09-10-2012, 12:00 AM
#1
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Since there seems to be confusion as to the term "glue bump" which was coined by Brian, IIRC. It really isn't a standard term, but it describes the attribute pretty well, so it will probably turn into a commonly referred to attribute.

So, let's start with what it is. The glue bump is the amount of glue, used to make the knot, that is evident above the handle. Glue is used to keep the hairs attached to the plug. Unless the knot is made by gluing the hairs directly to the handle, a plug is used to make the knot. See the picture below to see the glue that creeps up the hairs and hardens.

   

How the Glue Bump comes into existence


The glue bump makes itself apparent when the top of the glue bump is above the top of the handle. By drilling the hole deep enough, the glue bump can be sunk beneath the top of the handle and be incognito. You'll never know it is there.

If however, the hole in the handle is not drilled deep enough, the glue bump will of course be above the handle and be apparent.

This Rooney 2/1 has no glue bump above the handle
   

This Morris & Forndran has a significant glue bump
   

This TGN brush has a smaller bump than the M&F, but it's still there
   

This Semogue SOC 2 band has as big a bump as the M&F
   

This Shavemac has almost as big a bump
   

This Shavemac as well
   

The fact of the matter is quite simply that it really doesn't matter. It does not mean a brush is higher quality because it doesn't have a glue bump or not. However, it is an aspect of the brush. It does change the characteristics of the brush.

The glue bump also lowers the effective loft of the brush. As you can imagine the DR Harris Rooney will have more bend than the same brush in the same loft, but with 10mm of glue bump. The glue bump will stiffen the hairs by lowering the loft.

But, as I've said, the bump in and of itself is not an indicator of quality at all. It can serve a very useful function. In addition, drilling the hole deeper costs a few cents if that on the manufacturing level. So, there really isn't a point to have a bump unless the manufacturer designs it that way. Or if it is a mistake.

It is what it is. It lowers the effective loft, but that is all.

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 09-10-2012, 02:13 AM
#2
  • beartrap
  • Resident Цирюльник
  • Southern California
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Great info, thanks!

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 09-10-2012, 02:22 AM
#3
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....agreed........ great information, Lee....

....i didn't even know that this was even an issue.....

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 09-10-2012, 04:35 AM
#4
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Here's a nice picture of a Mühle glue bump from Gut-Rasiert-Forum:

[Image: pinselinnenleben.jpg]

More to see here (German language):

http://www.gut-rasiert.de/forum/index.ph...204.0.html

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 09-10-2012, 06:11 AM
#5
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Thanks for the information, Lee. That's good to know.

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 09-10-2012, 09:42 AM
#6
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(09-10-2012, 02:22 AM)leonidas Wrote: ....agreed........ great information, Lee....

....i didn't even know that this was even an issue.....

Thanks.

It's actually a non-issue in the vast majority of cases. But due to the hand made nature of the items, sometimes the worker uses too much glue and it rides up and makes the hairs stiffer than the designer intended.

(09-10-2012, 04:35 AM)IvoryRazorClub Wrote: Here's a nice picture of a Mühle glue bump from Gut-Rasiert-Forum:

*IMG omitted*

More to see here (German language):

http://www.gut-rasiert.de/forum/index.ph...204.0.html

Whoa! That is not a glue bump. That is a different and cheaper way of making the bulb shape.

A real glue bump is the glue the rides up the hairs. That is just German ingenuity. Lol. See the first picture I posted of a "normal" knot with a plug.

Thanks for sharing! I had no idea they did that. Very interesting.

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 09-10-2012, 09:48 AM
#7
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Excellent explanation!
This means that the SOC, while advertised as 55mm loft is probably effectively 50mm or slightly less which makes double sense: it *looks* more impressive while not allowing it to become floppy.
I am leaning to get this brush and was worried about that 55mm loft but now I feel more comfortable about it.
Thanks for sharing :-)

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 09-10-2012, 10:33 AM
#8
  • Teiste
  • Moderator Emeritus
  • Salt Lake City,UT
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Lee,this is a brilliant post,my friend,thanks a lot for sharing it.

Ivoryrazorclub,thanks for the pic...very interesting to see the form of that glue bump.It seems,as Lee pointed,that glue bump is just to give a bulb shaped to the knot,instead of doing "manually".

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 09-10-2012, 11:05 AM
#9
  • Johnny
  • Super Moderator
  • Wausau, Wisconsin, USA
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Excellent post gentlemen. There is always something new to learn around here.

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 09-10-2012, 07:43 PM
#10
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Great post, Lee. Thanks for sharing the information.

