From the WD-40 website:
"WD-40 Multi-Use Product protects metal from rust and corrosion, penetrates stuck parts, displaces moisture and lubricates almost anything. WD-40 Multi-Use Product 5-Gallon Pail is best used for heavy duty industrial jobs uses that require repeated treatment."
I wouldn't trust that. What a manufacturer will say is not always the same as the truth. WD-40 is a Swiss Army knife type of fluid. It does lots of things, but not many well.
WD-40 evaporates quickly, leaving a very light film of a waxy substance behind. A lubricant that evaporates is not desirable.
I can see why they would want people to use it to lubricate things. Imagine how much money oil companies would make if engine oil evaporated as fast as WD-40.
I buy it by the gallon, mostly for machining, so I know how fast it dries up.
As for Harbor Freight welders, I bought a Titanium 200 Unlimited, which does stick, MIG, and DC TIG. I already had a Lincoln MIG and an AlphaTIG, but I like toys, and I thought a Chinese welder would be good for backup as well as 120V MIG. Titanium welders have very short warranties, which sets them apart from Vulcan, but I have a basic knowledge of electronics, and I figured I could probably replace any bad components.
I love the Titanium. I rarely use the Lincoln. The Titanium has a nice nimble torch, and I like the digital display. I have different wires in my MIG's, so I am less likely to have to replace a spool. It has worked out great for me.
I'm a hack welder, but I have fabricated a bunch of things, so I know a little about MIG. I have seen claims that red and blue welders give welds that look better when cut open and etched, though. Don't know if it's true.
Nobody is certifying my welds, so it doesn't matter to me.
