Jump to content
I Forge Iron

Penetrating Welds with a lil' MIG


Recommended Posts

I'm currently building an anvil out of RR track, and trying to go abouts it the correct way. I'm using this page as a reference, specifically after this kind of end product;

Screenshot2012-07-10at84046PM.jpg

... Only I will have a double horn with gussets...


I have beveled an appropriate amount of the base track in order to get maximum penetration (1/2" gap max), and do plan on preheating the parent metals. My welding knowledge and abilities are still wet behind the ears mind you.

I'm working with a Lincoln pro mig 135, .30 flux-core wire, and 75 Ar/25 o2 mix.

Getting to my question...

My old boss used to run this dual-shield set-up for all his structural work, only he had an industrial sized mig with a spool gun... I've read a lot of back and forth banter about this not being the right way to go abouts "dual-shield welding", and that flux-core was meant to be used without gas.period.changes the integrity of the weld.etc.etc...

I just want these two pieces of metal to stick together, and I need some really good penetrating zero porosity welds...

With the above setup, right prep, right settings, running a bead then wire brushing off any left over flux, and building up the welds, with this method serve me well?

Also, I was wondering what kind of settings I might want to run with this kind of dual shield welding? I was going to run a few test welds just to see what I'm dealing with, but if someone knowledgable chimes in with some good advice, I'd appreciate what ever you had to offer...

Or, if this is just a fruitless and stupid endeavor, I can always have a friend tig it... I'd like to attempt it, but if there's no hope

Link to comment
Share on other sites

  • Replies 50
  • Created
  • Last Reply

Top Posters In This Topic

You could pre heat the steel pretty hot before welding and that will help you some but you really need some wire that is 1/16" or .072" to do a good job on that. Dual shield is good choice for this. Many different types of dual shield wire available.
You might try a practice piece if you have a good way to heat it.
smith out

Link to comment
Share on other sites

You could oxy/fuel weld that if you have a torch.... It would be miserable and take forever... but it could be done. If I had to tackle that and all I had was a little mig I think I would try.... It would take a huge bevel so you could weld your way back from the center, it would take keeping the whole thing at a hotter than pre heat temp (like over 1000F)... It would take at least a day to weld because of the duty cycle of the welder.... laying bead after bead stepping out in the bevel till you get to the edge.... And still it wouldn’t be like it was welded with a "real" welder..... I think Bruce should say "It cant be done properly" rather than cant be done...

Link to comment
Share on other sites

I think Bruce should say "It cant be done properly" rather than cant be done...


Those two large pieces being High carbon steel with mangenese thrown in are a recipe for falure. No penetration to boot is gonna make falure a given in imo. Sure it will stick but beating on it will eventually take it's toll, better a little anvil than a trailer hitch. Properly welded it will last forever, why take a chance.....
Link to comment
Share on other sites

Come on Bruce.... You gonna tell me you only do things that you have the proper tools for and never try to make due with what you have? If you have nothing but time then all you have to lose is time..... And your right, its not a good idea and I wouldnt try it if there was another option....

Link to comment
Share on other sites

Could you lay hands on an old lincoln tombstone welder? I picked up an old copper wound one for $40 for my shop and have been lusting after an AC/DC model that are often listed quite reasonable on Craigslist locally.

I currently have to plug mine into a disused electric stove plug in my kitchen---I have an "extension cord" for it that runs out the kitchen window---but you can do quite heavy welding with one and rods for most anything can be found pretty easily!

Very handy thing to have for items a little mig won't handle.

Link to comment
Share on other sites

Your little MIG welder will do the job if you do a "forged weld". I've been doing a lot of them these days :( You will need a ground forge with a lot of fuel and a helper. For the first project, a post anvil would be a better idea, since it will be less likely to burn off the appendages. Also, the guru of anvilfire suggests a smaller project just to get the technique down.

Or, you could just get a big fat stick welder. I just saw one being liquidated at a fab shop. It went for a song since it was kind of large, something like 650 amps. I bought the anvil that the guy welded with it.

