First try and need a nudge in the right direction.

[majorrich]

I am trying to install a new knot to a brush and have run into a bit of a problem which I am sure is easy once I see how it's done. Here is some background. I got an aluminum handled brush on the bay and the bristles were falling out by the handful and I knew I was going to need to re-knot it before even starting.


Note the crimp at the base of the bristles. This is where my woes begin. I was able to literally remove all the bristles and residual glue-like material by hand just by pulling them out. I figured I would need to order a knot fairly close to the opening size of 19mm which was the size of the opening at the crimp. Here is where I began to go awry I think. I took a wooden dowel and opened up the crimp so that it comes up straight to an diameter of about 21mm. I ordered a 20mm x 55mm knot figuring "heck, I'll just stuff it right in there, glue it down and re-crimp the top and I'll be good to go.

Then the knot came in. The hard plastic part slides neatly into the opening with a little bit of slop, but the bristles flare wildly from there and wont allow me to simply stuff it in there. I am a little hesitant to flare the opening much more for fear of splitting or not being able to squeeze it back.



Should I trim some of the bristles so that it bottoms out into the opening? I tried to compress the knot above the plastic using dental floss with no success. So now I turn to the guys I should have talked to in the first place. What should I do now?

Thanks in advance for your help,
Rich

 

[CigarSmoka]

As much as I hate to say it, buy a smaller knot and save this one for another day. I just encountered the same problem with a Virginia Sheng finest 23.5mm. It wouldn't go into a 1" (25.4mm) hole because the hair is 28mm just above the plug. You could trim it up, but why size it down to a less expensive knot? There will be plenty of chances to score a handle that it will mate with perfectly.

 

[bakerbarber]

Buy a smaller knot.

Buy another handle with a bigger opening.

 

[TobyC]

Wrap with plastic wrap, then string or rubber bands over that, take it off after you're done with the handle.

 

[TobyC]

How about a cup?

 

[DCRIII]

How about a cup?
View attachment 717706

That's a good idea [MENTION=89729]TobyC[/MENTION], could you by chance point us in the right direction of where one might find these. [MENTION=105872]majorrich[/MENTION] these might work or you should get a smaller knot.

 

[TobyC]

Good question, I found these...

https://www.pennstateind.com/store/PKRABHKIT.html

 

[Graydog]

I vote for the smaller knot

 

[majorrich]

I did find a good deal on 18mm knots so have one on the way. Is there a rule of thumb when it comes to the opening size and the size of the knot that is most appropriate?

 

[CigarSmoka]

I did find a good deal on 18mm knots so have one on the way. Is there a rule of thumb when it comes to the opening size and the size of the knot that is most appropriate?

Generally 1.5-2mm is enough but it depends on the knot, the size of the tuft of hair just above the plug has a bigger impact on the size of the hole than the plug itself. I know a guy that drills 3.5mm over, ie a 1" hole for 22mm knots. You'll have to experiment a bit and it helps to have the knot first, so you can measure the plug, tuft, and overall loft to know exactly the diameter and depth you want to drill to. I've order knots claiming to be 67mm loft that were 70mm, and some that were shorter. It depends on the QC of the manufacturer so don't just go by what they say, break out the calipers and measure that sucker!

 

[Big Jim]

The rule of thumb is to measure the knot and the hole before installing. Everything else is speculation.

 

[majorrich]

Yeh. I measured and ordered a best guess. I'll remember to figure on a little smaller relative to the existing hole than I reckoned before. Learning a lot on my first one.

 

[Spang]

Is there a rule of thumb when it comes to the opening size and the size of the knot that is most appropriate?

Sort of, depending on the source and type of knot. The "listed" sizes of knots refer to the diameter of the plug, and those typically run true to size. But, the "glue bump" above the base of the knot is typically at least 1mm or, more commonly, 2-2.5mm larger than the stated diameter of the plug. So, for an opening of, for example, 22mm, I usually assume a 20mm knot. There is a little variation between knots of different types from different suppliers, but when ordering I always error on the small side, unless the handle design and material allows me to enlarge the opening. Obviously with an aluminum handle, that isn't the case so the knot needs to be "undersized" by a couple of mm or so below the size of the measured opening.

 

[CigarSmoka]

Sort of, depending on the source and type of knot. The "listed" sizes of knots refer to the diameter of the plug, and those typically run true to size. But, the "glue bump" above the base of the knot is typically at least 1mm or, more commonly, 2-2.5mm larger than the stated diameter of the plug. So, for an opening of, for example, 22mm, I usually assume a 20mm knot. There is a little variation between knots of different types from different suppliers, but when ordering I always error on the small side, unless the handle design and material allows me to enlarge the opening. Obviously with an aluminum handle, that isn't the case so the knot needs to be "undersized" by a couple of mm or so below the size of the measured opening.

+1 Solid advice here.

 

[majorrich]

I have an 18 on the way, coming from China so it should get here in a couple weeks. I muse about poor Ling-Po who has to go shave the Badgers. That's what they have the new guys do.

 

[CigarSmoka]

I have an 18 on the way, coming from China so it should get here in a couple weeks. I muse about poor Ling-Po who has to go shave the Badgers. That's what they have the new guys do.

I just got a handful of knots in from different Chinese vendors to test, most got here in less than 2 weeks. Amazing really.

 

[majorrich]

It takes a couple of weeks for Ling-Po to heal up from shaving sessions.