Review of Eastwood's Spot Welding Kit for MIG Welders
Eastwood asked us to take a look at their spot welding kit and sent along with the kit, a can of their Self-Etching Weld-Thru Gray Primer.
According to the supplied instructions, the kit will work with both 220v and 110v welders. However for the 110v welders, you have to drill a hole in the top piece of steel.
For our first tests we cut and cleaned up several small pieces of 18 gauge steel and since our welder is 110v we drilled a couple of hole in each top piece of steel.
MIG settings based on Eastwood's own welders are included. For the Eastwood MIG135 (110v) welder, they suggested setting the voltage to a "J" setting and the wire feed to 7. Recommended trigger activation time: 2-3 seconds.
Our welder is a Lincoln Power MIG 140c, and it uses similar markings on the setting knobs, so the recommended settings seemed like a good place to start. Keep in mind, though, that our Lincoln Power MIG 140c isn't in its original configuration. Originally the Lincoln welder came equipped with a Magnum Pro 100L gun. We have a Tweco gun on ours, along with a different regulator than original. The spot-welding kit is advertised as only working with Tweco style guns.
Using recommeded settings, our first attempts produced a weld that piled about 1/8" high. We adjusted the wire feed and tried again, but with similar results.
We had prepared two long strips of steel to test the Welding Primer so we had a lot of spot welds to do and were confident we could find the proper welder settings to give us the spot welds we were looking for.
Our results weren't what we were looking for. In total we did about 30 welds using various combinations of voltage settings and wire speed and we weren't able to come up with a decent spot weld. In most cases we ended up with "nipples" sticking up on the welds. Often, these nipples could be ground off, and they would be ok welds, but they wouldn't have that spot-weld look. Additionally, we found that, unless you have the welding wire accurately aligned with the center of the hole, the weld would pile up before the hole would be filled with weld.
So not willing to accept defeat we tried something else. Even though our welder is a 110v variety, we decided to try it without drilling the hole first, just as you would have done with a 220v welder.
Our Lincoln welder has a top voltage setting of "J", but there's room on the dial for "J-1/2". We cranked the voltage to the maximum possible. We kept the wire-feed at 7. Our objective was for the arc to burn through the top piece and penetrate the bottom piece before it accumulated enough wire to fill in the weld.
We did a test and arbitrarily held the trigger for a count of "8". The results looked just like a spot weld should. But there was no penetration on the bottom piece.
We tried again, but reduced the wire feed to 6, then 5-1/2 and then to 5. In all instances we stayed with holding the trigger for the 8 count. The results seemed promising, but, of course, the only real way to test a weld is to destroy it.
The piece welded with a 6 wire feed setting, came apart with little effort. But we could see that penetration was starting to occur.
The piece welded with a 5-1/2 wire feed setting also came apart, but there was definitely penetration on the bottom piece and it required quite a bit more effort to pull it apart.
And lastly, the piece with the 5 wire feed setting, wouldn't come apart at all. There was good penetration and it was a strong weld. And we could get the same results repeatedly.
We think the final weld is pretty good. Everyone's welding set-up is a little different and it does take some fine-tuning to give you the results you want.
As for the Self-Etching Weld-Thru Gray Primer, we chiseled apart one of our test welds that had good penetration. There was no evidence of the paint burning and it didn't interfere with the welding at all. Sure beats having naked steel under there!