Jump to content
HybridZ

MIG welding


pjo046

Recommended Posts

I have been using my electric welder for some months now, and have learned how to do it by now. The only problem with electric welding is that I can't weld stainless or aluminium. The welder I have is a combined electric and MIG/TIG welder.

 

So, is it hard to do MIG welding compared to el-welding? When MIG welding, do you have to refill the gas bottle often, or is it very little gas that is used each time? I have never used a MIG or seen others do it, so if someone could explain what it involves that would be great. Is it hard to adjust the gas pressure properly etc?

 

Would like to be able to make the stainless exhaust system, the intercooler piping etc myself. :-)

Also, is there a problem with welding steel/stainless steel brackets onto an aluminium intercooler? The sparco unit I have came without any brackets on it... Also the flange for my Blitz BOV is steel, whereas my intercooler piping is stainless steel.

Link to comment
Share on other sites

I'm not an expert welder, but I've done a little MIG welding and just bought myself a Millermatic 175 (beautiful machine) recently. If you're going to get a MIG, get one with infinite voltage regulation and wire speed. Also, buy a more powerful welder than you think you'll need... you can use a big welder to weld small stuff, but can't use a small welder to safely do big stuff as easily.

 

MIG welding is pretty easy in my opinion... I have an 80 cu. ft. bottle... so it lasts a long time. Really, you don't use a ton of gas... and it is simple to set the pressure. Just turn the regulater dial, pull the trigger and see what pressure reading you get... then adjust accordingly.

 

When welding aluminum or stainless with a MIG though you need some slightly different equipment. You'll need a special gun for aluminum wire feed. Also, when welding aluminum or stainless (versus regular mild steel) you should use a different gas mixture.

 

Most MIG welders can also do flux core welding. This is a process which requires no external gas, but it tends to produce more spatter and the welder runs hotter (so blows through sheetmetal more easily).

Link to comment
Share on other sites

By electric do you mean SMAW (shielded metal arc welding), ie consumable electrode with a flux coating? If so I know you can weld stainless steel with SMAW, I'm not so sure about aluminum (I think you might be able to, it would just be difficult and messy)

 

MIG welding is alot harder for me than TIG. Other people will say the opposite.

When TIG welding I usually set the flow to 20 CFH (Cubic Feet per Hour).

 

Starting a MIG welder is easy, you pull the trigger, wire comes out of the gun, touches the metal, creates an arc, and starts depositing wire into the weld bead.

You could braze-weld steel/stainless to aluminum, but not weld. Welding aluminum is REALLY easy if you have a machine that will do AC and HF (High frequency).

Welding steel to Stainless steel is fine, you just need to use 309 filler rod.

Link to comment
Share on other sites

Are you sure it can do MIG and TIG? if it can do that then it can do stick(SMAW or "Arc welding) welding as well.

A welding power source to do MIG and TIG generally costs about $3000 and up.SMAW and TIG are both constant current processes.

MIG is constant voltage wire feed welding.

 

SMAW is the conventional welding with electrodes with flux and has been in use since the 1800s.

Link to comment
Share on other sites

currently you can't find a welding machine that is a 3 process (MIG,TIG,SMAW) that has High Frequency for aluminium or have HF arc start. all of that is for TIG. I have welded aluminium with SMAW-AC but it was not pretty...I could have welded better by spitting on the metal.

Link to comment
Share on other sites

I have been using my electric welder for some months now' date=' and have learned how to do it by now. The only problem with electric welding is that I can't weld stainless or aluminium. The welder I have is a combined electric and MIG/TIG welder.

 

So, is it hard to do MIG welding compared to el-welding? When MIG welding, do you have to refill the gas bottle often, or is it very little gas that is used each time? I have never used a MIG or seen others do it, so if someone could explain what it involves that would be great. Is it hard to adjust the gas pressure properly etc?

