Mounting Irregular shaped items on the lathe

[John Giem]

Via the 'grapevine' I heard that some attendees of the San Jose Symposium were discussing how difficult it is to mount irregular shaped items on the lathe, in particular using vacuum. If this of interest to you, see my article on Compliant Vacuum Chucking Systems in the current issue of the American Woodturner, June 2012. Due to space limititations, there was a lot I had to leave out of the article. In summary, I describe techniques that can be used to mount almost anything on the lathe without concern about the item's shape, surface texture or voids. It is not necessary to use any glue or screws or make any cuts into the wood other than that desired to achive the desired artistic shapes.
I am open to any comments or questions.
John Giem

 

[hockenbery]

Hey John,
I skimmed your article this morning. The journal was delivered with our held mail late yesterday.

Your compliant system has all the characteristics of shear genius.
Simple
Easy to make
Can this really work
Why didn't I think of it.....

I think I can make great use of it on and off the lathe.

Thanks for sharing.
Hope you aren't too close to the fires.

Al

 

[john lucas]

Ditto what Al said. I haven't had time to try it out but definitely will. Excellent article.

 

[Bill Boehme]

I have used a non-vacuum method that has some similarity to what John has done with the vacuum and rice. The difference is that I used epoxy putty to make a permanent mold sort of like the way that dentists make an impression of your teeth before making a crown. I use a piece of Saran wrap between the putty and the burl. After the mold is made, I cover it with a piece of cloth from a t-shirt held in place with spray adhesive. The advantage of my method is that the piece can be removed and then reinstalled and get the same alignment without any tweaking and fiddling. This was necessary on my latest project where I had to repeatedly remove the piece of buckeye burl to do a fit check with the curved maple base that it sits on. The disadvantage is that it is sort of expensive to make one of these molds. I need to find a suitable material that costs less than epoxy putty.

 

[Ian Robertson]

I need to find a suitable material that costs less than epoxy putty.

Fibreglass body filler (car bog)such as used by panel beaters?

 

[Bill Boehme]

Fibreglass body filler (car bog)such as used by panel beaters?

Thanks for the idea. That may work if it sticks well enough to its wooden faceplate. Even cheaper than fiberglass which tends to run until it starts to set is the two part plastic resin (brand name Bond-O over here). Bond-O is more like putty whereas fiberglass is more fluid-like before it sets up.

 

[hockenbery]

I used something called Bondo too. A few years go.
Put plastic over it press the piece into the stuff and it dries into a nice mold.
As I recall it worked before fully dry.
I think it holds to wood okay but I put a few screws partway into the wood backing to give it screw heads to hold onto
I think it was written up in the journal for some project.
Al