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