 

Would like to be able to make the stainless exhaust system, the intercooler piping etc myself. :-)

Also, is there a problem with welding steel/stainless steel brackets onto an aluminium intercooler? The sparco unit I have came without any brackets on it... Also the flange for my Blitz BOV is steel, whereas my intercooler piping is stainless steel.[/quote']

 

Its kinda hard to know what process you are reffering to when you say "electric welder". MIG, TIG, and stick (SMAW) welding are all "electric welding." TIG welding is kinda like oxy/acc welding but the heat comes from the electrical current that passes from the tungstan (sp) electrode through the shield gas (usually argon, or argon some mixture). to the base metal. metal is added by filler rod like with oxy/acc. Gas (argon) is used to shield the metal from oxidation when heated, almost like adjusting the flame on a oxy/acc torch to have a balanced flame.

 

SMAW you can weld stainless (I don't think alluminum) its just that this process produces to much heat and will cause the metal to warp alot more and/or burn through. SMAW is usually used on thicker metals.

 

You can weld alluminum with MIG or TIG. With MIG you need to switch to a new gun, line and spool, because if you use a line previously used for steal or other metal, you won't get the as good a quality that you normally would.

 

With TIG for alluminum, You need (don't really have to, ut it helps) to round off the end of the electrode and set the welder to AC current with electrode negative setting. This will cause the current to run from base metal to the elecetrode, causing the layer of oxydation on the alluminum base to "lift" off the base so when it switches the current to electrode positive cycle (AC current) it will leave the weld area cleaner to lay down some filler metal. Alluminum is som tricky stuff. The oxidized aluminum melts at a higher temp than the base alluminum. Welding with the AC current setting will cause the metal becing welded to heat up faster (and also it being alluminum). You would still want to try to remove the oxidized layer with a stainless steal wire brush. If you used a SS brush on steal already I wouldn't recommend using it, it has to do with ferious, non-ferious metals (sp).

Link to comment
Share on other sites

Hmmm. I wrote that other post very late yesterday, and obviously I was a bit tired. :-)

 

- When I say I have done electric welding with it, I meant welding without gas, by using a flux-core metall wire.

- I said it was a combined MIG/TIG welder, but what it is is a combined MIG/MAG welder. :-) Not sure what MAG stands for, perhaps it's a Norwegian term you don't use?

 

So sorry for the misinformation.

 

" MIG is constant voltage wire feed welding." Ok, so that means I have been MIG-welding all along then? Only withoug gas. So, MIG welding WITH gas, is in fact easier because you don't get the same amount of burn through and less splatter? All I'll need is a bottle of gas and a pressure regulator? Although I see it's recomended to get a separate gun, line and spool for SS welding. Does this make a huge difference, or will it be ok with using the same equipment as with the no-gas welding?

Link to comment
Share on other sites

I see, that clarifies thing.

 

Well when I was reffering to getting a separate gun, line and spool, I was reffering to alluminum. With stainless it doesn't matter. You can actually weld SS filler onto normal steal and vice versa, but its not recommended.

Link to comment
Share on other sites

depends. If its for currosion (sp, im tired) resistence I would go SS, but if its structureal I would go steal. Reason being, the carbon content of steal compared to SS. the more carbon the more stiffer the metal, but the downside to that is, it looses flexability which mean its more likely to crack intead of bend. Its a trade off, now SS is more flexable so not so good for structureal things. Thats why you don't see that many SS structureal pieces inless its in a tube or is a thick piece.

Link to comment
Share on other sites

ok...MIG and MAG are almost the same thing. MIG (Metal Inert Gas) uses a shielding gas that is inert (welds "softer" or "smoother"). MAG (Metal Active Gas) uses an active gas such as cO2 (welds stronger and has more penetration). FCAW (flux cored arc welding) uses the MIG setup but the wire has flux in the core so it can be used with or without shielding gas.

 

CAUTION do not MIG weld with solid steel wire without shielding gas!!! You will have all sorts of oxides in the weld and possibly have a lot of porosity. MIG welds without shielding gas are not safe!!!

