A couple of weeks ago I bought a used Miller Spoolmate 100 on E-Bay at what I thought was a good price, $167 including shipping. The gun showed nearly no signs of use, even the clear plastic covers over the wire feed rollers and the wire spool are still scratch-free. There's no splatter inside the nozzle and I'd guess that there haven't been 20 feet of wire run off the spool.

Now here is the thing, the wire that was (and is) in it is a 2-pound AlcoTec ER4043 in 0.035. I pulled off the nozzle and then the contact tip to take a look at them right after I got the gun. The nozzle was like new with nearly no splatter but the thing that caught my attention was the tip. It was nearly clean with only slight signs of use but instead of it being a .035 tip what was in it - to match the .035 wire being fed through it - the gun had a .030 tip in it. The wire seems to slip right through it with no binding what so ever and if I hadn't seen the engraved size in the side of the tip I'd never have guessed that it is a different size, smaller, than the wire it services.

So how is that the case? I didn't know you could do that, which should come as no suprise to anyone. I may have been sticking things together with a MIG welder for 40 years but that time number is misleading. I'm just another home-use, light repairs, "hobby" sort of guy with no formal training as I'm sure as many bad habits as one old guy can get. I'm perfectly ready to learn better so if someone would be good enough to explain to me about if and when its OK or even desirable to mix-to-match your wire and tip sizes if in fact its actually ever OK to do it at all. I am always appreciative of being taught better.

And on a somewhat different note, but Spoolmate-100 related. Every-time I see a discussion about them the things are treated with some derision. People imply that they are somehow poorly made and undersized for the duty they will receive. That said their specs seem to indicate they are more or less perfectly sized for the machines they are recommended for and after what seems to be about three years on the market, time enough to amass hundreds of Forum discussions about them across the internet, and I have never found a single instance of anyone reporting that one had broken or in any way failed to work. I've seen many cases of people not knowing how to work one, but no cases of anything gone wrong with the spoolgun itself. Granted the things have limited capability, nothing too thin, nothing too thick, but to say that they are junk really seems to me to be missing the mark. Granted a lot of guys just want to brag about the wondrous capability they have in their own perfect shop and contribute nothing useful to the discussion and a whole flock of other geese simply echo any negative opinion they hear in hopes it will make them look smarter, but when you get down to facts and experience I just don't see anyone saying something about the SM-100 was either poorly designed or somehow defective. What has your experience been with one?