OT - Welding Wire Size
 

I am novice at welding and feedback on others experiences would be a big help. I am starting the body work and rust repair on my truck. I am trying to get better at welding sheet metal. I have a Lincoln Mig 210 welder. So far, I have been using .025 weld wire. What wire size do most of you use and how does it impact the welding process? I am still playing with the weld settings. I think my welder runs a little hot for the metal because I blow through sometimes even on the new metal. I have it set on either 20 or 22 gauge which I think is a little thin compare to what the metal actually measures. I do have .035 wire but haven't tried it yet. Any advice on wire size or adjustments to the welder for better sheet metal welding would be greatly appreciated.
Rob

Re: OT - Welding Wire Size
 

I use .25 wire for welding sheet metal. Low wire speed and high heat is how I set it up. I have had to play around with different outlets to get the amperage I need to get good penetration - my garage outlets suck but the one on my front porch works; so that is what I use. You can tell from the sound and the heat, once you become familiar with your machine. I learned how to weld sheet metal on my '65 and what changed the game for me is reducing the butt-weld gap to the smallest possible gap (i.e., approximately the width of my welding wire). How I do it is to place the patch panel section OVER the spot to be repaired and tack it in place. Then take your cutoff wheel and hold it at about a 45-65 degree angle to cut through both the original panel and the patch - tacking corners as you cut. This will give you a gap that is smaller than the width of any cutoff wheel and perfect for good penetration without having to put more heat in the panel from filling a larger gap. Start with repairs no one will ever see (e.g., inner rocker and cab supports) to get accustomed to your machine and to train your ear for the sound of a good weld (i.e., nice consistent crackling like bacon frying in a hot skillet). Good luck!

Re: OT - Welding Wire Size
 

That's great^^^. Thanks for sharing it.

Re: OT - Welding Wire Size
 

I use .025 for sheet metal and .030 or .035 for thicker jobs. It is a big learning process and I still have a long way to go.

Re: OT - Welding Wire Size
 

With holding the cutter at angle, it didn't make a very thin edge of each piece that would burn through? I really wanted to start like you recommended with places you would see. But, when I got to working on the cab, it was too cold to paint. I wanted to have the interior of the cab blasted end then epoxy primer before I started make repairs in the floor. But it was too cold. I didn't want to stop work on the truck for a couple months, so I started on the rockers and cab corners. Maybe I should have been more patient. I have tried the adjustments on my welder, but looking back, my mistake was I probably made a couple adjustments at one time instead of one at a time. Ie, slowed wire feed and temp at the same time instead of adjust one. My garage is pretty far from my house and electrical panel. I do have an issue with power drop. I really can't do anything about that at this time. But, in the future if I keep doing this kind of thing, I wll have to figure something out.
Thanks for the advice. I will continue to play with the welder settings. Working on the rocker next and removed more of the original metal then maybe I had too. But, I wanted to make sure I had good metal. Each patch gets a little better, so hopefully this one won't be so bad as far as blow through. I am already working to make the gaps smaller like you suggest.

Re: OT - Welding Wire Size
 

For butt welding sheet metal. I prefer as close to zero gap as I can get. I set the welder for a plug/rosette weld. Which is hotter and faster than when set for a continuous bead weld. On average I probably use .030 more often than .024/5. I usually don't use .035 unless I'm welding structural type projects at around 3/16 and up. For a given wire size. With the welder settings left the same. A larger wire will weld hotter or transfer more heat.

A larger gap will blow out easier than a smaller gap. Dirty/rusted metal will blow out more than clean. Both sides need to be clean. Not just the side you're working from.

Re: OT - Welding Wire Size
 

Large diameter flat welds like that are what I think we should try for. I think mp&c is doing a green 55 wagon or nomad which is amazing with welds that look similar.

Re: OT - Welding Wire Size
 

Does your welder have a setting for rosette welds? Mine I think just has thickness of the metal settings. I am working on the next patch now and am going for the thinnest gap as possible. I now I got too wide in some of my patches I have done so far. My welds are definitely taller then the ones in your picture. Are they flatter because of heat, wire feed, short pulls of the trigger, or all of the above? I will be working on almost the same spot on my truck after I finish this patch on the outside rocker panel.

Re: OT - Welding Wire Size
 

The welds are flatter because of the higher/more aggressive settings. This gets the weld pool up to temp fast, where it will make a full penetration weld that flows out. Rather than producing a weld bead that sits on top of the base metal. With minimal penetration on the opposite side.

My welder has a spot/plug/stitch timer. With some recommended heat/wire feed settings for that. I don't usually use the timer, but use the heat/wire settings for it. Clipping your wire after each plug/spot weld can also help. To get more consistent welds if your doing multiple plug/spot welds.

Maybe check your manual to see if it has spot/plug setting recommendations in it. If it's not on the machine.

Re: OT - Welding Wire Size
 

Thanks. I will talk a look at the book and see if that is an option. I will also try turning the heat up a bit at a time and see how it does. I might do the rocker patch like I have been doing and try the higher heat when I move to the floor next. Just in case I make a mess, it will be under the carpet. Thanks again for the advice.

Re: OT - Welding Wire Size
 

Just for reference, my mig has settings 1-8 for voltage/amp settings and variable 1-10 for wire speed.

Recommended setting for a continuous weld, for 18ga with .030 wire is, 3 & 4 respectively.

For spot/ plug it's 7 & 6

which is almost exactly the same settings for a continuous weld bead for 1/8". With the wire speed being about a 1/2 setting slower for the spot/plug.

Re: OT - Welding Wire Size
 

Check out Fitzee Fabrications on you tube for great tutorials on the cut and butt method and other sheet metal tips.

Re: OT - Welding Wire Size
 

I watched one of Fitzee's videos yesterday and will be watching more. I watched the one that he describes cutting the panel at the 45 degree angle like you described. I will be trying that on my floor patch panels. Thanks for the tip.