Hi

I might have to do that: Weld some (hopefully many) brass cases for RF
shielding.
Now I could do that with OA or a TIG. I would have to lend that TIG (DC
only).

But I have never welded brass before. Neither with OA nor TIG. Is that
difficult (not a welding newbie at all). Can I simply use some brass
rod? Or will the Pb in it (most have) make problems?

The case will be 200 * 100 * 80 mm and 5mm thick. I fear it is more a
heat sink than a piece of cake. How much amps would be enough for TIGing
(if that is the way to go)?


Yes, I will make the prototype it with silver soldering, but I guess it
won't be much fun (regarding the size and the pieces fixing and falling
apart. All that with tight tolerances).


Nick
--
Motor Modelle // Engine Models
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DIY-DRO - YADRO - Eigenbau-Digitalanzeige

On Wed, 14 Dec 2005 12:28:14 +0100, (Nick Müller)
wrote:

But I have never welded brass before.

I can't think why anyone would want to. Brass doesn't like being worked
hot - it's mechanically fragile when hot and the melting point is too
low for comfort, relative to any likely filler rod. Because it has good
conductivity you have to pump plenty of heat in, but get that
temperature just a little too high and you've made a blowhole.

I'd silver solder them instead.

"Nick Müller" wrote in message
...
Hi

I might have to do that: Weld some (hopefully many) brass cases for RF
shielding.
Now I could do that with OA or a TIG. I would have to lend that TIG (DC
only).


If it's only for RF shielding, soft solder would be the way to go. If you
can make them with good sized overlaps on the joints they will be reasonably
strong.

A product called Solder-It now goes into my toolbox and
workbench. Paste hypodermic dispenser, great flux, probably
about 6 percent Silver, very, very strong, easy to use.

MUCH stronger than the wimpy 2 or 3 percent stuff we used to
get at Rat Shack. Seen in many hardware stores... / just my
1.7 cents worth / mark


jtaylor wrote:

"Nick Müller" wrote in message
...

Hi

I might have to do that: Weld some (hopefully many) brass cases for RF
shielding.
Now I could do that with OA or a TIG. I would have to lend that TIG (DC
only).



If it's only for RF shielding, soft solder would be the way to go. If you
can make them with good sized overlaps on the joints they will be reasonably
strong.

I've tried TIG on brass with limited success and went to soft soldering.
Than main issue was not Pb but Zn. When the brass gets hot enough to
melt you tend to get zinc burning out producing white zinc oxide which
is not good. Probably a better place to ask this question is on
sci.engr.joining.welding. It may be possible to TIG it with an
appropriate rod that melts lower than the brass so you are brazing it
rather than welding. I think this question has come up before and Ernie
has responded with useful info.

Nick Müller wrote:

Hi

I might have to do that: Weld some (hopefully many) brass cases for RF
shielding.
Now I could do that with OA or a TIG. I would have to lend that TIG (DC
only).

But I have never welded brass before. Neither with OA nor TIG. Is that
difficult (not a welding newbie at all). Can I simply use some brass
rod? Or will the Pb in it (most have) make problems?

The case will be 200 * 100 * 80 mm and 5mm thick. I fear it is more a
heat sink than a piece of cake. How much amps would be enough for TIGing
(if that is the way to go)?


Yes, I will make the prototype it with silver soldering, but I guess it
won't be much fun (regarding the size and the pieces fixing and falling
apart. All that with tight tolerances).


Nick

"David Billington" wrote in message
.. .
I've tried TIG on brass with limited success and went to soft soldering.
Than main issue was not Pb but Zn. When the brass gets hot enough to melt
you tend to get zinc burning out producing white zinc oxide which is not
good. Probably a better place to ask this question is on
sci.engr.joining.welding. It may be possible to TIG it with an appropriate
rod that melts lower than the brass so you are brazing it rather than
welding. I think this question has come up before and Ernie has responded
with useful info.

Nick Müller wrote:

Hi

I might have to do that: Weld some (hopefully many) brass cases for RF
shielding.
Now I could do that with OA or a TIG. I would have to lend that TIG (DC
only).

But I have never welded brass before. Neither with OA nor TIG. Is that
difficult (not a welding newbie at all). Can I simply use some brass
rod? Or will the Pb in it (most have) make problems?

The case will be 200 * 100 * 80 mm and 5mm thick. I fear it is more a
heat sink than a piece of cake. How much amps would be enough for TIGing
(if that is the way to go)?


Yes, I will make the prototype it with silver soldering, but I guess it
won't be much fun (regarding the size and the pieces fixing and falling
apart. All that with tight tolerances).


Nick



I tried tigging brass several years ago with a brazing rod that I'd sanded
all the flux off of. It didn't work as the zinc cooked out of the rod
making a mess as Mr. Billington noted above. I went to the National Welders
local shop, told them what I was trying to do, and they sold me the correct
rods. Worked just fine after that, but you've really got to turn up the
amps as the brass was very good at conducting the heat away.

