1st bowl...need pointers

[DWFII]

This is my first bowl...my first hollow form. It's made of New Zealand Rimu which was badly cracked and maybe even a bit spalted. I filled in the cracks with CA and turned the bowl.

The bowl is roughly 1.75" x 4". The walls are about an eight of an inch thick all the way down to the base. There was a small "foot" (?) cut to accomodate a chuck (externally) and it was ever so slightly hollowed out between the rims of the foot.

I finished it with pure Tung and Shellawax.

1st bowl


I know I've got a lot to learn especially about sanding. Some sanding marks are barely visible on the inside of the bowl despite the fact that I sanded to 12000MM.

But my real problem/question is that the chuck not only marked the edge of the foot, it actually chipped out sections of the foot when all was said and done. Anyone have any advice as to how to avoid both the chipping and the marking?

DWFII

 

[dkulze]

Lovely bowl.

For the sanding marks, you know about backing up and resanding until each grit shows consistant surface, right? Also, tearout can go deep so make sure and work with the grain supporting the cut.

As for the foot, you need to reverse the bowl and turn it off/down. You can use a jamb chuck, pressure chuck (suported with the tailstock) or a vaccum chuck. Pretty much always count on turning the foot last and not going with straight out of the chuck.

Good luck,
Dietrich

 

[Jeff Jilg]

Dietrich gave some good advice. I'll add that you need to be careful when cutting the foot off. If the piece is not real secure on the lathe a catch will pull it off your chuck or holding mechanism. Take light cuts and rub the bevel. And go slow. Also helps to have some shavings piled around the lathe "in case" to reduce dents.

I use large flat jaws with rubber buttons on a Oneway Stronghold. And lately that gets reinforced with plastic wrap to ensure it is securely held onto the assembly. The plastic wrap gets wrapped all around and across the bowl, leaving the foot clear. This may seem like a lot of trouble until you lose or dent a bowl because of a catch.

just my 2 cents

 

[arbud]

My $.02 worth

Actually, lad, I'd give both Dietrich and Jeff at least $.05 for that advise, it's very good. I have only one question: What's a chuck? I don't own one so I use "heck-for-stout," double-sided, carpet, tape and a face plate. I've turned up to 10" dia. bowls, albeit light weight wood, with this method. You might want to try it w/smaller bowls. It works well and damage seldomly occurs.

 

[DWFII]

Thanks, guys....

What about a donut (compression) chuck? A fellow on Woodturners Central posted a link to instructions for making one from plywood. Great idea especially for mini lathes but I wonder about getting the bowl centered between the two pieces of plywood.

DWFII

 

[DWFII]

Deitrich,

Please tell me about sanding the inside of bowls, I'm sure I don't know near enough.

DWFII

 

[Jeff Jilg]

We recently had a pretty good thread on sanding:
sanding thread

 

[dkulze]

Sanding inside is basically the same as sanding outside (except for the lost skin on your knuckles). The prob with inside, though, is that you can't get that nice wrap around grip with the paper. If you have a drill and a velcro sanding disk for it, power sanding is the way to go. Otherwise, patience is required.

The real trick, though, is to get the inside as clean as possible from tearout before sanding. When you're cutting side grain, this means your final cut is downhill into the bowl. Engrain, final cut is uphill. This way, the grain is always supported by longer grain and won't tear as easilly. After that, you have to learn how to shear scrap with a rounded scraper or the tip of a bowl gouge (careful with that bowl gouge or it'll do just that, gouge your bowl. Amazing how that works out). A good shear scrape will take off any tearout and irregularities in the surface, leaving a quick sand up through the grits to finish.

Finally, make sure and blow/wipe out the inside of the bowl between grits. Chunks of abrasive that come off the sandpaper will accumulate much quicker than on the outside and will tear the crap out of the inside of the bowl.

Dat's the advice I gots. Hope it helps out.

dietrich