ERC bowl

[Robert Hayward]

Unusual piece of red cedar from a tree I had removed from my front yard. Almost the entire bole of the tree had a grain pattern similar to this bowl. The bowl is 13 1/4" wide and 5" tall.

This piece of wood produced the worst grain tear out I have ever experienced. Extreme grain tear out coupled with wood chip tear out. I literally finished turning the bowl with 80 grit Abranet otherwise it would have ended up firewood. I could not stop the tear out. Lost over an inch of diameter and 3/4" height saving this bowl.

Then to top off the fun after I had the outside turned, bowl reversed and was working on the inside a bad wobble started. Tenon had cracked more than half way through. Pried it open and CA glued and clamped it back. Then the hard CA joint would not let the chuck jaws back into original position and I had another wobble. The top two inches of the bowl had already been thinned to 3/8" and I thought that was the end of the bowl again. Much finagling with the chuck and I got it back enough to turn the outside slightly and the inside top 2" slightly. The rim and top 2" or so ended up 5/16" thick. Then the wall tapers back to its intended 3/8".

[allan kuntz]

Nice save. Beautiful grain. Looks like marble

[robert baccus]

Great save and this piece of wood deserved it--great job on a tough piece.

[John K Jordan]

Sounds like it was a lot of effort! But worth it. Hard to tell from a still photo but it looks like it might have a lot of chatoyance.

I've had several ERC logs like that, beautiful figure, I've made a bunch of things with it. I haven't had any tearout though. Just curious, what tool gave tearout?

[Robert Hayward]

The bowl does have a lot of chatoyance. A serious amount. I have been asked if it is real wood.

I tried several different tools to stop the tear out. Easy carbide, Thompson bowl gouges in two sizes and a DWay negative rake scraper. The negative scraper freshly burred even produced tear out but no chips tearing out like the carbide cutter did. The only place I did not get tear out was facing off the bottom after I had turned away the tenon. That turned silky smooth with sanding only where the tenon stub was left for the tailstock to push the bowl into the jam chuck. I let the bowl sit on the lathe for a day while I worked up nerve to finish the bottom out of fear of ruining the project at that stage. I have done that before. Having the skinny stub of the tenon break and the bowl fly out of the jam chuck. Usually catching on the tool rest and scarring itself to ruin.

BTW, the finish on the bowl is 2# Super Blonde shellac and Johnsons paste wax.

Bob

[John K Jordan]

I find the flat-topped carbide cutters to be the worst for tearout and chipping. The Hunter cutter is far better or a razor-sharp bowl gouge. With tearout I'll sharpen then hone and strop the edge. And light cuts, of course.

I quit using tenons for most side grain (face work), especially for softer woods (unless the tenon is relatively large). I like expanding the jaws into a recess as long as there is enough wood for strength. (and don't use a gorilla grip when tightening!) If the design won't allow a recess the old glue block method is very strong, or a faceplate if there is enough wood. Good double-sided tape on a faceplate is also amazingly strong, able to hold large blanks. When I broke a tenon once I didn't feel comfortable using CA but used epoxy. I think I used a jam chuck and tailstock pressure to true up the tenon (vacuum would have been nice).

Figured cedar can certainly be tricky for tearout, even with the NRS! When I run into that I'll sometimes try another finish cut after applying a coat of sander sealer (or thinned sander sealer). Mostly I deal with problem areas with hand scrapers (small cabinet scrapers ground into a variety of curves).

The bowl does have a lot of chatoyance. A serious amount. I have been asked if it is real wood.

I tried several different tools to stop the tear out. Easy carbide, Thompson bowl gouges in two sizes and a DWay negative rake scraper. The negative scraper freshly burred even produced tear out but no chips tearing out like the carbide cutter did. The only place I did not get tear out was facing off the bottom after I had turned away the tenon. That turned silky smooth with sanding only where the tenon stub was left for the tailstock to push the bowl into the jam chuck. I let the bowl sit on the lathe for a day while I worked up nerve to finish the bottom out of fear of ruining the project at that stage. I have done that before. Having the skinny stub of the tenon break and the bowl fly out of the jam chuck. Usually catching on the tool rest and scarring itself to ruin.

BTW, the finish on the bowl is 2# Super Blonde shellac and Johnsons paste wax.

Bob