Welding Tips and Tricks

How do you prevent snotty welds when MIG welding. Is the voltage too low, wire to fast, not enough gas. I am welding on car chassis. Gave up learning TIG for now, need to get this chassis work done.
Thank You,
Bill

Stop learning on the car. Learn on the bench!

Get some scrap, put it on the workbench, and PRACTICE!

If you are on a chassis, you are likely welding 11 gauge or 3/16. Set your machine at 19.5V and 280-300 IPM, and try it, flat, on the bench. If your machine has a CV/CC switch, be sure it's on CV. Dial in your wire speed, not your voltage.

What gas are you using? Should be 75% CO2, 25% Argon. If you're using 100% Argon from your TIG attempts, that's a big part of your trouble.

Good luck.

Thats exactly whats going on. I am uding straight Argon, didnt think it would make too much difference. Will it make my welds weaker. They are not snotty anymore, they look more like stick welds, not flat.
Thanks,
Bill

Oh, yeah. BIG difference.

I once pulled the wrong bottle for a SS weld. I won't make that mistake again!

To MIG carbon steel, you need 75/25.

You will never get satisfactory results on 100% argon.

I wanted to finsh this weekend. What if I use the Flux Core instead? Will I get better results because I have been trying on scrap all day and it is not working very well. The MIG welder I borrowed is only a Hobart 140 Handler so there is not really much voltage control. It only has 4 settings for voltage. I notice the welds look like crap and it seems to be only on top and not blowing through and feels and sounds very choppy. Or will waiting until during the week when I can get the right gas the best thing? All my welds will most likely be ground down smooth anyway unless the 75/25 will make that much of a difference. I was on youtube watching guys MIG weld and see no resemblance.
Thanks,
Bill

67GTO,

Check out this site or Lincoln's or Miller's website for TIPS on MIG Welding.

Wait until you can get the correct gas mixture. Verify you have the correct flow rate (cfh).

Do not weld on a car frame with a 120 VAC welder, if the frame is 3/16" thick consider the mass of the metal you are welding.

At a minimum use a welder capable of 180 Amps, constant voltage DC MIG Welder. (Lincoln SP-180T, Millermatic 180AS)

Make sure you have the correct stick-out, and the MIG gun is at the correct angle relative to the metal you are welding.

Ensure you have a good ground on bare metal, on the frame, near the location you plan to weld.

Disconnect the (+) Positive side of the battery.

Practice on similar metal on the welding bench prior to welding on the car frame, remember the liability involved with welding on vehicle frames.

Wob

Actually the part of the chassis I am working on is the rear clip which is very thin, not 3/16" maybe 1/8" at best. I will wait for the gas, not happy with the stuff I finished, they look solid but need too much grinder work before painting. Also my ground was on a painted are, not sure how adversly that effects the weld but being an elevator guy and working with electricity all the time, painted surfaces are not very good conductors. I am borrowing this welder, dont really want to buy one, I will go back to TIG welding scrap sheet metal before I hit the body work. I am MIG welding the chassis repairs to save time and get this thing painted and start building the rolling chassis. I have boxes of all the parts and am tired of looking at them. Thank you for the input, I take all the advice and info very seriously as you guys know what your talking about.
Thank You,
Bill

OK I got the right gas 75/25 and just hit a piece of angle iron to see how it worked. It is not bouncy anymore and I can drag a bead. Is it supposed to look nice and shiney or should I be satisfied with a dark high bead. I had this thing set on level 4 which is the highest with gas at around 40. The angle iron is only about 3/16 at best. When I finished the bead there was an indentation in it at the very tip. Is that correct. I was welding two pieces together.
Thanks,
Bill

67GTO wrote:... When I finished the bead there was an indentation in it at the very tip. Is that correct. I was welding two pieces together.
Thanks,
Bill

Perfectly normal. What you do here is called "buttoning off/up". When you reach the end of your weld, stop, pause and let the color of your puddle go to brown, and hit the trigger again for a second. (Put a big, fat tack in that crater while it's still really hot!)

It sounds like you're getting closer to what you want.

Steve

Well thats good to hear. I am on vacation and staying home most of the week next week so I will get back at it, been working a bit of OT the past couple days, actually its been about 42 hours since I last slept. Blood money. Thanks for the pointer Steve.
Bill