My solution to the whole resin hands thing: buy the hands I want and recast 'em. :) The cost of expensive B-Club hands is therefore spread out over several projects. :)
Of course, that works a lot better if you have a pressure casting rig. I just got one, because of problems I was having with my cast hands. :) For the project I'm finishing up now, the HGUC Zaku, I recast a set of B-Club manipulators originally sold for the Gelgoog Marine kit (IIRC). There were a few problems with the originals: on the open hands some of the fingers were too thin and flat, and there were bubbles on the sides of the fingers... So I had to do a fair bit of clean-up before even making molds.
But I'll tell you what's great:
I was having trouble with the castings from one of the molds, (one of the open hands) even after getting the pressure casting rig, so I decided to remake the mold. This time I made it as a one-part mold. I had a real tough time getting the original out of the mold unfortunately, and the fingers broke off... That's the bad news. But the good news is that when I cast copies of the hand in that mold, the mold doesn't introduce any new seam lines like a two-part mold would. If you make a one-part mold of a part you've already done the cleanup on, and you do a good casting from the mold, you don't need to do much cleanup when you pull the new part from the mold. (I've done one-part molds in the past but there's more work involved in casting in a one-part mold since you have to work harder to get the air out... But with pressure-casting that's less of an issue.)
Don't have any proper status updates for the 1980 Zaku yet - but if anybody's curious, it now has working ankle joints for both feet and I've created a new knee joint that I'm going to recast and use...
The knee joint is kind of simple in principle: just a cylinder with a polycap in it, and two end-pieces for the cylinder that form the other half of a hinge. The tricky bit is getting the cylinder centered around the polycap, and making the end surfaces of the cylinder truly perpendicular to the axis. Both are important because if you turn the hinge, you don't want parts of it to suddenly become misaligned... I've taken various approaches to this problem in the past, but this time I tried something new...
Basically, I first cut a length of styrene tube with a tube cutter. This got me the basic cylinder shape, with fairly good ends (reasonably close to planar and perpendicular to the axis.) Then I stuffed the inside with epoxy putty and put a polycap in there, with a rod through it, and used a jeweler's caliper to try to get the position of the rod on each end centered within the tube. This got me a pretty good approximation of "centered" polycap... Then when the putty cured I started looking for errors: I got another, similar part I'd made earlier (i.e. a failed attempt at making one of these) and stuck it onto the rod along with the new part for a point of reference - then I turned the new part around the axis, looking for wobble relative to that point of reference. When I found something, I'd take the styrene tube off the new part and sand down the epoxy putty inside to make an adjustment, then put the thing back together and check it again. Any time the epoxy putty got sanded down too much, I'd put some super glue on it, hit it with accelerator, and then sand that surface down so I'd have a tight fit again.
The nice thing about that method was it wasn't reliant upon any single process being especially precise - I could simply check the precision and improve it if necessary, without affecting the quality of other pieces of the work. The part always remained cylindrical despite any adjustments I made, because the cylindrical shape was provided by the styrene tube, which I didn't really alter during this process. I put maybe a couple hours into that process and came away with a part that I was very happy with. From there it was a simple process to create the end-cap and center it properly (just use the cylinder as a reference to glue a minus-mold to the rod) - so now I just need to cast copies of the thing. For that I'll use one-part molds, and put the rod and a polycap inside the mold before pouring resin. I still need to figure out the mold layout, though.