In preparation for doing some simple OA welding on a rudder, I've been
practicing on some 4130 scrap. Since there is filler where it's not
structurally important, I"ve been filing the excess material. All
except one and it's as hard as if I were trying to file stainless.

Is this an indication that I was using an oxidizing flame on that
sample? - MIke

In article >,
Michael Horowitz > wrote:

> In preparation for doing some simple OA welding on a rudder, I've been
> practicing on some 4130 scrap. Since there is filler where it's not
> structurally important, I"ve been filing the excess material. All
> except one and it's as hard as if I were trying to file stainless.
>
> Is this an indication that I was using an oxidizing flame on that
> sample? - MIke

If you fill with 4130, the weld will be hard -- and brittle. That is why
you use regular welding rod on 4130 -- the thicker material in the weld
relieves stress and keeps things good.

'regular' welding rod?
What's that?
Not a 4130 rod for welding 4130? - Mike

In article . com>,
"Mike" > wrote:

> 'regular' welding rod?
> What's that?
> Not a 4130 rod for welding 4130? - Mike

Nope

4130 rod for welding 4130 will require heat treat, or it will be brittle
and crack. Use standard, off-the-shelf welding rod from your local
welding supplier.

Hi Orval,

I think what the OP is trying to get at, is there is no standard
off the shelf welding rod.

The most sold is probably 6010/6011. It requires a stitch welding
technique, and tends to stick when starting. It makes strong deep
all position welds that tend to be ugly. Not for beginners.

The easiest to use is 6013, but it makes really pretty looking, flat
position, non xray quality welds, and has little penetration.

The most common low hydrogen rod is 7018, but it is tricky to use,
and must be stored in an oven. It is used almost exclusively for all
position, structural steel welding.

And then there is a host of SS rods that some people like because of
their easy welding characteristics, and the toughness of the weld.

So, what do you mean when you state off-the-shelf? I would recommend
7018, and a whole bunch of practice.

-Chuck

Orval Fairbairn wrote:
> In article . com>,
> "Mike" > wrote:
>
>> 'regular' welding rod?
>> What's that?
>> Not a 4130 rod for welding 4130? - Mike
>
> Nope
>
> 4130 rod for welding 4130 will require heat treat, or it will be brittle
> and crack. Use standard, off-the-shelf welding rod from your local
> welding supplier.

Orval Fairbairn wrote:
> In article . com>,
> "Mike" > wrote:
>
>> 'regular' welding rod?
>> What's that?
>> Not a 4130 rod for welding 4130? - Mike
>
> Nope
>
> 4130 rod for welding 4130 will require heat treat, or it will be brittle
> and crack. Use standard, off-the-shelf welding rod from your local
> welding supplier.

Oh, I forgot to mention, the welded material gets just as hot as the
weld, so if you have cracking problems that require heat treatment, you
are going to have problems regardless of the rod you use. Most of the
time, cracking problems are hydrogen embrittlement, and are prevented
by using a low hydrogen rod, such as the 7018,8018,9018... series of rods.

-Chuck

Chuck..
Decent advice for stick welding, but the question was about gas welding.
There are a number of good filler rods for steel, and for small puddles
with small tips, one of the best is ER70sXXX mig wire. This lets you
place filler rod in the weld without chilling the puddle too hard with a
larger diameter rod. 4130 rod in 4130 welds isn't the best idea
and a softer filler material is advised. Rods for mild steel are preferred.

Have a great day

Scott


"Chuck Harris" > wrote in message
...
> Hi Orval,
>
> I think what the OP is trying to get at, is there is no standard
> off the shelf welding rod.
>
> The most sold is probably 6010/6011. It requires a stitch welding
> technique, and tends to stick when starting. It makes strong deep
> all position welds that tend to be ugly. Not for beginners.
>
> The easiest to use is 6013, but it makes really pretty looking, flat
> position, non xray quality welds, and has little penetration.
>
> The most common low hydrogen rod is 7018, but it is tricky to use,
> and must be stored in an oven. It is used almost exclusively for all
> position, structural steel welding.
>
> And then there is a host of SS rods that some people like because of
> their easy welding characteristics, and the toughness of the weld.
>
> So, what do you mean when you state off-the-shelf? I would recommend
> 7018, and a whole bunch of practice.
>
> -Chuck

Hi Scott,

Now I understand the question. It is impossible to prevent
hydrogen embrittlement when gas welding. A natural byproduct
of the combustion of oxygen and acetylene is water vapor, which in
the flame shows up as H+ ions. These H+ ions get mixed in
with the molten steel, and form a mess. These H+ ions turn
good steels into something that is full of glass hard fissures,
and will always crack... sooner or later. Gas welding is really
only suitable for mild steels.

If all you have is a gas rig, and you need to connect good steels,
like 4130, you should be brazing... which essentially is what you
are doing when you use a mild steel filler (coat hanger wire).
(don't really use coat hanger wire. Its a mystery steel. Its only
operating requirement is the alloy must be cheap and soft)

If you are trying to make a joint that is as strong as the base 4130
steel, you should be using a stronger filler steel, and a shielded
arc process. The best would be TIG, or MIG.

