Tuesday, February 14, 2012

Ask Auntie EM - How do I get a mirror polish?

Howdy! It's Tuesday and we are back again answering your questions in EtsyMetal's weekly blog post called "Ask Auntie EM". If you're new here, this is a weekly blog post written by Sue and Ann where we tackle your metalsmithing and non metalsmithing questions. Having trouble with your solder? Need some help with stone setting? Have a problem 2 year old? We and EtsyMetal's 100+ members probably have the answer. If you'd like YOUR question answered in the future, please email your questions to askauntie@etsymetal.com and we will get to it as soon as we can. Speaking of questions, I want to thank all of you who submitted questions this week! We got a lot of excellent material for future blog posts! Keep checking back every Tuesday, it might be your question we are answering! If you'd like to read past posts, they can be found here.

OK, let's get to this week's question. We got this a few weeks ago from Pennee:

"I do have a question about finishing. There are so many options now- 3M wheels, silicon wheels, bench polishers- what are the best steps and products to get that professional looking mirror finish?"

This is an excellent question and one that gets asked a lot. I learned how to polish the easy way...I got a job as a goldsmith and was more than inexperienced. The first job they gave me was polisher so you either learned or got fired. As I needed the job, I figured things out really quick. Polishing can make or break a piece. Experienced polishers can keep edges crisp and get into every nook and cranny without leaving a mark. Inexperienced polishers turn a great piece into a gummy looking mess, leaving drag marks and rounding off every corner and ruining prongs or other settings.

The first thing to remember when going for a high polish is to think ahead. As a piece is being assembled, think, "will this need to be shiny later? Will it be accessible to polish when the piece is assembled?" If the answer to the second question is "no", you need to prepolish. This is an intermediate step before the piece is completely assembled where you would polish components before actually soldering everything together. Prong heads and ring shanks are two examples of components that should be prepolished.

The second thing to remember is that you will cut your time at the polishing station DRAMATICALLY if your piece is properly prepared. For this, I love two products. First, I adore Cera Wheels. I learned about these as a goldsmith where, if a product doesn't work well it doesn't get reordered. These work so well and last so long, they are worth the money. I use all the grits and order the largest barrel shape. I have two of each, one for keeping flat, the other for shaping with a file to any particular shape I might need.

These will bring the inside of a ring up to almost a mirror shine. They are good mostly for inside ring shanks but I have used them on other curved surfaces. The second product I am in love with is 3M polishing paper. This stuff is amazing, it has cut my polishing time in half or more. I have two sheets of this as well, one that I keep whole to sand flat areas on a desktop and one that I cut in strips to use on small pieces by hand.
My only beef with this stuff is that it's almost impossible to tell which grit is which because it's not marked. I finally used a big sharpie to mark each sheet for easy identification. There are some big gaps between some of the grits but you can get VERY close to a mirror polish with these if you don't have access to polishing equipment.

So, now your piece is prepolished and well prepared for the final polishing. Now what? I know there are lots of metalsmiths out there who use their flexshaft to polish. I am not one of those people. I learned on a real polishing wheel and I have never gotten good results with just a flexshaft. I am lucky enough to have a tool hoarder husband so I have a modified bench grinder to polish on. There are LOTS of products out there to polish with but I use the same method I learned at the jewelry store. I start with tripoli on a stitched muslin buff and then move to rouge or Zam on a softer muslin buff. If I have to prepolish, I use a brush on a mandrel attachment. There are so many options for buffs, here is a very simple breakdown:

1. Felt laps: Unless you are a VERY experienced polisher, I'd stay away from these. They scare the bejeepers out of me because they can completely ruin a piece in about 2 seconds. If you're good with them, they are like magic. They will keep edges VERY crisp and they work fast.

2. Treated, stitched muslin buffs: These are good for the initial polishing with tripoli. They are hard so be careful. Light passes with very little pressure work best. These will keep most edges crisp but will also wear a piece down very fast. They should never be used anywhere near prongs or delicate details.

3. Stitched muslin buffs: These are good, all purpose buffs that can be used for tripoli or final polishing with rouge or Zam. The stitching keeps the layers of muslin together so you get some firmness which will keep some edges crisp. These may need a little more pressure to get a polish but don't ever press hard or you will get drag lines.

4. Balloon Cloth Buff: These are for final finishing only. They will round over a piece quickly if used with a more aggressive compound. These are great for organic pieces or pieces where a crisp edge doesn't need to be achieved.

5. Detail Brushes and Inside Ring Buffs: These are for getting into tight spots and inside rings. For detail brushes, you use this mandrel to hold small brushes and load them with compound to get into teeny tiny spaces. The first time you use the mandrel, screw it onto your spindle by hand or you'll burn yourself. Rings can be polished with these but load them the first time onto the spindle the same way.

There are so many types of compounds out there too and I have mentioned the few I use but I would advise you to call Rio's tech support and ask them about all the different kinds they sell. I just don't have enough experience with them to write about them. If you don't have an ultrasonic, there are a lot more water soluble compounds available now that would rinse off a piece with just soap and water.

OK, so now you know all about what to use but how the heck do you use it? I shot two very short videos that are lame, I know. But I wanted to show you how to polish. When you polish use a VERY light touch. With tripoli, I just keep lightly running the piece over the buff, I never linger for more than a second. With rouge, you can use more pressure and time but keep the piece always moving.

Here is how I use tripoli with a hard buff:

And here is how I use Zam with a loose balloon buff:

ALWAYS polish on the bottom 1/4th of the wheel, between 6:00 and 4:00. Never go higher or lower than those two positions. Hold on tight, wear a dust mask and have proper ventilation. Safety goggles are not a bad idea either. Above all else: NEVER POLISH A CHAIN, EVER. Chains need to be polished by hand only, unless you want to loose a finger. Pieces get HOT when you polish so take breaks often. Once you polish a lot, your fingers will toughen up and it won't be so bad.

So, I think that's enough for this post. I hope I demystified polishing enough for you to give it a try yourself if you can. It's an excellent skill we should all have, even if we don't always use it. If you make a trip to your local jewelry store, if they have a goldsmith on the premises you could also ask for a demo. Most jewelers are happy to pass their knowledge on if you don't take up too much time.

Thanks for checking in this week! Remember, email your questions to askauntie@etsymetal.com and we will get to an answer as soon as we can!

1 comment:

PPennee said...

Awesome post Ann- and I did love the videos- thanks so much

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