Hi all,

I tried out some of your recommendations today and welded a couple of
fillets. I took two pieces of 50 mm x 50 mm x 3 mm mild steel angle and
clamped them back to back with about a 25 mm overlap, so that I could
weld a fillet down each side. I know the steel looks rather rusty in the
pictures but I cleaned off as much as I could using a wire cup brush.
The rust really is very superficial.

First I tried the angles RoyJ suggested, together with Brian's idea of
hanging the cable over my shoulder, and made sure I watched the pool
like Grant said. For all the welds I used 3.25 mm 6013 rods, 145 amp
current setting and no weave. My welder is on the end of a long
electricity supply line so I reckon I get more like 120-125 amps.
Anyway, 145 amps is the next setting up from what I would normally use
for a butt weld in 3 mm plate. The first weld had a minor slag inclusion
at the beginning but it's way better than the fillets I was doing
before. Here's a pictu

http://www.mythic-beasts.com/~cdt22/fillet1.jpg

Next I tried using a 6013 rod as a drag rod. I've never tried this
before and only heard of the technique recently. No one ever told me
about it when I started welding, but then I didn't go to any classes - I
just chatted to a few people. Apart from a somewhat messy start I
thought it looked pretty good:

http://www.mythic-beasts.com/~cdt22/fillet2.jpg

Then I turned the angle sections over and reverted to the first
technique. I tried to join three sections of weld together neatly. Again
there's a little slag inclusion at the start, and the restarts could be
a bit neater, but I was pretty pleased with it:

http://www.mythic-beasts.com/~cdt22/fillet3.jpg
http://www.mythic-beasts.com/~cdt22/fillet4.jpg

The second of those pictures shows distortion in the metal, which is
probably the worst problem. Here's another view from the end:

http://www.mythic-beasts.com/~cdt22/fillet5.jpg

The next thing I'm planning to build is a frame to hold the motor and
transformer of a phase convertor. Probably the sections I will use to
build this will have 5 mm walls, so distortion should be less of a
problem. The weld produced by dragging the rod appears to distort the
metal less, but it's smaller and more sharply curved, which might make
it weaker. Which technique would people recommend for building a phase
convertor frame? Any general suggestions for reducing distortion?

My technique looks much improved. I think I was using the wrong angles
and not watching the arc closely enough. Now I reckon I just need to
practice a bit to get rid of those little slag inclusions at the start
of a weld, neaten up my restarts and banish the small patches of
undercut and spatter. Any suggestions?

Thanks very much for the help!

Chris

Nothing wrong with those welds that practice won't cure. 145 amps on
1/8" (3.25mm) rod sounds high, I'd be talking about 110-120 amps. Did
the rod get red hot at the end? If so, too hot.

The standard practice block is nothing more than a 6mm thick chunk of
strap about 50mm x 100mm (or whatever is handy) Run a clean bead down
one edge, chip the slag, inspect, run a second bead next to the first,
chip, inspect, repeat until the whole surface is covered. Do a second,
third, forth, etc layer. When you are done, use a per hacksaw to cut it
across the beads, should have NO slag inclusions. You will not do well
on the first one, it gets better with practice.

When you get that figured out, set the block on it's side, lay beads
horizontally on the vertical surface, etc etc.

Full length welds like you did will warp BADLY. Only cure is to weld
short sections on opposite sides (top/bottom, left/right). You can keep
it from getting as bad by just doing skip welds eg 1" (25mm) welds every
4" (100mm)

Christopher Tidy wrote:
Hi all,

I tried out some of your recommendations today and welded a couple of
fillets. I took two pieces of 50 mm x 50 mm x 3 mm mild steel angle and
clamped them back to back with about a 25 mm overlap, so that I could
weld a fillet down each side. I know the steel looks rather rusty in the
pictures but I cleaned off as much as I could using a wire cup brush.
The rust really is very superficial.

