4130 frame?

Steve Thomas wrote:

J,

Thanks for that helpful insight. I will keep it all in mind. Sice I do not
have a TIG machine or experience using one, and I do not have much
experience using a torch to weld with, would it be kosher to tack the pieces
together with a MIG and then have a professional welder finish the process
by using a torch? The local pro that I have used in the past for various
projects gave me the impression that he would rather weld with his a/o torch
than his TIG machine.

--
Have a good one!

Steve

A/O rig will cost as much as a good MIG set, but is a better choice
for welding thin wall 4130.

On the other hand, it's a lot easier to tack with the MIG since it
only takes one hand.

But if you are building a steel tube airframe, you are going to need
a good torch to weld on a thousand little tabs and such.

Either technique will require practice.

Richard

PS: Thank Barnyard for the link to WinMitre.
Very handy little tool there.

Richard.

The basic problem with Mig welders is the inability of the operators to set
them up.
As delivered, most home style 110 mig boxes are set up to use .035 wire.
The idea is to have a box for mild steel, cars trailers shovels etc......
Smaller wire
sizes are available and needed for thin wall applications. Use .023 instead
of .035.
Excuse me slaughtering exactly correct terms here, but the arc intensity is
a
function of the area of the wire. So heat control in BTU/Min is easier with
smaller diameters.
That means that the current carrying capacity of the smaller wire is 66% of
the .035 and
that go's a very long way towards making the job work.

For good fusion, the larger wire needs a btu/sec heat rate that in many
cases exceeds
the base metals "pour point" or the point where id is completely liquid and
flows away
from the weld. Using smaller wire gets the heat rate more in line with the
tubes fusion heat rate.

Scott Correa

"Richard Lamb" wrote in message
...
A/O rig will cost as much as a good MIG set, but is a better choice
for welding thin wall 4130.

On the other hand, it's a lot easier to tack with the MIG since it
only takes one hand.

But if you are building a steel tube airframe, you are going to need
a good torch to weld on a thousand little tabs and such.

Either technique will require practice.

Richard

PS: Thank Barnyard for the link to WinMitre.
Very handy little tool there.

spektr wrote:

Richard.

The basic problem with Mig welders is the inability of the operators to set
them up.
As delivered, most home style 110 mig boxes are set up to use .035 wire.
The idea is to have a box for mild steel, cars trailers shovels etc......
Smaller wire
sizes are available and needed for thin wall applications. Use .023 instead
of .035.
Excuse me slaughtering exactly correct terms here, but the arc intensity is
a
function of the area of the wire. So heat control in BTU/Min is easier with
smaller diameters.
That means that the current carrying capacity of the smaller wire is 66% of
the .035 and
that go's a very long way towards making the job work.

For good fusion, the larger wire needs a btu/sec heat rate that in many
cases exceeds
the base metals "pour point" or the point where id is completely liquid and
flows away
from the weld. Using smaller wire gets the heat rate more in line with the
tubes fusion heat rate.

Scott Correa


Yep.
And there in lies the rub, at least according to the old timers.
That tiny intensly heated bead can lock in strong stresses.
Which suggests post weldeding stress relief (old argument).

With a neutral flame...

I bought a Hobart 135 to build my shop.
Later sold it for more than I paid for it (because it had a
new roll of wire on it at the time and bought my O/A rig
for working on the Tailwind.

Each has merits.
Could probably justify both if you have the pockets.

But I prefer the torch for welding thin wall stuff.

Richard

Richard,

Do you know of a good source for the .023 wire for 4130? Do you use the
normal 75/25 mix for the shielding gas?

--
Have a good one!

Steve
www.americanspiritppc.com
"spektr" wrote in message
...


Richard.

The basic problem with Mig welders is the inability of the operators to
set
them up.
As delivered, most home style 110 mig boxes are set up to use .035 wire.
The idea is to have a box for mild steel, cars trailers shovels etc......
Smaller wire
sizes are available and needed for thin wall applications. Use .023
instead
of .035.
Excuse me slaughtering exactly correct terms here, but the arc intensity
is
a
function of the area of the wire. So heat control in BTU/Min is easier
with
smaller diameters.
That means that the current carrying capacity of the smaller wire is 66%
of
the .035 and
that go's a very long way towards making the job work.

