Restoring plaster filled vintage brush handles?

[Toulouse]

I've encountered my first plaster filled handle. I understand that is pretty common in these vintage brushes ...
My question is: if the plaster is in good shape, is it safe to leave it in place and just epoxy the knot to the top of the plaster or is it better to drill out the plaster completely?

The plaster on mine is in very good condition and the plastic walls of the brush seem very thin (its a Century brand), so I'd prefer to leave the plaster alone except for grinding it down to the depth I want.

Also, the walls of the handle are thin and the shape is such that the interior of the walls will not contact the base of the knot - is it okay to just bond the knot by its bottom surface?

Thanks in advance to all you restore pros.

 

[FL shaver]

I'd just drill out what is needed to set it at your desired loft.

 

[Snargle]

I would just remove as much as you need to get your desired depth. You might want to seal the exposed plaster with a thin coating of epoxy to make sure that no moisture gets in. And make sure there's no open splits or cracks in the handle. All it takes is a little water to get into the plaster, and it'll swell and possibly crack the handle. I've had to deal with a couple of handles that were damaged this way and it's a pain to remove the swollen plaster, seal the cracks, and try to make the handle look decent.

As far as the open space in the handle, I've filled the voids with epoxy putty. That provides some support to the thin plastic walls in case you drop the brush or whack it on the side of the sink.

 

[badrunner13]

Make sure you seal it! Plaster will damage a beautiful handle, while they can be repaired most of the time it isn't something you can do with children within ear shot. If I were to do it over I would have removed it all together a process but worth it long term.

 

[eastomjac]

you should soak all the plaster out.no need to chance it.refill it with modern material,and then dont have to worry down the road.

 

[tinker]

I always take the old filling out of those brushes and replace it with epoxy putty.
Old plaster can break up and rattle around inside the handle.
You'll find that the new putty will give added weight and a better feel to the brush.
tinker

 

[byscott]

On the one restore I've done so far (a quickie job on an old Ever Ready that I planned on using as a travel brush), I drilled out the handle all the way to the bottom. Then I measured the depth, subtracted how deeply I wanted to set the knot, and cut a piece of Delrin rod to fill the difference. I epoxied the Delrin into place, let the glue set, then epoxied the knot into place. This should work with something like cork also, but I prefer the Delrin because it is impervious to water.