First I tried the angles RoyJ suggested, together with Brian's idea of
hanging the cable over my shoulder, and made sure I watched the pool
like Grant said. For all the welds I used 3.25 mm 6013 rods, 145 amp
current setting and no weave. My welder is on the end of a long
electricity supply line so I reckon I get more like 120-125 amps.
Anyway, 145 amps is the next setting up from what I would normally use
for a butt weld in 3 mm plate. The first weld had a minor slag inclusion
at the beginning but it's way better than the fillets I was doing
before. Here's a pictu

http://www.mythic-beasts.com/~cdt22/fillet1.jpg

Next I tried using a 6013 rod as a drag rod. I've never tried this
before and only heard of the technique recently. No one ever told me
about it when I started welding, but then I didn't go to any classes - I
just chatted to a few people. Apart from a somewhat messy start I
thought it looked pretty good:

http://www.mythic-beasts.com/~cdt22/fillet2.jpg

Then I turned the angle sections over and reverted to the first
technique. I tried to join three sections of weld together neatly. Again
there's a little slag inclusion at the start, and the restarts could be
a bit neater, but I was pretty pleased with it:

http://www.mythic-beasts.com/~cdt22/fillet3.jpg
http://www.mythic-beasts.com/~cdt22/fillet4.jpg

The second of those pictures shows distortion in the metal, which is
probably the worst problem. Here's another view from the end:

http://www.mythic-beasts.com/~cdt22/fillet5.jpg

The next thing I'm planning to build is a frame to hold the motor and
transformer of a phase convertor. Probably the sections I will use to
build this will have 5 mm walls, so distortion should be less of a
problem. The weld produced by dragging the rod appears to distort the
metal less, but it's smaller and more sharply curved, which might make
it weaker. Which technique would people recommend for building a phase
convertor frame? Any general suggestions for reducing distortion?

My technique looks much improved. I think I was using the wrong angles
and not watching the arc closely enough. Now I reckon I just need to
practice a bit to get rid of those little slag inclusions at the start
of a weld, neaten up my restarts and banish the small patches of
undercut and spatter. Any suggestions?

Thanks very much for the help!

Chris

On Mon, 29 Aug 2005 00:28:25 +0000 (UTC), Christopher Tidy
wrote:

(snip)

The next thing I'm planning to build is a frame to hold the motor and
transformer of a phase convertor. Probably the sections I will use to
build this will have 5 mm walls, so distortion should be less of a
problem. The weld produced by dragging the rod appears to distort the
metal less, but it's smaller and more sharply curved, which might make
it weaker. Which technique would people recommend for building a phase
convertor frame? Any general suggestions for reducing distortion?

My technique looks much improved. I think I was using the wrong angles
and not watching the arc closely enough. Now I reckon I just need to
practice a bit to get rid of those little slag inclusions at the start
of a weld, neaten up my restarts and banish the small patches of
undercut and spatter. Any suggestions?

Distortion: tack in several places, then stitch together with
alternating short beads.

General: minor imperfections noted, but your welds look entirely
servicable to me. I'd say start building stuff you want to build.
A little slag inclusion here and there is not gonna make a rack fall
apart.

As Don said, your welds are certainly serviceable. If you are in doubt weld
the angles together for a length of one inch and see how much hammering and
twisting you will have to do to get complete separation.
People mentioned about tacking your assembly first before welding and
avoiding long continuous welds. I suggest that you also avoid over welding.
In many cases you do not need to weld everything up with continuous seams.
A one or two inch weld on such thin material will take a considerable of
load,
Randy

"Christopher Tidy" wrote in message
...
Hi all,

I tried out some of your recommendations today and welded a couple of
fillets. I took two pieces of 50 mm x 50 mm x 3 mm mild steel angle and
clamped them back to back with about a 25 mm overlap, so that I could
weld a fillet down each side. I know the steel looks rather rusty in the
pictures but I cleaned off as much as I could using a wire cup brush.
The rust really is very superficial.

snip

My technique looks much improved. I think I was using the wrong angles
and not watching the arc closely enough. Now I reckon I just need to
practice a bit to get rid of those little slag inclusions at the start
of a weld, neaten up my restarts and banish the small patches of
undercut and spatter. Any suggestions?

Thanks very much for the help!

Chris

On Mon, 29 Aug 2005 03:59:50 GMT, Ignoramus5361
wrote:

From a person 100% ignorant about welding, I must say that your welds
look extremely nice. I would try cutting your piece with a chop saw
to analyze penetration of the weld. Picture

http://www.mythic-beasts.com/~cdt22/fillet5.jpg

makes me wonder just how deep the penetration really was. Depth of
penetration seems to be important in more than just one human
endeavour!

i

I think that depth of penetration is far less important than it is
often made out to be. What is important is fused area.

