I will be making a gate for the entrance to a house and will need to
join some thick copper rectangular bar. The 0.5" x 1" 110 copper bar is
for the gate frame and the infill of the gate will mostly be .5" x .5"
square copper rod.

I've successfully fabricated copper grillworks for other gates using my
Thermal Arc 185TSW. The grillworks were a mix .75" x .1875" flat bar
and .1875" round bar and I've been very pleased with how the Thermal
Arc works on copper.

However, I made some copper hinges out of .1875" x 2" sheet and found
that my 185 amp welder is at the very limit of what it can do.

So knowing that my Thermal Arc won't be anywhere near able to handle
the .5" x 1" bar, I was wondering what would be the best way to make
the gate frame?

I have an O/A welding setup with #2 and #3 tips (and a 175 CuFt
Acetylene tank) and was considering pre-heating the metal until it was
red before trying to tig it. I guess another person holding the O/A
torch would be useful?. But even preheating it, I'm afraid that won't
be enough and I doubt I could get close with the tig torch to that much
red hot copper.

I've been experimenting with tig brazing 3/16" copper using silicon
bronze and haven't had very much luck. The bronze has been balling up
-- I didn't have that problem when tig brazing steel.

So would it be best to mitre the joints on the thick bar stock to a 45
degree angle and braze it using O/A? Will my O/A setup be enough to
braze copper this thick? Using coarse thread screws seems problematic
since I doubt soft copper
would hold screws well.

Thanks for any insight. (Yes, I was a fool for getting copper this
thick, but that is what the homeowner wanted and I couldn't find square
copper tubing).

-Aaron

Make that a 75 CuFt acetylene tank... Only reason I mention this is
that I'm not sure I can use a #3 or higher tip with that small of a
tank.

Interesting question. I will be following this one because it seems
impossible. My vision shows forging end cap T's onto the copper.

wrote in message
oups.com...
I will be making a gate for the entrance to a house and will need to
join some thick copper rectangular bar. The 0.5" x 1" 110 copper bar is
for the gate frame and the infill of the gate will mostly be .5" x .5"
square copper rod.

I've successfully fabricated copper grillworks for other gates using my
Thermal Arc 185TSW. The grillworks were a mix .75" x .1875" flat bar
and .1875" round bar and I've been very pleased with how the Thermal
Arc works on copper.

However, I made some copper hinges out of .1875" x 2" sheet and found
that my 185 amp welder is at the very limit of what it can do.

So knowing that my Thermal Arc won't be anywhere near able to handle
the .5" x 1" bar, I was wondering what would be the best way to make
the gate frame?

I have an O/A welding setup with #2 and #3 tips (and a 175 CuFt
Acetylene tank) and was considering pre-heating the metal until it was
red before trying to tig it. I guess another person holding the O/A
torch would be useful?. But even preheating it, I'm afraid that won't
be enough and I doubt I could get close with the tig torch to that much
red hot copper.

I've been experimenting with tig brazing 3/16" copper using silicon
bronze and haven't had very much luck. The bronze has been balling up
-- I didn't have that problem when tig brazing steel.

So would it be best to mitre the joints on the thick bar stock to a 45
degree angle and braze it using O/A? Will my O/A setup be enough to
braze copper this thick? Using coarse thread screws seems problematic
since I doubt soft copper
would hold screws well.

Thanks for any insight. (Yes, I was a fool for getting copper this
thick, but that is what the homeowner wanted and I couldn't find square
copper tubing).

-Aaron

On 20 Oct 2005 14:01:56 -0700, wrote:

I will be making a gate for the entrance to a house and will need to
join some thick copper rectangular bar. The 0.5" x 1" 110 copper bar is
for the gate frame and the infill of the gate will mostly be .5" x .5"
square copper rod.

It might be possible with the TIG if you can insulate and preheat
enough but copper is such a good conductor of heat that it wouldn't be
easy.

