What's new

First shaving brush glueing Knot Size help

Hello guys,
Good morning

a few weeks ago i bought a nice wooden shaving brush handle from an Us artisan, iam from europe.
I apologize in advance for any writing mistakes,.

Since this is the first time glueing a knot into a handle for me i have a few questions,

it seems that the glue to go for is 2 component epoxy glue right?

Are all 2K Epoxy glues the same or is there something special to look out for while ordering ?

As far as of what i found out in my research,the best seller for "cheaper" solid quality badger knots is Oumo.

The diameter in the wooden handle is 26mm,so what knot size do u think i should order?

can a 26mm Brush knot fit or do i need a smaller one? Or is oumo selling the knots "smaller" so a 26mm is a little bit smaller and will fit a 26mm hole?

ive found many opinions on the internet and of course it depends on many factors,

but it would be great to hear what size u recommed,so i dont make a big mistake.


thanks in advance


greetings
 
In my limited experience buying knots, I’ve found that size can vary a little. For example, out of 2 26mm knots from one vendor, one was 24.5 and one was 27. It may not hurt to reach out to Oumo on this one.

2 part epoxy is good, but it seems some people prefer silicone adhesive. The advantage to silicone is that if you want to replace the knot in the future, it’s easier to remove.
 
For a 26mm hole, you want a 24 or 25mm knot. 26 won't seat properly. Use coins or washers to set the loft. You can use 2 part epoxy, but it's very permanent. A lot of people have begun using silicone, as it holds nearly as well, but allows the knot to be removed without damage. Do a YouTube search and you'll find a few good videos.
 
On a recent order the 22 mm knots actually measured 22.4 mm. That's a bit unusual as most of the time they are slightly smaller than advertised. That measurement is for the base disc only. A little above where the hair emerges from the disc, it is wider. I call this area the "swell", others may have a better term. The added size from the swell can also vary considerably. This is what you really need to measure, and you can't until you have the handle and the knot in hand.

Almost always I need to enlarge the hole size for which I use a Dremel tool with a drum sander attachment.

Don't forget that you may want to raise the loft by spacing the knot up a little.

I prefer using two part epoxy glue, either amber or clear in color. That's my preference, but I know that silicon is becoming popular.
 
In my limited experience buying knots, I’ve found that size can vary a little. For example, out of 2 26mm knots from one vendor, one was 24.5 and one was 27. It may not hurt to reach out to Oumo on this one.

2 part epoxy is good, but it seems some people prefer silicone adhesive. The advantage to silicone is that if you want to replace the knot in the future, it’s easier to remove.
On a recent order the 22 mm knots actually measured 22.4 mm. That's a bit unusual as most of the time they are slightly smaller than advertised. That measurement is for the base disc only. A little above where the hair emerges from the disc, it is wider. I call this area the "swell", others may have a better term. The added size from the swell can also vary considerably. This is what you really need to measure, and you can't until you have the handle and the knot in hand.

Almost always I need to enlarge the hole size for which I use a Dremel tool with a drum sander attachment.

Don't forget that you may want to raise the loft by spacing the knot up a little.

I prefer using two part epoxy glue, either amber or clear in color. That's my preference, but I know that silicon is becoming popular.

What these 2 said. And another vote for the silicon. It allows a removal and reset if necessary. And I've had knots set with it for years with no issues.
 
I've only done one knot replacement, so take my words for what they're worth. The 20mm knot I purchased was actually 20.6mm. I used a 2 part epoxy instead of silicone, mainly because I already had epoxy in the house, though it's a 30-min set as opposed to the often recommended 5-min set that you'll see in videos. I didn't see a need for using anything different than what I already had.
 
The size of a knot is normally given to the diameter of the glue plug, so at the lowest part of the knot. Knots have a "swell", i.e. the diameter increases above the glue plug and this is also the area where the knot would be set into a handle (one never only glues the plug in...). Most knots have a 1-2 mm swell, so a handle would need a opening that is 1-2 mm larger than the nominal hole size. However, some knots have a much larger size increase. I have seen up to 4-6 mm !!
I think it is always better to have a knot first and measure carefully what the size is at the preferred loft. Otherwise, one must be aware that the hole might to be opened up -which could be quite a bit for certain knots. So, your 26 mm hole might need a knot that is 24 mm....
 
good evening guys,
thank you very much for the many tips and insights.

I measured the handle again with a tool and its around 27mm,

so i went with a 25mm knot. I hope it will fit, but of course you can only know for sure when u have knot and handle together,i will report as soon as it arrives.

now the only decision to make is the glue,

Since i dont plan on removing the knot,i like the more permanent aspect of the epoxy 2k,

but silicone is easier to handle,and it wouldnt be that easy to make mistakes.

another problem is,that the handle is pretty deep,so i guess i will need many coins to lift the knot up

to the right loft (is there any calculation for what loft is right?)

Do u think that 2k epoxy or silicone is the better choice for the wooden handle?

And which of the two would you guys recommend,considering that i need to fill up quite a bit of room at the bottom around the coins?

Or should i first glue the "coins" in,wait,and then glue the knot onto the hardened bottom?


Thanks


greetings
 

Attachments

  • handle.jpg
    handle.jpg
    4 MB · Views: 9
Coins is one way, and the way I usually do it, but you can also consider plastic washers or ordinary washers, preferably stainless steel. Consider that adding metal of any kind adds to the heft of the brush and if you are not careful you may end up with a brush that is heavier than you would prefer. Some have used wood doweling and even cork carved off from a wine bottle cork or bought from Hobby Lobby.

I would establish the floor first, probably using epoxy. If you intend to make the knot semi-removable to play with the loft setting, allow for some of the spacing coins or whatever to be left out until you set the knot with silicon. Be careful to keep the floor level.
 