If you welded the end of a rod to a block of steel, would you feel
that the fused region should go halfway down the length of the rod to
be sound? (Of course you wouldn't!)

Width of well-fused area does have some correlation with penetration
with single-pass welds, because puddles are not flat.

However, strength does depend on where metal is located relative to
load moments. Penetration could be important in a filet weld if
welded only on one side, to resist bending moment and avoid stress
concentration. You do want weld metal in regions where the
cross-section will be in tension under load, however it gets placed
there. The simple guidline is therefore that significant
penetration is necessary to have a strong weld. But it depends on the
joint design and how the joint will be loaded.


On Mon, 29 Aug 2005 00:28:25 +0000 (UTC), Christopher Tidy wrote:
Hi all,

I tried out some of your recommendations today and welded a couple of
fillets. I took two pieces of 50 mm x 50 mm x 3 mm mild steel angle and
clamped them back to back with about a 25 mm overlap, so that I could
weld a fillet down each side. I know the steel looks rather rusty in the
pictures but I cleaned off as much as I could using a wire cup brush.
The rust really is very superficial.

First I tried the angles RoyJ suggested, together with Brian's idea of
hanging the cable over my shoulder, and made sure I watched the pool
like Grant said. For all the welds I used 3.25 mm 6013 rods, 145 amp
current setting and no weave. My welder is on the end of a long
electricity supply line so I reckon I get more like 120-125 amps.
Anyway, 145 amps is the next setting up from what I would normally use
for a butt weld in 3 mm plate. The first weld had a minor slag inclusion
at the beginning but it's way better than the fillets I was doing
before. Here's a pictu

http://www.mythic-beasts.com/~cdt22/fillet1.jpg

Next I tried using a 6013 rod as a drag rod. I've never tried this
before and only heard of the technique recently. No one ever told me
about it when I started welding, but then I didn't go to any classes - I
just chatted to a few people. Apart from a somewhat messy start I
thought it looked pretty good:

http://www.mythic-beasts.com/~cdt22/fillet2.jpg

Then I turned the angle sections over and reverted to the first
technique. I tried to join three sections of weld together neatly. Again
there's a little slag inclusion at the start, and the restarts could be
a bit neater, but I was pretty pleased with it:

http://www.mythic-beasts.com/~cdt22/fillet3.jpg
http://www.mythic-beasts.com/~cdt22/fillet4.jpg

The second of those pictures shows distortion in the metal, which is
probably the worst problem. Here's another view from the end:

http://www.mythic-beasts.com/~cdt22/fillet5.jpg

The next thing I'm planning to build is a frame to hold the motor and
transformer of a phase convertor. Probably the sections I will use to
build this will have 5 mm walls, so distortion should be less of a
problem. The weld produced by dragging the rod appears to distort the
metal less, but it's smaller and more sharply curved, which might make
it weaker. Which technique would people recommend for building a phase
convertor frame? Any general suggestions for reducing distortion?

My technique looks much improved. I think I was using the wrong angles
and not watching the arc closely enough. Now I reckon I just need to
practice a bit to get rid of those little slag inclusions at the start
of a weld, neaten up my restarts and banish the small patches of
undercut and spatter. Any suggestions?

Thanks very much for the help!

Chris

On Mon, 29 Aug 2005 13:33:41 GMT, "R. Zimmerman"
wrote:

As Don said, your welds are certainly serviceable. If you are in doubt weld
the angles together for a length of one inch and see how much hammering and
twisting you will have to do to get complete separation.
People mentioned about tacking your assembly first before welding and
avoiding long continuous welds. I suggest that you also avoid over welding.
In many cases you do not need to weld everything up with continuous seams.
A one or two inch weld on such thin material will take a considerable of
load,
Randy

The biggest single mistake the beginning welder (and I Strongly
include myself in that catagory) are what are known as Gorilla Welds.

I can now look back at my early work and cringe in noting that Ive
used what looks like a half box of rod to put something together that
needed a couple 1" welds.

Ive taken to actually looking at how our everyday world is welded
together, exposed joints, pipe fittings etc etc to see how the pros
acomplished things. Fascinating to see exactly how few weldments are
used in building big Stuff

Gunner


"Christopher Tidy" wrote in message
...
Hi all,

I tried out some of your recommendations today and welded a couple of
fillets. I took two pieces of 50 mm x 50 mm x 3 mm mild steel angle and
clamped them back to back with about a 25 mm overlap, so that I could
weld a fillet down each side. I know the steel looks rather rusty in the
pictures but I cleaned off as much as I could using a wire cup brush.
The rust really is very superficial.

snip

My technique looks much improved. I think I was using the wrong angles
and not watching the arc closely enough. Now I reckon I just need to
practice a bit to get rid of those little slag inclusions at the start
of a weld, neaten up my restarts and banish the small patches of
undercut and spatter. Any suggestions?

