Cracked drum due to dry air and alma

[jorge]

This month, one of my congas cracked in 2 places. My hypothesis is that this was due to winter dry air and the alma. It is an ash SOS tumbadora and I live in NJ. The cracks are both at glue lines between staves, from the bearing edge down. What In think happened is, as the wood shrank due to low humidity in February, the circumference of the shell also shrank a couple of millimeters or so. All the bands get loose every winter, but maybe looser this winter. The steel alma inside the top of the drum did not shrink, so the circumference of the wood shell at the top became slightly less than the circumference of the alma, and something had to give. So the wood split.
This was an easy fix, I took off the top outer band and forced Titebond III glue into the cracks. When I removed the alma, the cracks almost completely disappeared, and forced glue out. I put the top outside band back on and forced it down on the drum tapping it down all around with a screwdriver and rubber mallet. This closed up the cracks completely and forced more glue out. I will let it set, then re-mount the alma and bands (new holes, fill the old ones) so they are moderately tight but not too tight. By summer, the outside bands will be really tight and the alma will be a bit loose inside. Hopefully the rivets on the bands won't pop from the increased tension. I don't think there is a way to keep the alma moderately tight year round, except adjusting its position a couple of times a year. It will be tight in the winter and loose in the summer. Ash seems to have more tendency to expand and contract with humidity changes and this has not happened to my cherry or oak SOS drums (yet!).
Anyone else have this problem?

[Sakuntu]

what a bummer, I hope it doesn't happen to your other drums. What about getting a humidifier and putting in the same room your drums are in?

[Psych1]

Sorry you had that problem - good at least that it opened along the staves. My old - 35 years - mahogany Gon Bops contract and expand a lot with the seasons - bands are very loose right now. But, no alma so everything goes with the flow.

[windhorse]

Interesting, first I've heard of alma CAUSING cracks.. But, it does make sense..
We go from moist to dry here quite often, don't detune, no alma,, and all of our drums are fine. Our teacher has a set of Mahogany Gon Bops over 20 years old and they're still ticking with I think only the second set of heads, and both Eric's and mine are Mahogany and original sets of heads. We just keep them tuned year-round.

But, I did slip and fall three weeks ago after a snow storm with Tumba under my arm. Broke it along the staves in 3 places. Eric put in wood glue on two of them, clamped them, and put gorilla glue into the third crack with the heat underneath to draw a thinned alcohol/glue mix it into the hairline crack. It's all back to new..
At one point, we thought to turn my hooks around, but they are pre-bent to face outwards. If we turn them to face inwards, the bend touches the drum. Bummer, I had always thought it was just an oversight at the Sol factory, but it turns out to be a little bigger. They are actually bent the wrong way.

Good luck with your project!

[bongosnotbombs]

At one point, we thought to turn my hooks around, but they are pre-bent to face outwards. If we turn them to face inwards, the bend touches the drum. Bummer, I had always thought it was just an oversight at the Sol factory, but it turns out to be a little bigger. They are actually bent the wrong way.

Good luck with your project!

I just looked at the Sol site, seems your model comes with the hooks pointing out for some reason...

http://www.soldrums.com/classic.html

[windhorse]

At one point, we thought to turn my hooks around, but they are pre-bent to face outwards. If we turn them to face inwards, the bend touches the drum. Bummer, I had always thought it was just an oversight at the Sol factory, but it turns out to be a little bigger. They are actually bent the wrong way.
Good luck with your project!

I just looked at the Sol site, seems your model comes with the hooks pointing out for some reason...
http://www.soldrums.com/classic.html

Thanks for looking it up.. Yeah, I had seen that before and suspected it was the picture of my set!
Unfortunately, I had the opportunity to double-check if that was the standard hook when I was there in SF before he moved,, but I didn't know to look.
Just an opinion, but I think it was a mistake. Someone made the bend go the wrong way, and they decided to just use them. I thought it couldn't be more than my set, now that you mention it, could have been the whole line..
Doesn't interfere with operating the drum in any way.. I've never been cut or scratched by them. It's just a cosmetic oddity.. Always gotta be a rock in the stream.

[Xeno]

I had the same thing happen recently while restoring a vintage Vergara drum. I had to glue all the staves back together with slow dry marine epoxy. Then I put the alma back in pretty snug. After awhile with weather change some of the staves opened up again because of wood shrinking around the snugalma. Had to fill gaps because there is a limit to how much strap clamping you can do around the steel alma, like you say it don't shrink.

Xeno

[Xeno]

Just practicing how to post a photo. When I take a pic of the Vergara, I will then know how to post.

(In reality I never ever put anything on a drum except my hands, some photographer took a bunch of photos and none of them were any good and I got talked into this silly shot.)

[Xeno]

Here is a snap shot of the Vergara that I put back together from a box of loose staves this winter. It was a struggle and it is a bit funky, but cool to take out to some sessions.
Had to make up a couple of the missing stainless hoops. I was not good taking before pics of the process which was kind of exotic actually, never did anything like it before.

[RitmoBoricua]

Not bad at all, you did good. I can't see any seams. Looks like you left the original finish and all, it has that vintage (patina) thing going for itself. I think steel bands may need some tweaking and the bottom steel band is probably a bit too wide in relation to the other steel bands, but this is just cosmetic stuff. All in all, fantastic work in bringing back to life that Vergara drum.

