Thread: Superglued crack strength

The beauty of CA glue here is its ability to be delivered to the whole surface easily unlike some other possibly stronger glues. In my opinion it is plenty strong enough and would be my first choice here.

Ross

CA should do the job but I'd clamp it as well. Big rubber bands cut from old inner tubes make good clamps for circular jobs.

OK, thanks for the comments.

I also thought it was the best way to get glue to all surfaces.

The crack closed pretty well with cross clamping with two parallel clamps. Just enough pressure to close the cracks.

I soaked the crack inside and out.
After about a minute (making sure the CA had plenty of time to feed right through the cracks - probably unnecessary), I gave it a good spray with the accelerator.

I know it should be set as soon as the accelerator is applied but there was a fair bit of hesitation as I released the clamps.

So for the moment the crack is closed. Tomorrow I will see how strong it feels.

Well the repair was looking good but a good knock was too much.

The whole piece was knocked clean out of the drum shell.

I talked to the local fibreglass shop.
They are confident that the West epoxy will do a good job.

I have fire brushed the old superglue off.
The used a dremel to carve shallow slots in the surface of the cracks.

The broken edges are a bit damaged so I will need to do some work to get the break to fit back into place.

Then I will use epoxy with a fibre addition to glue it back together.

Shoulda used hide glue ...

I have been contemplating Steel Bands.

I expected the CA to soak further into the fibres than it did.
Do you think hide glue would have penetrated a fine crack?

After cutting mating slots with the dremel and removing the rounded broken fibres, I glued it up this morning.

Even after much fiddling, I couldn't get a really neat fit on the outside. So it is not going to be very pretty.

The main thing is getting enough strength for it to hold together.
The epoxy should soak into the fibres and the keys should help. I hope.

If it looks like it is holding, I might put a patch over the inside of the whole area to give it some extra support.

It just doesn't look like it will be strong enough for solid bumps.
A bit like the top of a wine glass.

THe epoxy has been taking a good few days to harden so I don't plan to touch it until Friday.
He wants it for the Mamady Kieta workshp on the weekend.

a ratchet strap and foam/rubber/shaped timber blocks is good when glueing odd surfaces

Thanks Andrew.
It is a difficult shape to clamp.
I agree, straps and rubber bands are good for curved shapes.

After fiddling with different ideas, I found a decent clamping using bessey clamps.
Two long clamps from base to rim and
two klik clamps across each verticle break.

The glue tends to flow downhill ( surprise surprise), so I put masking tape over the gluelines. This has worked on the inside but not as well on the outside.
I will try to get a neater finish on the outside with another glue patch up.

Back to Super glue....
The guys at the fibreglass shop told me that I would have had more success with my superglue effort if I had added Baking Soda to the glue.

I have a vague recollection of this being mentioned before.
Does anyone have any experience with this mix??

as far as i know, the baking soda is added to fill the gaps where the surfaces dont meet.....

The epoxy repair has made it through the first two weeks of use.
It as been to workshops and performances so it will have had some good knocks.
See pics.

The big broken piece is still in place and feels quite solid.

I will get it back and make a tidier job of the glue-up. Then I might put epoxy and cloth across the inside of the break.

At the workshop in Sydney there were over a hundred djembe players so I had a chance to check out how others 'looked after' their drums.

The last pic shows a metal band around the bottom rim. It appears to have holes punched in the band. Fancy upholstory type tacks are nialed through the holes.
These are marketed as protecting the base from chips and bumps. I have also seen thick, maybe 3mm, rubber fixed to the base rims.

I think the metal band might be a good way of supporting the broken base of my friends djembe.
Now to see where to find them.