mig welding questions

[JDMills]

I am going to be doing some welding on a 46 WDX Power Wagon Cab, looking for any tips for producing a flat weld which wont need much grinding. Using arrgon/Carbon dioxide mix with a . 30 wire. (I think) Some of it will be a vertical weld, and I have had the most luck traveling down hill so far, but I am dont have tons of experince welding. My Buddy got me started, and I have found out that grinding down those welds takes for ever!!



so far a clean base metal, and slow wire feed seem to be working the best. is there a pattern to follow that works best at spreading the heat/work puddle out? (circles, zig-zag or some thing else)

Thanks,

Jason

 

[budctdca]

I like to make little "e's" with a steady hand and that seems to work well, for a good, flat weld, make sure you are getting enough penetration so that your not just beading up and splattering on the top of the metal. I prefer stick welding for flat welds, but for a wire fed, get some self-shielding unless you have gas.

Luke

 

[JDMills]

Thanks Luke, will try some 'e' s and see how that works. allready have the gas set up. played with flux cored wire, it makes a mess!!! and stick welding and I just seem to punch holes and make lots of smoke, so I stay away from it if I can.



J

 

[CIverson]

For sheet metal I like using a . 023 wire, seems to be easier at not burning through.



I usually just tack, spacing the tacks apart about 1 to 1. 5" then letting it cool a bit, then tacking between the other tacks, and so on until everything is welded w/ the tacks. Then I use a flap disk on my grinder to smooth it all out, don't use a grinding disk!



After that I fill any holes that might be there after grinding and check w/ a light behind the panel to see any pinholes. Grind, and recheck until it's perfect. Then go over it a bit w/ a rough sandpaper on a block to smooth it out a little better if it needs it.

 

[JDMills]

Dont use a grinding disk?? woops, all ready did, why is that bad? guess I should go get a 'flap pad' for my grinder? Have you got any suggestions for welding overhead?

 

[CIverson]

well, you can use a grinding disk, they just don't leave as nice a surface.



The disk tends to make more heat and gouge the metal more, from what I've experienced.



I use a 60 grit wheel (get mine at fastenal and like them) to get the weld down close to the sheet metal. It eats the weld alot better than a grinding disk I've found too, alot faster. Then I move to an 80 grit to smooth the weld right into the sheet metal.



When I have to weld overhead (I assume you mean lying on your back, welding up?) I try to have alitte more wire stickout, and hold the tip of the gun at about a 45deg. angle to the metal. That way you aren't pointing the nozzle straight up at the weld. Then tack like I mentioned before. That's the best way I've found for doing it, but I'm just a self taught backyard welder.



Here is a pic of a cab corner and rocker panel I did. The rocker I smoothed with only a flap pad, at it looks decent, you can see the tack method on the cab corner, which I hadn't ground on yet. I was pretty happy w/ the results for my 1st time doing body work.



#ad

 

[justinp20012500]

I would have to say metal preparation and cleanliness is key to a smooth weld.



You don't have to weld with a constant bead; you can just spot weld a smooth looking bead.







Justin

 

[JDMills]

Civerson, that looks like a real nice job to me. thanks for sharing you experiences. I will go get a flap pad to make this thing look better.



Justin, what you say is reinforcing my intuition. guess I will do some sandblasting next time, then it can be finished up all in one or two fell swoops.



Thanks fellas,



Jason

 

[CIverson]

now that you mention sandblasting, don't sandblast sheetmetal unless you are extremely good at what your doing.



Sandblasting makes alot of heat, and it is an abrasive, which means that it impacts with force to clean the surface. That translates to warping the sheet metal, I've heard people can do it w/o warping, but I've never met one yet!



Just thought I'd put that out there incase you hadn't heard.



I just bought myself a soda blaster for stripping the truck in that picture and my '72 cuda that is patiently awaiting it's turn to get worked on.



oh, and thanks for the compliment!

 

[JDMills]

The sheet metal on that old goat (the 46 dodge) is fairly thick, Not saying that I wont mess it up, but it as all but useless right now. I used a sand blaster on my M-37 and did not notice any trouble, although it was no prom queen when I got it done. dont see as I have any other economical options, and the 'get it done' devil growing louder... all of that being said, I think you are correct, and I probably will end up warping the metal a bit. will try to be as light handed as I am able.

Jason

 

[MMiller]

I agree, you have to be carefull sandblasting sheetmetal. I have seen many antique tractor hoods not fit right after sandblasting. It can very easily strech the piece you are working with.



As far as overhead welding, just flip the truck upside down for those welds. :-laf Or do like I do, call my brother when the welding gets out of my abilities. He used to work in a fab shop, were they welded a lot of stainless and everything else. He makes it look easy.



Michael

 

[DValentine]

I agree with most of the suggestions. Is your machine 230 volt? I would imagine it is, if you are going to run . 035 wire. I would go with the suggestion of using . 023 wire for sheet metal. The puddle is easier to make, and easier to control. To weld over head turn the amperage and wire speed up a little more than you use for flat welding. I suggest finding some scrap and practice a little. Butt welds are not easy in a vertical, or overhead postion when starting out. Down hand welds are ok, but not as strong as a vertical weld. Good luck.



Dave

 

[Hoefler]

I reverse the polarity for sheet metal. You can also go to a straight CO2 gas that will help with burn through.

 

[swankmetal]

if you can manage a gap between the two pieces that are being welded about the size of the wire you're using, you will do a lot less grinding too.



dave

 

[dgarcia]

Did change you polarity when you went to the fux core?

 

[Turbo Thom]

JD... ... ... ... ... The wire welder was intended to be welded down hill. . 030 wire will work, but like has been said, the . 023 is a very small wire that burns cool. I've had my best luck "walkin" the wire. The welds are a little flater and not as much build up to have to clean. Flux core? I hate it. But it's sold because other folks like it.



. . Preston. .

 

[JApol]

My dad rebuilt a '30 model A and is in the process of rebuilding a '52 F-100. He had both frames and body panels soda blasted. Yes Baking Soda, won't warp, burn streach or any other bad thing to them metal as it takes the paint and most of the rust off.

 

[CIverson]

My dad rebuilt a '30 model A and is in the process of rebuilding a '52 F-100. He had both frames and body panels soda blasted. Yes Baking Soda, won't warp, burn streach or any other bad thing to them metal as it takes the paint and most of the rust off.

I just started using my soda blaster I bought this spring. It's really cool how it takes off the paint and creates absolutely NO heat at all. Only drawbacks are that it will not remove rust or softer surfaces (at least not well) like undercoating, or trim adhesive. The soft material absorbs the impact of the soda, which removes it's effectiveness as it removes coatings by "exploding" on impact. It's not an abrasive like other blasting media.