Brushology: On Knot Depth-of-Set, Loft, and Conformation

[ChiefBroom]

This thread is intended to illustrate the relationships among knot depth-of-set, loft, and conformation as dependent on other factors such as knot girth, density, and height. All of these variable in combination significantly influence the performance (back-bone, splay, loading, lathering efficiency, quality of lather, water retention, flow-through, etc.) and subjective qualities of a brush in use. (See also this thread.)

Of course, no one has to care about any of this stuff to enjoy use of a brush in traditional wet-shaving. But I've been curious about badger-hair brushes since I started using them, and it's fun to share and discuss what we learn.

I was sorely tempted to use more knots, but that would have been too time-consuming, and I think two should serve well enough for present purposes.

Here's the first (designated as 26SLE5):

Here's the second (designated as 26SNL2):

25SLE5 has a base diameter of about 24.7 mm. 26SNL2's base measures about 25 mm.

The clear, acrylic handle I made with this demonstration specifically in mind is 56 mm high and 38 mm in outside diameter. Its socket (or knot hole) is precisely 26 mm in diameter and 22 mm deep.

I'll follow this with two more posts including only labeled series of photos. In replies (hopefully this will generate some discussion), it would probably be best not to repetitively include all the photos. I'll save my own comments for separate follow-up posts.

 

[ChiefBroom]

26SLE5 @ 49 mm:

26SLE5 @ 50 mm:

26SLE5 @ 51 mm:

26SLE5 @ 52 mm:

26SLE5 @ 53 mm:

26SLE5 @ 53.5 mm:

26SLE5 @ 54 mm:

26SLE5 @ 57.5 mm:

 

[ChiefBroom]

26SNL2 @ 48 mm:

26SNL2 @ 49 mm:

26SNL2 @ 50 mm:

26SNL2 @ 51 mm:

26SNL2 @ 52 mm:

 

[ChiefBroom]

The first time I ever had occasion to think prospectively about setting a knot in a handle was in connection with resolving dimensions for prototypes in advance of the 2013 M&F Group Buy. I studied philosophy and history as an undergrad, was especially interested in the ancient Greeks, and dug Pythogorean number theory. So, I fell right in line with the 2x diameter (begging the question diameter of what?) = Golden Loft rule. Accordingly, I gave solemn instruction that Group Buy Chiefs should have 25 mm knots lofted at 50 mm.

But then a couple months later Chiefs started showing up with lofts ranging from 49-53 mm. My faith was a shaken. And whatever of it remained took leave in early '15 when we got the first batch of 100 Paladin brushes back from Lee with knots he'd set. They were all over the place. I was forced to embrace diversity. But I still didn't like it.

I had a vision to restore order and harmony when I started setting knots myself that were made to our specifications. Then I finally crashed into the the light. Handmade knots might not be possessed of souls, but they certainly have preferences of their own and wills to match. Each knot has its own nature. (Lee had understood that very well.) It isn't in the nature of 26SLE5 to be set in a 26 mm socket at a loft of 52 mm. It wants to be set at 54 mm, although it could probably be content at 53.5 mm or endure 53 mm. (And some wet-shavers would undoubtedly love a brush with 26SLE5 set at 53 mm). 262SNL2 could be happy at just about any loft between 48 mm and 52 mm, although it would assume different personalities at different lofts.

I've got to where I can guess with pretty high confidence where a knot wants to be lofted when I pick it up, but I really don't know for sure until I try it out in a handle, and often I have to go up or down 0.5-1.0 mm (using spacers we make) to be sure. Then there are the occasions when a handle style rejects the loft preferences of a particular knot, or vice versa.

Bottom line: an important part of brush-making is match-making.

 

[ChiefBroom]

Next member (besides me) posting into this thread gets his/her choice of a Paladin shaving soap.

 

[Hoka Hey]

Yes​

 

[Hoka Hey]

And I was going to comment on the zen of knot setting. Science breaks down, and art picks up the slack. Thanks for sharing your insight. Explaining art isn't easy.

 

[ChiefBroom]

Yes​

Do you have my email address? If not shoot me a PM with yours, OK?

 

[Hoka Hey]

Next member (besides me) posting into this thread gets his/her choice of a Paladin shaving soap.

I about had a heart attack when I saw that!

 

[ChiefBroom]

And I was going to comment on the zen of knot setting. Science breaks down, and art picks up the slack. Thanks for sharing your insight. Explaining art isn't easy.