As for brazing it's definitely possible if you use the right filler
rod. If this is really copper (and not brass or bronze) then I'd
recommend using Sil-fos, Sil-flux or any of the other trade names for
the 90-95% copper, 5-10%silver, and trace amounts of phosphorus for
fluxing rods. Refrigeration contractors use this rod for joining
copper tubing and it's great for that job. No flux is needed do to the
phosphorus in the rod.

Wayne Cook
Shamrock, TX
http://members.dslextreme.com/users/waynecook/index.htm

Hello Wayne,

Thanks for the suggestions. I really am using 100% copper (Alloy 110).

I already figured out the insulating bit when I made the hinges. When I
was welding the hinges on the metal table, I couldn't get a puddle.
When I put the hinge in a little cave of fire bricks, I was able to get
a puddle.

I can try welding two 1' sections of the bar. However, considering that
copper seems to just suck up the heat, I'm not sure it would be a good
test considering that I'll actually be joining a 4' length to a 6'
length.

I like the end cap idea, but not sure how I would fabricate those. I
can always screw on gussetts to the bottom since there will be a copper
panel on the lower portion of the gate that would hide the gussets.
However, gussets on top would be ugly.

When/if I finish this, is this the kind of thing people would like to
see in the drop box?

On 20 Oct 2005 14:01:56 -0700, wrote:

I will be making a gate for the entrance to a house and will need to
join some thick copper rectangular bar. The 0.5" x 1" 110 copper bar is
for the gate frame and the infill of the gate will mostly be .5" x .5"
square copper rod.

I've successfully fabricated copper grillworks for other gates using my
Thermal Arc 185TSW. The grillworks were a mix .75" x .1875" flat bar
and .1875" round bar and I've been very pleased with how the Thermal
Arc works on copper.

However, I made some copper hinges out of .1875" x 2" sheet and found
that my 185 amp welder is at the very limit of what it can do.

So knowing that my Thermal Arc won't be anywhere near able to handle
the .5" x 1" bar, I was wondering what would be the best way to make
the gate frame?

I have an O/A welding setup with #2 and #3 tips (and a 175 CuFt
Acetylene tank) and was considering pre-heating the metal until it was
red before trying to tig it. I guess another person holding the O/A
torch would be useful?. But even preheating it, I'm afraid that won't
be enough and I doubt I could get close with the tig torch to that much
red hot copper.

I've been experimenting with tig brazing 3/16" copper using silicon
bronze and haven't had very much luck. The bronze has been balling up
-- I didn't have that problem when tig brazing steel.

So would it be best to mitre the joints on the thick bar stock to a 45
degree angle and braze it using O/A? Will my O/A setup be enough to
braze copper this thick? Using coarse thread screws seems problematic
since I doubt soft copper
would hold screws well.

Thanks for any insight. (Yes, I was a fool for getting copper this
thick, but that is what the homeowner wanted and I couldn't find square
copper tubing).

Copper melts at about 1984F, somewhat lower than steel. The problem
with copper is it's high thermal conductivity, which results in the
whole mass sucking heat away from the weld and conveying it by
radiation and convection to the environment.

Perhaps if you wrapped the bar in ceramic blanket, just leaving a
narrow region open for access to the actual weld site, you could
reduce the heat loss enough to get a good puddle going. It might
take a while for the TIG to heat up the thermal mass of the whole bar,
but it'll eventually get there if the blanket reduces the heatloss
rate to less than the heat output of the welder. The blanket would
also shield you from a large bar glowing within. If you run into
duty cycle limitation on the welder, you could preheat with O/A, with
blanket in place to limit heatloss rate. Might take awhile, but a
75 cu ft acetylene tank has a fairly long duty cycle...