Mod note: link removed at request of anvilfire owner

Link to comment
Share on other sites

Thanks for all the replies guys... I'm gonna set my Macgyver heart aside on this one and do it right the first time... The structural integrity of the anvil is numero uno on my list. I cant have a hot 15 pound double-horned anvil breaking under stress. Thats a bad day...

Times like these make me want a stick welder in the worst way... I've seen plenty affordable ones on CL, just outside my price range...


Guess it's time to phone a friend... ;)

Link to comment
Share on other sites

  • 4 weeks later...

You can definitely do this with a 110v FCAW machine with .030" wire.... Its all about preheat and metal prep. You won't be able to make large beads, mind you, because of the size of wire but you can make layers upon layers of weld to fill the weld joint as long as the particular wire allows it (some flux cored wires are single pass only.

Link to comment
Share on other sites

Another note, adding manganese to a high carbon steel keeps the steel from being brittle. Has nothing to do with penetration, and 1,000 degrees is a ridiculous number for preheat. You need nothing more than roughly 550-600 degrees fahrenheit. Bevel your parent metal down to 1/4" landing and weld out.....

Link to comment
Share on other sites

  • 2 weeks later...

Honestly, I ended up doing it myself, just as hillbilly described...

tacked, pre-heat... ran a bead, brushed of the flux/slag, then ran a bead on the opposite side... so on and so forth...

I've been working the hot stuff on it since... no issues as of yet in spite of using larger hammers... That Guru guy knows what he's talking about when it comes to making RR track into a suitable anvil... I'll post pics soon to close the thread off... Thanks to all!!!

Link to comment
Share on other sites

There is a problem with NR 211 innershield wire when you do multi pass welds on heavy plate. Dilution- the wire needs to be fused with the parent metal, running on heavy cross sections you will be laying beads on top of other beads. There were big problems with this in the Northridge quake that hit the LA area. This is why NR 211 is not "Recommended" over 1/2 inch base metal.
Will it work? Yes it may work. Will the weld be brittle? Very likely

Link to comment
Share on other sites


Your mig should eventually get it. You will be running against duty cycle, and you probably want some preheat.

Yes, you will be multipass welding all day.



even with multi pass how do you get the penitration with out the needed power from the machine ? Please explain that one, you seem to be the only one to know how to do this, please teach us.
Link to comment
Share on other sites


even with multi pass how do you get the penitration with out the needed power from the machine ? Please explain that one, you seem to be the only one to know how to do this, please teach us.

PREHEAT- If the metal is already close to welding temp it is that much less work for the machine to do.
Link to comment
Share on other sites


PREHEAT- If the metal is already close to welding temp it is that much less work for the machine to do.


I understand where you're comin from but there ain't no way you will get the metal anywhere close to welding temp unless you put it in a coke forge or the like. Pre heat is generally less than 1000 deg f......
Link to comment
Share on other sites

I did the best I could with what I had available to me... prep, pre heat. etc... If it fails, it's my femoral artery that's being jeopardized... I know, theres a bit of attitudinal adjustment on account of being somewhat confident that the weld will hold, because I did grind down my initial 1,2, and 3 welds looking for porosity, of which, I found not a bubble... Through watching the puddle I know I dipped into the parent metals as well...

It's like going crappie fishing with a buddy of mine, I show up with the decked out $$$ rig, he shows up with a 1970's donald duck Zebco with a braided steel leader... Then HE proceeds to clean up on 'em catching breakfast lunch and dinner, and I get skunked.... I shook my head so much, I got dizzy... :blink:

If you guys wanna play swords, just remember it's not a nuclear missile silo were talking about here... I appreciate the guidance, and value it greatly... I just needed something to pound on.... j

Link to comment
Share on other sites

Steve;

The mig will definitely get penetration no matter the power backing it up. If you run your voltage and wire feed in correct synchronization, it will do its intended purpose. And the fact that if you preheat and prep the base material correctly, there will certainly be no issues...... I've already build my friends wood chipper and hammer mill powered by a 4-cylinder Perkins diesel and a 6-cylinder Perkins diesel with his little Lincoln 140 HD pak (or something like that) which is a 110v powered wire welder.... And so far ( 2 years and running hard chipping solid lumber) has never had a single problem! Its not about the equipment, its about the worker.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...