Garrett Fulton

Mark wrote:

A product called Solder-It now goes into my toolbox and
workbench. Paste hypodermic dispenser, great flux, probably
about 6 percent Silver, very, very strong, easy to use.

I once used one like this. It was the giggest PITA I ever had. Must have
been a different brand.

I'll shop for that.

I just silver soldered the case. And it was the pain expected. This is
something that cries for a jig and a fan-burner (many little flames, not
just one big).

Nick
--
Motor Modelle // Engine Models
http://www.motor-manufaktur.de
DIY-DRO - YADRO - Eigenbau-Digitalanzeige

Andy Dingley wrote:

Brass doesn't like being worked hot - it's mechanically fragile when hot
and the melting point is too low for comfort, relative to any likely
filler rod.

I tried OA with some scrap. And scrap came out! :-)
I have welded Al with OA. But Al is easy compared to brass.

I'll stay with silver solder, (not soft soldering) because it has to
withstand quite some mechanical load, it is to big and doesn't have
enough overlaps.
Yes, I milled the sides to have a Z-shaped overlap.


Nick
--
Motor Modelle // Engine Models
http://www.motor-manufaktur.de
DIY-DRO - YADRO - Eigenbau-Digitalanzeige

gfulton wrote:

I went to the National Welders
local shop, told them what I was trying to do, and they sold me the correct
rods. Worked just fine after that, but you've really got to turn up the
amps as the brass was very good at conducting the heat away.

Now was this welding or brazing? Did the brass melt (and not just the
rod). I ask, because I found some brass welding rods that are also for
brazing steel.

Yes, the zinc is the problem. I just tried it with OA and both a
reducing and oxidizing flame. But, well, I won't try it again with a
stock brass rod. :-)


Nick
--
Motor Modelle // Engine Models
http://www.motor-manufaktur.de
DIY-DRO - YADRO - Eigenbau-Digitalanzeige

David Billington wrote:
I've tried TIG on brass with limited success and went to soft soldering.
Than main issue was not Pb but Zn. When the brass gets hot enough to
melt you tend to get zinc burning out producing white zinc oxide which
is not good. Probably a better place to ask this question is on
sci.engr.joining.welding. It may be possible to TIG it with an
appropriate rod that melts lower than the brass so you are brazing it
rather than welding. I think this question has come up before and Ernie
has responded with useful info.
I've torch-brazed a few HEAVY brass pieces and had good success with it.
This was a tank with a 1/4" brass bottom and .062 walls. I didn't
have my TIG at the time, but will have to try it the next time such a
job comes up. I have some low-temp brazing rod that melts at a low
enough temp that melting the brass is not a problem.

Jon

For tight tolerances and production, I suspect the best way would be
using furnace silver-brazing with a jig to keep things square and
together. Usually a paste flux with ground braze filler or
silver-braze filler preforms are used. There are books out there on
the subject. If you could find someone that has a pottery kiln, you
could probably prototype things using that. Or use soft solder if you
don't need the strength. It's available as a paste in flux as well.
You might be able to use a kitchen oven for that, depending on what
solder alloy you get.

Stan

wrote:

I suspect the best way would be using furnace silver-brazing with a jig to
keep things square and together.

Yes, I have to agree with the experiences I had today.
A jig is a must. But for the furnace, I have to step back. Would like to
have, can't afford.


Nick
--
Motor Modelle // Engine Models
http://www.motor-manufaktur.de
DIY-DRO - YADRO - Eigenbau-Digitalanzeige

On 14 Dec 2005 14:16:03 -0800, wrote:

If you could find someone that has a pottery kiln, you
could probably prototype things using that.

Don't braze in a pottery kiln. You'll destroy the refractory lining and
you'll annoy the potter. Flux spills eat right through it and fumes
aren't much better.

Nick Müller wrote:

Hi

I might have to do that: Weld some (hopefully many) brass cases for RF
shielding.
Now I could do that with OA or a TIG. I would have to lend that TIG (DC
only).

But I have never welded brass before. Neither with OA nor TIG. Is that
difficult (not a welding newbie at all). Can I simply use some brass
rod? Or will the Pb in it (most have) make problems?

The case will be 200 * 100 * 80 mm and 5mm thick. I fear it is more a
heat sink than a piece of cake. How much amps would be enough for TIGing
(if that is the way to go)?

Yes, I will make the prototype it with silver soldering, but I guess it
won't be much fun (regarding the size and the pieces fixing and falling
apart. All that with tight tolerances).

Nick
--
Motor Modelle // Engine Models
http://www.motor-manufaktur.de
DIY-DRO - YADRO - Eigenbau-Digitalanzeige

Try a carbon arc with a filler rod.

John

Have you ever tried Laser welding? I weld brass all the time with great
success. I have to say that most of what I weld is less than 5mm but,
I'm sure that it can be done. I use regular brass wire for the filler
and it's very strong when done right.

