Re-cobbled

The continuing saga of my path to discover an ‘easy’ way to sand the inside of hollow forms.
If you read the previous post and are following along then here is the next edition.

I previously purchased a rock tumbler at a garage sale this is a much faster turning devise than either of the BBQ motors I was trying earlier.

With the increase in speed I can in two days get the same revolutions I was getting in 2 weeks. I do realize that at some point if it spins too fast the glass will just cling to the outer walls and not tumble or grind the inside of the hollow form as I intend to.

The rock tumbler uses a 1725 rpm motor connected to a 1.5″ dia pulley which is then connected with a vee belt to a 9″ pulley. Please feel free to correct me if I’m wrong but by my calculations this devise now spins my hollow forms at  287.5 RPM. I wondered if it might be too fast but I can hear the glass and marbles (yes I have included marbles this time around) sliding and grinding as it spins. I am certainly not a machinest and the part that is in between my chuck and the shaft of the pillow block is not a tight fit and as a result the chuck ‘wobbles’ a little which i believe may add to it’s ability to sand.

Here’s a shot of my ‘re-cobbled’ devise.

I tip it slightly toward the bottom and alternately the top in an attempt to get the glass and the marbles working more on the ends where the torn grain is. I try to tip it about about 2″ and run about half time with it tipped each way.

Here is a comparison shot of one piece before sanding and after about 300,000 rotations.

And a closeup of the one on the right.

I think you can see quite an improvement as far as sanding and removal of ridges goes but as you can see it hasn’t cleaned up the torn end grain.

If I was to do a finished Hollow form I would spend a little more time with my tools to try to minimize the torn grain prior to using my sanding devise.

Please feel free to email me if you have any comments or questions.

Great Store

I have just reached an agreement with Cathy Goodman to sell some of my pieces in her new store here in Ladner at the  “Muddy River Landing”.

She has a wonderful store offering BC Coastal Curios and Bling including lots of local artists work!

If you live in the lower mainland of BC and would like to see or purchase any of my work this would be a great place to see it first hand.
Cathy has also kindly offered to exibit some of my whimisical wooden walking sticks.

Sanding the inside of a Hollow Form

Occasionally I really want a really good finish on the inside of a Hollow Form no matter how big the opening is. An example would be when I want to pierce the form with some sort of art that would allow people to get a good look at the inside. Another might be when I make a Hollow Form influenced by harvey Fein. His work frequently has openings in the shape of slits or slots that go all the way through the piece.
To this end I read somewhere that if pieces of broken tempered glass are put inside and slowly rotated they will eventually finely finish the inside.
I am presently experimenting with this process and have rough turned the inside of a couple of blocks of Birch. I used my Kobra hollowing system and made no attempt to get a smooth interior. I did perform a final light cut with a freshly sharpened cuter. The intention was to leave some roughness and some ridges.

The blocks are about 3″ square and 5 1/2 long.
Here is a photo of the devise I cobbled together with parts I had laying around.

It enables me to angle the turning if I want more finishing done towards either end. The original BBQ rotisserie motor turned twice as fast as my current one. I had planned to turn a week with it slanting towards the top and a week towards the bottom but during the process I decided I needed to keep track of revolutions rather than days/weeks.
Here is a picture of one of them prior to beginning the process.

Here is a photo comparing the one on the left (unsanded) and on the right the sanded one.

This was accomplished in about 8600 Revolutions.

As you can see the section on the left does have a much nicer finish and actually feels as if it has been sanded quite well. It did not however remove much of the ridges. I think I will devise a faster turning model and give it a try again. Sanding with more revolutions this time.

On another thread someone suggested the addition of marbles along with the glass and this I will try next.

Humming Birds?

Here is another piece in my indigenous people of the Pacific North Coast series.
It’s a quilted maple platter about 11″ in dia and 1/2′ thick. It was dyed while on the lathe then removed to do the pyrography. As you can see from the back shot I had a little trouble with ‘bleed through’.