but I figure that 4400 watts (185 amps x 24 volts) will heat up a .5"
x 1" x 10" copper bar to near melting in about 64 seconds if there is
no heat loss. The blanket won't eliminate heat loss, but it may
reduce it enough to make it almost like welding unblanketed steel. I
used 10", figuring 5" of shielded region on either side of an exposed
1/2" to 1" wide weld zone about the same as 1" of bare steel since
copper is 5X as conductive and assuming metal beyond that distance to
not be much of a factor.
..
Here is a source for small qty of Durablanket S at reasonable cost:
http://www.geocities.com/zoellerforge/flare.html



-Aaron

On 20 Oct 2005 15:30:16 -0700, "
wrote:

Hello Wayne,

Thanks for the suggestions. I really am using 100% copper (Alloy 110).

I already figured out the insulating bit when I made the hinges. When I
was welding the hinges on the metal table, I couldn't get a puddle.
When I put the hinge in a little cave of fire bricks, I was able to get
a puddle.

I can try welding two 1' sections of the bar. However, considering that
copper seems to just suck up the heat, I'm not sure it would be a good
test considering that I'll actually be joining a 4' length to a 6'
length.

I like the end cap idea, but not sure how I would fabricate those. I
can always screw on gussetts to the bottom since there will be a copper
panel on the lower portion of the gate that would hide the gussets.
However, gussets on top would be ugly.

When/if I finish this, is this the kind of thing people would like to
see in the drop box?
I'm no expert, but there was once a time when I had to weld copper. It
was 3/4" thick, 4" wide, and a little over 2 feet long. No way could I
weld it with a 300 amp tig torch. I called the welder who usually did
our fancy stuff and he said a good pre-heat would do it. So, using
fire bricks I was able to fill in the 1/2" deep 1" wide goof in the
part using copper wire as filler. It seems to me that after heating
the bar I covered it with fire brick. I for rested my hand on it while
welding. Even with the preheat I think it took at least 250 amps. And
I may have been using helium. We used helium for some aluminum jobs
and ran the torch DC. The metal had to be real clean but boy, could
you really lay in the rod.
Eric

On 20 Oct 2005 14:01:56 -0700, wrote:

I will be making a gate for the entrance to a house and will need to
join some thick copper rectangular bar.

Piece of cake if you braze it. Damned hard if you weld it, because of
the conductivity.

Are you going to patinate the copper afterwards?

In article 1129847416.285947.302270
@g47g2000cwa.googlegroups.com, says...
Hello Wayne,

Thanks for the suggestions. I really am using 100% copper (Alloy 110).


I'll second Wayne's recommendation of phos/copper brazing.
It's relatively inexpensive and a pretty good color match
for pure copper. I've brazed heavier (though not as long)
sections of copper bus bar than what you're looking at
using oxy-propane.

Ned Simmons

Hi Aaron,

Andy is right. Brazing (not brazed) is the best that you can use. I
suggest you use
AWS - Bag-1 Silver Brazing Alloy CD 45. it would cost $1 in USA.

For more info on How to do Heating and Brazing of Copper with CD 45

http://www.brazing.com/techguide/pro...er_welding.asp


Austri Basinillo (Philippines)

Don Foreman wrote:
but I figure that 4400 watts (185 amps x 24 volts) will heat up a .5"
x 1" x 10" copper bar to near melting in about 64 seconds if there is
no heat loss. The blanket won't eliminate heat loss, but it may
reduce it enough to make it almost like welding unblanketed steel. I
used 10", figuring 5" of shielded region on either side of an exposed
1/2" to 1" wide weld zone about the same as 1" of bare steel since
copper is 5X as conductive and assuming metal beyond that distance to
not be much of a factor.
Most of your comment I generally agree with. But, I think you will need
to blanket much more of the part, out to several FEET on each side.
The thermal conductivity of copper is amazing, and a heat sink several
feet away can prevent you from heating a part to the temperature you
need. I have some experience with soldering and brazing large copper
parts, and it is always amazing how much heat comes out the far end of
the part!

