Hole size or knot size. what's real.

Here's a thought for discussion... We compare vintage brush restores to current brushes in terms of specs. I have yet to see someone willing to drill out their Plisson or Simpson Chubby 2 to confirm-measure the knot size verses the hole size. The hole size has to be somewhat larger than the knot's glue-band size if you want a functional brush that seats and dries properly. The choice of which to advertise seems to be the marketing department.

When restoring, I experiment with hole size as much as knot size and loft setting. I like the hole size to look natural too. And if we made our own knots, we could absolutely tailor them to the handle, but we can't.

In pic #1, I recently installed a 22mm silvertip knot with a 29mm hole width (the same as a Chubby 2's advertised knot size) just to see its qualities. It has a 51mm loft and is drilled 17mm deep in a vintage, battle-worn Fuller handle. That's about 4mm deeper than I normally drill.

Frankly, it's a nice brush and functions great, even though it is certainly not as dense as a true 29mm knot would be in a similar rig. Yet it releases lather better that the denser knot described later. I doubt someone could fit a true 29mm knot in a handle with a 29mm hole unless it was drilled only for the band.

In pic#2, my 29mm hole size restores tend to have 27.5-28mm knots in them. It is quite luxurious but is almost too dense to be practical. I would have to assume the Chubby 2 would be similar. Sorry if the pictures are somewhat crude and don't show the best angle for this topic.

Pic #1 is post-bloom, 22mm knot in a 17mm depth, with a 29mm hole size, 51mm loft.
Pic #2 is pre-bloom, 28mm knot in a 13mm depth, with a 29mm hole size, 55mm loft.

hello virtualkelly. thanks for your previous responses to my threads.

and so, what to say about this entry of yours? there have been no responses since yesterday morning? that's a surprise considering the importance of the questions you raise. I am new to this discussion. I've made two brushes from scratch and am in the process of restoring four more. but I am starting to understand these relationships. the questions you raise are challenging. it has already become apparent to me that the terminology here is important. the combinations of hole diameter, hole depth, knot base (glue band) size, knot tuft size, knot height (sit it on a table and measure from the table to the top of the hair), hair texture and backbone, knot exposure above the hole (loft), and knot density are all variables that affect the final "face feel" and therefore the experience of the user. the combination of these factors affect how the brush lathers with soaps vs. creams vs. croaps, how it releases lather, how it feels on the face and how it dries. it seems that you are searching for the optimal combination? me too. I look forward to the ensuing discussion.

Thanks for answering, Sheb. There is much written here about loft, with an understanding that aesthetics matter too. But hole depth vs. hole diameter vs. actual knot size does matter to how the brush performs, due to the hair density once it emerges from the handle. In pic #1 it's easy to see the knot is not as dense as #2 (even though #2 is pre-bloom, it's easy to see), but #1 does perform well because it seems to strike a balance between holding soap and releasing it.

Brush #2, however, certainly is dense, softer and functions well with its bigger knot, but it doesn't hold and release soap like #1. The more relaxed opening seems to let it behave more naturally.

Brush #1 is very interesting to me. I have been shaving with my first self made brush for about a month, alternating with a couple of other brushes. It has a 24mm TGN Finest knot in a 26mm hole - - because the 2mm difference was recommended by several folks in other threads so I decided to go with it. I love the brush, but it does not release lather as easily as my old Rooney Best Badger. And it doesn't seem to dry as quickly. After seeing your post, on my next build, I'm going to go with a wider hole relative to the knot base size. I probably will not go 7mm like your brush #1 this time but I will definitely go more than a 2mm difference. How has the wider hole affected the backbone? Probably lessened it some, but is the difference dramatic or minimal?

We haven't talked about knot shape yet. Do you use all bulb shaped knots? My Rooney is a fan and I have wondered if that affects its ability to release lather? I have a fan knot in the queue to install in a later handle. It is a TGN silvertip grade A.

