Metal mix up.

Tue Feb 17, 2015 2:35 am

Has anyone ever really misjudged the kind of metal they were welding? I saw a guy trying to weld a brass door bolt with steel wire in a mig. (I didn't realise what he was trying to do until it was too late)

Coldman · Tue Feb 17, 2015 2:52 am

I tried to weld low carbon steel to cast iron assuming it was cast steel (it was supposed to be). Oops I let the smoke out of the cast iron.

AndersK · Tue Feb 17, 2015 4:39 am

I was trying to weld 4mm aluminum and had major problems getting the filler to fuse wirhout melting the base metal.

Turned out that it was 316 filler, not 4043 as the box was marked.

I should have noticed the weight diff....

exnailpounder · Tue Feb 17, 2015 6:28 am

I accidently grabbed a silicon bronze rod to do a lap weld on mild steel. She melted in great and welded great and I never noticed until I wire brushed the weld for paint and saw the funny color. Thats what you get when you hurry.

Tue Feb 17, 2015 6:36 am

I used steel wire to weld on a ss boss instead of 309. The drawing said GMAW, so I just kept ploughing on. Didn't tell me they tig them.

motox · Tue Feb 17, 2015 10:37 am

tried welding a crack in a honda 125 side case
thought is was aluminum, it was magnesium.
oops. later cases were aluminum..
craig

AndersK · Tue Feb 17, 2015 12:08 pm

So what was the problem?

Mag usually welds ok with 5356
Unless you try to gasweld

TRACKRANGER · Tue Feb 17, 2015 12:34 pm

motox wrote:tried welding a crack in a honda 125 side case
thought is was aluminum, it was magnesium.
oops. later cases were aluminum..
craig

Did it do the magnesium 'bright-lights' thing?

motox · Tue Feb 17, 2015 2:09 pm

andersk
every time i added filler it jumped to the electrode
as carefull a i tried.
a racing buddy who is a union welder gave me rod
(that he said was super expensive and grubby looking)
i cleaned the rod, re-ground the crack and it welded
up ok. not sure if a had enough gas coverage as the
arc seemed almost green and the weld looked dirty
as well.
craig

AndersK · Tue Feb 17, 2015 5:24 pm

It is usually some zinc in the mag alloys so you will have yellow-greenish smoke.

motox · Tue Feb 17, 2015 5:32 pm

andersk
its been a while since i welded the side case
but managed to find one of the rods my buddy
gave me. no markings just this grubby looking
rod.
craig

Wes917 · Tue Feb 17, 2015 6:22 pm

When I was first learning to weld someone gave me some Ti rod when I was doing aluminum. I tried like hell to no avail lol.

Bill Beauregard · Tue Feb 17, 2015 6:32 pm

exnailpounder wrote:I accidently grabbed a silicon bronze rod to do a lap weld on mild steel. She melted in great and welded great and I never noticed until I wire brushed the weld for paint and saw the funny color. Thats what you get when you hurry.

And I'm color blind?

Rick_H · Wed Feb 18, 2015 10:10 am

I had just started and they heard I could weld alum decent so a part broke and I was called upon. I was nearing the end of my first filler rod laying a beautiful bead and a co worker handed me another rod...damn stuff just would not puddle correctly, looked all gummy I was quite puzzled. It did melt lol

Rod was 308L....so I am known as the only mech there that can weld stainless and aluminum together...lol so now as habit I tap all rods against the table first...easy test to tell the difference.

danielbuck · Wed Feb 18, 2015 12:30 pm

I tried to bend cold rolled steel in my press brake, thought it was regular mild steel, until it cracked

MinnesotaDave · Wed Feb 18, 2015 12:39 pm

danielbuck wrote:I tried to bend cold rolled steel in my press brake, thought it was regular mild steel, until it cracked

I've done that in my floor mounted bender with a hardened 3/8" rod.
Almost went over backward when it snapped in two instead of bending - oops

Wed Feb 18, 2015 1:35 pm

What's the go with cold rolled V hot rolled? Is it just that the hot rolled is annealed? (we have very little cold rolled flat stock here in Aus. Australian made is all hot strip mill made.

exnailpounder · Wed Feb 18, 2015 3:19 pm

Bill Beauregard wrote:
exnailpounder wrote:I accidently grabbed a silicon bronze rod to do a lap weld on mild steel. She melted in great and welded great and I never noticed until I wire brushed the weld for paint and saw the funny color. Thats what you get when you hurry.
And I'm color blind?

Apparently I'm not the only one. Im pretty sure we all screw up from time to time. ^^^^^^^^^^

aeroplain · Thu Feb 19, 2015 10:22 am

At the risk of thread drift; it sure was fun watching Mr. " I can weld as good as you" (my boss) mild steel with the machine set for Alum.

I said nothing.

jesse · Fri Feb 27, 2015 3:18 pm

[quoteWhat's the go with cold rolled V hot rolled? Is it just that the hot rolled is annealed? (we have very little cold rolled flat stock here in Aus. Australian made is all hot strip mill made][/quote]

When they form the steel to the material form (round or square stock) at the mill there are two methods of working it. Hot working it allows the stresses to be relieved as it is worked so it does not become hard and brittle and stays tough. Cold working(cold rolling) traps the stresses inside making it very hard, strong and brittle and not so tough.