Jon

Do you have a rosebud tip for your oxyacetylene outfit? It generally
works much better that a regular welding tip for preheating. Even if
you gas braze, you could probably preheat with the rosebud, quickly
swap tips, and fire up the actual torch tip. The rosebud that I am
familiar with is an entire section like a cutting torch attachment and
not just a tip, although they may make a tip attachment also.

Xray, you don't have anything constructive to say, so why bother
posting? Why is it material I use to make a gate? The customer likes
they way aged copper looks. And if you bothered to google for copper
gates, you would find that there are plenty of gates made out of
copper.

By the way, the total cost of copper was $400. I just finished a wooden
gate that cost the same amount in materials. Do you go and complain
about people making furniture out of walnut? Or do you believe
everything should be made out of MDF? And as to coating steel with
copper, do you have any great ideas on how to do that in a small shop?

On 21 Oct 2005 08:27:15 -0700, wrote:
Xray, you don't have anything constructive to say, so why bother
posting?

Well, it's usenet, just killfile the people who aren't worth reading.
There'll always be more, but no reason to not keep the signal:noise
ratio as good as you can.

On 20 Oct 2005 15:30:16 -0700, "
wrote:

Hello Wayne,

Thanks for the suggestions. I really am using 100% copper (Alloy 110).

I already figured out the insulating bit when I made the hinges. When I
was welding the hinges on the metal table, I couldn't get a puddle.
When I put the hinge in a little cave of fire bricks, I was able to get
a puddle.


I can try welding two 1' sections of the bar. However, considering that
copper seems to just suck up the heat, I'm not sure it would be a good
test considering that I'll actually be joining a 4' length to a 6'
length.

Your 185 amp TIG might be a bit light for the task at hand. But
don't get in a hurry with preheat. Even insulated, it'll "suck up
the heat" until you have all of the copper within some distance hot --
which will be never if it isn't insulated.

Bulk thermal conductivity of copper is 5X that of steel.
Resistance is resistivity * length / area so a bar of given length
and cross section will have 1/25th the thermal resistance of a
same-size bar of steel. (I missed that first go, Jon). That suggests
(as Jon did) that you'll need to insulate for some length, perhaps the
whole bar. If sufficiently insulated, then the conductivity doesn't
matter. With heat input, the bar will continue to rise in
temperature until heat loss rate = heat input rate. If you
insulate for enough length, then *once preheated* it shouldn't be
appreciably different than welding a same-size bar of steel --
perhaps easier, given the lower melting temp. Once adjacent copper
is hot, its ability to "suck heat" is limited. However, it may
take a while to pour enough heat in to get the part of the bar inside
the blanket hot enough to proceed with welding.

The foregoing assumes that the insulation contains heat considerably
better (25 times better) than a bar exposed to free air. I don't
know if that's a reasonable assumption for an inch or two of ceramic
blanket, but it might be worth a try. As said before, I'd preheat
with O/A or oxypropane (lower temp but more heat) so as not to run
into the dutycycle limit of your welder.

I like the end cap idea, but not sure how I would fabricate those. I
can always screw on gussetts to the bottom since there will be a copper
panel on the lower portion of the gate that would hide the gussets.
However, gussets on top would be ugly.

When/if I finish this, is this the kind of thing people would like to
see in the drop box?

By all means, please do!

wrote in message
oups.com...
Hi Aaron,

Andy is right. Brazing (not brazed) is the best that you can use. I
suggest you use
AWS - Bag-1 Silver Brazing Alloy CD 45. it would cost $1 in USA.

For more info on How to do Heating and Brazing of Copper with CD 45

http://www.brazing.com/techguide/pro...er_welding.asp


Austri Basinillo (Philippines)


I agree also. Brazing is the way to go.

B.H.
http://www.totalprocessservice.com/

I brazed some 0.5 inch round rod, used my oxyacetylene torch. since I
did not have a regular rosebud, I used the cutting tip. It worked. Even
a number 4 welding tip was too small. Copper just sucks the heat away.

