mig penetration

[liftdoctor]

Just purchased a HH175. I am planning on doing a few projects with 1/8". I see a lost of questions about lack of penetraion. I was wondering what gas I should buy. CO2 or C25 mix?

I have also noticed that there are few f questions about flux core. Is there a reason people stay away from flux core?

[Blkvoodoo]

I use flux core mostly because I do most of my welding outside.
Using gas on a windy day is useless unless you flood the **** out of it .

As a hobby welder and not having much space it is also nice not to have a tank to drag around.

Weld spatter and having to clean off slag is a reason a lot of folks do not use it.

Kevin

[bitternut]

Liftdoctor

I also have a HH175 and I use flux-core all the time. I like it because even being a new welder things I have welded are definitely stuck together. I tried some regular wire with c25 and they looked okay but failed destructive testing. If you are welding rusty, scaley metal outside that you want stuck together flux-core is the stuff to use. I think a lot of people make a big deal about chipping flux and spatter. I picked up a needle scaler recently and that seems to do a slick job on the flux and any spatter. Here is a picture of a pintle adapter for my tractor drawbar that I welded up and my needle scaler.

[bitternut]

Here is a closer view of the weld after using the needle scaler. The welds clean up real easy with it. I was using .035" Fabshield wire E71T-GS for single pass and E71T-11 for multi passes. The settings were 4-60 and the material was 3/8, 5/8, 3/4, and 1.00 hot rolled steel. I don't think you could weld this with regular mig.

I have never seen any mention on this forum about needle scalers for some reason. Does anyone else use one? Would it work for peening cast iron repair welds?

[Arc Burn]

We used them when i was in bridge construction for maintnance projects when stripping rust and paint off hard to reach places,i think i put more hours on that stupid needle scaler than a welder!They seem like the cats azz till you use one for 10 hrs a day

[liftdoctor]

OK. So form what I am reading, flux core is better for penetration. Is that correct?
I don't mind the chipping so much. It just that when I have stick welded on vertical, and not being a welder, I always got what is called slag inclusion which means slag in the weld and a crappy weld.
I like the idea of the gas because I don't have to worry about where the slag runs. Also, I have noticed I can weld some really thin stuff with the mig at work because I can shoot, back off, shoot , back off and not worry about the slag being in the weld. And this is with .045 wire.

The question about gas is because I would like to use gas and my concearn is good penetration. I have a friend whose neghbor bought a disc for his farn tractor. It was all mig welded and broke apart at the welds. They ground out the welds and welded it with a stick welder.

I have read on this forum that CO2 is better for penetration but leaves more splatter. But how much better? If it gives 5% more penetration, I will buy the C25 mix.

[Guest]

Originally posted by bitternut
Here is a closer view of the weld after using the needle scaler. The welds clean up real easy with it. I was using .035" Fabshield wire E71T-GS for single pass and E71T-11 for multi passes. The settings were 4-60 and the material was 3/8, 5/8, 3/4, and 1.00 hot rolled steel. I don't think you could weld this with regular mig.

I have never seen any mention on this forum about needle scalers for some reason. Does anyone else use one? Would it work for peening cast iron repair welds?

I think the reason why, is that most we're dealing with MIG and TIG welding, and the stick questions mainly deal with welding vertical. Anyway, the best way to cut through mill scale and remove slag is with the needle gun like you have, which is a very nice one. I have seen some Chi-Com needle guns that the needled are like noodles, and bend on ya.

As far as stress relieving, I would stick to the impact gun because it hits harder and compresses the metal better.

[Dan]

Re: mig penetration

Liftdoctor

On a HH 175, C25 will work just fine on 1/8" material, or 3/16" for that matter. 1/4" and above I suggest you think about using a self shielded fluxcore wire instead.

Now as far as the welds all cracking on your friends disc, I would assume that more then likely the wrong mode of GMAW metal transfer was used. It is possible too that the frame work was to ridgid. These frames need to be able to flex some. My dad bought a used disc from a guy, and for some reason the guy had stick welded up every joint on the framework that was bolted together. Well, it didn t take long before everyone of these welded joints cracked. Obviously, these joints are bolted together to allow for some movement of the framework.

[Mike Sherman]

LiftDoctor, .125" steel is well within the range of a short circuit mig. Just try to achieve full penetration. Remember, the problem with short arc mig is the potential for lack of fusion, it is not a guarentee. It becomes more likely as you progress into thicker steels. Most people have problems when they try to weld .375" or .5" in one pass. This is when you should break out the fluxcore wire. I use 75/25 gas because the Argon helps stabilize the arc and you will have less spatter. It does cost more. Problems with fluxcore are due to operator error. Always. Either using it improperly or at the wrong time. Dan is correct about the disc, welding thick steel with short arc mig is not the way to go. Spray transfer, fluxcore, pulse spray or E7018. Any of these are better than short arc on structural or stressed thicker sections of steel.

[liftdoctor]

Mike and Dan: Thanks. You have answered my questions well. I am not up on some of the welding terminology, but hopefully the books and video I have reserved for pick up at the library will help.
The lift doctor.

[bitternut]

As far as stress relieving, I would stick to the impact gun because it hits harder and compresses the metal better

Rocky D.......What do you mean by a impact gun? I have an impact gun but that is used with sockets. Are you referring to a hammer drill? If you are what do you use with it for peening, a flattened drill bit or what? Could you please expand on this subject for me. The only tool I have ever used for peening was a ball peen hammer.

[Guest]

Originally posted by bitternut


Rocky D.......What do you mean by a impact gun? I have an impact gun but that is used with sockets. Are you referring to a hammer drill? If you are what do you use with it for peening, a flattened drill bit or what? Could you please expand on this subject for me. The only tool I have ever used for peening was a ball peen hammer.

An impact gun is a gun that hammers...used in aircraft for driving rivets...I take the same gun, and rivet set, and grind the end if the rivet set flat...they normally have a depression to hold the rivet, and there are different diameters and lengths, too...then the impact of the gun is excellent for compressing a weld. The same gun is used in body work, with a chisel to cut sheet metal....it makes a heck of a noise!

It looks like this one at HF

http://www.harborfreight.com/cpi/cta...emnumber=32940