 

I think what people do is use the SMAW/GTAW power supply and a spool gun to do MIG without buying a separate machine.

this is not possible 99% of the time. No major welding company has a set where you can attach a wire feeder system to a SMAW/TIG power source. The ONLY company I have seen that has this capability is ZENA. their website is www.zena.net. they make car mounted welding systems and a backpack welder that is REALLY cool and is a GREAT PRICE.

Miller XMT 304 welders can run all three processes except TIG-AC and they cost about 4 grand with the MIG/TIG/SMAW setup.

 

Welding Stainless to mild steel will work with a stainless wire BUT...The stainless in the weld and near the weld will no longer be as stain resistant and will easily rust. Stainless is not stain-proof!!! that is why they call it stainLESS...because it stains less than regular steel. just leave a piece of stainless outside for a while and see what happens. Medical grade stainless is the most resistant to oxidation(rust) because it must go into your body and not damage you from an operation.

Link to comment
Share on other sites

The best way to weld stainless to mild steel is with the 309 wire, it's formulated just for this. Another filler that works pretty good for bi metal welds is RN-82, it's kind of hard to find in most weld shops, as it's used for welding on Inconel piping on nuclear reactors. If you can get some though, it will weld just about anything to anything within reason of course. Aluminum to steel is not going to happen with any process available to hobbyists. The big shipyards weld strips of aluminum and steel together by a process called explosion welding, basically bringing both metals to a molten state and exploding them into each other. These strips are then used to weld aluminum superstructures onto steel hulls. It's been my experience that TIG welding is the best all around process for aluminum. Sure, you can weld some really pretty beads with a MIG gun, but at the expense of several hours of setup time to get it running well. TIG is more about technique than machine setup. Chances are pretty good that if you have a crappy looking weld with TIG, it's not the machines fault :) I've seen and tried SMAW aluminum welding, and can say with complete confidence that it is a complete waste of time. Aluminum brazing rods are available, and I've seen demonstrations where aluminum has been brazed to steel with decent results, this would probably be the best option for welding steel brackets to an aluminum radiator other than using epoxy.

 

Mike

Link to comment
Share on other sites

The best way to weld stainless to mild steel is with the 309 wire' date=' it's formulated just for this. Another filler that works pretty good for bi metal welds is RN-82, it's kind of hard to find in most weld shops, as it's used for welding on Inconel piping on nuclear reactors. If you can get some though, it will weld just about anything to anything within reason of course. Aluminum to steel is not going to happen with any process available to hobbyists. The big shipyards weld strips of aluminum and steel together by a process called explosion welding, basically bringing both metals to a molten state and exploding them into each other. These strips are then used to weld aluminum superstructures onto steel hulls. It's been my experience that TIG welding is the best all around process for aluminum. Sure, you can weld some really pretty beads with a MIG gun, but at the expense of several hours of setup time to get it running well. TIG is more about technique than machine setup. Chances are pretty good that if you have a crappy looking weld with TIG, it's not the machines fault :) I've seen and tried SMAW aluminum welding, and can say with complete confidence that it is a complete waste of time. Aluminum brazing rods are available, and I've seen demonstrations where aluminum has been brazed to steel with decent results, this would probably be the best option for welding steel brackets to an aluminum radiator other than using epoxy.

 

Mike[/quote']

I agree. You can weld Aluminum with oxy/acc but the heat affected area is so much greater and all that cleaning to get the oxy/aluminum off takes so much time.

 

I've seen demos of aluminum brazing with propaine torches. I saw it on a "low budget" (homemade) infomercial on tv, I think they called it aluminoid or something like that, I know its called something else though.

Link to comment
Share on other sites

  • 2 weeks later...
Guest SoCal_Brian

Just TIG weld the aluminum, that way you it's easier to control the heat. Welding aluminum isn't the easiest task, but it's really good if you can do it. :mrgreen:

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...