When I do a restore, I will order a knot then shape the hole to fit. Some knots have a significantly larger tuft above the plug and required opening the hole more than my standard 2 mm larger. Each brush restore is a drive into the unknown, that is part of the fun.

I have drilled out a Chubby 2, then opened the hole a bit more to fit the new knot. I could not tell what the original plug size was however.

Have you found a golden ratio of loft to diameter (hole diameter, not plug)?

Please don't forget that knots will vary. Sometimes, it about a half a mm either way. You just have to adjust a wee bit for it. As far as loft, my prediction is that it will vary as much as every user. Not only height but firmness and backbone. We have adjusted backbone by flattening out the curve for someone who thought it was too strong. Others thought it was just right. Goldilocks

Sheb said:

Brush #1 is very interesting to me. ... How has the wider hole affected the backbone? Probably lessened it some, but is the difference dramatic or minimal?

We haven't talked about knot shape yet. Do you use all bulb shaped knots? My Rooney is a fan and I have wondered if that affects its ability to release lather? I have a fan knot in the queue to install in a later handle. It is a TGN silvertip grade A.

Click to expand...

Sheb, I probably ought to mention my usual routine is to lather a well-drained brush off the puck for about 30-40 seconds and then face lather with it. I swirl a while, then paint a couple of strokes. I mention this as it's germane to the discussion. If I need to add a touch of water on second or third passes, I flick the base of the hair under the water, not the tips. I then hold it up-side-down for a couple of seconds. This allows the drops of water to run from the base of the hair to the tips inside, rather than thinning the soap at the tips. This seems to help interior lather to flow toward the tips, rather than the other way around.

To answer your question, silvertips are not particularly know for backbone, but there isn't much of a difference because you are using largely the tips to load lather anyway. It should flow up the hair as you're loading. Clustering the knot into a deep-seated wad with a smaller hole would increase stiffness, but it becomes a crowded place for lather in there (and flow-through), not to mention a tough place to dry.

I use bulb knots almost exclusively, except in barber-style handles (aka, cowboy brushes), where a fan, longer loft, and less hair looks more natural to me. Silvertip fans are even more flexible than bulbs, so its characteristics would be more of an accuracy issue than flow through, in my view.

Mike H said:

I have drilled out a Chubby 2, then opened the hole a bit more to fit the new knot. I could not tell what the original plug size was however.

Have you found a golden ratio of loft to diameter (hole diameter, not plug)?

Click to expand...

Mike, I would really like to know about that Chubby 2's knot size, alas.

I have drilled out vintage Simpson brushes before, but they were older pumpkin-colored Catalan and the hole was just sized for the glue-plug. Although the original knot was best or silvertip, it was what it was... not particularly dense or with significant backbone. I replaced it because I wanted a new, slightly larger knot, but I used a low-profile dense replacement knot in them and kept the original depth. The originals were all under 19mm knots and only about 8mm deep. That's why I wonder about the Cubby 2's insides.

To address your question. No, I don't believe in a golden ratio, because the knots can vary and handle aesthetics are important to me too. I eye-ball it, drill, look, and so on until it looks right to me over the course of a few days. Then I glue it. Also, even with precision tools, old knots can be a pain and you sometimes work with what happened.

I usually order several knots, say two blacks, two finest and two silvertips and pick the best for each brush in two sizes, generally 20mm short loft and 22mm regular loft. If I use a finest, I like to take the black part of the hair into consideration, same with black badger and it's silver-colored base. If I'm using silvertip, the black stripe might work well with black coloring in the handle, but at a certain depth, and so on.

Lastly, I think loft only means one needs to adapt the technique to get good lather. I can get a good shave with any knot and loft. Not that I'm that smart; it just requires a different technique, much like using an Old Type vs. a Super Speed. Using the exact same technique would likely cause irritation on the former or a bad shave on the latter.