By the way, I often TIG weld 0.040 inch copper sheet, usually set the
TIG welder at 90 amps, so it would take lots of current, and probably
preheat, to weld 0.5 inch thick copper.

I like the suggestions for preheat and insulate, but I have no
experience with that approach.

richard


woodworker88 wrote:
Do you have a rosebud tip for your oxyacetylene outfit? It generally
works much better that a regular welding tip for preheating. Even if
you gas braze, you could probably preheat with the rosebud, quickly
swap tips, and fire up the actual torch tip. The rosebud that I am
familiar with is an entire section like a cutting torch attachment and
not just a tip, although they may make a tip attachment also.

Don Foreman wrote:

On 20 Oct 2005 15:30:16 -0700, "
wrote:



Hello Wayne,

Thanks for the suggestions. I really am using 100% copper (Alloy 110).

I already figured out the insulating bit when I made the hinges. When I
was welding the hinges on the metal table, I couldn't get a puddle.
When I put the hinge in a little cave of fire bricks, I was able to get
a puddle.





I can try welding two 1' sections of the bar. However, considering that
copper seems to just suck up the heat, I'm not sure it would be a good
test considering that I'll actually be joining a 4' length to a 6'
length.



Your 185 amp TIG might be a bit light for the task at hand. But
don't get in a hurry with preheat. Even insulated, it'll "suck up
the heat" until you have all of the copper within some distance hot --
which will be never if it isn't insulated.

Bulk thermal conductivity of copper is 5X that of steel.
Resistance is resistivity * length / area so a bar of given length
and cross section will have 1/25th the thermal resistance of a
same-size bar of steel. (I missed that first go, Jon). That suggests
(as Jon did) that you'll need to insulate for some length, perhaps the
whole bar. If sufficiently insulated, then the conductivity doesn't
matter.

This has been bothering me since we started this discussion. I have
this image
in my head of Aaron K. getting this thing half built, and it is going
slower and
slower as the pieces are assembled. Finally he gets to a point where
he's going
to need every Oxy/Acetylene torch in the entire county all at once to do the
preheating! The only other alternative is to do the entire job while
sitting inside
a furnace! That's what furnace brazing is for.

Maybe I'm overstating the heat loss problems here, I don't have a clear
idea how
many cross members there are. If this thing is a square frame with vertical
bars, and no other members, maybe it can be built, but it may not support
its own weight. If this is for a person to pass through, that may not
be much of
a concern. If it is to span a driveway, I really have doubts. Either
way, if it
has a few more horizontal bars of the .5 x 1" size across the middle of
the gate,
it is going to get messy as the joints are brazed and the number of heat
paths
increase.

Jon

You might want to look into MAPP or Propylene. It is a LOT cheaper
than Acetylene. It is sold in moderate-pressure bottles filled with
liquid. So, you get many times more fuel in the same size cylinder,
due to the liquid and the lack of packing needed to keep acetylene safe.
It works great for brazing.

Jon

wrote:

Make that a 75 CuFt acetylene tank... Only reason I mention this is
that I'm not sure I can use a #3 or higher tip with that small of a
tank.

On Fri, 21 Oct 2005 17:18:11 -0500, Jon Elson
wrote:


Your 185 amp TIG might be a bit light for the task at hand. But
don't get in a hurry with preheat. Even insulated, it'll "suck up
the heat" until you have all of the copper within some distance hot --
which will be never if it isn't insulated.

Bulk thermal conductivity of copper is 5X that of steel.
Resistance is resistivity * length / area so a bar of given length
and cross section will have 1/25th the thermal resistance of a
same-size bar of steel. (I missed that first go, Jon). That suggests
(as Jon did) that you'll need to insulate for some length, perhaps the
whole bar. If sufficiently insulated, then the conductivity doesn't
matter.

