Welding question for the pros | GTAMotorcycle.com

Welding question for the pros

nobbie48

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A number of years ago I bought a Lincoln P-135 + Mig welder and use it for mainly ornamental items. As I am not a pro my number one rule is to never stand under anything I have welded. I don't weld anything that is life safety related. I may tack something together to have it later properly welded by a pro.

I have good results with thinner mild steel, sheet metal etc running mig mode but when I try flux core on heavier steel 1/8" or so I have concerns. I run Lincoln Innershield .035 NR-211-MP wire and find it brittle when I do destructive testing of my welds. The weld looks OK but when bent the weld bead breaks while the base metal bends.

The bead also wrecks my cold cut blades, I assume from hardness.

Is this normal? Any suggestions?
 
You're not gonna like my answer.
That model appears to be a 110V
Home owner buzzbox
They are good for what you are doing
Hobby type ornamental work
Would have to spend $$$
To get. Might rig to do what you need
Better option $ wise would be to get
a 220V DC stick welding machine
and burn 7018 low hydrogen rods
Keep you your little mig unit for the fancy stuff
Sorry bro
 
But what you might try with what you have
Is to preheat before welding
A propane torch is fine for this
Get it up to say 250 F
Then wrap with insulation after welding
To slow the cooling
It's worth a try
See what happens
 
I welded my work bench with a 110v flux core. 1/8" is about max that it will do. Needs more power (and therefore 240v) to do a good job. Welding with shielding gas is better also.
 
You're not gonna like my answer.
That model appears to be a 110V
Home owner buzzbox
They are good for what you are doing
Hobby type ornamental work
Would have to spend $$$
To get. Might rig to do what you need
Better option $ wise would be to get
a 220V DC stick welding machine
and burn 7018 low hydrogen rods
Keep you your little mig unit for the fancy stuff
Sorry bro

Fate accepted. I just wanted to confirm there wasn't some easy trick or different wire that would make life beautiful for $1.99.

I'll try some of the suggestions but another tool isn't in the cards. For the rare heavier stuff I do I'll just tack it to get the alignment I want and let a pro finish it up right.
 
I'll try some of the suggestions but another tool isn't in the cards. For the rare heavier stuff I do I'll just tack it to get the alignment I want and let a pro finish it up right.

If it happens rarely and you don't want stick, this is probably your cheapest route by far.
 
Without seeing it's hard to say
but if the welds are not breaking away
I assume you're getting penetration

If the welds themselves break
As you said they are brittle
Thats usually from cooling to quickly

The low current from that welder
Is not hearing the parts enough
Then when you stop welding
The heat is very quickly conducted
Out of the weld by the cold pieces

Some preheat and slower cooling
May help this
It's a cheap thing to try
A $20 propane torch
And a bit of rockwool are all you need
 
Without seeing it's hard to say
but if the welds are not breaking away
I assume you're getting penetration

If the welds themselves break
As you said they are brittle
Thats usually from cooling to quickly

The low current from that welder
Is not hearing the parts enough
Then when you stop welding
The heat is very quickly conducted
Out of the weld by the cold pieces

Some preheat and slower cooling
May help this
It's a cheap thing to try
A $20 propane torch
And a bit of rockwool are all you need

If appearance didn't matter would a practice bead about 1/2" back from the actual bead work as preheat? After the real weld is done cover with rock wool.

I have the propane but I like to be difficult :)
 
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Certainly worth a try...
anything that slows the cooling is likely to help

if it does help
then you know that coolling too quickly is the problem
 
1/8" isn't very think and you should be able to weld it fine with that size machine.
Brittle metal could be caused by cooling it to quickly (quenching it in water), not cleaning properly (absorbing shmoo from the surface), or trying to weld a higher carbon iron (like cast iron), or probably a million other things that I don't know.

Can you post a picture of the before (weld prep)after (with out grinding it)?
What settings are you using on the welder?
Is it the weld the weld itself breaking or is it breaking at the transition to the base metal?
 
1/8" isn't very think and you should be able to weld it fine with that size machine.
Brittle metal could be caused by cooling it to quickly (quenching it in water), not cleaning properly (absorbing shmoo from the surface), or trying to weld a higher carbon iron (like cast iron), or probably a million other things that I don't know.

Can you post a picture of the before (weld prep)after (with out grinding it)?
What settings are you using on the welder?
Is it the weld the weld itself breaking or is it breaking at the transition to the base metal?

I can't find my ambition pills but when I do I'll make some samples based on JavaFans suggestions. When steel cools rapidly it can undergo some weird changes. I am working on the assumption that rapid temperature change is the problem.
 
.035 wire is larger than I would use,, and I have seen the issue with welds that don't have penetration to come from poor supply to the machine..... tooo long of a feeder to the recept,, too long of an extension cord... wire awg too small...
12awg, very short run to the main feeder,, or 10awg ...
 
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You can cheat the penetration issue a little by leaving a small gap between the materials you are welding..,,,,,
 
I'm no pro, but I did at one point in life do automotive welding that needed to not come apart.

I'm using a similar welder now for home stuff, CTC/mastercraft 110v fluxcore mig. going to gas produces a much better weld, if thats not in the cards what I've found works for me
a. grind the parts to be joined to a clean surface, get rid of rust/oil whatever
b. grind a small V in the joint so the weld has a better area to join to
c. practice and learn to do a push weld , not a pull weld. the pull is easier, but seems to produce a higher bead with less penetration, the push gives a better 'puddle' that heats as you go.
d. if you leave a gap with these welders you seem to get the blow through and holes instead of welds.
e. dont waste time preheating or trying to slow cooling, if its low carbon steel your problem is technique not circumstance
f. cutting the weld with a cold cut saw will wreck the bald almost every time, cut first - weld after

these welders are better than toys, used within there limitations. They are used all over the planet where 220v isnt readily handy
 
110V welders are used all over the world?

ahhhh......no

and they are hobby machines
will not find a pro welder using one

but I do agree with the first 3 words of your post
 
my garage door mechanic had one the other day when a lift truck backed into the door track. He put the track back onto some new brackets. I'll let him know it didnt work.
 
not sure which way he went. he sent me an invoice for $400. its 12 gauge metal (so the invoice says) it probably didn't need a whole lot of heat.
 

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