Apropos of my wiper Q, here's more info, with another Q.....
Since I don't think this wiper thing is going to be so easy to solve, and since from a sliding/friction pov it don't get much worse than alum on/in alum, I'm experimenting with making the slider ITSELF out of a nylon-ish/UHMW material. Altho I would still like a wiper, a plastic slider (and the lubricity thereof) should intrinsically help, from a friction/galling pov.
So the Q is: what would be a good substitute for the alum slider? I'd like a good combo of strength and lubricity, as stuff is attached to this slider, via 10-24 screws, 3/16 pins, etc. The 10-24 screws will not be threaded into the slider itself, but rather thru the slider and into another pc of substantial alum.
I've always liked nylon, delrin, teflon. Nylon seems to be a kind of ref. std, ito plastic strength, durability, and it seems that altho it doesn't have the lubricity of delrin, it's OK. Would delrin be better? Anything else?
fyi, the actual size of this particular slider is approx. 3/8 x 3/4, with a1/8x1/8 rabbet on each side (so the captured sliding part is 1/4 x 3/4), with a 4.5" L
Any class of materials I should specifically avoid?
I suppose I could test various materials, by buying or making something of a power hacksaw, and just let various materials reciprocate for a few days, see what stuff looks like at the end. Hopefully I won't have to go that route, tho.