How To Fix Bearing Edge

Advice and questions on making and fixing instruments

How To Fix Bearing Edge

Postby drtom » Sat Jun 03, 2017 5:01 am

How would you fix this djembe's bearing edge? Notice it isn't just that one big rut that needs help. The surrounding area is not level as well.

I'm pretty sure at least two suggestions will emerge, but I'm hoping for solutions beyond my own meager imagination. All ideas are welcome, even the strictly theoretical.
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Re: How To Fix Bearing Edge

Postby djembefeeling » Sat Jun 03, 2017 6:58 am

Yuck, that one looks nasty. RIP! I myself would declare this patient dead, I like well build djembes in the first place.

I guess you have to level the djembe first. This will cause the fix of sawdust and glue in the rut to disintegrate. I am not fond of those fixes anyway. Did someone ever try a mix of sawdust and epoxy? Does that work? I am fond of epoxy lately, that's why I ask.

Another possibility is to seriously level the bowl. Now I am out of made up solutions...
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Re: How To Fix Bearing Edge

Postby drtom » Sat Jun 03, 2017 3:43 pm

djembefeeling wrote:Yuck, that one looks nasty. RIP! I myself would declare this patient dead . . .


Aw come on DF! Somebody loves this djembe.

djembefeeling wrote:I guess you have to level the djembe first. This will cause the fix of sawdust and glue in the rut to disintegrate. I am not fond of those fixes anyway.


That crossed my mind as well, that the patch would begin to crumble as the base to which it is anchored was removed.

djembefeeling wrote:Did someone ever try a mix of sawdust and epoxy? Does that work? I am fond of epoxy lately, that's why I ask.


I have not tried such a concoction myself. Hopefully someone with first hand knowledge will chime in.

djembefeeling wrote:Another possibility is to seriously level the bowl. Now I am out of made up solutions...


Are you talking here about leveling the bowl below the patch? That would be pretty serious alright - several inches off the top. Just levelling to the top of the patch, which is the lowest point of the bearing edge, would remove nearly half an inch.
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Re: How To Fix Bearing Edge

Postby the kid » Sat Jun 03, 2017 6:16 pm

Take it down 1/4 of an inch to the edge of the gap. Take out the glue what ever it is and go for the epoxy route to restrengthen the shell.

Other than the hole and the poor edge it doesn't look to bad. At least the shell looks thick ;)
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Re: How To Fix Bearing Edge

Postby drtom » Sat Jun 03, 2017 6:25 pm

the kid wrote:Take it down 1/4 of an inch to the edge of the gap. Take out the glue what ever it is and go for the epoxy route to restrengthen the shell.


I can see that working and working well. Plenty of work.

the kid wrote:Other than the hole and the poor edge it doesn't look to bad. At least the shell looks thick ;)


Yes, I understand some of us are partial to thick.
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Re: How To Fix Bearing Edge

Postby michi » Mon Jun 05, 2017 3:01 am

This is totally fixable, even though it'll be a lot of work. Use a planer to level the bearing edge. No need to go deep because you can build up the dip where the shonky repair is afterwards. Just take off enough wood so you have a level edge other than where the repair is.

Knock out the bad repair. Then use a mix of sawdust of a matching colour and epoxy to rebuild the section where the repair was. Use a slow-setting epoxy, not the 5-10 minute stuff. The slow-setting one retains more flexibility as the wood moves with changing temperature and humidity.

You can also buy wood-filling epoxy mixes in various colours. Less messy than mucking around with sawdust.

Once the repair has set, sand and level and then re-shape the bearing edge. Should come up a treat. Of course, I have no idea what the rest of the shell looks like, so I can't tell you wether it's worth fixing.

Note that, if you apply a reasonable hourly rate, you will almost certainly exceed the value of the shell (even if it were in good condition). So it's definitely going to be labour of love if you decide to go ahead.

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Re: How To Fix Bearing Edge

Postby djembefeeling » Mon Jun 05, 2017 5:37 am

Michi, how do you hold the slow setting epoxy in the dip? I did work with that stuff all day yesterday. It was fluid for hours. I can't imagine how it will hold it's shape before it hardens. Or does the sawdust hold the form with the epoxy?

