Subject: Tube bending reprise

From: [email-masked] (gregor)
Date: Sun, 26 Feb 1995 23:03:17 -0800

Gentlemen, it is a delight to find so many kindred spirits who appreciate
a clever shop tip, however, in the spirit of craftsmanship, I must protest
the use of materials or methods which defeat common sense application.
Most of the discussions centered on cerrobend, and other compounds.
Although I am happy to learn about these other techniques, I don't think
anyone has adequately explained what the advantages of cerrobend or other
compounds have over sand. Sand has the advantage of being dirt cheap,
indeed, you can mine some right in your back yard (if its dry) but its
probably best to get some cleaned and washed sand from the local building
supply store for about a dollar fifty (.75L). Or if you need to be even
more economical, get a dump truck load for about twenty bucks.

-- 

*********************************************************************

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From: [email-masked] (David Hoopes)
Date: Tue, 28 Feb 1995 14:33:17 GMT

[email-masked] (Joel Bristor) writes:

>In article <[email-masked]>
> 
>I have never found the more affordable and available fillers such as sand
>and lead to work very well.  The sand doesn't stay where I want it and
>lead is prone to cooling with irregularities and air pockets.  As much as I
>like Cerrobend, I cannot justify using it that much.  I mainly use pitch.  It
>is cheap, provides nearly foolproof support/filling and is easily removed.

Ok, so where do you get pitch?

-- 
David Hoopes                              Exabyte Corp.
[email-masked]                       11100 W 82nd St.          
Voice: (913) 492-6002 x3323               Lenexa, Ks  66214

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From: [email-masked] (Tim Kirby)
Date: 27 Feb 95 19:29:21 CST

gregor ([email-masked]) wrote:
: Although I am happy to learn about these other techniques, I don't think
: anyone has adequately explained what the advantages of cerrobend or other
: compounds have over sand.

I think one of the main advantages is that it stays put. With sand one has
to make sure it stays well packed or a kink may just push it out of the way.
Leastways, that seems a good reason to me...

: Sand has the advantage of being dirt cheap...

*ouch* :)

Tim
--
Tim Kirby                    - [email-masked] -                +1-(612)-683-5390
Software Division System Support ________________ Cray Research, Eagan MN, USA
----------------- Ask not for whom I speak - I speak for me ------------------
If you are sure you understand everything that is going on,
you are hopelessly confused...                                - Walter Mondale

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From: [email-masked] (Joel Bristor)
Date: Mon, 27 Feb 95 19:08:02 EST

>more economical, get a dump truck load for about twenty bucks.
I applaud your good sense.  I thought we were keeping plenty busy
providing lists of alternate materials.  Granted, we were dwelling on
this Cerro stuff.  If you want to shift gears to justification, that's fine.
I bend thin wall brass tubes for custom work on musical instruments.  The
wall thickness is .015-.020".  The smoothness and uniformity of bore is
crucial for accoustic reasons.  I must also be able to get a high finish
on the outside (no ripples, dimples, waves, etc.) without sanding through
the part.
 
I have never found the more affordable and available fillers such as sand
and lead to work very well.  The sand doesn't stay where I want it and
lead is prone to cooling with irregularities and air pockets.  As much as I
like Cerrobend, I cannot justify using it that much.  I mainly use pitch.  It
is cheap, provides nearly foolproof support/filling and is easily removed.
However, I must take exception with the suggestion of removing residue by
heating hot enough to burn the pitch.  This anneals the tube, leaving it overly
soft and subject to denting.  I melt the residue out as possible and soak the
tubes in solvent (i.e. trichloroethane 1-1-1) to dissolve the residue.
 
I applaud those who can get the quality my business requires by using sand.
Given that, I am in favor of anyone using sand if it will suit his needs.
 
Regards, Joel Bristor, picky band instrument repairer

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From: [email-masked] (Carla Fong)
Date: 27 Feb 1995 09:48:51 -0800

>Most of the discussions centered on cerrobend, and other compounds.

[snip]

A much more suitable (and cheap) filler for tube bending is ordinary 
table salt.  It's cheap, and when you're done bending the salt can be 
completely removed by a tap water flush. 

Unless you get very dry sand, some of it always seems to stick inside the
tubing. 

-- 
[email-masked]          God has angels to help with her work, 
                             The devil has politicians

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From: [email-masked] (Jeff Sweeney)
Date: Tue, 28 Feb 1995 14:19:24 GMT

In article <[email-masked]>,
Joel Bristor <[email-masked]> wrote:
>I bend thin wall brass tubes for custom work on musical instruments...
>and lead to work very well...
>I mainly use pitch...

Has anyone tried frozen soapy water? Somebody said they saw this on
Mr. Roger's Neighborhood.

-- 
Jeff
[email-masked]

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From: [email-masked] (J. Kimberlin)
Date: 28 Feb 1995 16:47:45 -0800

>Ok, so where do you get pitch?

Should be able to get it in blocks at a roofing store.  That is what the 
tar boys use to put on a tar & Gravel flat roof.  Use an axe or chisel to 
chip off what you need and, for gosh sakes, don't melt it in the kitchen!

JerryK

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From: [email-masked] (Joel Bristor)
Date: Tue, 28 Feb 95 19:50:04 EST

>Mr. Roger's Neighborhood.
 
I can only do a little better than watching Mr. Roger's.  I once visited
the Vincent Bach factory in Elkhart, Indiana and watched them bend the
tail end of trumpet bells while they were filled with a frozen substance.
I dare say there is more to this than soapy water.  I have tried bending tubes
filled with ice and it does not work at all well.  The soft tubing cannot
resist the inside-out dents caused by chards of cracked ice.  They filled
the trumpet bells with a greenish liquid, then placed them flare up, in an
open-air piece of equipment that quickly froze them.  I suppose this may
simply be soapy water frozen to a carefully controlled hardness.  To add
to this argument, they bent the bells a few steps from the freezing
station.
 
Joel Bristor

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From: [email-masked] (Mark Kinsler )
Date: Wed, 1 Mar 1995 16:55:36 GMT

In article <[email-masked]>,

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From: [email-masked] (Barry Workman)
Date: Thu, 2 Mar 1995 08:47:51 GMT

>Ok, so where do you get pitch?

Uh, most props have *LOTSA* pitch. :-)

After that, try your local jewelry supplier.
-- 
    - Barry Workman

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From: [email-masked] (Joel Bristor)
Date: Tue, 28 Feb 95 20:01:08 EST

>Ok, so where do you get pitch?
 
Some purists with whom I have apprenticed over the years would say to mix
your own.  I can't seem to find my notes on the ratio of rosin to tar.
Anyway, I get it from one of the bizaar suppliers of band instrument
repair stuff:
       Allied Supply Corp.
       P.O. Box 288
       Elkhorn, Wisconsin  53121
       (800) 558-3226
       (414) 723-5455
       FAX:
       (800) 800-6189
       (414) 723-2051
 
Item # A884 Pitch    $9.00/gallon
 
Regards, Joel

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From: [email-masked] (Steve Rayner)
Date: Thu, 2 Mar 1995 11:02:14 GMT

>Unless you get very dry sand, some of it always seems to stick inside the
I just fill small diameter tubes with solder, bend, and melt the stuff
out.  If you make a mould from angle iron, you can melt accumulated blobs of
solder from this operation, pour into the mould and use it again.

-- 
                                Steve Rayner.