I had an old Rek-o-Kut which had the usual rusted pitted chrome going on. I first sanded off the bubble chrome and polished the arm, which looked pretty good, but it also looked a little unfinished. I've been thinking about it for days, I but I decided I couldn't take that raw aluminum look, so I sanded the arm tube an spray painted it with Rustoleum Metal Finish Chrome. Looks FANTASTIC!
I just did the arm tube and not the base or the rest of the arm. I only had rust on the arm tube, so I masked off as close to the pivot bearings as possible (easy, a little painters tape) and sprayed. Now, it takes practice with spray paint. Go light. You don't want to leave tape lines, so you need to tape off what need to be covered but "blur" the paint touchup by not using the blue tape as a guide, but just a shield. leave the "blend" area open, and use the natural air-brush-like flow of the spray paint to you sort of lightly blend the edge, that way you won't get a "tape edge" it takes practice, but it's not hard. Always to practice runs on cardboard.
But Rustoleum makes killer paint, and their Metal Finish line of paints is great (and cheap). Their gold is the best around, and this chrome did a great job. I did a lot of research of Chrome paint, don't believe the hype on some of these youtube videos, it's very hard to beat Rustoleum for quality. I bought some really expensive gold paint because someone was touting it on youtube, and it look okay. But when I compared it to a three dollar can of Rustoleum, the Rustoleum killed it for looking geniune. This chrome is really nice and it's almost a perfect match for the Rek-o-kut arm. I can't tell which part was painted and which wasn't. So, yeah, you can certainly spray paint a tonearm, especially a heavier one, the weight difference will be negligible with a single coat of spray paint. And Rustoleum is such good paint, one coat will do it.