Hey guys, first time posting on here! I’m a first year apprentice in Australia and I’m struggling to get a really nice finish on two 18k yellow gold rings that I have just resized. The jeweller I work with is out of action atm as he recovers from eye surgery so I’m turning to you good people for some advice.
This side of both shanks have these pretty uniform lines going across the metal, sometimes there is lines going in two direction making a sort of criss-cross pattern. My emery finish was all good (or so I think, but what do I know!) so I’m guess i did something wrong in the polishing stage. This hasn’t happened to me before or if it has its been pretty minor and a little bit of a touch on the rouge has been all it needs to go away.
Basically all i need to know is, am I over or under polishing, or is it something completely different? Am I going too hard on the tripolli, not hard enough on rouge or is my technique wrong?
Any help is much appreciated!
p.s. sorry from the shitty quality photo
Check closely after polishing with tripoli to see if this pattern is evident …I would suggest that either your tripoli wheel or your rouge wheel is contaminated with grit… those striated marks are indications that one of your buffs is creating the issue
I agree. Look for some sort of contamination on one of your wheels. The one that you used right before you saw the problem is the likely culprit. Clean it out with a rake or just the tang of a file. Get it good and clean and then recharge it with whatever compound you were using. Good luck…Rob
what is your emery process…what grits did you use?
what buffs did you use?
that is a fairly crisp edge…
thank you so much! mops are cleaned and rings are looking a lot better now. thanks again
brilliant, never knew i needed to clean them. thanks so much for the tip!
Hey Julie, I use a 400 grit to start off then up to a 1000 making sure to run it in perpendicular to the 400. i find wrapping the emery paper around aluminum instead of the normal wood sticks helps at well, it flexes a bit less so you can get a really smooth plane. then i use a black bristle brush for my tripolli and a swansdown mop for rouge, again if i can running each one in a different direction the the previous step.
are you on a polishing lathe? (speed low or high?) or flex shaft?
is your bristle brush hard, medium, or soft?
Also, in addition to what equipment are you using, what polishing compounds are you using?
It sounds like you’re doing a good job of pre-finishing with progressively finer grits of sand paper, so that’s probably not an issue.
I mostly use a polishing lathe, generally I only use my flex shaft for inside of rings and difficult to get to parts. the lathe has a rpm of 3450 and the bristle brush is hard! hope that helps
the only thing i can think of to add is that i read in a polishingok
Skip the e brush and use a treated cotton buff…Rob
opps! my reply got cut off earlier for some reason…
I was saying…i read somewhere that using a black bristle brush for too long can create grain lines from brushing…perhaps over brushing is the culprit…
I don’t want to contradict what you have been taught so far but considering you are going to 1000 grit emery you might be able to skip the tripoli. I used tripoli on a black bristle brush during my apprenticeship but have since done away with it. Also I didn’t see a mention of a hard felt disc - very handy for doing sides of rings.
You’re right Rodger! The more prefinishing you do, the less buffing that you need to do. I was taught that tripoli is equal to 800-1000 grit. A Google search says the same thing. So yes, if you sand with sandpaper to 1000+ grit, you shouldn’t need to do as much on the buffing machine and you might be able to skip the tripoli step.
One thing that I’ve learned about polishing is that there are many ways to accomplish the same thing. It’s another one of those things in life where there are multiple different answers and they’re all potentially correct. A lot of it comes down to personal preference/experience and how you were taught.
For me, I’m not a fan of hard bristle brushes for general polishing. In most cases, I prefer softer wheels, like a fluffy cotton buff for general polishing. But there are plenty of exceptions depending on the situation and I use whatever I need including hard felt wheels and bristle brushes.
The last jewelry store that I worked in the owner used a variety of rubberized abrasives, like Shofu and EVE wheels. Those are expensive, but they work well for pre-finishing (especially if you’re not paying for them!)
This topic of issues related to polishing is a full one that goes back to the beginning of the Orchid forum with many threads.
Thanks for mentioning that Roger!
I do very little filing or hand sanding. Most of my pieces go straight to a medium Eve wheel then tripoli and rouge. I do use my lapidary expansion wheel with a worn 220 grit belt on some pieces first. I am also using my tumblers a lot more than I used to, especially the SS shot rotary tumbler and now new magnetic pin finisher. A high polish is basic to all of my work, even if it gets textured or colored later. I have also found that sharp tips like prongs, rivets and the ends of ear wires can be nicely dulled with my pulse arc welder. You are right Jeff, there is no one right way, just the way that works for you (sounds Mandalorian). I hope that you all had a great Thanksgiving and are strapped in for the ride to Christmas Day. Good luck…Rob
Further to my use of Eve wheels. They can just refine a surface or change it depending on how much pressure you use. You can also shape the wheel with an old file to get into places that the flat wheel won’t fit into. Yes, they are a bit expensive, but they save a lot of time. Besides, I hate to file…Rob
looks like your problem was solved by cleaning your buffing wheel…just wanted to add that tripoli can be aggressive if you push to hard against the wheel. It will cut fast… go lightly.
Hi Matt, hope the Jeweller gets better soon. That’s a funny looking problem that you have there. Just by chance look again at the polishing compound, is it black by chance. There is a compound with a grit in it! If you have a Blue Hubble compound, go with that one. If you have put the wrong compound on then you will need to get it off again. The best thing for this is the tang off a " 6" hand file" and get the motor running and rip into that polishing wheel. Even if you haven’t put the wrong compound (or to much) on, the mop will love you for it, so it seems. And don’t forget to turn on the dust extractor and mask. The Blue Hubble’s finish isn’t good enough for a high street jeweller but it’s not as aggressive as other cutting compounds.
use a new cotton polishing wheel. It will be clean to start with… salvaging the old one, if well cleaned could be repurposed for rough first step polishing…also make sure that your polishing compound wasn’t contaminated by grit falling on it.