Thanks very much for the help!

Chris

Gunner wrote:
On Mon, 29 Aug 2005 13:33:41 GMT, "R. Zimmerman"
wrote:


As Don said, your welds are certainly serviceable. If you are in doubt weld
the angles together for a length of one inch and see how much hammering and
twisting you will have to do to get complete separation.
People mentioned about tacking your assembly first before welding and
avoiding long continuous welds. I suggest that you also avoid over welding.
In many cases you do not need to weld everything up with continuous seams.
A one or two inch weld on such thin material will take a considerable of
load,
Randy


The biggest single mistake the beginning welder (and I Strongly
include myself in that catagory) are what are known as Gorilla Welds.

I can now look back at my early work and cringe in noting that Ive
used what looks like a half box of rod to put something together that
needed a couple 1" welds.

Ive taken to actually looking at how our everyday world is welded
together, exposed joints, pipe fittings etc etc to see how the pros
acomplished things. Fascinating to see exactly how few weldments are
used in building big Stuff

I learnt not to weld every possible seam a few years back when I was
building an enclosure to house the control system for my power hacksaw.
I tried welding a seam on the inside of the box and ended up with bad
distortion. I probably do still have a tendency towards "gorilla welds",
though, but I have a couple of objections to intermittent welds.

First is that I've noticed they tend to harbour corrosion. You weld
everything together before you paint your project, then the paint seals
the unwelded sections of the seams. But it doesn't take much flexing or
weathering to open up a gap which moisture can enter. Of course the
joint is unpainted inside and it rusts. You paint over it again and -
damn - the rust shows through again. I hate that!

Second is that I don't like the appearance of intermittent welds if
they're in a very noticeable place. I prefer the appearance of a
continuous, neat bead. When I build an enclosure for my phase convertor
I think I will weld continuous seams, partly to thoroughly seal the
electrical enclosure, and partly to look neat.

Point taken, though: you can overdo it!

Chris

Don Foreman wrote:
On Mon, 29 Aug 2005 03:59:50 GMT, Ignoramus5361
wrote:

From a person 100% ignorant about welding, I must say that your welds

look extremely nice. I would try cutting your piece with a chop saw
to analyze penetration of the weld. Picture

http://www.mythic-beasts.com/~cdt22/fillet5.jpg

makes me wonder just how deep the penetration really was. Depth of
penetration seems to be important in more than just one human
endeavour!

i


I think that depth of penetration is far less important than it is
often made out to be. What is important is fused area.

If you welded the end of a rod to a block of steel, would you feel
that the fused region should go halfway down the length of the rod to
be sound? (Of course you wouldn't!)

Width of well-fused area does have some correlation with penetration
with single-pass welds, because puddles are not flat.

However, strength does depend on where metal is located relative to
load moments. Penetration could be important in a filet weld if
welded only on one side, to resist bending moment and avoid stress
concentration. You do want weld metal in regions where the
cross-section will be in tension under load, however it gets placed
there. The simple guidline is therefore that significant
penetration is necessary to have a strong weld. But it depends on the
joint design and how the joint will be loaded.

I think the penetration is better than it looks in that end-on photo
because I stopped welding just before I reached the end of the seam (in
the past I've managed to blow ugly holes in the metal at the end of a seam).

Out of curiousity, which of my fillets do people think would be
stronger? Here are the pictures again:

http://www.mythic-beasts.com/~cdt22/fillet1.jpg
http://www.mythic-beasts.com/~cdt22/fillet2.jpg

The first was made using RoyJ's suggested technique and the second by
dragging the rod. The first is about twice as wide as the second, and is
concave rather than convex. Instinctively I would guess that the first
is stronger because (i) there's more metal in the weld, and (ii) the
radius of curvature is much larger and therefore the stress
concentrations should be less severe. However, the heat affected zone
around the first weld is also larger, which might weaken it. What do
people think? I'd be interested to hear.

