt clamps for truckers.

also, if you dont clamp the entire drum, it may split in places you have not clamped, especially with expanding glue.

The net gives even tension, but you can get a specific spot even tighter.

So, you wrap the drum with said netting, and where they meet, you put thick hardwood sticks (about an inch thick and a foot long) through the net, and twist to tighten.

after using 3 to 4 sticks to "close" the net around the drum, i go to the specific spot of the crack, and put a stick into the net and twist at that point.

Im working out a method of stitching in smaller nylon loops to hold the dowel when it is at its tightest - ie you twist and then tuck the stick into the loop to hold it tight.

This gives way more clamping force than any other method ive found. Probably twice as much force as the belt clamps. It closes the worst of cracks.

http://www.jammarmfg.com/outdoor.html

the only draw back ive seen, is its hard to clean any expanding glue that oozes out of the crack while curing (leading to more finish work). And it may dent less dense wood, like cedar, or mahogany. Also, in time, the net gets covered in glue, itself, and needs to be replaced.

Perhaps Taiko's non slip mat under the net would solve the denting issue.

Any thoughts?

Tony

[taikonoatama]

Ahhhhhhhhhh.

When you told me about it I didn't clue in that your were using the netting itself as the tightening material.

Very interesting idea.

~Taiko

[bdrbongo]

Thomas,
Your picture made my heart ache, that is one horrible split.
Good luck with that repair, let us know how it goes.

[taikonoatama]

Thats great, my wife has some of them, thanks for sharing, I'll try it soon on my solid wood quinto!
All the best, Tom!

Oh, Tom, that's just nasty! This must be one of those drums you got from UK ebay ... did they mention the fact that it was completely split in two??? Ugh.

If the two halves really don't line up at all anymore, with that thick solid shell I can see getting them back together with clamps/ropes/netting to be seriously challenging, as you run a real risk of shattering the shell elsewhere should you apply the extreme torque that might be necessary to get the halves back together evenly.

I have a possibly crazy, possibly brilliant idea for you, and would love to get everyone's feedback. If the wood has warped and bent so much that there's seemingly little hope of getting it back together like it is, what if you stripped everything to bare wood and completely soaked everything in a big garbage can full of water for a couple of days (or whatever it takes to get the wood bendable) and then, using some kind of appropriate glue that could work with moist wood (Gorilla glue, maybe? Not sure what would be best) clamp/rope it and close the cracks with the now softer, more easily bent wood. Keep it clamped until it's completely dry (weeks? months?). The stress could transfer to a new, weaker part of the shell and start a new crack, who knows, but this would be a problem regardless of which way you might close the cracks.

Also, I know that other solid shell drums I've seen, Mambizas and Del Cielos, both have a sealer on every drum surface, the inside as well as the outside, to try to reduce the wood drying out too much, or unevenly, and reduce the cracking that's a common issue with solid shells.

~Taiko

[blango]

Thomas and Taiko,

Firstly, Id like to thank Thomas for your work in this tradition. It is inspiring, for sure.

As a European (Austrian) American, people such as yourself are pioneers for us all to follow.

Regarding the cracked solid shell you have - how old is this crack? Was it previously repaired? I see some 'splintered' material that looks like it has been cleaned of old glue from a prior fix?

In the past, i had a really nasty shell i rebuilt. it had some very old cracks that were just filled.

I bound it up as tightly as i could, and set it on the porch while it was raining. It was not getting wet, but just in the very humid air.

I gave it a twist to tighted every other day for the week it was outside. As the crack came together, i kept it bound, and let it dry inside for a week.

That worked quite well, and the crack came together very nicely.

Im not sure about the garbage can thing. You dont want it wet, but more humid.

In the dry California summer, i tried the bathroom, but that didnt work for me, and pissed the girl off as well

I think one has to get constant humidity around the drum for extended periods of time. The real deal would be a steam chamber, but...

How about this idea - put a small pot of water in a garbage bag, put the bound drum over the pot inside the bag. Seal said bag. That would keep the water away from the wood, and would create a humid environment. - id change the bag every couple of days, to prevent any fungus growing, or any funk developing. (or perhaps a few drops of bleach in the pot). The only thing i see as a potential problem - keeping the bag away from the shell so as not to drip on it.

Perhaps like a rain fly on a tent like system might work.

In fact, why not a small tent? a four season tent can be sealed up more tightly, and may be best. But the rain fly would negate the condensation dripping problem.

brain storming in action!

Tony

[Congadelica]

Great ideas tony , But im sure Thomas will agree the Humidity is very high at the moment in central and northern europe. My drums have sounded different every day in this weather its hard to tune . It s been rainging with temps of 18 to 21 oC in the uk and not too disimilar in Austria I expect .
So this would be a great time to try those theories Tony .