For good fusion, the larger wire needs a btu/sec heat rate that in many
cases exceeds
the base metals "pour point" or the point where id is completely liquid
and
flows away
from the weld. Using smaller wire gets the heat rate more in line with
the
tubes fusion heat rate.

Scott Correa

"Richard Lamb" wrote in message
...
A/O rig will cost as much as a good MIG set, but is a better choice
for welding thin wall 4130.

On the other hand, it's a lot easier to tack with the MIG since it
only takes one hand.

But if you are building a steel tube airframe, you are going to need
a good torch to weld on a thousand little tabs and such.

Either technique will require practice.

Richard

PS: Thank Barnyard for the link to WinMitre.
Very handy little tool there.

On Sun, 24 Aug 2003 14:57:36 GMT, "Steve Thomas"
wrote:

J,

Thanks for that helpful insight. I will keep it all in mind. Sice I do not
have a TIG machine or experience using one, and I do not have much
experience using a torch to weld with, would it be kosher to tack the pieces
together with a MIG and then have a professional welder finish the process
by using a torch? The local pro that I have used in the past for various
projects gave me the impression that he would rather weld with his a/o torch
than his TIG machine.

Steve, you don't need a joint jigger to cut and fit tubes for the
fuselage, and gas welding is something you can learn to do, and do
well. You'll be glad you learned as you can use the knowledge for
many projects.

I tried using the joint jigger and ended up sticking it in a corner
where it's sat for years now. Why? Because it was a pain in the ass
to use and you literally don't need a precision fit when you are
welding. Remember, you aren't gluing the joints, you are melting the
base metal and adding more with a filler rod. You bridge a LOT this
way.

In addition, the welded tube fuselage is an inherently strong
fuselage. Even if you totally botch the welding, because you weld all
the way around the tube, it probably won't matter in your lifetime.

All the tubes are interlocked and welded in this manner. There's just
no where for any slippage to occur, everything is triangulated.

Think about it, aluminum tube fuselages aren't welded, they're fitted
together and held in place with riveted gusset plates. Steel tube
fuselages are just about the strongest fuselage there is.

You can do it yourself, and I think you'll agree that a simple
grinding wheel with a round shaped rough wheel is all you need to fit
the tubes.

Corky Scott

PS, you can dress the grinding wheel to the shape you need yourself
too.

Corky,

I made all of my joints like you mentioned for my mild steel frame and it
worked great. I can het them pretty darn close fitting just using a hole saw
on a drill press and then finishing them off with a 4" grinder. Thanks for
the encouragement.

--
Have a good one!

Steve
www.americanspiritppc.com
"Corky Scott" wrote in message
...
On Sun, 24 Aug 2003 14:57:36 GMT, "Steve Thomas"
wrote:

J,

Thanks for that helpful insight. I will keep it all in mind. Sice I do
not
have a TIG machine or experience using one, and I do not have much
experience using a torch to weld with, would it be kosher to tack the
pieces
together with a MIG and then have a professional welder finish the
process
by using a torch? The local pro that I have used in the past for various
projects gave me the impression that he would rather weld with his a/o
torch
than his TIG machine.

Steve, you don't need a joint jigger to cut and fit tubes for the
fuselage, and gas welding is something you can learn to do, and do
well. You'll be glad you learned as you can use the knowledge for
many projects.

I tried using the joint jigger and ended up sticking it in a corner
where it's sat for years now. Why? Because it was a pain in the ass
to use and you literally don't need a precision fit when you are
welding. Remember, you aren't gluing the joints, you are melting the
base metal and adding more with a filler rod. You bridge a LOT this
way.

In addition, the welded tube fuselage is an inherently strong
fuselage. Even if you totally botch the welding, because you weld all
the way around the tube, it probably won't matter in your lifetime.

