Sanding with expanding chucks

[ahoiberg]

I make a lot of shaving brushes and with that comes various sized holes for where the knot goes, depending on knot size, which makes a 'one size fits all' approach not necessarily work for sanding/finishing the pieces on the lathe.

I have more or less found ways around my issue but I'm just wondering if anyone else has encountered similar problems and come up with a more creative solution than I have so far.

This picture describes the basic nature of the problem:

Some times, there is a small bore in the bottom, so I can 'jam' the piece with the forstner bit I used to drill the top and a live center in the tailstock, and there is plenty of room to sand and finish the 'top' of the pice. Other times, when the bottom is also finished, I have to use one of my expanding jaw sets to finish the piece without anything supporting the bottom end. This is where i run into the problem - there isn't enough 'clearance' on the top side to effectively get sandpaper in there or get a finish applied very well.

I've also tried the Beall IX collets, and those work well if I have the right bore size to use one of the collets, but that's not always the case. Plus, there is a small 'lip' on those collets that prevents me from getting the entire top surface finished.

Anyway, this is a long winded way to ask if anyone has any thoughts on how to 'push' the piece away from the headstock while still being able to use the expansion jaws? I've searched for a tool that specifically addresses this, but have come up empty handed to far. I suppose fitting something into the bore that pushes the jaws further 'up' in the bore is a possibility but I know that will cause a lot of wobble if I have to remount it.

I appreciate any thoughts on this!

 

[Timothy White]

Here’s how I do it. Start between centers make a tendon on the top of the brush. You can turn to shape or rough shape if you wish. Mount tenon in chuck bring up tailstock to help center handle. Refine shape. Bore hole. Sand the piece. Reverse the piece. ( like in your picture) Part off the tenon sand the nub and viola!
Your done

 

[ahoiberg]

Here’s how I do it. Start between centers make a tendon on the top of the brush. You can turn to shape or rough shape if you wish. Mount tenon in chuck bring up tailstock to help center handle. Refine shape. Bore hole. Sand the piece. Reverse the piece. ( like in your picture) Part off the tenon sand the nub and viola!
Your done

Good idea - thanks for the suggestion!

 

[Mike Johnson]

Andrew,

You can also glue a tenon or waste block onto the shaving brush billet to provide more room to machine the piece and not waste any quality wood.

 

[Glenn C Roberts]

Tim, Once the hole is bored and the piece sanded, you mention to reverse it. How is this finished end fastened to the chuck so the tenon can then be parted off? Are you making a jam "stick" to fit in the hole on one end of the stick, and fit to the chuck on the other?

 

[Timothy White]

In the main post Ahoiberg shows the the brush handle chucked in the bristle hole. 25 mm dove tail jaws should work for both tenon and bristle hole.

 

[John Altberg]

I use my bottle stopper mandrel from Ruth Niles. It will most always seat in the hole unless one is using a very small knot. The entire brush can be turned and finished in one position once the two holes are drilled.

 

[Clifton C]

Some good suggestions so far. And some experimenting seems to be in order. A few thoughts, use the brittle quality of CA glue and accelerator, as in turn a dowel that fits the knot hole, CA on just the dowel end, accelerator in the knot hole. Turn handle with tailstock support, turn down tailstock nubbin to maybe 1/8 and finish sand handle, turn off t/s nub, finish sand end. A quick wack would break the CA bond. Hot melt would be another adhesive to try. Alcohol breaks that bond so don't use an alcohol based finish. Remember, alcohol doesn't dissolve hot melt glue, just breaks the bond.