How to deal with this rust on fender

[Welder Sam]

Start as cold as itll run smoothly. Make sure the orange glow of the heat fades evenly toward the center of the weld/tack. If its off to one side, it didnt stick on that side. Play with some scrap till ya get it "feeling" right.

 

[plym49]

Start as cold as itll run smoothly. Make sure the orange glow of the heat fades evenly toward the center of the weld/tack. If its off to one side, it didnt stick on that side. Play with some scrap till ya get it "feeling" right.

Not being a welder, I am not sure I have a good enough idea of where to start. I realize that to you, this seems silly. Where would I start? BTW someone told me that the wire speed number should always match the heat setting. Is that right? Playing around with scrap, I find that a lower wire speed is better for me as it gives me more time to figure out what exactly I just messed up.

I usually staqrt folling around set at three heat and three or less wire speed. Where would you start?

 

[yolner]

I'm definitely no expert but my welder has a chart on it that suggests speed and heat for each thickness of metal. Another tip I heard on a tv car show was to start at high power and work your way back until you stop burning holes. Obviously you'd do this on a piece of scrap metal.

 

[Welder Sam]

Not being a welder, I am not sure I have a good enough idea of where to start. I realize that to you, this seems silly. Where would I start? BTW someone told me that the wire speed number should always match the heat setting. Is that right? Playing around with scrap, I find that a lower wire speed is better for me as it gives me more time to figure out what exactly I just messed up.

I usually staqrt folling around set at three heat and three or less wire speed. Where would you start?

Friend, trying to learn isnt silly. Not being familiar with your rig, i cant really say where to start. The last time i used a single phase machine, it was a 110v lincoln. I dont remember the model #. I ran it wide open on 14ga. Thats just where it felt right to me. Another good indicator for having it set right is the sound of the weld. A "tight, smooth sizzle" is real nice. If it pops and throws wire(stubbing), you have the eire speed to high. If it sound more like a pop... pop.. pop... your eire speed is to slow. You should have your nozzle about 1/2" from the material(stick out) and at a 10 degree angle. I really wish i knew how to explain it better. I just do it. Id be happy to show ya but i imagine thats a heck of a drive. Keep asking and trying. U will get it

 

[F18hornetM]

All my wire welders [i have 3 at home and 6 at work] have charts inside the door. Just set it at what the chart says for the thickness of material, wire speed, heat setting etc. Will be very close and often need no changing.
Also i don't usualy weld all the way around when putting a patch in. Tac good all the way around and it will hold just fine, with much less heat put in it. Also very thin metal can be welded this way without much skill.

 

[F18hornetM]

Forgot the picture.
Tig is nice and I have one I love, but I use it mostly on aluminum, wire feed can handle most stuff on these trucks and is easier to learn to use. I also dont like flux core wire on sheet metal. Lots of guys use it with good success, I just dont like cleaning off the slag and the flux can bleed through paint if not cleaned off very good.
I keep .023 solid wire in one and .035 solid wire in the other so I dont have to change wire becasue of material thickness

 

[plym49]

All my wire welders [i have 3 at home and 6 at work] have charts inside the door. Just set it at what the chart says for the thickness of material, wire speed, heat setting etc. Will be very close and often need no changing.
Also i don't usualy weld all the way around when putting a patch in. Tac good all the way around and it will hold just fine, with much less heat put in it. Also very thin metal can be welded this way without much skill.

My welder does not have a chart. It is a fairly large 240 volt single-phase unit. I looked up the Miller specs and chart on line, and it looked like it wanted me to set the level up at 6 for sheet metal with as high a wire speed. That just does not sound right. I do all right with light bracketry set at 3 heat and 3 wire or 3 heat and 2 1/2 wire. I once tried to spot weld sheet metal on the lowest setting and I had trouble either not burning through or just getting a cold lump with no penetration. Hence my questions as to where to start with sheet metal. I have not meant to hijack this thread so I can take this to a better place on this forum.

 

[Welder Sam]

If thats mid range on ur unit, give it a shot. Then go up or down from there

 

[F18hornetM]

All my MIGs are 240 volt, and all have charts, but the oldest one is only about 10 years old...Maybe yours is older. I have Miller and Lincoln. Sheet metal should be one of the lowest settings, not the hottest. What model/brand welder do you have? Sheet metal is very thin as you know, i wouldnt start at the hottest and move down, I would do the opposite.

 

[plym49]

All my MIGs are 240 volt, and all have charts, but the oldest one is only about 10 years old...Maybe yours is older. I have Miller and Lincoln. Sheet metal should be one of the lowest settings, not the hottest. What model/brand welder do you have? Sheet metal is very thin as you know, i wouldnt start at the hottest and move down, I would do the opposite.

Miller 200 and well over 10 years old.

Right, I did start at the lowest setting and I had the problems stated above. The Miller 200 chart I found on line said 6 and 6, and that just seems like crazy talk.

My welder:

 

[F18hornetM]

That looks like an old one we have at work, great welder, let me check for you, see what i can come up with

 

[F18hornetM]

If this is the right machine you have, Page 35 is welding parameters, its might be voltage 6 and wire speed at 50% on low range, depending on wire size

Miller - Service - Owners Manuals Search Results

 

[plym49]

If this is the right machine you have, Page 35 is welding parameters, its might be voltage 6 and wire speed at 50% on low range, depending on wire size

Miller - Service - Owners Manuals Search Results

Yep, that's the same manual I found on line. Voltage level 6 is the highest, I believe. Can that be right?

 

[Beerslayer]

That Millermatic 200 is a great machine. I wore out several of those.

If the drive rolls are spinning on a wire welder, replace the rolls and the liner too. The liner gets filled up with gunk and won't let the wire through. Don't forget to keep a fresh tip in there too. They wear out pretty quick.

All I have now is a Lincoln 120vac that I bought gently used off of CL. It works great on sheet metal and anything up to about 3/16". I just run .023 wire in it and use the CO2 tanks off of my kegerator. Works fine and I bought it used for $150

 

[F18hornetM]

Yep, that's the same manual I found on line. Voltage level 6 is the highest, I believe. Can that be right?

Depending on the metal thickness.
using .023 wire

18-16 gauge, voltage 3 or 4 with wire speed between 19-30%
16-14 gauge, voltage 5 and wire speed 40%
14-12 gauge, voltage 6 and wire speed of 50%
All on low range. Im not sure the thickness of what your welding. Someof the sheet metal on these old trucks is pretty thick, but then rust makes it lots thinner. just guessing, I'd start with about 4 and 30..and see what happens. Also on sheet metal, a continious bead is not necessary and will probably burn through.."stiching" or "pulsing" the trigger, making lots of good tacs, will usually do just fine. Good luck

 

[F18hornetM]

That Millermatic 200 is a great machine. I wore out several of those.

If the drive rolls are spinning on a wire welder, replace the rolls and the liner too. The liner gets filled up with gunk and won't let the wire through. Don't forget to keep a fresh tip in there too. They wear out pretty quick.

All I have now is a Lincoln 120vac that I bought gently used off of CL. It works great on sheet metal and anything up to about 3/16". I just run .023 wire in it and use the CO2 tanks off of my kegerator. Works fine and I bought it used for $150

We have several of those at work we use for sheet metal on the road. They are tough. I have a Lincoln 180 220 volt i keep small wire [.023] in my shop at home for sheet metal repairs. Pretty good machine. For bigger stuff i use a Miller 250 with .035 wire in it at home.