-Chuck


pbc76049 wrote:
> Chuck..
> Decent advice for stick welding, but the question was about gas welding.
> There are a number of good filler rods for steel, and for small puddles
> with small tips, one of the best is ER70sXXX mig wire. This lets you
> place filler rod in the weld without chilling the puddle too hard with a
> larger diameter rod. 4130 rod in 4130 welds isn't the best idea
> and a softer filler material is advised. Rods for mild steel are preferred.
>
> Have a great day
>
> Scott
>
>
> "Chuck Harris" > wrote in message
> ...
>> Hi Orval,
>>
>> I think what the OP is trying to get at, is there is no standard
>> off the shelf welding rod.
>>
>> The most sold is probably 6010/6011. It requires a stitch welding
>> technique, and tends to stick when starting. It makes strong deep
>> all position welds that tend to be ugly. Not for beginners.
>>
>> The easiest to use is 6013, but it makes really pretty looking, flat
>> position, non xray quality welds, and has little penetration.
>>
>> The most common low hydrogen rod is 7018, but it is tricky to use,
>> and must be stored in an oven. It is used almost exclusively for all
>> position, structural steel welding.
>>
>> And then there is a host of SS rods that some people like because of
>> their easy welding characteristics, and the toughness of the weld.
>>
>> So, what do you mean when you state off-the-shelf? I would recommend
>> 7018, and a whole bunch of practice.
>>
>> -Chuck
>
>

On Mon, 08 May 2006 10:30:28 -0400, Chuck Harris wrote:

< big snip >

> Hi Scott,
>
> Now I understand the question. It is impossible to prevent
> hydrogen embrittlement when gas welding. A natural byproduct
> of the combustion of oxygen and acetylene is water vapor, which in
> the flame shows up as H+ ions. These H+ ions get mixed in
> with the molten steel, and form a mess. These H+ ions turn
> good steels into something that is full of glass hard fissures,
> and will always crack... sooner or later. Gas welding is really
> only suitable for mild steels.
>
> If all you have is a gas rig, and you need to connect good steels,
> like 4130, you should be brazing... which essentially is what you
> are doing when you use a mild steel filler (coat hanger wire).
> (don't really use coat hanger wire. Its a mystery steel. Its only
> operating requirement is the alloy must be cheap and soft)
>
> If you are trying to make a joint that is as strong as the base 4130
> steel, you should be using a stronger filler steel, and a shielded
> arc process. The best would be TIG, or MIG.
>
> -Chuck
>
>

The desire to use TIG with a higher end rod and post heat treat is the
best but the question is answered correctly for a repair in structural
aircraft members where heat treatment is not possible would be with an
ER70 rod and OA welding. It was only a few years ago that the FAA
even addressed TIG in the AC43.13.

Mike

Mike Anderson wrote:

> The desire to use TIG with a higher end rod and post heat treat is the
> best but the question is answered correctly for a repair in structural
> aircraft members where heat treatment is not possible would be with an
> ER70 rod and OA welding. It was only a few years ago that the FAA
> even addressed TIG in the AC43.13.
>
> Mike

Here is what Linde says in the "The Oxy-Acetylene Handbook", p233:

Talking of 4130 "chrome moly steel:

"One of the more familiar applications of this material is in structural
tubing for aircraft. In such structures the light gage base material is
welded using a slightly excess acetylene flame and the normal steel welding
technique. Although the strength of the weld metal in such a weld is
lower per unit area than that of the base metal, the weld is made to develop
the desired strength by increasing the normal reinforcement considerably.
By following such a procedure, this "Chrome-Moly" base metal can be successfully
welded. On the other hand, if a S.A.E. X-4130 rod were used in welding
such structures or if an attempt were made to follow a similar procedure
in X-4130 plate material 1/2 or 3/4 in. thick, the weld would not be at all
successful."

They then direct us on to Chapter 22 to discuss the correct welding technique
for 4130. There, they spell out in depth the problems with welding an air
hardening steel, such as 4130. They mention that most of these problems can
be handled by preheating welding areas to relieve hidden stresses, and using
a low carbon steel rod, similar to Norway iron. They specify Oxweld No. 7 as
being the desired rod for tubing of less than 0.1" thickness. They then go
on to say that for tubing greater than 0.1" thickness, you will need a stronger
steel in your rod, and suggest Oxweld No. 1 with a recommendation of heat treatment.
For more rigorous applications, they then recommend Oxweld No. 32 with a
requirement of heat treatment.

Going into Linde's appendixes, finds that the Oxweld No. 7 rod isn't even a
steel rod, but rather a pure iron rod with a 45KPSI tensile strength. The No. 1
rod is a High Test Steel (low carbon steel), and the No. 32 is Chrome Moly Steel
(eg. 4130).

