Thread: Can brush hairs be replaced?

I guess we all become victims of what has worked for us in the past, which makes it that much harder when someone comes along with something better.

For my method, the hardest part is in the very beginning when you are first forcing the drill bit into the knot. It's very easy at that stage for the bit to skip or slip sideways, and that can hurt your brush handle or (even worse) your hand. For that reason, I like to use a comparatively narrow drill bit to get down into the glue and only then widen out the hole by angling it back and forth. My concern with the forstner is that it would be difficult to get it through the dense part of the brush hair without it skipping and slipping all over the place, given how wide the forstner bits usually are. Maybe the trick is using a really narrow forstner, I don't know.

Anyway, thanks for the tip and I will wait to hear more!

Above, I mentioned that a friend uses a forstner bit for removing old hair knots from shaving brushes. I asked him for a little more info. Here's his response...

"drilling a smaller hole makes sense if you are cutting down the hairs to about 1/8 to get to the knot, the forster bit eliminates that. You cut the hair down with a boxcutter so it is level with the top of the knot, put it in the vise, using the fosthner bit get 1/16 down in the hole very slowly and it's over pretty quick after that."

I replaced a knot today, using a forstner bit to remove the old knot. It worked very well! Cut the old knot off flat to give the forstner bit a good surface. Determine the exact center of the knot hole. Drill slowly, making sure the outer edges of the drill are properly centered. Drill down very slowly until the bit is below the surface of the handle to make sure the drill doesn't jump out of the hole. Once below the surface level, drilling goes more quickly. But, more easily also.

The glue heated and melted under the forstner bit. Not a problem. Only, while drilling, it is a good idea to take the bit out of the hold periodically and check for this type buildup, and blow out any residue before continuing.

Forstner bit... a great way to go!

A Forstner bit will work but, having restored several brushes, I consider them a last resort. The potential for slipping up and damaging the handle is high, especially for someone inexperienced.

Most of the brushes I have restored have been able to have the old knot removed by hand. Here's what you do.

First just give the knot a slow but firm twist. You never know your luck. Sometimes the knot will just pull out in one piece.

If not, grab some scissors and cut the knot off straight across the handle. Now grab a pair of large needle nose pliers. Get hold of a smallish patch of hair in the middle and then do what you need to do to yoink it out. Once you remove that, working slowly, pull out small tufts of hair, working from the middle to the outside and pulling the tufts up and in towards the centre. 8 out of 10 times this will remove all the hair from the brush, especially in the old brushes that had the knot set in rubber.

Only if this doesn't work would I risk taking a Forstner bit to it.

Good day all,

Been on Navy Reserve duty for the last 3 weeks and am now on vacation at my in-laws so just a quick post.

Here is the brush and (bonus) cup. Both seem to be silver -





Now comes the restoration.

Jim

I would like to resurrect this conversation about the various methods to remove hair knots, and specifically the advisability of using the forstner bit. Since the last few threads above some weeks back, I have done quite a bit of experimenting and have a little more personal experience.

I find that I am using a variety of tools and approaches, and in fact am using everything mentioned above. And, then more. I use the forstner bit. I use a regular bit at times. I use diamond-tipped Dremel bits. I use routing-like Dremel bits.

I now believe you have to use a wide range of tools and approaches. Some knots have glue so hard that it is almost like concrete. Some knots come out by pulling on them with a pliers. You need a wide range of tools.

The bits I use are in the picture.

A few comments...

The advantage of the forstner is that it removes a lot of brush quickly and uniformly. The disadvantage of the forstner is that if not careful it can damage the edges of the brush into which the knot is seated. I tend to use a bit slightly smaller than the knot diameter and remove the rest of the knot on the edges with the Dremel router.

At times a regular old drill bit works very well.

After removing most of the hair knot with the forstner and/or regular drill bit, there is often a ring of hair and glue around the edge that is maybe 1/8-1/16 inch thick. The Dremel "router" bit does a very good job removing that ring of hair. Fine toothed bits gum up with heated, melted glue. I like bits with wider tooth gaps.

Finally, at times I use the Dremel diamond-tipped needle bit. When sinking the anchor hole in the center of the knot, the hole that will guide the forstner bit, a regular drill bit can skip around on the surface making it hard to create the hole in the exact center of the knot. This needle bit almost melts into the knot wherever it is placed. Nice! Another scenario... Sometimes hair and glue is so hard that it is difficult for any bit to chew thru it. At times, I have used the needle bit to honeycomb the glue/hair mass to soften it up. Doing this somehow makes drilling with something like the Dremel router more effective.

That's it...

Forstner bit is a term totally unknown to me so i had to check it from Google.
Yes it works well. I've removed hair from a brush with a forstner in a drill press. Using clamps to secure brush in it's place will eliminate the risk of drill bit moving sideways.
I've planned testing regular router next time i'm about to remove a brush knot. With router it is easy to limit drill depth and using clamps or self made jig eliminates brush or router from moving sideways. Will tell you more as soon as i've tested it.

You have better equipment than me, Sailor. I am a little envious.

I also use a vise. But, having learned the hard way, it is very easy to crack some brush handles. Be careful!

Originally Posted by LarryAndro

You have better equipment than me, Sailor. I am a little envious.

I also use a vise. But, having learned the hard way, it is very easy to crack some brush handles. Be careful!

It is true that is easy to crack handle using vide. I wouldn't try it unless making some kind of jig of wood to protect the handle. That is why i use clamps. If using drill press you can secure handle in its place by clamping it into a piece of wood etc. It is better to use at least two clamps as one might not be enough.
I'm not sure if my equipment is any better. At least of me the hardest part on any project is to think and get some inspiration before making any damages. Sometimes it works and sometimes not.
In any case i wouldn't try to remove brush knot freehand with any electric tool as all the elements of catastrophe are hanging in the air (and this comes from experience )

Edit: Simple jig if you want to mount your brush handle into vise. Take simple piece of wooden plate with a thickness about 5 - 10 mm. The measurements of that plate should be little wider than the diameter of the handle but not too much. About 5 cm per side. Small enough to mount in your vise. Now check the outer diameter of your handle and drill the round hole exact the same size into the wood. Now put the jig into vise and put your handle in it. The vise holds the jig that secures your handle from moving. If the mouth of your vise is too deep for the brush you can simple put any piece of extra wood under the handle to prevent it from getting too deep.
There's nothing that a cup of strong black coffee wouldn't help resolving.

Any recommendations on how to approach this? I don't have to worry about the knot but not sure how to restore the opening without scratching or making to dents worse. Not sure if the other half of the brush holder can be repaired.

Also not sure how the cup is used here. My mother-in-law said that the soaps use to come half round and that you used it by pouring water over it and only used the soap if you had a thick area.

BTW it turns out this is my wife's great grandfather's set. Seems it would be a shame to let it keep tarnishing on a book shelf.

Thanks for you time,
Jim