Chris

Christopher Tidy wrote:
Don Foreman wrote:

On Mon, 29 Aug 2005 03:59:50 GMT, Ignoramus5361
wrote:

From a person 100% ignorant about welding, I must say that your welds


look extremely nice. I would try cutting your piece with a chop saw
to analyze penetration of the weld. Picture
http://www.mythic-beasts.com/~cdt22/fillet5.jpg

makes me wonder just how deep the penetration really was. Depth of
penetration seems to be important in more than just one human
endeavour!

i



I think that depth of penetration is far less important than it is
often made out to be. What is important is fused area.
If you welded the end of a rod to a block of steel, would you feel
that the fused region should go halfway down the length of the rod to
be sound? (Of course you wouldn't!)
Width of well-fused area does have some correlation with penetration
with single-pass welds, because puddles are not flat.

However, strength does depend on where metal is located relative to
load moments. Penetration could be important in a filet weld if
welded only on one side, to resist bending moment and avoid stress
concentration. You do want weld metal in regions where the
cross-section will be in tension under load, however it gets placed
there. The simple guidline is therefore that significant
penetration is necessary to have a strong weld. But it depends on the
joint design and how the joint will be loaded.


I think the penetration is better than it looks in that end-on photo
because I stopped welding just before I reached the end of the seam (in
the past I've managed to blow ugly holes in the metal at the end of a
seam).

Out of curiousity, which of my fillets do people think would be
stronger? Here are the pictures again:

http://www.mythic-beasts.com/~cdt22/fillet1.jpg
http://www.mythic-beasts.com/~cdt22/fillet2.jpg

The first was made using RoyJ's suggested technique and the second by
dragging the rod. The first is about twice as wide as the second, and is
concave rather than convex. Instinctively I would guess that the first
is stronger because (i) there's more metal in the weld, and (ii) the
radius of curvature is much larger and therefore the stress
concentrations should be less severe. However, the heat affected zone
around the first weld is also larger, which might weaken it. What do
people think? I'd be interested to hear.

Chris


I believe your second weld will be not only stronger, but substantially so.

I can't believe you're going to fabricate an enclosure box for a phase
converter. I think the last one I used I paid like $18 for. Of course, I'm
getting ready to make a welding rod oven, and lacking sheet metal skills
entirely, I'll probably weld it up, sigh. You won't see me using 100% welds,
though. I'll skip weld it together, then fill the cracks with Bondo, sand,
prime, and paint. Then insulate and line. I seriously doubt it'll rust.

GWE

Grant Erwin wrote:
Christopher Tidy wrote:

Don Foreman wrote:

On Mon, 29 Aug 2005 03:59:50 GMT, Ignoramus5361
wrote:

From a person 100% ignorant about welding, I must say that your welds



look extremely nice. I would try cutting your piece with a chop saw
to analyze penetration of the weld. Picture
http://www.mythic-beasts.com/~cdt22/fillet5.jpg

makes me wonder just how deep the penetration really was. Depth of
penetration seems to be important in more than just one human
endeavour!

i




I think that depth of penetration is far less important than it is
often made out to be. What is important is fused area. If you
welded the end of a rod to a block of steel, would you feel
that the fused region should go halfway down the length of the rod to
be sound? (Of course you wouldn't!) Width of well-fused area does
have some correlation with penetration
with single-pass welds, because puddles are not flat.

However, strength does depend on where metal is located relative to
load moments. Penetration could be important in a filet weld if
welded only on one side, to resist bending moment and avoid stress
concentration. You do want weld metal in regions where the
cross-section will be in tension under load, however it gets placed
there. The simple guidline is therefore that significant
penetration is necessary to have a strong weld. But it depends on the
joint design and how the joint will be loaded.



I think the penetration is better than it looks in that end-on photo
because I stopped welding just before I reached the end of the seam
(in the past I've managed to blow ugly holes in the metal at the end
of a seam).

Out of curiousity, which of my fillets do people think would be
stronger? Here are the pictures again:

http://www.mythic-beasts.com/~cdt22/fillet1.jpg
http://www.mythic-beasts.com/~cdt22/fillet2.jpg

The first was made using RoyJ's suggested technique and the second by
dragging the rod. The first is about twice as wide as the second, and
is concave rather than convex. Instinctively I would guess that the
first is stronger because (i) there's more metal in the weld, and (ii)
the radius of curvature is much larger and therefore the stress
concentrations should be less severe. However, the heat affected zone
around the first weld is also larger, which might weaken it. What do
people think? I'd be interested to hear.