The ER70 mig wire is a 70KPSI tensile strength mild steel. It is the same filler
steel as any of the E70xx rods.

Linde's book would be a very good place to go if one wanted to learn how to
properly OA weld 4130.

-Chuck

On Sun, 21 May 2006 10:39:03 -0400, Chuck Harris wrote:

> Mike Anderson wrote:
>
>> The desire to use TIG with a higher end rod and post heat treat is the
>> best but the question is answered correctly for a repair in structural
>> aircraft members where heat treatment is not possible would be with an
>> ER70 rod and OA welding. It was only a few years ago that the FAA
>> even addressed TIG in the AC43.13.
>>
>> Mike
>
> Here is what Linde says in the "The Oxy-Acetylene Handbook", p233:
>
> Talking of 4130 "chrome moly steel:
>
> "One of the more familiar applications of this material is in structural
> tubing for aircraft. In such structures the light gage base material is
> welded using a slightly excess acetylene flame and the normal steel welding
> technique. Although the strength of the weld metal in such a weld is
> lower per unit area than that of the base metal, the weld is made to develop
> the desired strength by increasing the normal reinforcement considerably.
> By following such a procedure, this "Chrome-Moly" base metal can be successfully
> welded. On the other hand, if a S.A.E. X-4130 rod were used in welding
> such structures or if an attempt were made to follow a similar procedure
> in X-4130 plate material 1/2 or 3/4 in. thick, the weld would not be at all
> successful."
>
> They then direct us on to Chapter 22 to discuss the correct welding technique
> for 4130. There, they spell out in depth the problems with welding an air
> hardening steel, such as 4130. They mention that most of these problems can
> be handled by preheating welding areas to relieve hidden stresses, and using
> a low carbon steel rod, similar to Norway iron. They specify Oxweld No. 7 as
> being the desired rod for tubing of less than 0.1" thickness. They then go
> on to say that for tubing greater than 0.1" thickness, you will need a stronger
> steel in your rod, and suggest Oxweld No. 1 with a recommendation of heat treatment.
> For more rigorous applications, they then recommend Oxweld No. 32 with a
> requirement of heat treatment.
>
> Going into Linde's appendixes, finds that the Oxweld No. 7 rod isn't even a
> steel rod, but rather a pure iron rod with a 45KPSI tensile strength. The No. 1
> rod is a High Test Steel (low carbon steel), and the No. 32 is Chrome Moly Steel
> (eg. 4130).
>
> The ER70 mig wire is a 70KPSI tensile strength mild steel. It is the same filler
> steel as any of the E70xx rods.
>
> Linde's book would be a very good place to go if one wanted to learn how to
> properly OA weld 4130.
>
> -Chuck


O.K., you are correct.

I agree that learning the proper method of joining any material you work
with is important and I haven't any idea what FSDO he will try to use or
who will be signing the log book or the 337 if it turns into that big a
job.

It was foolish to answer without enough information....

Who is going to sign the work off?

There is where the answer should be sought.

Mike

This question , about welding with O,A is right . or should I say the
answer . I have noticed while welding I tend to use just a little richer
Acetylene. mixture to keep from oxidizing the weld . the bubbles and so on
and even cracking is the result of my running too much oxygen .Too much heat
will also do the same thing. now what I mean by that is too big a flame for
the job.. This usually happens when I try and weld a thick piece to a thin
piece , seems one tends to get too much heat ( the thin ) and pop and bubble
and crack . I also have found , for myself of course , that welding with a
4130 rod to 4130 frame I will get cracks in the weld , and even on the sides
.. seems to me that as the metal cools it draws up and that's when I get the
cracks . Going back over my weld with the torch before it get too cold
sometimes helps . but I have found that using a soft metal rod works best
on a hard metal weld . Using a coat hanger wire once to patch a frame was
proof enough for me. I started buying soft metal rods to weld 4130 and 4140
.. But I am not a tickler for exact and perfect welding . An aircraft bolt is
soft and will stretch allot before it breaks as compared to a grade 8
hardened bolt . It's just I was reading and learning from all of you and I
remembered from my experiences .I pray I did not over step my bounds here .
Thanks for allowing me to butt in . wesmarso
"Chuck Harris" > wrote in message
...
> Orval Fairbairn wrote:
>> In article . com>,
>> "Mike" > wrote:
>>
>>> 'regular' welding rod?
>>> What's that?
>>> Not a 4130 rod for welding 4130? - Mike
>>
>> Nope 4130 rod for welding 4130 will require heat treat, or it will be
>> brittle and crack. Use standard, off-the-shelf welding rod from your
>> local welding supplier.
>
> Oh, I forgot to mention, the welded material gets just as hot as the
> weld, so if you have cracking problems that require heat treatment, you
> are going to have problems regardless of the rod you use. Most of the
> time, cracking problems are hydrogen embrittlement, and are prevented
> by using a low hydrogen rod, such as the 7018,8018,9018... series of rods.
>
> -Chuck