And I do agree that fixing that djembe will hardly pay in anything other than a good reputation as a Mother Theresa of djembe and intrinsic satisfaction from the work-process.
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Re: How To Fix Bearing Edge

Postby michi » Mon Jun 05, 2017 6:16 am

I use gaffer tape or similar to keep the glue in place. (The sawdust will make the glue mixture a bit more viscous, but not so much that it won't run.)

You can also buy epoxy wood putty that is quite firm and will stay in place without support.

Cheers,

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Re: How To Fix Bearing Edge

Postby drtom » Mon Jun 05, 2017 10:40 pm

michi wrote:Should come up a treat.


I agree. I also agree it's a lot of work. Actually, it's the same advise as the kid's, but you go into detail. I mean, WOW! Many will appreciate that gem of a post.

Thanks michi.
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Re: How To Fix Bearing Edge

Postby boromir76 » Tue Jun 06, 2017 8:01 pm

Mixture of fine saw dust and wood glue work best for me. The tricky part is to put the right ratios of them together. In this case and with only hand tools available, I would mark the lowest point on the edge to which it would be needed to be cut off. Than I would measure distance between dot and ground and apply same distanced dots throughout the whole edge area and than connect them with marker. This marker line would be future drum edge. Done this once and with only hand tools. Hard work but it worked out all right in the end.
Last edited by boromir76 on Tue Jun 06, 2017 10:55 pm, edited 8 times in total.
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Re: How To Fix Bearing Edge

Postby drtom » Tue Jun 06, 2017 9:16 pm

boromir76 wrote:Mixture of fine saw dust and wood glue work best for me. The tricky part is to put the right ratios of them together.


So you pretty much would do as the kid and michi suggest, but use a different filler. How is wood glue and sawdust better than epoxy and saw dust?

boromir76 wrote:I would mark the nearest point on the edge to which it would be needed to be sanded off. Than I would measure its distance from it to the ground and apply same distanced dots throughout the whole edge area and than connect them with marker. This marker line would be future edge.


I'd never thought of that. I'll have to try it. Of course, there are situations when this might not be a good idea - when the base of the drum is not level, for example.

boromir76 wrote:Hard work but it worked out all right in the end.


Again with the hard work. :p We just can't seem to get away from that hard work stuff.
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Re: How To Fix Bearing Edge

Postby boromir76 » Tue Jun 06, 2017 9:39 pm

drtom wrote:So you pretty much would do as the kid and michi suggest, but use a different filler. How is wood glue and sawdust better than epoxy and saw dust?


I don't know. I haven't tried epoxy yet, but fix everything with the wood glue/ saw dust mixture. It has to be just the right mixture, so it is not to liquid or to hard...

drtom wrote: I'd never thought of that. I'll have to try it. Of course, there are situations when this might not be a good idea - when the base of the drum is not level, for example.

You can put litlle wooden wedges under the bottom to fixate and level the drum. ;)
The base could be leveled with simillar aproach as playing edge, but meassuring distance from lower point of new bottom to the start of the bottom of the bowl. But than again, the stem and bowl shape has to be symetrical in principles and not skewed to much. Also decorated and carved stem bottoms are not suitable for excessive sawing and sanding for obvious reasons. :-)
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Re: How To Fix Bearing Edge

Postby Worcester Djembe » Wed Jun 07, 2017 10:45 am

i haven't read all the comments, sorry if this has been mentioned already.

id build up the main gap with an epoxy, (kiwkwood or somerhing along those lines), then level it, then router it off.
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Re: How To Fix Bearing Edge

Postby drtom » Fri Jun 09, 2017 5:04 pm

OK, I guess that's it for the suggestions. Thank you for the great feedback.

drtom wrote:. . . I'm hoping for solutions beyond my own meager imagination. All ideas are welcome, even the strictly theoretical.


Nothing radically innovative was suggested, but the floor remains open.

Here's the repair. From this point it just took a little sanding to shape and blend the augmentation in.
Last edited by drtom on Fri Jun 09, 2017 11:40 pm, edited 1 time in total.
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Re: How To Fix Bearing Edge

Postby djembefeeling » Fri Jun 09, 2017 9:45 pm

Looks like you did work with epoxy. Looks good. Doesn't even look like excessive work hours. How did you hold it in shape? From that angle one can see the dimensions of the djembe much better than from the one you posted in the first post, btw.
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