This has been bothering me since we started this discussion. I have
this image
in my head of Aaron K. getting this thing half built, and it is going
slower and
slower as the pieces are assembled. Finally he gets to a point where
he's going
to need every Oxy/Acetylene torch in the entire county all at once to do the
preheating! The only other alternative is to do the entire job while
sitting inside
a furnace! That's what furnace brazing is for.

Maybe I'm overstating the heat loss problems here, I don't have a clear
idea how
many cross members there are. If this thing is a square frame with vertical
bars, and no other members, maybe it can be built, but it may not support
its own weight. If this is for a person to pass through, that may not
be much of
a concern. If it is to span a driveway, I really have doubts. Either
way, if it
has a few more horizontal bars of the .5 x 1" size across the middle of
the gate,
it is going to get messy as the joints are brazed and the number of heat
paths
increase.

Jon

I agree, if the whole thing were made of heavy stock like that it
would eventually become a humongous radiator. I had the (perhaps
erronious) impression that most of the stock would be considerably
smaller, just the outer frame was the heavy stuff.

I noticed that there are actually phosphor bronze electrodes for SMAW.
According to the datasheet (http://tinyurl.com/dhx5u), these rods could
be used to weld copper. Has anyone used these? In any case, I'm sure I
would have to buy a minimum of 10lb and I don't need that much.

I think I'm going to try brazing, though.

I have some Stay-Silv 56 from another project. Would that be a good
alloy? Or should I use their phosphor copper alloy? I guess one would
use the phosphor copper for better color matching? However, using the
staysilv 56, I would only have to get the copper to 1200F instead of
1400F.

If I braze the copper bars, would a mitre joint be the appropriate
joint? It seems there would be more surface area than a butt joint, but
it still seems like there should be more of a mechanical fitup for
brazing.

I'm beginning to think I got in way over my head on this one. The gate
was supposed to look something like this:


+--------------------------+
| |
| | |
| | |
| | | | |
| | | | |
| | | | | | |
| | | | | | |
| | | | | | | | |
| | | | | | | | |
| | | | | | | | |
| | | | | | | | |
| | | | | | | | |
+--+--+---+---+---+---+--+-+
|**************************|
|**************************|
|**************************|
|**************************|
+--------------------------+

with the bottom portion a copper panel attached with brass rivets. So
there would be three horizontal members and two verticals. The spikes
in the center are .5"x.5".

As far as sagging, I figured if the bottom panel was tightly attached,
it would add some rigidity to the gate.

I could use the copper for some other projects. I'm thinking now that
this project just isn't going to work with the tools I have.

Thanks for all of the insight and help.

-Aaron

On 21 Oct 2005 17:43:16 -0700, wrote:

I noticed that there are actually phosphor bronze electrodes for SMAW.
According to the datasheet (http://tinyurl.com/dhx5u), these rods could
be used to weld copper. Has anyone used these? In any case, I'm sure I
would have to buy a minimum of 10lb and I don't need that much.

I think I'm going to try brazing, though.

I have some Stay-Silv 56 from another project. Would that be a good
alloy? Or should I use their phosphor copper alloy? I guess one would
use the phosphor copper for better color matching? However, using the
staysilv 56, I would only have to get the copper to 1200F instead of
1400F.

If I braze the copper bars, would a mitre joint be the appropriate
joint? It seems there would be more surface area than a butt joint, but
it still seems like there should be more of a mechanical fitup for
brazing.

I think that a lap joint would be the best joint for brazing.
Wayne Cook
Shamrock, TX
http://members.dslextreme.com/users/waynecook/index.htm

wrote:
I'm beginning to think I got in way over my head on this one. The gate
was supposed to look something like this:


+--------------------------+
| |
| | |
| | |
| | | | |
| | | | |
| | | | | | |
| | | | | | |
| | | | | | | | |
| | | | | | | | |
| | | | | | | | |
| | | | | | | | |
| | | | | | | | |
+--+--+---+---+---+---+--+-+
|**************************|
|**************************|
|**************************|
|**************************|
+--------------------------+

with the bottom portion a copper panel attached with brass rivets. So
there would be three horizontal members and two verticals. The spikes
in the center are .5"x.5".