Thanks for your reply. If I had any God-given talent, it was drawing (long ago atrophied). In any case, I don't think of myself as an artist. But I do love working with form. I'm far too obsessive-compulsive to make handles free-hand. What I can get deeply into is design -- exploring opportunities in tradition shapes. Then I want the high fidelity execution that CNC enable.

Knots defy that kind of control over outcome. I definitely have aesthetic preferences, but I've had broad enough experience with brushes to work with a pretty confident sense of how a knot will feel and perform at a given loft when I put it in a handle at a given loft. And with spacers cut in .5 mm increments, we can vary and dial in loft very precisely - not with a target number but a target conformation and balance.

I'm pretty sure 262CNL2 would made a delightful brush set at 49 mm. It would also make a great brush at 50-52 mm. But it would have a distinctly different personality. 26SLE4 will be more narrowly particular. I wouldn't set it for myself under 53.5. I know I'd like it best at 54 mm. I'm sure it would work fine at 55 mm, but it wouldn't balance with a 26 mm Chief or PK-47. A Lotus could probably stand up to it at 54.5-55 mm. Even though the Lotus isn't as tall as a Chief. it has a combination of height, girth, and overall gravitas that balances well with "bigger" knots.

 

[Hoka Hey]

Making a brush or 2 is definitely something I want to try. I follow the work in the brush making and restoration forum. We've got some talented folks around here that might be interested in this thread. @CigarSmoka , @Graydog, @DCRIII, and probably a few other folks I can't think of at the moment.

 

[clyde72]

I have one of your 26mm chiefs and I love it.
Ken is this something you can measure, or is it just a fell kind of thing? But if it is a fell kinda thing, how does one know? I mean your feel for what a loft should be, doesn't necessarily match my feel, right.

 

[DCRIII]

Making a brush or 2 is definitely something I want to try. I follow the work in the brush making and restoration forum. We've got some talented folks around here that might be interested in this thread. @CigarSmoka , @Graydog, @DCRIII, and probably a few other folks I can't think of at the moment.

Thanks for pointing me in this direction. This is a very interesting read.
I'd never put much thought into before, but after reading this I realized that no two brushes of mine have ever had a knot set at the identical depth even if they're the same type/size from the same manufacturer.
I use primarily badger knots, so I wonder if this holds true to synthetic knots since each synthetic knot should theoretically be identical.

 

[Useless shaver]

I about had a heart attack when I saw that!

Hope you hadn't.... We need your opinion about the soap!

 

[Useless shaver]

Very, very interesting, Ken. Now there's a chance I may learn something....

 

[cvargo]

Thanks for the info Ken. This is all very interesting.

I tend to like a brush that some say is "floppy"

I face lather, and find that a floppy brush allows the tips of the brush to be used on my face giving me the best feel. I don't need to scrub. I want to make lather.

 

[ackvil]

Interesting read, Ken. Unlike many others on this forum, I'm not an expert on brushes. My first brushes were all on the smaller side, all 22 mm or less. I do not recall seeing larger brushes back then. An example of one such brush is the Hoffrtiz brush I bought in 1993. The brushes were soft but not very dense.

When I joined B&B I bought some larger brushes: 23 mm and larger. I realized that my preference was for larger, more dense brushes. I tried various Shavemac and TGN knots.

When Paladin started production I liked the way they looked but was never lucky enough to get one of the brushes. Then the Sue Moore auction came up and I picked up a PK 47 (the second from the left below). When the brush arrived I tried it and was blown away. The brush loaded like a Shavemac D 01 two band knot but without the harsher feel of that knot. Rather, it feels soft and luxurious on your face. I liked it so much I picked up another PK 47. Ken, I realize the two PK 47s have different knots. However, I find them comparable in feel and performance.

I then waited for a larger brush to come up and was able to get the El Dorado (the one on the left.) It is a large (28mm) brush and very dense. Then the final brush was the 28 mm Chief on the right. My two favorite brushes of all the brushes I own are the El Dorado and Chief. After that comes the two PK 47s.

 

[Adam Jensen]

This is intensely interesting. I haven't met a Paladin that didn't fit me like a glove. Be it a 26mm fan or the formidable WC-XL bulb. Setting the knots in the clear resin is a stroke of genius. Being able to see the graphic difference in loft setting is really something. Thank you for this education.

 

[ChiefBroom]

Setting the knots in the clear resin is a stroke of genius.

Have to confess it was a knock-off.

 

[Useless shaver]

Have to confess it was a knock-off.

View attachment 806985

Ha! I got that one!



..Years ago, I must say....