It looks a nastry split Thomas good luck , keep us posted with your progress.

marco

[Thomas]

Thanks brothers for your nice and encouraging words!
The cracks are new, they were caused by the courier. I was very pissed off when I received them, but luckily the insurance company will pay everything (of course they won't repair them, but I payed nothing for the tubs now, and can spend enough money repairing them).
I contacted a german conga maker (Munz and Simonsen) and he suggested to try to close the cracks with a belt clamp without any glue first to see if the cracks can be completely closed. Thats what I did, and it worked, so he suggested to just glue them together and tighten them with belt clamps. I don't know if it will work, but I'll try it asap. I will keep you informed.
Taiko, whats the "sealer" you mentioned, is it the palm oil- beeswax mixture which you've suggested grateful in the djembe repair thread?
Thanks again for your suggestions (well some kind of "steam humidifier" in a tent could work, but unfortunately I don't have either of them and our weather is rainy like Marco mentioned but I think its not enough to really make the wood evenly bendable)
All the best, Tom!



Edited By Thomas on 1183573053

[deadhead]

What is the best type of adhesive to use when rejoining a crack? My quinto has a split between 2 staves and the previous owner glued it back together but did a pretty crappy job. It had a thick layer of residue that seeped out of the crack and dried. After scraping off that layer I noticed that there is a good 1-2mm gap in between the staves that is filled with dry glue and they are not flush with eachother. It almost looks like the guy glued it but didn't use any kind of tensioning or not enough to hold the staves together. What is my best bet for repairing this "bad repair"? Should I try to split it again and reglue or will it close up if I just clamp it for like a week?

[taikonoatama]

Taiko, whats the "sealer" you mentioned, is it the palm oil- beeswax mixture which you've suggested grateful in the djembe repair thread?

Tom,

Actually, I was really just using the term sealer in very generic sense (polyurethane, lacquer, varnish, oil, whatever) - something applied to the inside of the shell, maybe the same as what's on the outside, to prevent it from drying/shrinking/cracking. I know that oils and waxes eventually dry out a bit, so I'm not sure they'd be best for this (though my djembe, with the Dr. Bongo's Palm Oil/Beeswax, has never cracked). I'd almost think something a bit tougher and longer lasting for such a big drum, like a polyurthethane or lacquer, but I can't really say what might be best, sorry.

What happens is that when a sealer is applied only on the outside of a big, thick shell like this, a lot more drying out and shrinking happens on the inside than the outside, creating stress in the wood leading to cracking.

When I was up getting a tour of Sky Whaley's Del Cielo Percussion workshop (solid shell master craftsman) a couple of years ago , he explained it to me like this:

Solid shell drums have to be cut/worked wet. One of the main reasons is that this wood is usually quite hard when dry, and too hard on the tools to really work/cut properly when dry. So the main hollowing out and shaping of the drum is done wet. Then they're slow-dried in a carefully-controlled de-humidifier room over about 6 months. At this point the wood throughout the shell should have a pretty consistent moisture content that's close to ideal. He then takes it out, does the finishing shaping and sanding, puts the thing on a big lathe and sprays insides and out with a specially formulated clear coat (I don't know what he uses). After it dries he puts the hardware and skin on and it's done (no holes in his drums).

Now your drums are likely African made and likely did not have the high-tech manufacturing that Del Cielos have, so who knows what may have been done. My Mambizas also have a clear coat inside and out. Just something to keep in mind.

Oh, but then, of course, one of my Mambizas has cracks. I just figure it would have been a lot worse without the coating on the inside.

~james



Edited By taikonoatama on 1183672147

[blango]

Sandseal is probably what you need to seal your drum, Tom.

I use sandseal to seal the grain before any poly coat, but after the staning. This prevents all the poly from soaking into the grain. you can get a mirror finish with half the number of poly coats.

I assume it would be a good moisture barrior as well, but not sure. Perhaps marine paint on the inside??.

Re the porch on a rainy day technique - this is only for a crack that is old, or previously repaired and cleaned. one that has developed a memory of its new incorrect position, but is not that far off.

Closing this kind of crack one does not need as much humidity as bending a stave, for example. It works well, over a week or so.

Re:previous bad repairs - see how easy it is to clean out the glue using an exacto knife, or some really thin metal, like a auto points gap tester.

If the old glue kind of pops out without damage to the wood, clean it all out, as best as you can. If it requires some real digging, you are either going to have to split the drum apart by Maestro Smith, or glue up and renforce the existing repair.

I use Gorilla glue, kinda messy, but strong as hell. It gets into the smallest cracks, but you have to watch for it slitting cracks as it dries.

Hope that helps,

Tony

[Thomas]

Thanks for the interesting infos james! Yes I think so too, they seem to be made in Africa out of some kind of tropical hardwood. Originally they weren't treated on the inside. On the pic you can see some darks spots on the inside, its resin coming out of the wood, those spots are all over on the inside. What do you think, is it a good or a bad sign? Or is it common on solid wood tubs?
So you're suggesting some kind of maybe clear varnish on the inside as well as on the outside? Or will it affect the sound too much?
Thanks again,
all the best, Tom!

[bongosnotbombs]

Thanks for the interesting infos james! Yes I think so too, they seem to be made in Africa out of some kind of tropical hardwood. Originally they weren't treated on the inside. On the pic you can see some darks spots on the inside, its resin coming out of the wood, those spots are all over on the inside. What do you think, is it a good or a bad sign? Or is it common on solid wood tubs?
So you're suggesting some kind of maybe clear varnish on the inside as well as on the outside? Or will it affect the sound too much?
Thanks again,
all the best, Tom!

Should'nt affect the sound as much as that crack does






(sorry for the cheap shot, could'nt resist)