I'm not exactly sure what you mean by this. But here is what I have found. This material is a composite of stainless AND bronze. This is different than an alloy. You can get very close to mirror finish, but you must realize the surface of this material is made up of areas with different hardnesses and colors. If you look at a prepared specimen under a microscope you can see the dispersion of the two materials. It is a matrix of two materials. Because of this fact it is not possible to bring it up to the same degree of polish when compared to solid wrought or cast stainless steel. Also, because of the bronze inclusion, the color when polished, has a slight reddish yellow tint. Personally, I find this aspect appealing. I will also say that on small jewelry sized objects these limitations are hardly noticeable. If however you wanted to make a large polished plate (like a mirror) you would have fits trying to get it right. -G
That pretty much answers it. I'm not looking for a mirror finish from it, but I drew a mini parabolic dish that I was hoping it would be reflective enough to light a match.
I'm not saying that would be impossible, but the material would be very uncooperative. Maybe better to try your hand at shaping some alloy 304 stainless sheet metal?
My other thinking was to make the shape in stainless so it could be used as a mold for Plexiglas or even glass.
Vacuum formed plexi might make a good substrate for a mirror. I suppose you could print a female mold for this purpose. Then find someone to apply a mirror coating. Trying to cast or slump glass with a mold made from the SW stainless would be a disaster. Remember that this composite contains bronze, which melts at a much lower temp than the stainless component. The glass would fuse to the mold. Even if you used a release coating (boron nitride) the surface would still require grinding/polishing to turn it into a decent mirror. Look to find out how telescope mirrors are made. Better yet, find a ready made. This would be a whole lot cheaper. The reflector from a burned out mini halogen spotlight comes to my mind. The bulb is easy to remove and you are left with a condensing mirror with a small slot in the center. Perfect place to mount a target for incinerating something small. I'm all for 3dp, but I also believe in appropriate technologies. If a chisel will work why bother with laser? Know what I mean?
Yes as far as using it as a mold for glass would kind of be counter productive. Really i was just hoping it could be polished enough to light a match. Which machining a parabolic dish would not be cheap. Unless you rip the satellite dish in your back yard down for it . I still haven't polished that thing up to see what I could get from it.
If you were keen on it, you can vacuum metallize SLS. You'll have to impregnate with a resin in order to achieve the necessary surface finish. Its actually not too expensive either. Problem remains that for a parabolic mirror to be any good it has to be perfect, and thats just something thats never going to happen with 3DP (yet, anyway).
It would be hard to machine it perfect also. I Haven't seen a dish yet with a needle head focal point. But thank you for the vacuum metalized idea. May have to look into that.
This question reminded me of a video that shows how to make a parabolic mirror by using silvered plexiglass, a table saw, and your oven. http://www.youtube.com/watch?v=23kkZZN1ACs