On Monday, July 29, 1996 1:00:00 AM UTC-6, Jerzy S. Krasinski wrote:
writes:

Has anyone constructed a homemade induction brazing coil powered from
a salvaged home microwave oven? I think the usual oven is rated around
1000 watts, so it should provide enough power for a small coil, say maybe
1-inch inside diameter. I want to join brass to 1/8-inch O-1 drill rod and make
a nice clean joint without any surplus squirting out the edges. I've used
paste of silver/flux and also stick silver solder with a propane torch, but
haven't developed the skills to make a perfect joint. According to the
AWS, for a tubular type joint, the space allowed for the filler metal should
be around 0.002 to 0.005 inches. Any comments will be welcome. Dave

Good day Dave

I have seen spot welders made from MOTs. A nice one on youtube is from the "King of Random." It looks nice and works well. I am planning to run two MOTs in parallel on 240 volts for higher power and faster welding time. Please be careful when messing around with MOTs. The high voltage side can cause nasty burns or even kill you.

Have fun and be safe.

On 10/17/2014 11:16 AM, wrote:

I have seen spot welders made from MOTs. A nice one on youtube is from the "King of Random." It looks nice and works well. I am planning to run two MOTs in parallel on 240 volts for higher power and faster welding time. Please be careful when messing around with MOTs. The high voltage side can cause nasty burns or even kill you.

My MOT spotwelder:

http://www.mwdropbox.com/dropbox/MOT...rPrintable.pdf

On Fri, 17 Oct 2014 19:21:49 -0400, Bob Engelhardt
wrote:

On 10/17/2014 11:16 AM, wrote:

I have seen spot welders made from MOTs. A nice one on youtube is from the "King of Random." It looks nice and works well. I am planning to run two MOTs in parallel on 240 volts for higher power and faster welding time. Please be careful when messing around with MOTs. The high voltage side can cause nasty burns or even kill you.

My MOT spotwelder:

http://www.mwdropbox.com/dropbox/MOT...rPrintable.pdf


NICELY DONE!! Bravo!!

Saved for a project later this winter!!

Gunner, who gave away a American 45KVA spot welder 6 months
ago...didnt have enough power to run it (included chiller)




"At the core of liberalism is the spoiled child,
miserable, as all spoiled children are, unsatisfied,
demanding, ill-disciplined, despotic and useless.
Liberalism is a philosophy of sniveling brats."
PJ O'Rourke

Bob Engelhardt wrote in
:

On 10/17/2014 11:16 AM, wrote:

I have seen spot welders made from MOTs. A nice one on youtube is
from the "King of Random." It looks nice and works well. I am
planning to run two MOTs in parallel on 240 volts for higher power
and faster welding time. Please be careful when messing around with
MOTs. The high voltage side can cause nasty burns or even kill you.

My MOT spotwelder:

http://www.mwdropbox.com/dropbox/MOT...rPrintable.pdf

There's an easier way to build one of these provided the transformers are
very similar. Line up the transformers so you can see straight through
the apertures the seconaries were removed from and use a one turn winding
through both cores, which can simply be a U shaped piece of aluminium or
copper. This puts the secondaries in series so they no longer need to be
two turn. If the output voltage is negligable, one of the primaries
needs to be reversed.

I would suggest varnish soaked cartridge paper as insulation where the
winding goes through each core. Paint alone is a bit risky on the
corners.


--
Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
[at]=@, [dash]=- & [dot]=. *Warning* HTML & 32K emails -- NUL

On 10/17/2014 7:21 PM, Bob Engelhardt wrote:
On 10/17/2014 11:16 AM, wrote:

I have seen spot welders made from MOTs. A nice one on youtube is from
the "King of Random." It looks nice and works well. I am planning to
run two MOTs in parallel on 240 volts for higher power and faster
welding time. Please be careful when messing around with MOTs. The
high voltage side can cause nasty burns or even kill you.

My MOT spotwelder:

http://www.mwdropbox.com/dropbox/MOT...rPrintable.pdf


Brilliant! (just watched a Harry Potter movie)

My MOT spotwelder:
http://www.mwdropbox.com/dropbox/MOT...rPrintable.pdf

Very nicely done.