Kelly, I've been exclusively bowl lathering - - and getting better results with creams than soaps. But, tomorrow I'm going to try your face lathering method. I have a short beard, so I only shave my neck and upper cheeks. And I have a cool old hand made pewter bowl that my parents bought on one of our visits to Williamsburg, Va. back in the 50's. Oh shucks, did I just give my age away? Please ignore the previous statement! But I am going to try your method to see if I can get better results with soap. Wish me luck.
What do you think of a situation in which a knot is buried in the handle only to the depth of it's plastic base? I want to use a copper collar around the bottom of the knot in my next brush. The exposed portion will be about 10mm tall and it will be buried in the handle by about the same distance. The collar will be made from copper plumbing pipe that is available in my area. That means an inside diameter of 3/4". A 20mm knot will fit inside but only to the depth of the plastic base of the knot. I think the epoxy will keep it from working loose, but I wonder about the lathering characteristics. What do you think? The knot is a TGN Best Badger. I also have a 20mm boar that I bought for a future restoration brush, but I could use it here. Mike, if you see this post I'd love to have your thoughts as well.

Sheb said:

...
What do you think of a situation in which a knot is buried in the handle only to the depth of it's plastic base? I want to use a copper collar around the bottom of the knot in my next brush. The exposed portion will be about 10mm tall and it will be buried in the handle by about the same distance. The collar will be made from copper plumbing pipe that is available in my area. That means an inside diameter of 3/4". A 20mm knot will fit inside but only to the depth of the plastic base of the knot. I think the epoxy will keep it from working loose, but I wonder about the lathering characteristics. What do you think? The knot is a TGN Best Badger. I also have a 20mm boar that I bought for a future restoration brush, but I could use it here. Mike, if you see this post I'd love to have your thoughts as well.

Click to expand...

Sheb, I think loading from the puck and then face lathering gives a denser, slicker lather, similar to using a tube soap applied to the brush and then face lathering with that. When I used to go from soap to bowl to face, I had a good "Santa Claus" lather that was airy and fluffy, but not particularly slick due to thinning. I'm sure other soaps are different as is using more product.

Many, many vintage brushes have the knot only as deep as the glue ring, especially nicer, solid Catalan brushes. The loft will be higher of course, or you can order a low-loft knot, which is what I do in this case. These are available from Shavemac... and Virginia Shang has a 20mm, low-loft dense knot.

I'm assuming your looking at the copper collar for adding weight to the knot and to fill space as you mention it will be around the bottom of the knot? From your description, it doesn't seem that it's going to be seen. Many use copper pennies for weight inside brushes. However, you used the word "exposed" so I'm confused. Would the total equal 20mm then, 10mm in the collar and 10mm inside the handle? If it will emerge from the handle and be seen, copper will eventually turn dark, and then green unless sealed from the elements (like with epoxy).

Regarding performance, if you use a low-loft dense knot instead of a standard knot, you should not have an issue with performance. If you stay with a standard knot, which is about 67-68mm delivered, you will have a remaining loft of about 57-58mm when set at 10mm deep. Most glue plugs I've seen are actually about 8mm deep. In both cases, I would recommend a knot with a bit more backbone, like a pure, black, or finest... maybe best. I usually stick with 55mm or less with silvertip. You will likely find 58mm loft a bit floppy in a silvertip. JMO. If the total depth will be 20mm, you should be fine as the loft would be firm 47-48mm.

I don't use boar brushes anymore since the 70's. I'm the wrong person to ask on that one. Now I've shown my age.

Kelly,
here is a pic that gave me the idea for a copper collar. I just like the aesthetics of this one. My handle will be wood.



The copper collar will be 20mm tall with 10mm exposed. A protective coating on the copper would be a must to keep it shiny for a while. Not sure how long it might last, but eventually oxidation will occur. I like the look of aged copper, so maybe not all bad there. I'm planning to use a 20mm Best Badger from TGN because it's the only 20mm that I have right now.

That's a nice looking brush, Sheb. Good luck with it. I haven't seen one like that before. I would expect about a 47-48mm loft with the current offerings in a 20mm hole depth.