and Bondo...


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This isn't quite an article, as I only have a couple of  pictures.  Occasionally I've turned a bowl to finished thickness from green wood.  The trouble is sanding.  Sanding while the wood is still wet seems so wasteful of time and sandpaper.  So I've tried letting them dry for a few days first, and then sanding with cushioned sanders such as pneumatic drums or foam balls.  Trouble is it's hard to avoid leaving facets or flat spots.  I thought remounting the bowl on the lathe and sanding it while it turns VERY slowly would work.  But how to hold the no longer round bowl on the lathe?  The bowl in question didn't even have a foot.  Enter Bondo...


I turned a tenon for the chuck on a waste block and dished it in the middle a bit.  Then I mixed up some Bondo and applied it to the waste block.  I covered the Bondo with piece plastic grocery bag and pressed the bowl foot into it, holding it in place with the tailstock.  I made a pencil registration mark on the blue tape on the bowl and the waste block so I could return it to the same orientation.  After the Bondo set I traced it on the blue tape to further aid in re-registration. 

I removed the tailstock and bowl and sanded the Bondo lightly.  This seems to be very important for the hot-melt glue to get a good bond.  Then I used more hot-melt glue than usual to mount the bowl, paying attention to the registration marks.  It's also possible to let the Bondo adhere directly to the blue tape on the bowl, although you may find this bond to be a bit stronger than required.

 Bondo Bowl

The bowl ready for the first mounting.  The Bondo cast has been sanded lightly for a better glue bond.  You should be able to see the registration marks at the top of the waste block and the side of the bowl towards the headstock.

I turned the lathe on VERY slowly and sanded the inside of the bowl.  I used a foam ball sander for the first grade of sandpaper and then switched to hand held abrasive, sometimes with a sponge backup.  After sanding I applied a couple of coats of lacquer sanding sealer.

I applied tape to the now finished inside of the bowl and prepared another waste block.  I shaped the surface of the block roughly to an ellipse to try and match the inside of the bowl.  I mixed up Bondo, applied it to the waste block, and after covering it with plastic held it inside the bowl with the tailstock center until the Bondo cured.  I made some registration marks to aid in relocating it in the same position.

I removed the tailstock to free the waste block and sanded the Bondo surface to aid glue adhesion.  Then I glued it in place with hot-melt glue again aligning the registration marks. 

I sanded the outside of the bowl with the lathe on very slowly, using a foam cone sander for the first grade, then switching to hand held abrasive.  After sanding the outside I applied lacquer sanding sealer.  After removing the bowl from the waste block I cleaned up any residual glue with mineral spirits.  The last step was buffing with the Beall system.

Bondo Bowl

The finished bowl with both Bondo waste blocks.