A long time ago, I worked in a shop where the products were housed in deep-drawn steel cans. The covers were soldered in place with a big soldering iron. To open them for repairs, they were clamped between carbon blocks connected to a rather huge filament transformer.

I was wondering whether a similar setup could work for the OP, with the MOT clamped to the assembly near the braze area. Resistance, rather than induction heating.

On 10/20/2014 9:35 AM, rangerssuck wrote:

My MOT spotwelder:
http://www.mwdropbox.com/dropbox/MOT...rPrintable.pdf

Very nicely done.

A long time ago, I worked in a shop where the products were housed in deep-drawn steel cans. The covers were soldered in place with a big soldering iron. To open them for repairs, they were clamped between carbon blocks connected to a rather huge filament transformer.

I was wondering whether a similar setup could work for the OP, with the MOT clamped to the assembly near the braze area. Resistance, rather than induction heating.

Nice Job.
I built a single transformer 120V one for welding battery tabs.
Repeatability was horrible until I implemented a cycle counter
that turned on the SSR synchronously at zero crossing and did full
multiple cycles of AC. Solved the core saturation issues too.
Takes about six cycles to weld a battery tab.

On Friday, October 17, 2014 11:16:54 AM UTC-4, wrote:
On Monday, July 29, 1996 1:00:00 AM UTC-6, Jerzy S. Krasinski wrote:
writes:

Has anyone constructed a homemade induction brazing coil powered from
a salvaged home microwave oven? I think the usual oven is rated around
1000 watts, so it should provide enough power for a small coil, say maybe
1-inch inside diameter. I want to join brass to 1/8-inch O-1 drill rod and make
a nice clean joint without any surplus squirting out the edges. I've used
paste of silver/flux and also stick silver solder with a propane torch, but
haven't developed the skills to make a perfect joint. According to the
AWS, for a tubular type joint, the space allowed for the filler metal should
be around 0.002 to 0.005 inches. Any comments will be welcome. Dave

Good day Dave

I have seen spot welders made from MOTs. A nice one on youtube is from the "King of Random." It looks nice and works well. I am planning to run two MOTs in parallel on 240 volts for higher power and faster welding time. Please be careful when messing around with MOTs. The high voltage side can cause nasty burns or even kill you.

Have fun and be safe.

I wouldn't say all that about welding, because remember, the act of welding is emitting microwaves. So you are cooking yourself while you are welding..

As a result, welding can cause skin diseases and even cancer if you don't have the right wear (or exposure).

On Thu, 23 Oct 2014 11:27:19 -0700 (PDT), wrote:

On Friday, October 17, 2014 11:16:54 AM UTC-4, wrote:
On Monday, July 29, 1996 1:00:00 AM UTC-6, Jerzy S. Krasinski wrote:
writes:

Has anyone constructed a homemade induction brazing coil powered from
a salvaged home microwave oven? I think the usual oven is rated around
1000 watts, so it should provide enough power for a small coil, say maybe
1-inch inside diameter. I want to join brass to 1/8-inch O-1 drill rod and make
a nice clean joint without any surplus squirting out the edges. I've used
paste of silver/flux and also stick silver solder with a propane torch, but
haven't developed the skills to make a perfect joint. According to the
AWS, for a tubular type joint, the space allowed for the filler metal should
be around 0.002 to 0.005 inches. Any comments will be welcome. Dave

Good day Dave

I have seen spot welders made from MOTs. A nice one on youtube is from the "King of Random." It looks nice and works well. I am planning to run two MOTs in parallel on 240 volts for higher power and faster welding time. Please be careful when messing around with MOTs. The high voltage side can cause nasty burns or even kill you.

Have fun and be safe.

I wouldn't say all that about welding, because remember, the act of welding is emitting microwaves. So you are cooking yourself while you are welding.

Welding does not emit microwaves. It emits light in the range of
infrared through ultrviolet C. It can be severely damaging to the eyes
in several ways, but the skin cancer possibility is the same as for
exposure to UV from the sun. It depends on the amount of exposure,
while eye damage can occur almost instantaneiously.