All the tubes are interlocked and welded in this manner. There's just
no where for any slippage to occur, everything is triangulated.

Think about it, aluminum tube fuselages aren't welded, they're fitted
together and held in place with riveted gusset plates. Steel tube
fuselages are just about the strongest fuselage there is.

You can do it yourself, and I think you'll agree that a simple
grinding wheel with a round shaped rough wheel is all you need to fit
the tubes.

Corky Scott

PS, you can dress the grinding wheel to the shape you need yourself
too.

Yes, Maule does it every day.


"Steve Thomas" wrote in message
nk.net...
Has anyone on this list ever welded a thinwall 4130 frame with a MIG
welder?

What is a good source of 4130 seamless and welded seam tubing?

Thanks,

--
Have a good one!

Steve
www.americanspiritppc.com

I am just about ready to take the plunge and order in the materials
necessary to duplicate my current airframe out of 4130. Thanks to all of you
guys for the tips and sources. I have one more question. What other metals
are compatable with 4130 when welding? My problem is in locating any angle
in 4130. So far all I have found is seamless tubing and flat stock. My frame
currently uses some angle 1"x1" angle. I would like to stay with using angle
in these locations if possible. So, now this may sound dumb, but can you
weld mild steel or another alloy to 4130 tubing that I can get in angle? Or
better yet, do you know of a source for 4130 angle?

--
Have a good one!

Steve
www.americanspiritppc.com
"log" wrote in message
...
Yes, Maule does it every day.


"Steve Thomas" wrote in message
nk.net...
Has anyone on this list ever welded a thinwall 4130 frame with a MIG
welder?

What is a good source of 4130 seamless and welded seam tubing?

Thanks,

--
Have a good one!

Steve
www.americanspiritppc.com

On Tue, 26 Aug 2003 01:02:50 GMT, "Steve Thomas"
wrote:

I am just about ready to take the plunge and order in the materials
necessary to duplicate my current airframe out of 4130. Thanks to all of you
guys for the tips and sources. I have one more question. What other metals
are compatable with 4130 when welding? My problem is in locating any angle
in 4130. So far all I have found is seamless tubing and flat stock. My frame
currently uses some angle 1"x1" angle. I would like to stay with using angle
in these locations if possible. So, now this may sound dumb, but can you
weld mild steel or another alloy to 4130 tubing that I can get in angle? Or
better yet, do you know of a source for 4130 angle?

You can weld 4130 to mild steel. You can weld many other weldable
alloys to 4130.

Steve.

If you want to use 4130 angls, they are available from lots of
different places. If you don't like the prices, use plates and
weld them up yourself. You can have plate brake bent and
slice out what you need. Lots of ways to get it done,
don't get locked into mixing stuff like 1018 to 4130 because you
are having a tough time thinking it out. Think it out CLEARLY.
Go find yourself an EAA chapter and get a hold of one of
their Tech Counsellors. They are really nice to work with
and usually respond quite favorably to steak and beer.
Proper planning of the task ensures trouble free completion.

Scott Correa


"Steve Thomas" wrote in message
nk.net...
I am just about ready to take the plunge and order in the materials
necessary to duplicate my current airframe out of 4130. Thanks to all of
you
guys for the tips and sources. I have one more question. What other metals
are compatable with 4130 when welding? My problem is in locating any angle
in 4130. So far all I have found is seamless tubing and flat stock. My
frame
currently uses some angle 1"x1" angle. I would like to stay with using
angle
in these locations if possible. So, now this may sound dumb, but can you
weld mild steel or another alloy to 4130 tubing that I can get in angle?
Or
better yet, do you know of a source for 4130 angle?

--
Have a good one!

Steve
www.americanspiritppc.com
"log" wrote in message
...
Yes, Maule does it every day.


"Steve Thomas" wrote in message
nk.net...
Has anyone on this list ever welded a thinwall 4130 frame with a MIG
welder?

What is a good source of 4130 seamless and welded seam tubing?

Thanks,

--
Have a good one!

Steve
www.americanspiritppc.com