I'm doing some trunk repair and have one question and one issue. 1st my question; what size holes are you punching or drilling for the spot weld; 1/8"/#30?? 2nd my issue. I welded a few pieces that I trimmed off the new panels with my flux core welder and they were pretty good (Bet you know where this is going). Then I moved over to fill a few spots where I had drilled a little too far when removing pieces. Splatter City. The spot welds have voids that eat my brain. Am I going t have to buy a mig unit to have good results. TIA, kent. Anyone crazy enough to rent me one for a day?

I went down to the local rental place and was able to rent one with gas and everything for $55 a day!

You will NEVER get a clean weld with flux core. I used one for a long time before switching and won't go back. Its good for the farm, not so good for auto repair.

Kent, you have a PM
Cesar

Good idea. BTW, your car sounds nice.


You had some of those flux welds in your build thread early on, didn't you? Thx for the input.

Thanks!!

Luckly I managed to purchase a good welder "very" cheep for this car!!

Sure did... I got a ready-to-go MIG setup on craigslist for <200$.

I got fairly good with flux and rosette welding. Slow wire speed and middle heat (B or C on my welder for heat, wire speed ~3. )

You won't get pretty welds like mig. But you can get strong welds.

Zach

Kent,

Plug weld size SB twice the diameter of the thickness of the metal or the thickness of the section. So if it is your metal is .062 or 16 gauge....1/8 is sufficient. I like just over an 1/8 so I can make sure the full section or "plug" is completely fused.

With respect to your problem....not quite sure of "drilled to far"...means but, the way the flux core (SMAW) works is to shield the hot metal from oxidizing and hence the "voids that eat my brain". Since the design of the "plug" is to melt the parent metal first ( the metal to which has no holes) and the flux is in the center of the wire...it has a tendency to not melt the parent but pile the flux where you want fused metal.

Bottom line is that for that joint design (plug welds).... GMAW is a better choice.

I would suggest "tri mix" for the gas.

Hope that helps.

Does that help? I feel smarter already. Thank you.

Kent, if you have an inexpensive flux core welder like mine, you don't have a gas option. You didn't mention what kind of flux-core wire you're using.

I was having fits with this junk I tried at HF. Decided to hunt online for the good stuff I had before: Lincoln Innershield NR-211-MP (.035). You can get it in .03 also if you prefer that.

Here's an example of some butt-welds with this wire. Good luck.

Kent, I have a portable MIG at home that uses C02. You're welcome to come borrow it, or drive the car down, and we can weld it up, and send you on your way. Hell, I could even come up and weld it for you...haha

Might be worth a short drive down to Vista?

I've had similar experiences with the Lincoln .030 and .035 Lincoln wire. If you snap off the end each time (you don't need wire cutters with flux core) and strike your arc close with no wind blowing, you can make good plug welds. And of course clean metal and a good ground. The Lincoln .030 costs about $14.00 a pound at Lowes, you can get a 10 pound spool of .035 for around $70.00. The HF flux core is much cheaper, and is absolute crap. I generally use a 3/16th, sometimes a 1/4" bit.

use a small propane torch from HD racing (home depot) to pre-heat area. this helps reduce the splatter by cooking off the offending contaminants and moisture

That make sense. I do have HF wire. I will get some Lincoln wire for future use around the garage. Thx.


Thx Ethan, PM sent.

Thx to all for your valuable inputs. I see many others have tried this. But with my short fuse I think I'll go for true MIG. Otherwise I could "blow a fuse" and end up with more body work to repair after "going berserk" over shitty flux welds. D, you got a great deal on that Craigslist purchase. I've been perusing those ads for a month, now.