[Xeno]

Not bad at all, you did good. I can't see any seams. Looks like you left the original finish and all, it has that vintage (patina) thing going for itself. I think steel bands may need some tweaking and the bottom steel band is probably a bit too wide in relation to the other steel bands, but this is just cosmetic stuff. All in all, fantastic work in bringing back to life that Vergara drum.

Thanks.

The relatively thin oak staves had been painted black in a previous incarnation, so after gluing the staves back together with slow drying marine epoxy I gave it another coat of black to bring it back to life. I had to use a special old wood worker tool to scrape the old glue off the stave edges so as not to distort those edges. The trickiest thing was finding a system for reassembling all the staves once glue was applied and the clock was ticking. I made a low table with a circle cut out, then used specially fabricated assembly hoops with tabs on them, through which long (and slightly bent) rods of all-thread could be used to pull the staves together into their original configuration. I used two pairs of these assembly hoops. Before the glue set up there was much pounding with a rubber mallet to get all the staves lined up.

You are correct about the bottom hoop, I did make it kind of wide because I copied an old prototype GonBop in my collection, I just thought I wanted all that surface to help pull together the ragged ends of these staves. So it was a conscious decision even though knowing it probably was not the way it was originally. Cutting out and fabricating these stainless steel hoops was another tricky process. Stainless is not exactly easy to work with and after the curve was determined the pieces were cut out of a flat sheet of stainless on a band saw, then riveted. For some reason, in spite of my careful calculations these newly made replacement hoops did not sit down perfectly on the drum, that is why some look a bit off. I tried pounding them down with a special coopers tool I made, but they just didn't work perfectly and then I had to use screws to hold them in place, which you do anyway.

The top hoop, which was original, seemed too high to get the crown down over it very far. I knew that the heads sit up very high on the Vergara by design, but I decided to change this hoop to go down a bit further, that is why you see the bottom edge of the top hoop sitting right on the top edge of the side brackets. I needed every bit of room at top for the crown to be able to move down a bit more. I simply undid one of the two rivets and put it back together using only the one rivet. Meanwhile as the weather changed the snugglyl fit alma caused pressure on the staves and opened up a couple of the joints, so I had to address this and do a bit of re-gluing, no problem. Try as I would, I had to leave the other hoops they way they were in spite of a couple not fitting just right. I wasn't about to try making them over again, knowing how difficult it was in the first place, and not being sure I could do any better the second time.

As you see, the crown still sits is up pretty high, considering, and yet I still felt the need to cut some pieces of small diameter pipe as bushings (like washers) before the nuts on the pull down lugs. Many of my drum restorations end up needing this because one runs out of threads on the pulls.

The hard oak staves show some of the history of the drum and I did not feel any need to hide this, even though I gave it three coats more of black paint. This old hard oak does not yield much to sanding and it is a very old drum that had been around. There were several dents and large gashes that needed bondo. One could see the original oak surface under the old hoop positions, so I think it was originally showing the wood grain before someone along the way painted the drum black. There was over-spray evidence on some of the original stainless hoops. You can see a round plug in one of the staves, and all the staves are different widths. These drums were made from re-cycled oak barrels and the staves had been shaved down to make them thinner and more flexible and more sonorous. The alma itself shows evidence that it was recycled from some previous use in the Vergara shop since I see remnants of blacksmith rivets that serve no purpose in its use as an alma.

This is a 11 1/2" head, and the skin I used, although very high quality, probably needs to be a bit thicker, although it is nice and easy to play, there is somewhat of a ring, not helped by all the epoxy that ended up on the inside surface after all the re-gluing. I will play it like it is for awhile exploring all the nuances and sounds I can extract from this present skin. I have another old 10" Gon Bop that I restored which is the exact same height (~30") which pairs nicely with this Vergara as the lower drum. The Vergara is very tuneable, responding well to alterations of tensioning. There seems to be some wisdom to the fact that the head is so close in and sitting up high like this, if you know what I mean (as opposed to the trend to lower heads so much to "get the crown well out of the way". I have no problem at all with the crowns sitting up high on these vintage drums. I guess that crown was originally meant to sit up way higher than it is just under the top surface of the head!

Zeno

[RitmoBoricua]

I love the vintage/weathered down look if you will. When you look at the drum it tells a story. Sometimes vintage drums are completely refurbished to almost new and in my honest opinion they loose some of that vintage look in the process.I understand better now why the wider steel band at the bottom of the drum, more of a functionality thing than aesthetics. Cutting and rolling them steel bands can't be easy. There is probably a trade secret or trick on how the get them steel bands all snugged and even on the shell. The high crown looks good. It does not look like is way too high where you can hurt your hand while playing it. Enjoy your Vergara drum you sure put some work into it.

[KING CONGA]

Wow that is amazing a true historical relic, thanks for sharing with us. I dont know of any other current forum members that own a vergara, you are in deed lucky, enjoy it. Can you tell us how you came across it?

[Xeno]

Wow that is amazing a true historical relic, thanks for sharing with us. I dont know of any other current forum members that own a vergara, you are in deed lucky, enjoy it. Can you tell us how you came across it?

Believe it or not, it turned up in a local auction near where I live. I won it, I think for about $65 but really didn't know what it was at the time. It was falling apart but looked interesting and different and I am obsessed like you all, right. Eventually I saw something similar on the old Ray Barretto LP and asked around and was told about the Vergara that everyone in that era desired and used. Later I noticed the tell-tale hardware on other drums depicted on Cuban LPs in my collection. I am happy and proud to have it.

Zeno

[GuruPimpi]

Great work, story and best of luck!
Lucky Vintage...

PimpS