316 SS 3D Printed parts

[Bob Quinn]

We talked about this some in another thread. I thought it might be a good idea to start a new thread on this as it might become a long term project that could apply to many parts.

So anyways I got the sample part from Proto labs so that I could see how the surface finish turned out. As expected it looks a little grainy, possibly similar to a cast stainless steel part.
Pic's below.

Now the next test is to see if I can polish this to an exceptable level of shine.

I have never had to polish anything like this, similar to a cast part.
Before I screw this sample up, just wondering if anyone has experience polishing cast stainless steel to a nice shine and might be able to offer some suggestions as to the best procedure to do so?

 

[bostonhatteras]

We just had a typical #4 brushed stainless steel sink polished to a mirror finish. For a one basin sink 16x20 it was $2400., and that's the one place that was willing to do it. Electropolish isn't the same as abrasive sanding/polishing and won't give a mirror finish.

 

[SEVEN]

I have polished most everything on my boat. I used a one HP bench buffer and rouge. It’s not like a mirror but darn close.

 

[DougD]

I've never polished anything that rough - you'll probably have to start by sanding with emery cloth or an abrasive disc - start with something in the 100 to 240 grit range to get the surface flat and smooth. Once you have something that looks like bostonhatt's brushed stainless sink, polish with a series of compounds and buffs. I've had the best luck with traditional buffs, where the stiff ones for abrasive compounds are sewn radially and cut fast, while the soft ones are loose and will get you that mirror finish with a fine polishing compound. 10" buffs do a lot of work quickly but require a strong motor. Wear gloves and respirator, and good luck.

 

[Avenger]

That's going to be a ton of hand work.

What about a vibratory with ceramic media?

 

[Bob Quinn]

That's going to be a ton of hand work.

What about a vibratory with ceramic media?

Thats a good question. I would hate to make a $30 to $150 part and have to hand polish for 3 hours and turn it into something unaffordable to sell, or even want to do!

I think like Doug was saying it might have to be sanded first anyways.

There must be an automated way out there as all the s.s. marine parts can't all be hand polished I wouldn't think? But who knows, maybe that's why so much comes from China.