As far as sagging, I figured if the bottom panel was tightly attached,
it would add some rigidity to the gate.

I could use the copper for some other projects. I'm thinking now that
this project just isn't going to work with the tools I have.
Well, I wouldn't give up without at least a test. You say the sheets
will be riveted on. No brazing there at all? Then you'd definitely
want to put that on LAST. So, you are going to have the spikes
unsupported for most of their length? Some delinquents might be
able to bend them and make a total mess of the thing. I guess once
the copper work hardens in the weather, that might be real hard to do,
though. I think a person could do that in the annealed state.

So, these spikes are welded just into the middle crossmember? Or do
they pass through into the bottom horizontal? If the former, I think
maybe you could assemble the spikes to the crossmember, build the
square frame, and then you only have two difficult joints to do.
Those might be possible to do with sufficient heat sources and
insulating blankets. Anyway, you ought to try preheating and then
TIG welding a sample of the material. If it seems a breeze, you
might try to push ahead with it. If the simple test proves a
very difficult job, then you know that it is going to get worse as
the parts are assembled.

Keep us informed, some info on what turns up is always useful when
trying to advise on unusual projects like this.

Jon

I did some brazing a few weeks ago - been a long time - and long re-learning...

It was on copper sheet - 32oz and 64oz - 110 copper - 99.99999% IIRC.
It was a rough go - using lots of oxy on it.
It was copper to copper with bronze filler and a small torch.

What I found was - used some borax type flux that was around the filler -
but what did the trick - paint the area with electronic flux - then braze
on top of it. Get a nice puddle - and naturally alloy - then add the item
that needed to be added. This was while it was hot and fluxed. The white
flux around the filler worked to a lessor extent but worked only in protected
air space - no air flow.

Copper was a pain in the neck. I did the exact same thing with the sheet of steel
and the add on part still copper pipe. Beautiful flowing glob - and adding the
copper, it froze the top, but adding heat, it flowed around both nicely.

I think the real trick is this : Must get the brazing material to whet on the
surface and flow. Once it is on one then the other is the job.

Might be best to do two jobs and then heat them together.

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


Wayne Cook wrote:
On 21 Oct 2005 17:43:16 -0700, wrote:


I noticed that there are actually phosphor bronze electrodes for SMAW.
According to the datasheet (http://tinyurl.com/dhx5u), these rods could
be used to weld copper. Has anyone used these? In any case, I'm sure I
would have to buy a minimum of 10lb and I don't need that much.

I think I'm going to try brazing, though.

I have some Stay-Silv 56 from another project. Would that be a good
alloy? Or should I use their phosphor copper alloy? I guess one would
use the phosphor copper for better color matching? However, using the
staysilv 56, I would only have to get the copper to 1200F instead of
1400F.

If I braze the copper bars, would a mitre joint be the appropriate
joint? It seems there would be more surface area than a butt joint, but
it still seems like there should be more of a mechanical fitup for
brazing.


I think that a lap joint would be the best joint for brazing.
Wayne Cook
Shamrock, TX
http://members.dslextreme.com/users/waynecook/index.htm

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On Fri, 21 Oct 2005 23:37:23 -0500, Jon Elson
wrote:




Keep us informed, some info on what turns up is always useful when
trying to advise on unusual projects like this.

Jon

Yeah, I'm curious too. If I had some chunks of copper I'd have tried
it -- have the blanket and TIG, but no copper.

I would not give up without thinking about it a little more. I know
you have the design already done and approved, but do the spikes have
to be square?

