Welding techniques for 4130?

Welding means to fuse two metals together by melting them, often with
the addition of a filler.


good stuff snipped

Thanks Corky. I appreciate your input.

On 30 Aug 2003 19:08:53 GMT, onloser (Building The
Perfect Beast) wrote:

I'm going to assume you will be welding 4130 steel structures
exclusively. If you are a relative novice to welding, use oxy-acetylene
equipment and mild steel rod. Do a Google search on this newsgroup,
paying extra close attention to posts by Bruce Frank and a guy named
"Highflier." Also, the EAA puts out an excellent publication on
aircraft welding.

Thanks Del. That's what I was looking for. I did a Google search and just
came up on too many hits. I was hoping that I might get it narrowed down and
you've done just that for me.


Unless you are already an accomplished welder, ignore suggestions to
purchase an expensive TIG welding machine. It is not necessary and may
lead to undesirable results unless you have already mastered the basics
of welding with oxy-acetylene equipment. I use a small TIG machine and
like it, but I also use it for other things (like aluminum and
automotive projects) and had quite a bit of oxy/acetylene experience
before trying it. If I couldn't afford a TIG unit, I would weld
together my airframe using oxy/acetylene with no hesitation.


Luckily I've got a buddy who is going to build with me and he is a master
welder. I plan on learning a lot from him. As for my experience, well, most
of it is on farm equipment and about all I've ever used oxy/acetylene for was
cutting stuff up. I'm a fair stick welder but I know I've got a lot to learn.
And I'm looking forward to it.

Done properly, do you feel that there is any difference in the quality of weld
produced by oxy/ace vs. TIG? Is the TIG just less hassle or what?

TIG is easier to control. The heat is more intense and localised. The
"flame" is always neutral.

On the other hand, the flame on Oxy Acet is more forgiving. You don't
polute the electrode every time you get the tip too close to the
puddle.

A lot easier to learn to weld with ocy Acet than with TIG.

On 30 Aug 2003 11:08 AM, Building The Perfect Beast posted the following:

Done properly, do you feel that there is any difference in the quality
of weld produced by oxy/ace vs. TIG? Is the TIG just less hassle or
what?

Well, many knowledgable and experienced welders believe that the
narrower heat effected zone (HAZ) causes more stresses to be
concentrated right next to the weld, rather than spread out over a wider
area adjacent to the weld. The problem is that while the weld may be
sound, these stress concentrations might cause cracking right next to
the TIG welds. The cure for this is to either weld using oxy-acetylene,
or to post heat the TIG welds using an O/A torch with the "rosebud"
heating attachment, which stress relieves the joint, moving the stresses
away from the more highly loaded weld clusters, and preventing the
cracking. For every welder who holds this opinion, you can probably
find another equally qualified welder (including the guy who helped FAA
revise the welding portion of AC43.13) who believes it to be a non-issue
and the post heating to be unnecessary.

As a mostly self-taught amateur welder, my position is that I don't know
enough to say either way, but that nobody has been able to convince me
there is a downside to post heating the TIG welded joints, other than
the time and cost of the gases used. My plan is to do as Bruce has
suggested in the past, and not worry about it for the most part, but to
also go over some of the more highly stressed critical areas with the
rosebud. Places like the wing and landing gear attach fittings, and the
tailspring and engine mount points.

For the record, I *really* like my TIG unit (a Lincoln square wave 175)
and I feel that the precision, cleanliness, and convenience of the TIG
process outweighs the disadvantages of cost and possible need to strain
relieve welds. But in your case, since you will need to develop oxy/
acetylene skills anyway before you can even think about trying the TIG,
you should just use the O/A torch for your welding since it is easier
and more forgiving. I already had plenty of O/A welding experience
under my belt and I did quite a bit of welding on non-aviation stuff
with the TIG before I ever started putting aircraft parts together with
it.

----------------------------------------------------
Del Rawlins-
Remove _kills_spammers_ to reply via email.
Unofficial Bearhawk FAQ website:
http://www.rawlinsbrothers.org/bhfaq/

Kent White gives forums on gas welding and brazing all week long. No
need for EAA to do it.

I do remember one EAA forum instructor saying the ER70S- series for
welding rod.

