I wasn't sure whether to put this in maintenance, repair, or modification, but I'm just throwing it in here. I have a 68cm DF-H boy body that I got made with Switch rosy white resin (or DF-H's equivalent to matching rosy white) and the resin is SO rough. There was resin dust everywhere when I unboxed it and the body itself was rough and almost sharp in some places. I've washed and scrubbed him with a magic eraser and it took the loose dust off obviously, but did nothing for the roughness. I know the obvious answer is to sand him with a light grain sandpaper, but I'm worried about making him more rough than he already is or create scratch marks. Any advise on better ways to make him a little softer/smoother?
I'd absolutely go with sandpaper, very fine grit, and start on the very worst areas (like where you said it was sharp) and go VERY slow in circles. I've found that when trying to get the least amount of scratches, doing wet sanding works a bit better. But starting with the very worst areas will let you see if it's worth it to sand the whole doll versus just doing a more "spot treatment" with just the biggest problem areas. The only time I've noticed sandpaper making my doll rougher in a way (I've sanded pretty much all of the dolls I have so your mileage may vary) is when they're already very smooth to begin with, such as when reversing modifications on a Ringdoll body (which from my experience, are SUPER smooth and kind of buttery), the areas where I sanded with up to about 1000 grit paper were a tiny bit less buttery, but not rough (it was still smooth but not in the polished way the resin was before, if that makes sense). Given how rough of shape the resin seems to be, I think just finding a small area and testing it could be good, but I'd definitely go as high grit as you can
I also agree with going with sand paper and using finer grits, as your starting point. Which is what you want for polishing, anyway. If you are comfortable with an X-acto knife or any other craft knife, I would suggest using that to remove the sharper or more raised areas, to reduce the workload. Otherwise, sand paper is probably the easiest safest way. I have read people using human meant, nail buffing blocks, but having never tried those myself I can't go around recommending those. However, it might be something worth looking into, for larger dolls like in your case, and with such a large area like a whole body, to work on. Hope that helps, and good luck.
So here's a great thing about sand paper, if you use fine grit there will be no noticeable scratches. I have sanded a lot of things; woods, resins, various plastics. You can start with a medium grit like 300-400 to remove really rough parts, then you go to a finer grit about 600-800, to get it really smooth you use super fine, I prefer 2000. Wet sanding is fantastic, it decreases the amount of dust and it works to keep the sanding more mild. Make sure the sandpaper you get is dry/wet because some sandpapers can not be used for wet sanding. If you find there are scratches, do it in stages where you go up in grit coarser to fine, jumping about 200-300 grit. How it works is that each finer sanding you do buffs out the rougher parts of the previous sanding, until all of it is smooth. So nail buffing blocks are pretty much just really fine sandpaper. Maybe 800 or 1000+
Nail buffing blocks and nail files work wonderfully! The ones that come in 4 different roughnesses and also have a polishing part are great for the last finish especially (you might want to get a couple of them for the size of the body, though). Very high grit sandpaper is sometimes hard to find in hardware stores so it's a good alternative at least. Chinese companies often sandblast the dolls to get rid of seamlines and it sounds like they didn't finish the work and packed the doll before cleanup? If you haven't already, also report this to the seller, bad QC shouldn't go unnoticed.
I know the blocks are high-grit sandpaper, and thusly why they are buffing blocks. I just don't know how well the blocky shape would function, on all areas of a doll's body without completely smoothing everything out (I know, hard to do with high-grit sandpaper, but not impossible). Sandpaper can be reshaped, folded, bent, even rolled in to a ball if needed. So, that's what I was thinking -- probably over thinking, having never used a nail buffing block myself. (:
I use these as well. I first start with a more course sand paper, I cut the large sheets into small squares. I'll use the course sand paper only if there is large seams, like if a doll comes unsanded. I then move to a very fine grain, I find I don't need a between stage medium grade. This just fine tunes the sanding and removes and larger scratches that might have occurred in the initial courser sanding. Then I move on the nail buffer blocks going from steps one though four. By the time I finish the shine on step four the doll is smooth all over and I can't even tell where the seams once were. If the doll is just rough with no seams, I would just try the nail buffing block on it. I have a DF-H doll and it's not rough at all. I wonder if it is in the resin that they used. My Little Monica doll has that very rough feeling to the resin. I never bothered with sanding her though as I don't really mind the way she feels. My thought is, if it is the resin itself, which I believe it to be the case with my Little Monica doll, I'm not sure if sanding would help, because it might be the type of resin that was used.