Thread: Where does this go???

Yesterday I decided to see if it was possible to salvage anything from the undersized shell.

I cut the shell at staves 1 and 10.

Adjusted the bevels to fit on the jointer.

Then glued it up again.....This time with stave No.20.

It looks OK......from a distance.


It is now an oval.

When the glue dries I will see if it is possible to make on oval into a 13.850" diameter circle.

I am not confident but maybe??

Bad luck Scally. It happens to me all the time and I don't attempt anything near so ambitious as your coopering.

It is interesting that you were able to glue up the 19 staves - with bevels cut for a 20 stave job - and find that even so the bevels fitted well. Does his mean that the angles of bevels are a bit more forgiving than one would think?

Whether you will be able to pull it back into a circle is interesting too, I supposea lot will depend on the kind of glue, whether it has got much give in it. I'd love to hear how you get on.

Good luck.

Scally, sometimes things just don't work out do they? I get a lot of those days.

I just run my calculator over the 19 stave drum concept and come up with an answer of
Included angle = 360/19 = 18.94 degrees, so the mitre on each part is 9.47 degrees, less than half a degree different fom what is required for the 20 stave drum. Unless you were using a Wixey or similar, you would probably struggle to get the mitre any more accurate than half a degree anyway.

Now had it been a 10 stave drum, a missing stave would induce a 4 dgree error in the mitres and it would be a bit more obvious at assembly time.

Unfortunately I dont hold a lot of hope for transforming the oval into a circle now that the glue has set.

Thanks for the sympathy.

I only admit the interesting stuff ups.

I cut the bevels on the tablesaw then clean them up on the jointer.
I use the Wixey on both.

The half a degree error per stave went together surprisingly well - not as easily as when using the full 20.

Maybe I wont be as fussy setting the angle in future.

The plan is not to try and force the new shell into a circle. I am sure I would break something.

The attached pic shows the router-lathe setup that I just started using to round the staves.

I can pull the wall thickness down to 12mm if necessary. That gives me about 8mm to play with.It sounds like a fair amount.

When I glued it up it was obviously oval.
I haven't been game to check but it didn't look promising.


Maybe I can use it as a base for a small coffee table.

This is what a good join should look like.


A couple of pic of the router lathe and the finish you can get......if you pay attention.

That's a most impressive project Scally . Heavy engineering there were the circular forms running on ball bearings?

Hi Scally,
Done a few coopering jobs similar to yours and found an easy way to assemble the staves to form the cylinder was to lay out two strips of that plastic packaging tape, sticky side up and lay the staves edge to edge on the tape. The tape was flush one end and about 100mm too long on the other end. Run glue into the joints and simply roll the drum up. Saves loosing one stave and getting them out of sequence. Maybe next time eh?
Jim

I do it the same way Jim.

Lay them down on the bench with the outside facing up.
Then run three strip of wide tape across them.
Turn them over.
Run glue into the gaps.

Stand them up.
Put a couple of occy straps around the cylinder to hold them together.
The put three belt clamps on them.
Check they are even along the joins. Add more pressure.

It works well but can be tricky with the longer/heavier drums.