As a result, welding can cause skin diseases and even cancer if you don't have the right wear (or exposure).

--
Ed Huntress

On 10/23/2014 1:38 PM, Ed Huntress wrote:
On Thu, 23 Oct 2014 11:27:19 -0700 (PDT), wrote:

On Friday, October 17, 2014 11:16:54 AM UTC-4, wrote:
On Monday, July 29, 1996 1:00:00 AM UTC-6, Jerzy S. Krasinski wrote:
writes:

Has anyone constructed a homemade induction brazing coil powered from
a salvaged home microwave oven? I think the usual oven is rated around
1000 watts, so it should provide enough power for a small coil, say maybe
1-inch inside diameter. I want to join brass to 1/8-inch O-1 drill rod and make
a nice clean joint without any surplus squirting out the edges. I've used
paste of silver/flux and also stick silver solder with a propane torch, but
haven't developed the skills to make a perfect joint. According to the
AWS, for a tubular type joint, the space allowed for the filler metal should
be around 0.002 to 0.005 inches. Any comments will be welcome. Dave

Good day Dave

I have seen spot welders made from MOTs. A nice one on youtube is from the "King of Random." It looks nice and works well. I am planning to run two MOTs in parallel on 240 volts for higher power and faster welding time. Please be careful when messing around with MOTs. The high voltage side can cause nasty burns or even kill you.

Have fun and be safe.

I wouldn't say all that about welding, because remember, the act of welding is emitting microwaves. So you are cooking yourself while you are welding.

Welding does not emit microwaves. It emits light in the range of
infrared through ultrviolet C. It can be severely damaging to the eyes
in several ways, but the skin cancer possibility is the same as for
exposure to UV from the sun. It depends on the amount of exposure,
while eye damage can occur almost instantaneiously.

Microwaves (1x10^11) come right after far infrared (1x10^14) in the
electromagnetic spectrum. So I don't think a blanket statement that
welding does not produce microwaves would be perfectly safe.

I doubt that heart pacemakers are worried about IR.

On Thu, 23 Oct 2014 14:05:01 -0500, Richard
wrote:

On 10/23/2014 1:38 PM, Ed Huntress wrote:
On Thu, 23 Oct 2014 11:27:19 -0700 (PDT), wrote:

On Friday, October 17, 2014 11:16:54 AM UTC-4, wrote:
On Monday, July 29, 1996 1:00:00 AM UTC-6, Jerzy S. Krasinski wrote:
writes:

Has anyone constructed a homemade induction brazing coil powered from
a salvaged home microwave oven? I think the usual oven is rated around
1000 watts, so it should provide enough power for a small coil, say maybe
1-inch inside diameter. I want to join brass to 1/8-inch O-1 drill rod and make
a nice clean joint without any surplus squirting out the edges. I've used
paste of silver/flux and also stick silver solder with a propane torch, but
haven't developed the skills to make a perfect joint. According to the
AWS, for a tubular type joint, the space allowed for the filler metal should
be around 0.002 to 0.005 inches. Any comments will be welcome. Dave

Good day Dave

I have seen spot welders made from MOTs. A nice one on youtube is from the "King of Random." It looks nice and works well. I am planning to run two MOTs in parallel on 240 volts for higher power and faster welding time. Please be careful when messing around with MOTs. The high voltage side can cause nasty burns or even kill you.

Have fun and be safe.

I wouldn't say all that about welding, because remember, the act of welding is emitting microwaves. So you are cooking yourself while you are welding.

Welding does not emit microwaves. It emits light in the range of
infrared through ultrviolet C. It can be severely damaging to the eyes
in several ways, but the skin cancer possibility is the same as for
exposure to UV from the sun. It depends on the amount of exposure,
while eye damage can occur almost instantaneiously.

Microwaves (1x10^11) come right after far infrared (1x10^14) in the
electromagnetic spectrum. So I don't think a blanket statement that
welding does not produce microwaves would be perfectly safe.