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 09-10-2012, 07:46 PM
#11
  • Andrew
  • Senior Member
  • Austin, TX
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I would think a more densely packed knot would bend the way the knots in your glue bump pictures do, Lee. Kind of like folding a paper in half over and over again. You get to a point where you can't make a crease because of the thickness of the folded paper. Stuff enough hairs into a knot, and I think it would do the same when you try to "fold" the base of it like that. Maybe I'm wrong,

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 09-10-2012, 07:48 PM
#12
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(09-10-2012, 07:46 PM)Andrew Wrote: I would think a more densely packed knot would bend the way the knots in your glue bump pictures do, Lee. Kind of like folding a paper in half over and over again. You get to a point where you can't make a crease because of the thickness of the folded paper. Stuff enough hairs into a knot, and I think it would do the same when you try to "fold" the base of it like that. Maybe I'm wrong,

I agree, of course bending the knot like this is the only way to visually show the bump. However, it's very easy to tell by feel by squeezing the base of the knot.

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 09-10-2012, 07:53 PM
#13
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(09-10-2012, 07:46 PM)Andrew Wrote: I would think a more densely packed knot would bend the way the knots in your glue bump pictures do, Lee. Kind of like folding a paper in half over and over again. You get to a point where you can't make a crease because of the thickness of the folded paper. Stuff enough hairs into a knot, and I think it would do the same when you try to "fold" the base of it like that. Maybe I'm wrong,

Nope. Do it with a Chubby and it looks exactly the same as the DR Harris.

I'd show you, but I don't have a Chubby on me at the moment.

Now, if the knot was 30mm thick, you might have an issue folding the hair over because the knot is so large, but you can still feel the hard glue.

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 09-10-2012, 08:43 PM
#14
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Interesting and yet another thing to consider when buying a brush.

YIKES! So many variables. Especially if it varies from knot to knot.

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 09-10-2012, 09:44 PM
#15
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Now I know what a glue bump is thanks so much

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 09-11-2012, 05:33 AM
#16
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(09-10-2012, 09:42 AM)asharperrazor Wrote:
(09-10-2012, 02:22 AM)leonidas Wrote: ....agreed........ great information, Lee....

....i didn't even know that this was even an issue.....

Thanks.

It's actually a non-issue in the vast majority of cases. But due to the hand made nature of the items, sometimes the worker uses too much glue and it rides up and makes the hairs stiffer than the designer intended.

(09-10-2012, 04:35 AM)IvoryRazorClub Wrote: Here's a nice picture of a Mühle glue bump from Gut-Rasiert-Forum:

*IMG omitted*

More to see here (German language):

http://www.gut-rasiert.de/forum/index.ph...204.0.html

Whoa! That is not a glue bump. That is a different and cheaper way of making the bulb shape.

A real glue bump is the glue the rides up the hairs. That is just German ingenuity. Lol. See the first picture I posted of a "normal" knot with a plug.

Thanks for sharing! I had no idea they did that. Very interesting.

Not necessarily cheaper... but different, yes.

You can see here some photos of the Mühle factory, and of an employee making the knots. The "bulb shape" is shaped by hand, and the glue is added afterwards:
http://www.foroafeitado.com/foro/brochas...uhle-2818/

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 09-11-2012, 10:45 AM
#17
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(09-11-2012, 05:33 AM)oversaturn Wrote: Not necessarily cheaper... but different, yes.

Upon receiving more information, having that plastic nub may actually be more expensive and better. More information to come shortly I imagine.

I'm going to have to do more digging myself.

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 09-11-2012, 11:20 AM
#18
  • Teiste
  • Moderator Emeritus
  • Salt Lake City,UT
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Lee,you are right : more info here! Biggrin

As I told Lee on a pm,I did "sacrificed" a Li Jun 24 mm two band badger which had a glue bump over 11 mm. The brush was super stiff (like a wooden stick basically) and its a shame that a badger have to die to make brushes like this.If the bump would be lower,this brush would be a nice one,but with that bump being so high...

Anyway,check the interior of a blue bump:

[Image: P1250330.JPG?m=1347390987]

[Image: P1250332.JPG?m=1347390988]

[Image: P1250331.JPG?m=1347390989]

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 09-11-2012, 01:26 PM
#19
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Wow that's very interesting to know to bad the factory or the website won't know anything if u ask how big the glue bump is and I'm sure there are some but I doubt very many

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 09-11-2012, 01:30 PM
#20
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(09-11-2012, 01:26 PM)Tylerbrycen Wrote: Wow that's very interesting to know to bad the factory or the website won't know anything if u ask how big the glue bump is and I'm sure there are some but I doubt very many

Up until now, this has been a non issue. In fact, it's still really a non-issue as the vast majority of brushes have the glue bump in some form or another. Even M&F has it. Some Simpsons have traces of it. Most don't.

It really doesn't affect anything unless the loft is under 50mm and the bump is 10mm or larger. Then you get a 40mm loft, making for a pretty stiff brush. Trust me, I would know. Blush

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