Trueing an Old Drum Shell

D. B. Cooper

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Any of you have any experience pulling an old wooden shell back into round?
How did you do it? What tools and materials were needed?

Thanks,
Mac
 

ARGuy

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I used a couple of turnbuckles and eyebolts that I pieced together at a hardware store. I also got some large rubber fender washers and a couple of regular fender washers as well. I found the long side of the drum, threaded the bolts with the rubber washers against the shell through the holes where the lugs were - I should have mentioned that I removed the lugs. Hooked everything together, tightened the turnbuckle slowly and carefully to pull the drum back into round, and let it sit for a long time. This is probably kind of vague - sorry.
 

D. B. Cooper

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I used a couple of turnbuckles and eyebolts that I pieced together at a hardware store. I also got some large rubber fender washers and a couple of regular fender washers as well. I found the long side of the drum, threaded the bolts with the rubber washers against the shell through the holes where the lugs were - I should have mentioned that I removed the lugs. Hooked everything together, tightened the turnbuckle slowly and carefully to pull the drum back into round, and let it sit for a long time. This is probably kind of vague - sorry.
No. Not at all. Could maybe use a rachet strap too?

Did it stay?
I'm wondering what a pro shop would do? Probably detach the re-rings and re-install?
 

ARGuy

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No. Not at all. Could maybe use a rachet strap too?

Did it stay?
I'm wondering what a pro shop would do? Probably detach the re-rings and re-install?
The turnbuckle is inside the drum. Actually, if you could find one or two long enough you could use them to push the drum back in to round. Once again, put them inside the drum with scrap wood against the shell to keep the shell from getting marked up.
 

Tommy D

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Basic threaded rod would work as well. Just run it through the lug holes and tighten some nuts with big washers and likely some sort of cushioning piece, like a rubber washer, against the finished shell so it doesn't damage it. The more threaded rods you use, the less stress each individual hole will have on it and less risk of damaging the shell.
 

D. B. Cooper

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Basic threaded rod would work as well. Just run it through the lug holes and tighten some nuts with big washers and likely some sort of cushioning piece, like a rubber washer, against the finished shell so it doesn't damage it. The more threaded rods you use, the less stress each individual hole will have on it and less risk of damaging the shell.
Have you ever had ply separation happen with this method?

And did yours stay round? How long did you leave it?
 

Matched Gripper

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I used a couple of turnbuckles and eyebolts that I pieced together at a hardware store. I also got some large rubber fender washers and a couple of regular fender washers as well. I found the long side of the drum, threaded the bolts with the rubber washers against the shell through the holes where the lugs were - I should have mentioned that I removed the lugs. Hooked everything together, tightened the turnbuckle slowly and carefully to pull the drum back into round, and let it sit for a long time. This is probably kind of vague - sorry.
Have you had permanent success with this? How long a time did you hold the shell in place? I would suspect that the drum might return to its previous shape, if not right away, within a few hours or days.
 

D. B. Cooper

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When a pro shop does this, do they remove and re-glue the rings?
 

MillerMav

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When a pro shop does this, do they remove and re-glue the rings?
Yes. Usually what a good shop would do is pull the rings and apply "pressure fit" rings. These are a bit thicker and do not require 100 clamps. They actually push the shell out back into round. If you check out Kirsch in the US or Kentville in Australia this is how they do it. Its the best way but much more specific and time consuming.
 

ARGuy

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Yes. Usually what a good shop would do is pull the rings and apply "pressure fit" rings. These are a bit thicker and do not require 100 clamps. They actually push the shell out back into round. If you check out Kirsch in the US or Kentville in Australia this is how they do it. Its the best way but much more specific and time consuming.
And probably much more expensive?
 

MillerMav

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And probably much more expensive?
I've never had it quoted but I would imagine it is more expensive, but if you have an out of round shell I think this is probably the best way to get it back in.
 

thugdrummer

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I wiped inside of shell with some tung oil, put on ratchet straps, actually used my body weight to push more into round, tightened straps and then put heads on both sides and let it sit for a week or two... or more.
You need to compress and hold the long axis enough so that it's actually shorter than the desired diameter, so that when the tension is released it springs back to a circle. With straps, the most you can compress the long axis is still slightly longer than the desire final diameter, so it's going to spring back to an oval shape, though maybe less out of round than before.

One thing that *may* help the shell hold the new shape would be to increase the moisture in the wood while it's under tension. Maybe place a portable humidifier inside the shell for a day or two to raise the wood's moisture, compress it so the long axis is now a slightly short axis, let it gradually dry out for a few days back to normal moisture content, then remove the compression.
 
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D. B. Cooper

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You need to compress and hold the long axis enough so that it's actually shorter than the desired diameter, so that when the tension is released it springs back to a circle. With straps, the most you can compress the long axis is still slightly longer than the desire final diameter, so it's going to spring back to an oval shape, though maybe less out of round than before.

One thing that *may* help the shell hold the new shape would be to increase the moisture in the wood while it's under tension. Maybe place a portable humidifier inside the shell for a day or two to raise the wood's moisture, compress it so the long axis is now a slightly short axis, let it gradually dry out for a few days back to normal moisture content, then remove the compression.
Awesome. Thanks a lot!
 


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