I doubt that heart pacemakers are worried about IR.

The infrared from normal arc welding tails off to nothing, or nearly
nothing, by around 800 nm. You are not "cooking yourself" when you
weld. Infrared at the deep end can heat your skin, but not
dangerously, unless your nerves are dead and you can't feel it. The
microwaves, if any, are too weak at that point to do anything.

The danger in welding comes from UV B and UV C, with some danger from
the extremely brilliant visible light (possibility of cataracts and
conjunctivitis sp?) The UV produces burns to the eyes -- retinas and
lenses -- and to the skin.

--
Ed Huntress

On Thursday, October 23, 2014 3:24:26 PM UTC-4, Ed Huntress wrote:
On Thu, 23 Oct 2014 14:05:01 -0500, Richard
wrote:

On 10/23/2014 1:38 PM, Ed Huntress wrote:
On Thu, 23 Oct 2014 11:27:19 -0700 (PDT), wrote:

On Friday, October 17, 2014 11:16:54 AM UTC-4, wrote:
On Monday, July 29, 1996 1:00:00 AM UTC-6, Jerzy S. Krasinski wrote:
writes:

Has anyone constructed a homemade induction brazing coil powered from
a salvaged home microwave oven? I think the usual oven is rated around
1000 watts, so it should provide enough power for a small coil, say maybe
1-inch inside diameter. I want to join brass to 1/8-inch O-1 drill rod and make
a nice clean joint without any surplus squirting out the edges. I've used
paste of silver/flux and also stick silver solder with a propane torch, but
haven't developed the skills to make a perfect joint. According to the
AWS, for a tubular type joint, the space allowed for the filler metal should
be around 0.002 to 0.005 inches. Any comments will be welcome. Dave

Good day Dave

I have seen spot welders made from MOTs. A nice one on youtube is from the "King of Random." It looks nice and works well. I am planning to run two MOTs in parallel on 240 volts for higher power and faster welding time. Please be careful when messing around with MOTs. The high voltage side can cause nasty burns or even kill you.

Have fun and be safe.

I wouldn't say all that about welding, because remember, the act of welding is emitting microwaves. So you are cooking yourself while you are welding.

Welding does not emit microwaves. It emits light in the range of
infrared through ultrviolet C. It can be severely damaging to the eyes
in several ways, but the skin cancer possibility is the same as for
exposure to UV from the sun. It depends on the amount of exposure,
while eye damage can occur almost instantaneiously.

Microwaves (1x10^11) come right after far infrared (1x10^14) in the
electromagnetic spectrum. So I don't think a blanket statement that
welding does not produce microwaves would be perfectly safe.

I doubt that heart pacemakers are worried about IR.

The infrared from normal arc welding tails off to nothing, or nearly
nothing, by around 800 nm. You are not "cooking yourself" when you
weld.

"ultraviolet radiation can cook bacteria in a way that slow poisoning with copper might not. "

http://www.rediff.com/news/report/bac/20050530.htm

On 10/23/2014 2:05 PM, Richard wrote:
On 10/23/2014 1:38 PM, Ed Huntress wrote:
On Thu, 23 Oct 2014 11:27:19 -0700 (PDT), wrote:

On Friday, October 17, 2014 11:16:54 AM UTC-4, wrote:
On Monday, July 29, 1996 1:00:00 AM UTC-6, Jerzy S. Krasinski wrote:
writes:

Has anyone constructed a homemade induction brazing coil powered from
a salvaged home microwave oven? I think the usual oven is rated
around
1000 watts, so it should provide enough power for a small coil,
say maybe
1-inch inside diameter. I want to join brass to 1/8-inch O-1
drill rod and make
a nice clean joint without any surplus squirting out the edges.
I've used
paste of silver/flux and also stick silver solder with a propane
torch, but
haven't developed the skills to make a perfect joint. According
to the
AWS, for a tubular type joint, the space allowed for the filler
metal should
be around 0.002 to 0.005 inches. Any comments will be welcome. Dave

Good day Dave

I have seen spot welders made from MOTs. A nice one on youtube is
from the "King of Random." It looks nice and works well. I am
planning to run two MOTs in parallel on 240 volts for higher power
and faster welding time. Please be careful when messing around with
MOTs. The high voltage side can cause nasty burns or even kill you.

