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And that's why he'll never let you drive it.

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mobilito ergo sum
I drive therefore I am

I can explain it to you,
but I can't understand it for you.

Again, I really doubt you can properly judge a weld from a photograph. In person, yes, if you're good. I cut up too many perfectly good welds early on in my build based on people looking at photos and declaring the welds were cold. Shadows and lighting.

After that frustration I went and got a professional welder friend of mine to come out and inspect the finished chassis. He wasn't wildly impressed, but said he'd ride in it when I was done. And he has.

I know, have to crash my own first

uh oh, more thread hijack.

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The B-3 build log: http://www.locostusa.com/forums/viewtopic.php?f=36&t=13941 unfortunately, all the pictures were lost in the massive server crash

The beginnings of the Jag Special,
https://www.locostusa.com/forums/viewtopic.php?f=36&t=19012
Again, all pictures were lost.

I know right? I got myself over that by doing some destructive testing before I touiched my welder to my frame. on my youtube page theres a video from 2010 (with over 46,000 views!!!! no lie!) called "MIG Welding practice" towards the end, I have a bunch of fun with a big old ball peen.

once I bashed on that awhile, I wasn't so worried about weld adhesion, based on looks.

over the last three years though, I've some to understand that the general look of the bead isn't as important as the appearance of good heat sign in the joined pieces.

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The B-3 build log: http://www.locostusa.com/forums/viewtopic.php?f=36&t=13941 unfortunately, all the pictures were lost in the massive server crash

The beginnings of the Jag Special,
https://www.locostusa.com/forums/viewtopic.php?f=36&t=19012
Again, all pictures were lost.

Oh there never was an issue with strength with the size of the tubes and the amount of weld but I liked your choice of engine and you sound like a practical guy who's keen on always improving and that's why I chimed in about your welds and will again ....



Then I suggest the next steps for you to try is to reduce your stickout if you're confident with your hand control and turn the gas down as far as you can.

All MIGs incorrectly come with recessed tips but this is good because it stops amateurs welding a ball onto the tip every 5 minutes but the downside is it keeps the pool cooler. Just trim your torch gas shroud shorter, if you don't like it just put a standard length one back on, nothing lost.

Nearly every home welder uses far too much gas cooling the pool too quickly, try slowing your flow down as far as you can especially in tight areas where the gas can't escape easily. Saves money too.

Good tip, thanks. I did burn through this last bottle of gas really quickly, I think I do have the flow turned up too high. My nozzle is about due for replacement too, maybe I will try modifying it before buying a new one.

Bg, when I got back into MIG (after a 25 year hiatus) I was surprised at how fast I went thru shield gas too, even at the recommended 25 CFM setting. I've gotten a bit better at saving it, but I'm going to try lowering my flow as well, on the next batch of welds.

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The B-3 build log: http://www.locostusa.com/forums/viewtopic.php?f=36&t=13941 unfortunately, all the pictures were lost in the massive server crash

The beginnings of the Jag Special,
https://www.locostusa.com/forums/viewtopic.php?f=36&t=19012
Again, all pictures were lost.

The HAZ is definitely the first place to look for penetration. If the weld looks clean (no brown, yellow, or black), has no porosity (visible holes in the bead), joins smoothly into both parent pieces, and leaves a HAZ that is at least the parent material thickness width from the edge of the weld, then you are likely good to go. If one of those simple criteria is not met, you should be looking at it more carefully. That said, bgkast's welds look good in the pictures.

25Cfm is probably excessive for the rate that most people weld at (slow feed and travel). If you are welding in an enclosed area that has no appreciable drafts, your flow can be turned down even further. If you get too low, you lose your laminar flow and air can be drawn into the weld by the turbulent gas swirling around the nozzle tip. When you hit this point, you'll know it. The sound of the weld will change and the finished product will show contamination.

The roll cage works!



I'm almost done welding everything up. I also got a fuel door from an SRT-8 off of Ebay. It fits the Miata filler neck great!

After much gymnastics the chassis is completely welded.

Except for the 2 joints I noticed after taking off all of my welding gear for the night.

I'll show my age here, but when I went to welding school we ran 100% CO2 at 10-15 cfh

0.020 wire, medium cup, cup and tip set flush. If you were welding in a really drafty area and noticed porosity, turn the flow up, but we never got above 20 cfh.

Most "modern" settings are aimed at selling gas, not making great welds.

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Too much week, not enough weekend.

OOPS I did it again
http://www.locostusa.com/forums/viewtopic.php?f=35&t=17496

Blood Sweat and Beers
http://www.locostusa.com/forums/viewtopic.php?f=35&t=15216

i use 11 litres per min. but then i'm european, and my tip sticks out about an 1/8"(3.2mm)

i have only changed the shroud once since 1993 and this one is still going strong.

in europe, we used 75% co2 and 25% argon or 100% co2 with a bottle heater on a syphoning bottle.

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this story shall the good man teach his son,
and chrispin chrispian shall ne'er go by,
from this day to the end of the world.
but we in it shall be remembered.

Yeah john, C25 Is the common steel mig shield gas from my suppliers. Now that i think about it, I'm not sure where i got the 25 cfm figure. Might just be hearsay from which i cant remember the source.

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The B-3 build log: http://www.locostusa.com/forums/viewtopic.php?f=36&t=13941 unfortunately, all the pictures were lost in the massive server crash

The beginnings of the Jag Special,
https://www.locostusa.com/forums/viewtopic.php?f=36&t=19012
Again, all pictures were lost.

I dialed it back to about 20 cfm and think I could go lower still. I also switch to running my nozzle flush. Welds look about the same so far.

I always tried to stay on the high side of 20. Maybe 22, 23. It's different if you're welding for a living. I can afford a few extra cfms for the peace of mind. They say too much gas will cool the weld, but judging how many holes I blew, the gas wasn't helping.