Thanks again guys,
I am going to try agian today, if it doasn't work I guess I will go get the gas setup. I wish it was aluminum so I could just use rivets. I am much better at bucking rivets than welding. I will let you all know how it goas.

Thanks again for all the help. <img src="/forums/images/graemlins/cheers.gif" alt="" />

links fixed (too many http's in there)
Image 1

(try a Snickers bar for cooling)

Well, I tried again today with the .030 flux core wire, still burning holes in the metal. I am ordering the gas conversion kit tonight. I am thinking of going with the CO2/Argon mix gas. What do you think? Or should I go with staight CO2?

definetly use the C25 mix. It is much cooler and spatters less. You might need to back your hole with a piece of sheet metal and just weld it in place. THe larger lincoln welders have a thin sheet metal setting that you turn on and off like this: with welder off turn wire speed all the way down. Hold the trigger when you turn on the welder, and listen for 3 or 4 clicks. then let go of the trigger. Turn off the setting: by turning the wire speed all the way down with teh welder off, then turn the welder on while holding the trigger. THe clicks indicate the change in the setting.

BAsically it makes the wire come out very very slow for 4 seconds while you build develop a steady current, and then it runs at a the selected speed. I doubt your little welder has the feature, but it is worth a try.

Thank, Trythis.
As you expected, my little Lincoln doas not have this setting. I should have my MIG upgrade kit by the weekend and I can try again. If I still cant weld with it I guess I will have to switch to Oxy/Acet.
Do you guys think I'll be able to weld exhaust tube with this welder? I'm begining to wonder if I waisted my money on this thing. <img src="/forums/images/graemlins/barf.gif" alt="" />

That's a handy little welder. You will get your money out of it. I did 95% of my straight axle swap with one. Use the flux core on heavy duty stuff (may still need to make multiple passes in some cases), and use the gas when you need to do finer welding with less spatter.

As for the thin sheet metal, use the gas at a higher flow rate than normal to help cool the weld area. You will also probably need to do lots of small spot welds and "connect the dots."

In the picture that is posted it looks like you are using a metal grinding disk to take off the paint in the trucks bed. I would suggest that you use a grinding wheel that looks like a green SOS pad; these are sold under the names 3m Roloc Disk, or Clean and Strip Disk (google it). The reason for this is that the grinding wheel you are using is removing too much metal (causing burn through) when all you want to do is strip the paint and remove contaminants. The roloc disk will strip the paint, lightly abrade the metal, and not leave behind any contaminants.

In your circumstance using a buzz box and some 0.035ö flux core wire is not ideal for welding sheet metal. It burns too hot. Like others said get the GMAW setup and thinner wire but if you cannot afford investing into the setup right now you could get away with doing some non cosmetic sheet metal work in your trucks bed with what you have right now.

Use these pointers that have been passed to me and I have figured out while welding hundreds of patch panels in my toy with the same flux core setup that you have:

The most important thing to do is prep the metal with proper fit up and cleaning. After you cut out the rust and prep the area with the grinding wheel clean it really well with a cloth and acetone. After you remove the corrosion and mill scale from the edges of the patch piece with a wire brush clean this piece by wiping it with acetone as well, even oil from your hands will contaminate the weld. Make sure the paint and all contaminants are removed at least 1ö around the weld.
I find that it is easiest to cut the sheet metal so that it covers the hole like a patch so you are lap welding it just like you are attempting in the pic above. Cutting the sheet metal so that it fills the hole (butt joint) might look better but it takes waaay longer and is much harder to weld into place.
As others have said ôTACK WELDö the sheet metal only, disperse the heat by evenly spacing tacks out and moving around the panel to be welded until you fill in the entire surface of the joint to be welded. Get you welder dialed in by turning the heat down and wire speed and practicing a lap joint on scraps. Get a good ground!!

Fit the patch to the truck bed so that the gap between the base metal and the metal to be welded is less than the thickness of the welding filler wire. Get comfortable aim the gun and pull the shade (or nod), make your tack and move on to another spot to let the tack cool. Hammer the sheet metal to shape as you go with a ball peen hammer or body type hammer. Push the metal together with the hammer, make another tack and move on. Repeat hundreds of times.

If you still burn through a couple of times (and you will) grind the weld down and weld little tacks on the edge of the hole until it is filled. Make another patch if the burn through hole is big and thin. Try preventing burn through by aiming the gun more at the base metal (the truck bed). The reason for this is that the edge of the sheet metal heats up quicker than the base metal (think of lighting some cardboard on fire, the edges and corners will burn quicker than the middle of the sheet).

Also remember that flux core wire will deposit flux on top of the weld, for best results remove the flux from the tack weld before you weld beside it. Use a chipping hammer, or your trusty lil wire brush!

Well give this a try! I am sure it will help; it just takes a lot of time and patience! If you are fed up with this route and want to consider using pop rivets DONÆT. Use sheet metal screws they are quicker and work better.

Cheers and happy welding Brah

Got a gas torch and some brazing rod? Will get the same result as a good argon setup. You just have to spot it in. That is the way it was done before migs and tigs....

If you go Oxy-fuel, consider using silicon bronze, it doesnt have teh zinc in it and is much less toxic than brass

I am using 3M role lock, I'm using a course sanding pad rather than the scotch brite type pad. Thanks for the tips, I was trying to get the bed to look new so I did not want to do a lap patch. If I had the room I would tack a piece undernieth to help support my patch and disipate the heat. Unfortunately where I am working is just above the fuel tank and the frame runs undernieth as well. If I cant get it done with the gas attachment on my machine, I guess I will have to buy a oxy/acet torch.(new toy <img src="/forums/images/graemlins/smile.gif" alt="" />) I am cutting out the piece that I burnt holes in and starting over. Can't wait for my gas attachment to come in.