Hi,
yes i was worried about the weight
i will try to get some plastic coins or kork.

It sounds good,to first assemble the floor with epoxy and coins and after that is hard glue the knot onto that.

What are the professionals using these days? Is silicone the new "gold standard" for glueing the knot in or is is just what someone prefers?
(because i saw that maggards was selling small silicone bags for glueing in the knot)
 
I've used both epoxy and silicone and find silicone a little easier and more comforting, if I make a mistake. Be careful when building a platform for the knot that it doesn't get too heavy. I over weighted a small brush some years ago done in epoxy, and every time I pick it up I'm reminded.
 
DO NOT USE COINS OR ANY METAL MATERIALS TO SHIM THE KNOT.

I have run into a few problems when re-knotting with coins or such under the knot...if you do not test with a thin drill bit before, then you will have a great surprise when your large forstner bit will hit the metal - don't ask me how I know.
The simple and easy (and safe for future work) to shim a knot to proper size is a slice of cork - it can be cut to the correct size needed. Or, use cut offs from small wooden popsicle sticks, aka Craft Sticks. They have a defined thickness and one can use one or two or more if needed. They can be cut and sized to fill the hole correctly. Just do not use metal....
 
Hi All,
This thread is really of interest to me as I am planning to make some brush handles next week. In particular now I know that I need to make the hole 1-2mm larger than the knot size (possibly more depending on swell). I think most of my questions have been answered, but I did have one perhaps stupid question.

Am I correct that one always is gluing the bottom of the knot to either to bottom of the handle hole, or to the top of whatever spacer material is being used to shim? Or can one skip the shim and simply glue the sides of the glue plug to the sides of the handle hole thus allowing the loft to be tweaked during the curing process?

Thanks!
 
Hi All,
This thread is really of interest to me as I am planning to make some brush handles next week. In particular now I know that I need to make the hole 1-2mm larger than the knot size (possibly more depending on swell). I think most of my questions have been answered, but I did have one perhaps stupid question.

Am I correct that one always is gluing the bottom of the knot to either to bottom of the handle hole, or to the top of whatever spacer material is being used to shim? Or can one skip the shim and simply glue the sides of the glue plug to the sides of the handle hole thus allowing the loft to be tweaked during the curing process?

Thanks!

I'm no brush maker, but I've set at least 10 knots over the past few years, so take my advice with a grain of salt.

I would go with 2mm larger. 1mm is cutting it a bit too close IMO, especially given the variation in knot diameters listed vs actual.

You can glue just the sides. That's basically what you would do with a knot going into a removable ferrule. But there are a few difficulties doing that.
  1. It's hard to make sure it's level. You don't want your knot canted to one side.
  2. If you try to adjust the loft down, you run the risk of getting adhesive on the knot fibers down toward the glue plug.
  3. It won't be as sturdy long term. If you use 2 part epoxy, you may not notice much difference. But I would bet if you go that route with silicone the knot is going to pop out a lot sooner than if you used a spacer and glued it to the bottom of the knot.
 
I'm no brush maker, but I've set at least 10 knots over the past few years, so take my advice with a grain of salt.

I would go with 2mm larger. 1mm is cutting it a bit too close IMO, especially given the variation in knot diameters listed vs actual.

You can glue just the sides. That's basically what you would do with a knot going into a removable ferrule. But there are a few difficulties doing that.
  1. It's hard to make sure it's level. You don't want your knot canted to one side.
  2. If you try to adjust the loft down, you run the risk of getting adhesive on the knot fibers down toward the glue plug.
  3. It won't be as sturdy long term. If you use 2 part epoxy, you may not notice much difference. But I would bet if you go that route with silicone the knot is going to pop out a lot sooner than if you used a spacer and glued it to the bottom of the knot.

Probably should have mentioned one other thing - in this case I already possess the knots that I’m going to set, so I should be able to dial in the gap exactly where I want it, assuming I know what the target is! I likely will use a Forstner bit to get close to the desired hole diameter and then finish with a gouge or scraper.
 
I'm no brush maker, but I've set at least 10 knots over the past few years, so take my advice with a grain of salt.

I would go with 2mm larger. 1mm is cutting it a bit too close IMO, especially given the variation in knot diameters listed vs actual.

You can glue just the sides. That's basically what you would do with a knot going into a removable ferrule. But there are a few difficulties doing that.
  1. It's hard to make sure it's level. You don't want your knot canted to one side.
  2. If you try to adjust the loft down, you run the risk of getting adhesive on the knot fibers down toward the glue plug.
  3. It won't be as sturdy long term. If you use 2 part epoxy, you may not notice much difference. But I would bet if you go that route with silicone the knot is going to pop out a lot sooner than if you used a spacer and glued it to the bottom of the knot.

What he said.
 
Thanks for the comments! I plan to be sorting through available stock by tomorrow night and knocking the rust off of my lathe skills by Saturday morning. Already have some silicone RTV and the knots set aside. Still debating the finish. On my other turned projects I tend to flip between CA and a wax-based finish.
 
DO NOT USE COINS OR ANY METAL MATERIALS TO SHIM THE KNOT.

I have run into a few problems when re-knotting with coins or such under the knot...if you do not test with a thin drill bit before, then you will have a great surprise when your large forstner bit will hit the metal - don't ask me how I know.
The simple and easy (and safe for future work) to shim a knot to proper size is a slice of cork - it can be cut to the correct size needed. Or, use cut offs from small wooden popsicle sticks, aka Craft Sticks. They have a defined thickness and one can use one or two or more if needed. They can be cut and sized to fill the hole correctly. Just do not use metal....

Hey, Rudy, does that advice extend to knots set with silicone rather than epoxy?
 
Top Bottom