Some good advice here as always. Been playing with the new regulator. Removed the fixed regulator and replaced it with a $25 one from Amazon. Also bought one from Harbor Freight but liked the Amazon one better. It has a glass tube with a steel ball in it and the Harbor Freight had a gauge. Amazon also cheaper. That helped. Watched a couple of vidios that helped. They advised that the ground clamp on the Hobart was junk and advised replacing it or wraping it with a piece of copper stranded wire. Did that and it works better. Also discovered that the tip was not extended out of the gas shield properly. Adjusted that and it works better. The more I weld with it the better I get and the more confident. Also adjusted my auto darkening helmet to a lighter setting and I can now see the weld better which helps. Another thing I need to try is to clean the back side of the metal. I've been hitting the front side with a sanding disk but realized that on an old fender the back side is rusty and dirty. With a butt welld I think this may be an issue. Will work on that when I get back to it tomorrow. Thanks again for all the help.

Another thing you might consider is the wire size you are using.  Wire for small MIG welders comes in two diameters 0.023 and 0.030.  The smaller dia takes less energy to melt and so you can use a lower setting for thin sheet metal. The dis advantage with thin wire is that it will buckle at the metal liner for the cable if the wire does not start an arc as you pull the trigger.  This is another reason for very clean weld joint preparation. I would check with a welding supply house for a recommendation of which wire size to use (not Harbor Freight!)  The wire should be bright copper color color. And if I get a dingleberry on the end of the wire I cut it off so that I am starting the arc with a clean sharp wire end which will establish the arc faster. 

If you are filling trim holes by welding them over Eastwood sell a nifty device that magnetically holds a copper heat sink over the hole.  The copper chills the molten metal in the hole and makes filling small trim holes much easier without a lot of excess heat. You still need to remove all traces of paint and rust.  But I don't think solvent cleaning is necessary for MIG on carbon steel and I would not have acetone anywhere near a spark!

My Hobart 110V machine recommends 20 CFM argon/CO2 for all metal thicknesses but this might depend on your torch's "gas lens"  Harbor freight does sell a useful regulator for under $40.00

Doug T

The Highlands, Louisville, Ky.

You got a lot of good advice here. A few other things to think about. A gas regulator on the tank will not be able to raise your pressure from a factory preset, unless you bypass the preset some how ( I've never seen a preset one either). Check to make sure your gas hose isn't kinked,cutting off gas supply. That happened to me once, and it was bad. Also check your that you tip is the right size and moves freely on the wire. Tips are cheap , and a deformed one will mess up your feed. Good luck.

Hi there.
 
First I am no welder and have no knowledge of the MIG process. I am in the middle of building a dual 2.5 inch stainless exhaust using a small basic TIG unit.
 It uses a pure Argon tank with a single gauge (tank contents) and two flow meters reading cf/h, one for the torch and one for purge.
The one thing I have learnt is practice, practice, and more practice.  I purchased several feet of tube cut it into about 1- 1.5 inch lengths and started sticking them back together after about 2 months I could stick them together.  I still cannot achieve the  stack of dimes look but I have penetration and no holes.
Cleanliness is very important. Bright shiny metal and an Acetone wipe. At present I have an attack of Hives that I believe was triggered by the Acetone so be careful.
Re MIG most people I know who use MIG on sheet metal (auto bodywork) use spot welds rather than running a bead. I believe some MIG machines have a specific spot welding setting.
Lastly I would highly recommend a visit to http://www.weldingtipsandtricks.com/  . I have not watched any MIG videos but I picked up a ton of info regards TIG.
stuey


 
 

I'm using argon/co2 mix. Got a retulator today and starte at 30cfm and tinkered with it for some time today. Kicked the heat up a noch. Working better. I know to make very short welds on sheet metal. I never thought about the wire having gotten rusty or dirty in storage, It was in an unheated wood storage shed for a lot of years. Will look at that next time I am working on it. I've already had to play with the tension on the drive wheels. I was always prety good with an acdtyliene torch but only fair with a stick welder. As with anything practice makes perfect. I figure by the time I get this Mustang done I should at least be getting decent with it.

metal being welded must be clean,any rust or paint will cause issues, if welding a repair part be sure the 2nd part is sound. also start with small tacks till you are sure the 2parts are correct. re alignment.  I found but welds are for those who are experts.. get a crimper so you are ending to good metal. on a mustang work on arias that are not visible to get practice,they are on the thin side to start. don't do long welds as heat builds  burn threw is always there

Rusty wire is at the top of the list for creating problems for MIG welders.  This ends up being an issue with welders that are stored in non-heated areas.  Never used a ‘fixed regulator’ for the gas and until you mentioned it, didn’t know one was even available.  I've also had issues using straight argon as it welds at a cooler temperature.   For MIG welding I use a mix of argon and carbon dioxide.   I typically have my regulator for wire welding set at about 20 cfm..

Lorena, Texas (South of Waco)

I had issues like that when I was learning.  I discovered that I didn't have the wire drive wheels tight enough so the wire feed was inconsistent.  Made that tighter and I was instantly a better welder.


Lawrenceville, GA

Is the polarity right?

  Vic Correnti

Do you have a book of any kind with the machine? Some things that can be a problem are; Poor fitup, contamination in weld area, heat setting wrong,  I've seen a book that indicated that most welds should be pulled, but sometines it's better to push the weld where more heat is needed. Best to try a sample piece sometimes rather than make a mess of the needed weld. Also, 110V machines should be avoided for heavier work that is critical, such as say a heavy truck trailer hitch.. I don't weld any more & a lot of my work was with stick, so others here more into it, may have other suggestions.   


Paul