Okay --- those are "dirty" MIG welds --- so something is going on. There's too much splatter and crap around the series of tack welds you've laid down and they don't look to be "wetted" out much either.

#1 - Are you sure your gas bottle is on and it's not down to the bottom in pressure??

#2 - Give us some data -- tube gauge - and your welder settings including GAS flow rate

#3 - Are you cleaning the INSIDE of the tubing?

#4 - what wire are you using - as in specs and supplier.

#5 - are you snipping the end of the wire at a 45* angle after or just prior to welding so you're not welding with a ball and smoke on the end of the wire.

Answers are in blue. By wetted, do you mean the welds don't appear to be melted into the steel and are more on top of the metal?

Thanks Greg.

I also noticed you had a lot more of spatter around the weld than I usually get but didn't mention it because I didn't have a solution? (I barely qualify as novice, darn sure don't need to be critiquing).

What's causing all that excess spatter, experts?



Jeff-

Wire feed on a MIG machine is controlling AMPERAGE -- while your other control is VOLTAGE... turning down the feed speed is turning down AMPERAGE. Welding is the combo of voltage and amperage.... So, of course, without being there and seeing what's happening etc - I'd bump the feed up rather than turning it down. Increasing the amperage will help you wet out the weld --- which is something I noticed right away.

Also -- after NOT welding for awhile (like hours/days) - the shielding gas can/does escape your MIG gun.... so before welding after not having welded for awhile - run 10" or wire and this will purge the gas.

Snipping the wire at a 45* angle will have the machine using the voltage on a smaller contact point - thus increasing the heat momentarily - it's a good trick on thin materials. Think of this like the tip of a spark plug and the 'gap' and size and shape of the electrode strap.

If you're still having issues -- I'd turn the VOLTAGE down before I'd turn the WFS (wire feed speed) down. But try to learn to weld with the parameters they say first. The machine is dumb - and you're smart - and you can make adjustments to yourself that the machine can't. LOL

Far from an expert but here is a good reference. Page 15:

http://www.millerwelds.com/pdf/mig_handbook.pdf

Don

Get a piece of same gauge material and test your settings and techniques until it's right. I'm a fan of .023 wire for this application.

The RECOMMENDED wire diameter for this gauge material begins at .030 and up to .045


.023 is for 18 gauge and thinner materials. This is the Welding companies chart not mine.


BTW -- a GOOD welder can weld most anything with anything - like a golf stroke - it's not the club...

Thanks for the information everyone. I appreciate the feedback. I'm going to play some more with it this afternoon.

The pieces I've welded so far are test pieces. I have a lot of joints to weld on the headers. No sense in making it harder on myself by doing it wrong the first time.

Remember to back grind out the contaminated welds that were previously put down.

Better?

http://i472.photobucket.com/albums/r...pscgsf4npj.jpg

http://i472.photobucket.com/albums/r...psu3agpa4e.jpg

http://i472.photobucket.com/albums/r...psqutydmzm.jpg

Only changes I made from previous was to go down to setting number 2 and upped the wire speed a little. To me, it looks a lot better. I tried a couple different techniques including just moving in a straight line. Going around the tube is some what of a pain, but oh well, I'll practice. The last picture is after grinding. Initial tests show it doesn't leak through those welds. That was a pair of welds, too.

Thanks