Chris


I believe your second weld will be not only stronger, but substantially so.

Is that because the heat affected zone around it is much smaller?

I can't believe you're going to fabricate an enclosure box for a phase
converter. I think the last one I used I paid like $18 for. Of course,
I'm getting ready to make a welding rod oven, and lacking sheet metal
skills entirely, I'll probably weld it up, sigh. You won't see me using
100% welds, though. I'll skip weld it together, then fill the cracks
with Bondo, sand, prime, and paint. Then insulate and line. I seriously
doubt it'll rust.

There are two reasons for fabricating the enclosure. First, I have no
sheet metal working equipment. Second, it needs to support a 240 V -
415 V transformer bolted to the side of it, which weighs 150-200 lbs.

Best wishes,

Chris

Transformer hanging off the side ?
That has to be some strong side.

I'd think about mounting the box on the transformer!
Actually, I'd mount the transformer on the wall - up somewhere
and run wires.

The local Home Depot has a great power panel - about the size of my living room
in length and deeper than normal boxes. Massive pipes run up and down the wall -
so as I was scanning the cat-5 internet link and where the server was :-) I also
spotted their transformers about 2/3 up the high wall. I suppose they didn't want
trucks to steer around them or have low rent people on forklifts to fork them.

The transformer might hum if locked to metal.

Don't know your shop or the actual situation. Think on this one first.
You might have another way.

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



Christopher Tidy wrote:
Grant Erwin wrote:

Christopher Tidy wrote:

Don Foreman wrote:

On Mon, 29 Aug 2005 03:59:50 GMT, Ignoramus5361
wrote:

From a person 100% ignorant about welding, I must say that your welds




look extremely nice. I would try cutting your piece with a chop saw
to analyze penetration of the weld. Picture
http://www.mythic-beasts.com/~cdt22/fillet5.jpg

makes me wonder just how deep the penetration really was. Depth of
penetration seems to be important in more than just one human
endeavour!

i





I think that depth of penetration is far less important than it is
often made out to be. What is important is fused area. If you
welded the end of a rod to a block of steel, would you feel
that the fused region should go halfway down the length of the rod to
be sound? (Of course you wouldn't!) Width of well-fused area does
have some correlation with penetration
with single-pass welds, because puddles are not flat.

However, strength does depend on where metal is located relative to
load moments. Penetration could be important in a filet weld if
welded only on one side, to resist bending moment and avoid stress
concentration. You do want weld metal in regions where the
cross-section will be in tension under load, however it gets placed
there. The simple guidline is therefore that significant
penetration is necessary to have a strong weld. But it depends on the
joint design and how the joint will be loaded.




I think the penetration is better than it looks in that end-on photo
because I stopped welding just before I reached the end of the seam
(in the past I've managed to blow ugly holes in the metal at the end
of a seam).

Out of curiousity, which of my fillets do people think would be
stronger? Here are the pictures again:

http://www.mythic-beasts.com/~cdt22/fillet1.jpg
http://www.mythic-beasts.com/~cdt22/fillet2.jpg

The first was made using RoyJ's suggested technique and the second by
dragging the rod. The first is about twice as wide as the second, and
is concave rather than convex. Instinctively I would guess that the
first is stronger because (i) there's more metal in the weld, and
(ii) the radius of curvature is much larger and therefore the stress
concentrations should be less severe. However, the heat affected zone
around the first weld is also larger, which might weaken it. What do
people think? I'd be interested to hear.

Chris


I believe your second weld will be not only stronger, but
substantially so.


Is that because the heat affected zone around it is much smaller?

I can't believe you're going to fabricate an enclosure box for a phase
converter. I think the last one I used I paid like $18 for. Of course,
I'm getting ready to make a welding rod oven, and lacking sheet metal
skills entirely, I'll probably weld it up, sigh. You won't see me
using 100% welds, though. I'll skip weld it together, then fill the
cracks with Bondo, sand, prime, and paint. Then insulate and line. I
seriously doubt it'll rust.


There are two reasons for fabricating the enclosure. First, I have no
sheet metal working equipment. Second, it needs to support a 240 V -
415 V transformer bolted to the side of it, which weighs 150-200 lbs.