I am thinking 1/2 inch copper pipe with 1/2 inch steel rod inside for
the spikes. And a pointy copper arrow head added to the top
afterwards. If it really has to be square, then make a tapered steel
piece and pull it through either 1/2 or 3/4 copper pipe. Obviously
this will take some experimentation. But I think it could be done.
Start with copper pipe that is longer than you need and braze on at one
end something to hold it. Use 1/4 inch steel cable and a come-a-long
to do the pulling. You may have to make several square tapered steel
pieces of increasing size and anneal the copper pipe after each pass.
And of course use lube. I can see you now doing this between two
trees.

If you can make square copper tubing, then you can use two of them
brazed together ( or welded ) to make your 1/2 by 1 rectangular bit.
Or if you can use rounded pieces then two copper pipes side by side or
spaced so the " spikes can fit between.

Whitman college in Walla Walla, WA has some gates made of copper pipe
that are attractive. As I remember they are of quite a bit bigger pipe
and so probably don't have the steel inside.


Dan

" wrote:
....
I am thinking 1/2 inch copper pipe with 1/2 inch steel rod inside for
the spikes.
....
If it really has to be square, then make a tapered steel
piece and pull it through either 1/2 or 3/4 copper pipe. Obviously
this will take some experimentation. But I think it could be done.
Start with copper pipe that is longer than you need and braze on at one
end something to hold it. Use 1/4 inch steel cable and a come-a-long
to do the pulling. You may have to make several square tapered steel
pieces of increasing size and anneal the copper pipe after each pass.
....

I think pulling the pipe through two sets of rollers (one set
vertical, one set horizontal) would work better than using the
interior square mandrels you suggest.

I don't have a good size chart handy for copper pipe, but
imagine that 1/2" type M copper pipe is 0.625" OD and 0.569"
ID. So the inner periphery would be 1.788", and the outer
1.963", which would give an inner width of 0.447" and outside
width of 0.491". Half-inch rod wouldn't fit inside, but 7/16"
would. Or perhaps use 4 sets of rollers angled at 45 degree
intervals, and roll an octagonal shape with .5" steel rod
already inside.

-jiw

Last night I did a little experimenting. 3/4 inch copper pipe will
square up to fit over 1/2 inch square steel tubing. I just beveled the
end of a piece of 1/2 square tubing. Annealed the copper by heating it
dull red and then after it cooled used a dead blow mallet to square it
a bit as I pushed the steel tubing inside.
I only did a short piece, but it was pretty easy.

I agree rollers would be the ticket, but not sure it would be worth the
trouble for less than 100 feet of squared up pipe.

Dan

So say I wanted to squaring a 4 foot section of pipe, what would be the
best way to heat the entire section? Hmmm, I guess annealing 1'
sections and then welding them together would be doable, although time
consuming.

I just got off the phone with Weld Mold. They make SMAW electrodes for
tough pitch copper and their technical person seems to think it would
be fairly easy to weld the copper bar using their 4333 electrode with a
pre-heat of around 500 degrees.

So if brazing doesn't work, I might just try their rod. I'm feeling
pretty confident that I can get this all worked out. I'll probably
start working on this project in the next two weeks and will give a
status report then.

To anneal copper you just heat it to dull red and let it cool or quench
it. The rate of cooling makes no difference. The only way to harden
copper is to work harden it.

So I would anneal the whole length of pipe.
You don't have to get it all red hot at the same time. Just start at
one end and get that red hot and work your way down the pipe. As you
square it, the copper will be work hardend. But only the part that you
have done something to work harden it.

Using a mallet works, but the square copper tubing shows that it was
hand done. It does not have factory looking flatness. Could be a good
thing or a bad thing. Depends on the look you are trying to achieve.

Stop by Home Depot, Lowes or wherever and get a ten foot length of 3/4
copper pipe and try a couple of experiments. Copper pipe is not too
expensive.

Dan