Smoothing sand blasted parts

frankc · 02-23-2007, 08:28 PM

I took some front suspension pieces in to be powder coated and the shop sand blasted the old finish off. I'm not blaming them as I knew they were going to use sand which would leave a rough finish, but since they were going to be PC'd anyway I wasn't too concerned.

Well, I took some additional pieces up before they coated the blasted parts, and since I was going to have some other pieces zinc plated, I thought maybe I would have the control arms plated as well rather than PC'd (or perhaps clear PC'd after plating). The issue is the metal surface is now very rough from the blasting which will result in a rough plated surface rather than a nice smooth finish. I spent a little time with a ScotchBrite and was able to smooth a section out to where it was nearly as smooth as a non blasted part, but not quite.

My question is, before I invest too much time in this, is there an easier/better way? Can I have them blasted with a different medium? Can I ask the plater to plate them with something else first to smooth things out, then with the zinc?

Had I known I was going to plate these in the first place, I would have had them chemically stripped, or found a place that does soda blasting.

btw, the parts I did have PC'd came out very nice.

thanks,
Frank

Jeff Hail · 02-23-2007, 10:15 PM

Quote:

Originally posted by frankc
I took some front suspension pieces in to be powder coated and the shop sand blasted the old finish off. I'm not blaming them as I knew they were going to use sand which would leave a rough finish, but since they were going to be PC'd anyway I wasn't too concerned.

Well, I took some additional pieces up before they coated the blasted parts, and since I was going to have some other pieces zinc plated, I thought maybe I would have the control arms plated as well rather than PC'd (or perhaps clear PC'd after plating). The issue is the metal surface is now very rough from the blasting which will result in a rough plated surface rather than a nice smooth finish. I spent a little time with a ScotchBrite and was able to smooth a section out to where it was nearly as smooth as a non blasted part, but not quite.

My question is, before I invest too much time in this, is there an easier/better way? Can I have them blasted with a different medium? Can I ask the plater to plate them with something else first to smooth things out, then with the zinc?

Had I known I was going to plate these in the first place, I would have had them chemically stripped, or found a place that does soda blasting.

btw, the parts I did have PC'd came out very nice.

thanks,
Frank

Sand blasting is really old school now. The sand makes bigger pits out of the small pits and is rough. Next time have them blast with walnut media of if you want a really smooth surface blast with soda. I prefer powder coat than plating. Weight is not an issue and personally think it looks better, cleans up easy. I dislike plated metals because in a two years it looks like galvanized fence posts.

GMR911 · 02-25-2007, 05:04 PM

As a former sandblasting/bridge painting contractor we used differant media for differant jobs. Whether using silica sand or black beauty, most media have a degree of courseness. We used a silica sand supplier that had 4 grades of silica, 1-4. The 1 size being very fine and the 4 size being course. The 1 size would almost polish the steel whereas the 4 size could pit and roughen the steel, which may be desireable for adhesion. I recently had some susp parts sandblasted by my uncle, who is still in the business, using the 1 grade. Came out smooth as silk. Need to use the proper grade of silica, the 4 grade would have pitted the parts. Jerry