I do find the welding instructors to have other small
inconsistencies...how to hold the torch, dipping the filler rod, etc.

Kent White gives forums on gas welding and brazing all week long.

Where is he located?

See http://www.tinmantech.com/html/kent_white.html
He has a forum on working aluminum at Oshkosh, very well attended and
informative.
Ray

"Building The Perfect Beast" wrote in message
...

Kent White gives forums on gas welding and brazing all week long.

Where is he located?

Kent White is in forum tent 21 most of the time, but does change here
and there. check the forum schedules.

On Sat, 30 Aug 2003 13:30:40 -0700, Joe Maj wrote:

I was one of those instructors, and I always state that R45 is
completely satisfactory for gas welding 4130 steel. I use it myself.

The older guy giving it said that nothing but 4130 is acceptable now, and
furthermore you do not need to stress relieve, but then a younger guy,
maybe you, disagreed with what he said. In fact, a young guy who was
supervising the welding said that if you followed the older guys advice
you would blow up your shop, cracking the valves before attaching the
regulator.

What did people think of the OSHA-industrial-grade lecture on gas
welding safety? Having listened to it twice a day for a week, I think

I thought for a person who's never been behind the torch it was
appropriate, however, if you've welded it was much too long.

don't express an opinion, we'll all have to go through that again next
year.

I suspect you need to give it since you have a lot of people who've never
welded before. It could be shortened up by not parroting what the video
tape says.

What I believe needs to happen is to have consistency between instructors,
as was I found the EAA welding forum to be next to worthless due to the
conflicting information. How is a newbie to differentiate between the
instructor who says do this, and then he moves on the hands on part and
they say don't do that. Your forum in my opinion created confusion in the
minds of some of the participants, or so I noticed when I was watching
them.

One of the most outstanding issues was if you attended any of the other
welding forums, Budd's or Kent's, what they did and said was not at all
what the EAA said. I'm not good enough to judge the correctness of what
the EAA instructors said, but I will do what people have been doing for a
very long time in contrast to what the EAA instructors said and as the
other two whom I respect have said.

On 30 Aug 2003 19:08:53 GMT, onloser (Building The
Perfect Beast) wrote:

Luckily I've got a buddy who is going to build with me and he is a master
welder. I plan on learning a lot from him. As for my experience, well, most
of it is on farm equipment and about all I've ever used oxy/acetylene for was
cutting stuff up. I'm a fair stick welder but I know I've got a lot to learn.
And I'm looking forward to it.

Done properly, do you feel that there is any difference in the quality of weld
produced by oxy/ace vs. TIG? Is the TIG just less hassle or what?

Done properly there is not much difference and both can produce
similar looking welds although it often takes a while to build up the
skills to produce quality looking welds every time.

Dell mentioned that the cost did not bother him. For me, cost is a
huge issue. I don't weld all the time, and once the fuselage was done
the welding dropped off to a bit here and there, maybe once every four
to five months, if that. So having a $1300 rig sitting in the shop
that wasn't being used doesn't make sense to me when the Oxy/Acet
torch welds tubing just fine. Remember, before there was TIG, ALL
fuselages were built using the torch, and none of them pulled apart.

Remember, you are welding a fillet entirely around each joint. When
you do that, you encapsulate the cluster with filler and fused metal.
It's as indesctructable a connection as there is.

TIG has a lot going for it but ease of use when welding a fuselage
isn't one of them. The handle is heavier to hold for long periods
than a torch and you have to have the foot pedal near by to be able to
use it, or you must buy a hand operated trigger. The handle gets hot
after a while unless you have water cooling, which adds weight and
complexity.

A torch setup will cost around $300 new. The gasses aren't expensive
to rent, and besides, you need Argon for the TIG welder too.

The TIG machine is more versatile and is capable of welding thicker
metals with less distortion, if you need to do so.

Corky Scott

"Matthew P. Cummings" wrote:

On Sat, 30 Aug 2003 13:30:40 -0700, Joe Maj wrote:

I was one of those instructors, and I always state that R45 is
completely satisfactory for gas welding 4130 steel. I use it myself.

The older guy giving it said that nothing but 4130 is acceptable now, and

Acceptable to Whom?