4130 frame?

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 Sat, 23 Aug 2003 01:44:47 GMT, "Steve Thomas"
wrote:

:Has anyone on this list ever welded a thinwall 4130 frame with a MIG welder?

Most aircraft welding is done TIG

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

Dillsberg Aero. They don't have a website, but you'll get their
address if you google them.

Steve Thomas wrote:
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,


I use a Lincoln Weldpak 100 to tack everything together, but the MIG has
a tendency to either not penetrate or blow holes. Very hard to
balance on the line. I just tried TIG, after putting nearly the whole
frame together with oxy/acetylene. I'll stick with the oxy/acetylene,
because the TIG gave me the same results that I got with MIG. Either
not penetrating or blowing holes.

--
----Because I can----
http://www.ernest.isa-geek.org/
------------------------

MIG is not normally recomended for airframe construction but many people do
it. I have TIG and O&A welded and prefer TIG but hard to get into clusters
with the TIG torch. See news:sci.engr.joining.welding for lots of good
(factual) helpfull information.

Jim


"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

Dillsburg in Pa. is the best source that I know of for steel and al..You
can use mig with a lot of practice but you might like o/act.a lot
better.Go to tinman . com for further advise.

A few years back, a manufacturer of 4130 tube frames for a popular high-wing
kit used TIG because of production and training considerations over
oxy/acetylene. They had to call back fuselages because of cracking in the
4130. They modified their approach and used oxy/acetylene to pre-heat and
post-heat the weld. They ended up with nice welds, but why not just train
enough welders to the a real good job with oxy/acetylene?

4130 is very touchy about cracking from too little pre-heat and from too
fast cooling of the weld AND the metal around the joint. It should be
welded in absolutely calm air and the torch flame must be adjusted correctly
to avoid a brittle failure from random hydrogen in the air.

Some of the race car guys who were using 4130 found that they could get very
strong joints (with less high-heat problems)by using a brazing technique
rather than true welding. In fact, the technique seemed to provide better
joints due to difficult clusters and different levels of expertise. There
are some very good brazing alloys out there now with very high PSI ratings.
As with a good 4130 "weld" the joints must be a very good fit (NO gap
filling with the rod) and clean, clean, clean. You can shape various
grinding wheels, or you can use something like the "joint jigger" with high
quality hole saws to form the various "fish mouth" shapes. The best jigs
permit adjustment of the vise angle and the drill angle. The best quality
of the hole saws will do an entire frame before sharpening or replacement is
required.

Finding a full selection of tubing wall/id/od combinations is difficult
today. We ran into a source problem a couple of years ago when we needed to
find some sections that would telescope over an existing tube during some
airframe repair. This was a case where replacing the entire length of the
structural member would have required a re-cover of the fuselage. If you
are working on a definate project and have too much trouble finding the size
you need from one of the three aircraft suppliers that still stock a decent
selection of 4130 tube, send me an email and I will pass along a couple of
sources that don't generally advertise.

J

"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

Where can you get these "high quality" hole saws? Even with cutting fluid
and cool air from a compressor I'm luckey to get 20 or so cuts from your
standard Milwakee hole saw.


"You can shape various
grinding wheels, or you can use something like the "joint jigger" with
high
quality hole saws to form the various "fish mouth" shapes. The best jigs
permit adjustment of the vise angle and the drill angle. The best quality
of the hole saws will do an entire frame before sharpening or replacement
is
required.

Find a copy of Winmiter.zip.
THis little program allows you to print out cutting templates
on your computer. Then just grind to shape.

I use a modified 4" angle grinder to cut the tubes.

It's spooky how accurate this works.

Richard


Sandy wrote:

Where can you get these "high quality" hole saws? Even with cutting fluid
and cool air from a compressor I'm luckey to get 20 or so cuts from your
standard Milwakee hole saw.

"You can shape various
grinding wheels, or you can use something like the "joint jigger" with
high
quality hole saws to form the various "fish mouth" shapes. The best jigs
permit adjustment of the vise angle and the drill angle. The best quality
of the hole saws will do an entire frame before sharpening or replacement
is
required.

Richard Lamb wrote:

Find a copy of Winmiter.zip.
THis little program allows you to print out cutting templates
on your computer. Then just grind to shape.

I use a modified 4" angle grinder to cut the tubes.

It's spooky how accurate this works.

Richard
++++++++++++++++++++++++++++

Sheesh!
Whatz really spooky is --
how you leave a poor soul dangling with...

FIND A COPY OF WINMITER.ZIP


Barnyard BOb to the rescue....
[I think]

ftp://ftp.ihpva.org/pub/software/winmiter/
ftp://ftp.ihpva.org/pub/software/index.html

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
www.americanspiritppc.com
"Flightdeck" wrote in message
ink.net...
A few years back, a manufacturer of 4130 tube frames for a popular
high-wing
kit used TIG because of production and training considerations over
oxy/acetylene. They had to call back fuselages because of cracking in the
4130. They modified their approach and used oxy/acetylene to pre-heat and
post-heat the weld. They ended up with nice welds, but why not just train
enough welders to the a real good job with oxy/acetylene?

4130 is very touchy about cracking from too little pre-heat and from too
fast cooling of the weld AND the metal around the joint. It should be
welded in absolutely calm air and the torch flame must be adjusted
correctly
to avoid a brittle failure from random hydrogen in the air.

Some of the race car guys who were using 4130 found that they could get
very
strong joints (with less high-heat problems)by using a brazing technique
rather than true welding. In fact, the technique seemed to provide better
joints due to difficult clusters and different levels of expertise. There
are some very good brazing alloys out there now with very high PSI
ratings.
As with a good 4130 "weld" the joints must be a very good fit (NO gap
filling with the rod) and clean, clean, clean. You can shape various
grinding wheels, or you can use something like the "joint jigger" with
high
quality hole saws to form the various "fish mouth" shapes. The best jigs
permit adjustment of the vise angle and the drill angle. The best quality
of the hole saws will do an entire frame before sharpening or replacement
is
required.

Finding a full selection of tubing wall/id/od combinations is difficult
today. We ran into a source problem a couple of years ago when we needed
to
find some sections that would telescope over an existing tube during some
airframe repair. This was a case where replacing the entire length of the
structural member would have required a re-cover of the fuselage. If you
are working on a definate project and have too much trouble finding the
size
you need from one of the three aircraft suppliers that still stock a
decent
selection of 4130 tube, send me an email and I will pass along a couple of
sources that don't generally advertise.

J

"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