Have fun and be safe.

I wouldn't say all that about welding, because remember, the act of
welding is emitting microwaves. So you are cooking yourself while
you are welding.

Welding does not emit microwaves. It emits light in the range of
infrared through ultrviolet C. It can be severely damaging to the eyes
in several ways, but the skin cancer possibility is the same as for
exposure to UV from the sun. It depends on the amount of exposure,
while eye damage can occur almost instantaneiously.

Microwaves (1x10^11) come right after far infrared (1x10^14) in the
electromagnetic spectrum. So I don't think a blanket statement that
welding does not produce microwaves would be perfectly safe.

I doubt that heart pacemakers are worried about IR.
That is 1000 times if those are the correct values of 10^11 vs 10^14.
That is a wide band difference.

Martin

On 10/23/2014 10:38 PM, Martin Eastburn wrote:
On 10/23/2014 2:05 PM, Richard wrote:
On 10/23/2014 1:38 PM, Ed Huntress wrote:
On Thu, 23 Oct 2014 11:27:19 -0700 (PDT), wrote:

On Friday, October 17, 2014 11:16:54 AM UTC-4, wrote:
On Monday, July 29, 1996 1:00:00 AM UTC-6, Jerzy S. Krasinski wrote:
writes:

Has anyone constructed a homemade induction brazing coil powered
from
a salvaged home microwave oven? I think the usual oven is rated
around
1000 watts, so it should provide enough power for a small coil,
say maybe
1-inch inside diameter. I want to join brass to 1/8-inch O-1
drill rod and make
a nice clean joint without any surplus squirting out the edges.
I've used
paste of silver/flux and also stick silver solder with a propane
torch, but
haven't developed the skills to make a perfect joint. According
to the
AWS, for a tubular type joint, the space allowed for the filler
metal should
be around 0.002 to 0.005 inches. Any comments will be welcome. Dave

Good day Dave

I have seen spot welders made from MOTs. A nice one on youtube is
from the "King of Random." It looks nice and works well. I am
planning to run two MOTs in parallel on 240 volts for higher power
and faster welding time. Please be careful when messing around with
MOTs. The high voltage side can cause nasty burns or even kill you.

Have fun and be safe.

I wouldn't say all that about welding, because remember, the act of
welding is emitting microwaves. So you are cooking yourself while
you are welding.

Welding does not emit microwaves. It emits light in the range of
infrared through ultrviolet C. It can be severely damaging to the eyes
in several ways, but the skin cancer possibility is the same as for
exposure to UV from the sun. It depends on the amount of exposure,
while eye damage can occur almost instantaneiously.

Microwaves (1x10^11) come right after far infrared (1x10^14) in the
electromagnetic spectrum. So I don't think a blanket statement that
welding does not produce microwaves would be perfectly safe.

I doubt that heart pacemakers are worried about IR.
That is 1000 times if those are the correct values of 10^11 vs 10^14.
That is a wide band difference.

Martin


They are.

And you have math!

Martin Eastburn fired this volley in
:

That is 1000 times if those are the correct values of 10^11 vs 10^14.
That is a wide band difference.


It doesn't much matter how wide the difference is.

Lacking a tuned tank, any arc (AC or DC or HF modulated) is a "broadband
emitter", radiating RF all the way from SLF (audio) frequencies clear up
to ultra-short wavelength UV. (and maybe beyond).

Some welders have chokes and various tank circuits (generally in the form
of low-pass filters) to help prevent emission through the body of the
unit, but the welding leads always act as antennae.

Of course, any electrical apparatus has "tuning peaks" that tend to
absorb or radiate certain frequencies preferentially over others.
Manufacturers try to make their units suppress radiation in the ranges
where radio communications is done -- with varying degrees of success.

It's generally recommended that people with electrical cardiac or
neurological assistance devices avoid close proximity to arc welders of
any kind.

Lloyd