Best wishes,

Chris


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Martin H. Eastburn wrote:
Transformer hanging off the side ?
That has to be some strong side.

I'd think about mounting the box on the transformer!
Actually, I'd mount the transformer on the wall - up somewhere
and run wires.

The local Home Depot has a great power panel - about the size of my
living room
in length and deeper than normal boxes. Massive pipes run up and down
the wall -
so as I was scanning the cat-5 internet link and where the server was
:-) I also
spotted their transformers about 2/3 up the high wall. I suppose they
didn't want
trucks to steer around them or have low rent people on forklifts to fork
them.

The transformer might hum if locked to metal.

Don't know your shop or the actual situation. Think on this one first.
You might have another way.

I want to build the phase convertor on a trolley, so I'd rather not
mount the transformer on the wall. It is, however, built for wall
mounting so the brackets are on the back. The neatest way to mount the
transformer would be to bolt it to the control box, and if I'm going to
fabricate the box it shouldn't be hard to make it strong enough.
Nevertheless, I plan on wiring the phase convertor up before I build a
trolley, so that I can test its performance. At this stage I can see how
much the transformer vibrates.

Chris

I think the drag rod weld is a better weld for a couple of reasons: Less
weld (and less heat) and more uniform. The uniformity comes from not
having to maninuplate the rod. The smaller weld comes from being forced
to run donw the weld line much faster. Your first weld would look the
same if you had the practice and dexterity to get a clean weld. As it
is, you are spending a lot of weld puddle time pasting weld all over the
place.

Drag rod technique is OK to get the idea but it does not work with all
rod types. Try to learn to manipulate the rod to do the same thing.

Christopher Tidy wrote:

Don Foreman wrote:

On Mon, 29 Aug 2005 03:59:50 GMT, Ignoramus5361
wrote:

From a person 100% ignorant about welding, I must say that your welds


look extremely nice. I would try cutting your piece with a chop saw
to analyze penetration of the weld. Picture
http://www.mythic-beasts.com/~cdt22/fillet5.jpg

makes me wonder just how deep the penetration really was. Depth of
penetration seems to be important in more than just one human
endeavour!

i



I think that depth of penetration is far less important than it is
often made out to be. What is important is fused area.
If you welded the end of a rod to a block of steel, would you feel
that the fused region should go halfway down the length of the rod to
be sound? (Of course you wouldn't!)
Width of well-fused area does have some correlation with penetration
with single-pass welds, because puddles are not flat.

However, strength does depend on where metal is located relative to
load moments. Penetration could be important in a filet weld if
welded only on one side, to resist bending moment and avoid stress
concentration. You do want weld metal in regions where the
cross-section will be in tension under load, however it gets placed
there. The simple guidline is therefore that significant
penetration is necessary to have a strong weld. But it depends on the
joint design and how the joint will be loaded.


I think the penetration is better than it looks in that end-on photo
because I stopped welding just before I reached the end of the seam (in
the past I've managed to blow ugly holes in the metal at the end of a
seam).

Out of curiousity, which of my fillets do people think would be
stronger? Here are the pictures again:

http://www.mythic-beasts.com/~cdt22/fillet1.jpg
http://www.mythic-beasts.com/~cdt22/fillet2.jpg

The first was made using RoyJ's suggested technique and the second by
dragging the rod. The first is about twice as wide as the second, and is
concave rather than convex. Instinctively I would guess that the first
is stronger because (i) there's more metal in the weld, and (ii) the
radius of curvature is much larger and therefore the stress
concentrations should be less severe. However, the heat affected zone
around the first weld is also larger, which might weaken it. What do
people think? I'd be interested to hear.

Chris

RoyJ wrote:
I think the drag rod weld is a better weld for a couple of reasons: Less
weld (and less heat) and more uniform. The uniformity comes from not
having to maninuplate the rod. The smaller weld comes from being forced
to run donw the weld line much faster. Your first weld would look the
same if you had the practice and dexterity to get a clean weld. As it
is, you are spending a lot of weld puddle time pasting weld all over the
place.

Drag rod technique is OK to get the idea but it does not work with all
rod types. Try to learn to manipulate the rod to do the same thing.

To manipulate the rod and get a bead as tight and small as that sounds
like a tough challenge. I'll have a go, though...

Don't the very sharp corners in the drag rod weld weaken it at all?

