Hai,

I am a bit fed up with sanding. It takes a lot of time and the results, even when using the finest grain, is not always optimal.

I have seen small drilling machines in a jewelry shop with special tools that are used for polishing gold or silver.

Are there similar tools on the market that could eb used for plastic? and which are affordable?

I'm a bit unsure from your post as to how un-optimal your sanding is and whether you are talking about sanding flat surfaces or the edge of parts.

Generally when sanding you should "progress down through the grit size". Coarse Grit removes most material but leaves big scratches, medium grit removes less material and gives a sort of "brushed" finish and fine grit removes even less material but gives a much smoother finish. It depends on the material being sanded as to how long this takes. For modelling start with about a 500 grit then 750 and finish with a 1500. Some people suggest sanding at right angles to the previous pass.

If you are trying to get a very smooth finish you need very fine grit. Most fine sandpapers are about the 1500 mark, which is not fine enough to look polished on plastic/resin. You can get special polishing abrasives such as micromesh (http://www.ss-sci.com/micromesh.htm) which go down to 12000 which can polish clear plastic effectively.

This method can be very time consuming as you point out. You can get sanding wheels/drums for modelling tools, which can speed the process up considerably, but gives less control and you can easily cut through parts or get a lumpy finish.

The things for polishing you mention, sound like buffer/polishing wheels. These are normally used with a fine polishing powder, which is a very fine grit. These are designed to be used after another sort of abrasive has been used and the buffers must be used with polishing medium.

You can get cheap power craft tools for the about 20Euros or good ones like Dremel for about 70Euros plus. But for smoothing flat surfaces using sand papers is the best but not quickest way for a good smooth finish.

I use super fine steel wool as my final treatment - works like a charm and is dirt cheap!

The problem you may have with a polishing wheel or anything that spins at high RPM is the heat that will be created can melt the plastic very quickly.

C.

wow, this is an aspect that I had not thought about

I can confirm from experience of hand polishing gold and silver on a buffing wheel, small pieces of leather were often of benefit to stop the heat immediately causing pain. The speed of the wheel and even with the finest polish used, if it did not melt the material would cut through it in an amazingly short time. A few moments too much saw me having to replace a proper heavy duty Glass watch face after I polished right through it in a matter of moments.

Stick to the normal recommended polishing methods for plastic kits.

John

Totally Agree. I often use a motor tool (Dremel) on my models, but I've found anything over 5000 RPM can cause problems Fast, even slower RPM require a light touch.