Vapor Smoothing PLA

I was just looking at the new CopperFill and BronseFill filaments from Colorfabb and one video mentioned that polishing the print in a rock polisher turned out quite well. It immediately made me think of this thread. I noticed that it did poorly with the Woodfill, but has anyone tried EA polishing some of the Colorfabb metal-impregnated PLA filaments?

I have. It is promising, but possibly not necessary.

I polished with EA, which made it smooth and then tried a bunch of different things in a rock tumbler. If your part has the right geometry, EA polishing for this to not be too tedious and then burnishing brings out a really nice brushed metallic appearance. It does oxidize quickly after that though so some sealing or oiling is necessary.

I've been trying a lot of different things to try to figure out a good batch polishing process for bronzefill and copperfill. Jeremy Simon at 3D Printing Universe seems to have one of the best so far with simply burnishing the parts in a tumbler with wood screws. However, I've tried this with more delicate parts and they all break. Giving it another go with steel shot. Once I get something that is reliable, I'll post about it.

I tried the steel shot in a tumbler as in the video, and didn't have too much effect over 24 hours. I switched to ceramic and saw a much bigger change. I also found a post by Nervous Systems where they use ceramic cylinders in a vibratory with a water flow through. Basically just a few drips a minute so a 5 gallon bucket lasts 8 hours. I just bought the 18lb tumbler from Harbor Freight which has a drain, so I'll give that a try later today though without the water. The water keeps the residue off the parts so there isn't the need to clean up after.

I bought the same dremel polishing set, but everything I've tried instantly removes any shine provided by the barrel tumblr, even at the lowest speed. It might be worth doing that before tumbling, since the smoother the part is going in, the better the results should be coming out.

Aargh, I wish you had told me a day ago. There goes $16 down the drain.
Actually, I'm going to try it a little different. Stainless steel shot in water, but only for 2 hours and with distilled water and dish soap. There is a tutorial video on it on the riogrande site.

I was also playing around with soaking in vinegar and salt and then scrubbing with the salt. Saw some decent results there, so might try tumbling with vinegar and rock salt.

I have a whole pile of mini metal makerfaire bots with their arms broken off that make perfect test subjects.

Looking forward to seeing your results.

If you are using a dremmel to shine bronzefill. Sanding radial disks are the way to go. Dremmel makes some for higher grits (http://www.dremel.com/en-us/Accessories/Pages/SubCategories.aspx?catid=2083&catname=Detail+Abrasive+Brush) for for better shine would want to get down to even further microns by the end with the 3M radial sanding radial disks or other kinds etc. ( [solutions.3m.com] ). I start with a maybe 200 grit and end up using a 1 micron.

And for a final cloth smoothing you can use these polishing papers [www.amazon.com] . They work much better then you would think they would, but really adds that final shine. In fact if you didn't want to bother with the dremmel stuff and used some other way for a general polish...I recommend this polishing paper. The combination of the radial polishing disks and the papers I have gotten decent results, though I have not tried a tumber.

And yes...can't wait for Copperfill!

- Tammy

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Tammy
Solidoodle2 w/E3Dv5 Hot End

Dremel did a Q&A at Reddit about their new printer, which was detailed and very interesting. They said part of their interest in getting into 3D printing was seeing the widespread use of their tools to finish prints. Smoothing prints with power tools is tricky because it is easy to just melt the plastic from the friction, especially with PLA. They said they have people currently working on the problem. I'm thinking that there isn't really anything special about polishing bronzfill. No matter how much you sand it, you will have a surface made of 80/20 bronze to plastic. You get the metallic look by getting the surface as smooth as metal usually is. That just happens to be smoother than most people need to make their prints, and most people who do want them that smooth use fillers, which isn't an option here.

Can you imagine if Bronzefill were made with ABS instead? It would look fantastic with an acetone vapor treatment.