Neill

""Nick Müller"" wrote in message
...
gfulton wrote:

I went to the National Welders
local shop, told them what I was trying to do, and they sold me the
correct
rods. Worked just fine after that, but you've really got to turn up the
amps as the brass was very good at conducting the heat away.

Now was this welding or brazing? Did the brass melt (and not just the
rod). I ask, because I found some brass welding rods that are also for
brazing steel.

Yes, the zinc is the problem. I just tried it with OA and both a
reducing and oxidizing flame. But, well, I won't try it again with a
stock brass rod. :-)


Nick
--
Motor Modelle // Engine Models
http://www.motor-manufaktur.de
DIY-DRO - YADRO - Eigenbau-Digitalanzeige

No, these were rods for welding brass. I was trying to weld up an adapter
fitting so I could put braided steel fuel lines on my old '56 Panhead. The
rods the welding supply gave me just melted straightaway along with the
brass fitting with no more of the smoky zinc mess and contamination. I
ruined the first fitting as it was similar to aluminum in that it was hard
to tell at first when you were putting too much heat to it and it caved in
on me. Just took a little practice, but I finally made a nice weld of it.
Sorry, Nick, but I don't remember the specs on the rods. If you want, I'll
stop at the welding supply place next week and ask those guys.

Garrett Fulton

gfulton wrote:

No, these were rods for welding brass.

Sorry that I asked, but some people can't distinguish between welding
and brazing. You are _NOT_ one of them. :-)


The rods the welding supply gave me just melted straightaway along with
the brass fitting with no more of the smoky zinc mess and contamination.

That sounds very good!


I ruined the first fitting as it was similar to aluminum

I saw that with my quick-hack-test. :-)


Sorry, Nick, but I don't remember the specs on the rods. If you want, I'll
stop at the welding supply place next week and ask those guys.

Thank you for the very kind offer, but I fear I won't get that brand
here in Kraut-land. But I'll stop by at my welding shop and ask for it.
Now I know it exists and I know I can get acceptable results.


Nick
--
Motor Modelle // Engine Models
http://www.motor-manufaktur.de
DIY-DRO - YADRO - Eigenbau-Digitalanzeige

Wonder if a gas box would help - Argon maybe - Not only is the zinc vaporizing,
but oxidizing also ?
Might never beat it. Unless under a heavy layer of flux.

I was able to braze a bronze pipe to a 1/4" copper sheet the size of note book paper.
That took a lot of heat.

I then did the same thing to a sheet of 16ga steel - and brazed a line - within
heavy flux - then added the bronze pipe - and when the bronze rod attached to the
pipe - it flowed into the puddle already on the steel. In a sense - I tinned the steel
with a layer of bronze before trying to put the pipe on.

'tinning' is done in Tin-Lead soldering all of the time. It is useful in other
metal applications as well.

Martin
Martin Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder



Nick Müller wrote:
gfulton wrote:


I went to the National Welders
local shop, told them what I was trying to do, and they sold me the correct
rods. Worked just fine after that, but you've really got to turn up the
amps as the brass was very good at conducting the heat away.


Now was this welding or brazing? Did the brass melt (and not just the
rod). I ask, because I found some brass welding rods that are also for
brazing steel.

Yes, the zinc is the problem. I just tried it with OA and both a
reducing and oxidizing flame. But, well, I won't try it again with a
stock brass rod. :-)


Nick

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Not sure of your exact application, try jigging with castable
refractory. Jewelers do it all the time. The soldering heat for hard or
soft solder can be a transformer soldering machine. Google on American
Beauty, one brand name. Can be homebuilt.
Yes, I will make the prototype it with silver soldering, but I guess it
won't be much fun (regarding the size and the pieces fixing and falling
apart. All that with tight tolerances).


Nick
--
Motor Modelle // Engine Models
http://www.motor-manufaktur.de
DIY-DRO - YADRO - Eigenbau-Digitalanzeige

Not sure of your exact application, try jigging with castable
refractory. Jewelers do it all the time. The soldering heat for hard or
soft solder can be a transformer soldering machine. Google on American
Beauty, one brand name. Can be homebuilt.
Yes, I will make the prototype it with silver soldering, but I guess it
won't be much fun (regarding the size and the pieces fixing and falling
apart. All that with tight tolerances).


Nick
--
Motor Modelle // Engine Models
http://www.motor-manufaktur.de
DIY-DRO - YADRO - Eigenbau-Digitalanzeige

anotherMike wrote:

Google on American Beauty, one brand name. Can be homebuilt.

Is that "American Beauty" the lady on the lower left on this page?
http://www.americanbeautytools.com/

Or is it the resistance soldering on the same page?


Nick
--
Motor Modelle // Engine Models
http://www.motor-manufaktur.de
DIY-DRO - YADRO - Eigenbau-Digitalanzeige