Chris

Christopher Tidy wrote:

http://www.mythic-beasts.com/~cdt22/fillet1.jpg
http://www.mythic-beasts.com/~cdt22/fillet2.jpg


I believe your second weld will be not only stronger, but
substantially so.

No, it's because of the evenness and correctness of the second bead. The first
bead, being thicker then thinner then thicker then thinner, is much weaker where
it's thinner. The second bead wastes no metal and I believe is simply more
efficient at distributing forces, and thus stronger.

Is that because the heat affected zone around it is much smaller?

I can't believe you're going to fabricate an enclosure box for a phase
converter. I think the last one I used I paid like $18 for. Of course,
I'm getting ready to make a welding rod oven, and lacking sheet metal
skills entirely, I'll probably weld it up, sigh. You won't see me
using 100% welds, though. I'll skip weld it together, then fill the
cracks with Bondo, sand, prime, and paint. Then insulate and line. I
seriously doubt it'll rust.


There are two reasons for fabricating the enclosure. First, I have no
sheet metal working equipment. Second, it needs to support a 240 V -
415 V transformer bolted to the side of it, which weighs 150-200 lbs.


Why not make a simple frame from a discarded (free) bed frame, and bolt a
purchased enclosure *and* your transformer to it?

GWE

On Tue, 30 Aug 2005 03:53:24 +0000 (UTC), Christopher Tidy
wrote:

Martin H. Eastburn wrote:
Transformer hanging off the side ?
That has to be some strong side.

I'd think about mounting the box on the transformer!
Actually, I'd mount the transformer on the wall - up somewhere
and run wires.

The local Home Depot has a great power panel - about the size of my
living room
in length and deeper than normal boxes. Massive pipes run up and down
the wall -
so as I was scanning the cat-5 internet link and where the server was
:-) I also
spotted their transformers about 2/3 up the high wall. I suppose they
didn't want
trucks to steer around them or have low rent people on forklifts to fork
them.

The transformer might hum if locked to metal.

Don't know your shop or the actual situation. Think on this one first.
You might have another way.

I want to build the phase convertor on a trolley, so I'd rather not
mount the transformer on the wall. It is, however, built for wall
mounting so the brackets are on the back. The neatest way to mount the
transformer would be to bolt it to the control box, and if I'm going to
fabricate the box it shouldn't be hard to make it strong enough.
Nevertheless, I plan on wiring the phase convertor up before I build a
trolley, so that I can test its performance. At this stage I can see how
much the transformer vibrates.

Chris

I've hung a lot of transformers on boxes for the same reason (powering
carts on wheels), but the approach I've used is to design a or buy a
standard box (14 ga. I think), and weld a 1/2" thick plate drilled and
tapped to the transformer mounting pattern on either the rear or side
of the box.

By the way, I always add a structure ground to my rigs. Since they
are mostly 480 V. 3 ph., I usually use green jacketed 2/0 welding
cable, lugged and bolted on the frame and an appropriate building
ground. Where I run a lot of carts I either bolt to wiring duct where
it's rated for the fault currents, or a separate copper bus. The
welding cable is more flexible than normal cable.

Pete Keillor

I think the first weld is the stronger. The answer may depend on which
way the forces are. Since at least two people think the second weld is
stronger,
I would suggest you try to break the welds and let us know who is
right.

I do think that the second weld would be more than adequate especially
since you intend to do a cantinuous weld.

Dan


Christopher Tidy wrote:



Out of curiousity, which of my fillets do people think would be
stronger? Here are the pictures again:

http://www.mythic-beasts.com/~cdt22/fillet1.jpg
http://www.mythic-beasts.com/~cdt22/fillet2.jpg

I'd restate my comment to say that the second weld is BETTER, since it
is much more compatable with the thickness of the base metal plus it is
much more uniform. The first weld might (or might not) be stronger, but
it is much bigger than is needed.

wrote:

I think the first weld is the stronger. The answer may depend on which
way the forces are. Since at least two people think the second weld is
stronger,
I would suggest you try to break the welds and let us know who is
right.

I do think that the second weld would be more than adequate especially
since you intend to do a cantinuous weld.

Dan


Christopher Tidy wrote:



Out of curiousity, which of my fillets do people think would be
stronger? Here are the pictures again:

http://www.mythic-beasts.com/~cdt22/fillet1.jpg
http://www.mythic-beasts.com/~cdt22/fillet2.jpg