Bowl Turning

[David Turner]

I have a variable speed Powermatic (old) lathe and have done a substantial amount of spindle turning for period furniture but I would like to try some bowl turning. I've read Dennis Peacock's "processing a bowl blank" and understand the process. Do you have to have a Super Nova chuck or are there other ways of bowl processing? What is in the Alky bath?

David Turner
Plymouth, Mi.

[Ken Fitzgerald]

David,

They were turning bowls for centuries I'm sure without the aid of a chuck but it sure makes it easier and you can get it done without leaving screw holes.

The alky bath (Arkanese) is soaking a rough turned bowl blank in denatured alcohol (DNA) to reduce cracks. DNA bath or procedure is one method of many people use to try to reduce cracking in blanks...roughed out bowl blanks. You do a search on DNA here and you will find hours of reading on the subject.

There is a guy in Washington state who did a lot of research on it.

Boiling roughed out blanks is another method used.

Some folks just rough them out and wrap them in paper and check them in 4-6 months
.
Basically, when the wood is allowed to dry too fast it will warp and tends to crack. These methods are ways used to try to minimize it. It is important to find a method that works for YOU.

[Bernie Weishapl]

I agree with Ken in that you can turn a bowl without a chuck but it sure does make it easier to do. I use the DNA bath on some woods (fruit woods mainly) but have started using another technique I learned from Mike Mahoney in which he coats the whole bowl with anchorseal after roughing out to 10% thickness but that is a whole other subject. It take quite a bit longer to dry (6 months to 12 months) but so far have about 50 or 60 rough outs and so far none have cracked on me. I keep them on the floor in a cool dry place with not much air movement. With the DNA I soak for about 5 days, wrap them in a brown grocery sack and cut a opening in the bowl opening. It takes about 3 to 4 weeks to be totally dry. DNA is getting just to expensive so that is why I looked and am trying Mike's method. Mike said he has hundreds of rough outs so always has stock to turn.

[Art Kelly]

...are there other ways of bowl processing?...

If I'm working on a small piece, or unusual wood where I don't want to sacrifice anything to a screw hole or tenon, I make a small flat on the piece and attach a home-made "faceplate" using hot-melt glue. This way, all I've given away is the small flat, and once I get started I might decide that the faceplate is on the wrong end. I just face off the other end and glue another faceplate there, reverse the piece and part off the original faceplate.

In this piece made from a limb cut off of a pine gall, I actually changed my mind about "which end is which," and swapped ends after I saw the grain pattern inside.


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$0.02
Art

[Bob Hamilton]

There are quite a few ways to mount a piece of wood for turning a bowl without using a chuck. Here is an article about one way: http://bobhamswwing.com/Articles/No%20Chuck%20Bowl/No%20Chuck%20Bowl.htm
And a video series showing another way: http://www.youtube.com/view_play_list?p=EAE200FF4AC117E3

Take care
Bob

[Art Kelly]

I forgot to mention the other advantage of using a glue block: You can part the piece from the block (0r wooden faceplate in my case) by turning away the block rather than the piece. Saves wood and tools. A

[Wally Dickerman]

David, you no doubt have a faceplate. Using a glue block with a faceplate is a method that has been used for a very long time. Before about 1990 the 4-jaw scroll chuck that is so popular didn't exist.

To sucessfully use a glue block there are a couple of "musts". You are making a glue joint, so the surface of both the blank and the glue block must be flat and true. I use CA med. glue, but yellow glue can be used. Difference is, CA can be mounted on the lathe immediately and yellow glue has to dry for an hour or more. Almost all glue joint failures are because not enough glue was used. I always want to see squeeze-out glue. When applying CA glue, just use firm hand pressure for a few seconds.

Glue blocks typically are made of 4/4 soft wood. I use alder. Poplar is good. Never use mdf or plywood. They will separate.
To remove the glue block I just use a parting tool and part along the glue line. When the joint is smaller than a nickle I pop the piece off with my hand while holding the piece with my other hand. I've done this procedure many hundreds of times with just about no failures so it does work well.

Even though I usually use a chuck I often use a glue block and cut a tenon in that. Works for me.

Wally

[Art Kelly]

...the surface of both the blank and the glue block must be flat and true...

Flat and true is good, but on the ones I've done--certainly not hundreds--the surface of the piece is done with a chainsaw. Sorta flat, sorta true.

I think the hot-melt glue really works well in this case. I put a big gob of it on the glue block, then press the piece on, usually with the tailstock, but sometimes on the drill press. The hot-melt fills the grooves from the chainsaw. Also, it may absorb some of the shock if you're turning a piece from a log where there's a lot of whacking going on until the piece is round. haven't had one come off. Yet.

$0.02
Art