# Best way to clean a gold-plated yoyo bearing?

I have a gold-plated yoyo bearing which needs cleaning. Most people clean regular non-gold-plated bearings with mineral spirits (naphtha), lighter fluid (hexane/heptane), and acetone, but these gold bearings are somewhat new and we don't have a consensus on a cleaning method. There's debate as to whether the gold plating influences spin time or if it's the precision manufacturing, but they do spin forever and are quite silent. Anyway, these bearings are $22, so constant replacement is an enormous barrier to using these outside of competitions. I've researched gold cleaning techniques, and all the results say to rinse with water. That's not a very good option since all yoyo bearings have tight spaces where dust gets trapped. To understand this particular bearing's sensitivity: I did try rinsing with tap water last night, and now it barely spins. It seems even the contaminants in the tap water were enough to block up this bearing. Also, while most bearings can be used with a very thin lubricant to prolong life and decrease noise, this one cannot. I could try distilled water, but we really need a precision solution. • My question is: Why are you using gold metal for moving parts? Is it just for looks? – user5593 May 23 '14 at 14:52 • Sorry I kinda disappeared forever... It spins for a long time. As I mentioned above, I don't know if the gold is helping at all, or if it's a marketing gimmick, but either way, they are good bearings. – Lumify Mar 13 '15 at 16:09 ## 3 Answers In most of the case distilled water is enough, but you should be sure that there are no salts inside your object if you can perform a Conductometry test on the washing water follow this procedure: Wash the item inside a buck for 3 minutes with distilled water measure Conductometry, take another bucket with the same amount of water wash the item for 3 minutes, measure Conductometry repeat these steps until conducibliy drop down. This is a Conductometry test I've made while restoring an ancient metal object. You can see that I needed 5 washing to get good result. If you have high conductivity you should identify the salts with some spots test to understand where they came from. If you have grease you can use a surfactant like Plysorbate 20 2% in distilled water not more! Eventually if there to much salts and grease you can use: Thiourea solution 8-10% Sodium thiosulphate 30% EDTA 10 % (reference here). Remember to dry very carefully the object with a hair dryer, NEVER leave the object wet for more than a couple of minutes! Eventually you can use a protective like Soter or Zapon these normally cause in terms of colour change a$\Delta E\$ of 2-4 so ask to your self if you really need it for a gold object.

In my opinion avoid ultrasonic cleaning for composite materials! If you really care about the object ask for a metal restorer!

• It's mostly dust, maybe some pocket lint. I doubt grease and salts are getting in there. The reason harsh chemicals are usually used is because the spaces are so tight, and dust gets trapped. I'll try distilled water next time, if I end up using the bearing again. Drying is an issue; a brush wouldn't be able to dry this. yoyoyo.com.au/image/cache/data/magicyoyo/… – Lumify Mar 13 '15 at 16:20
• I wont be so sure, grease and salts are everywhere.Sorry I meant an Hairdryer! – G M Mar 15 '15 at 12:54

You could use the same method they use to clean gold rings, gold-plated watchbands, etc. Get an ultrasonic cleaner and put in distilled water with a few drops (depending on the tank size) of dishwasher detergent. This will remove oil, grease, contaminants, etc. If you don't have an ultrasonic bath, just stop in at the jewelry store at the mall and 9 times out of 10 they'll be nice enough to clean your bearing in less than 5 minutes.

• The problem here is that it's not the same as a ring (a "one-piece" object) – Gaspa79 May 24 '14 at 17:48

As the structure of the gold bearing is the same as other 'metal' bearings then the wash cycle will also be the same.

I am pretty sure the gold is a cosmetic finish to fleece the engineering challenged. The gold finish on the larger parts if plastic or aluminium will likely be paint or anodizing dye and not gold either. Any gold in the bearings will be MUCH softer than the typical hardened steel bearing balls and races and will make then fail if it gets (or is put) in there requiring regular re-purchase. If someone is selling ceramic bearings they might be interesting, they are sometimes used in industry where lubrication is not practical (heat, speed, process contamination, viscous drag, dirt collection) but there are pretty much no common uses of gold in bearings (I had never heard of it before now)

There are very few household/hardware store chemical that can attack gold and hydrocarbon solvents are not on the list. Keep chloride salts and compounds away or the gold plating may be damaged.

EDIT:
As the gold plated, hardened steel and ceramic bearings in this application are usually unlubricated to prevent dirt pickup and drag and unsealed for the same reason so any volatile solvent will wash out dirt and evaporate quickly. Kerosene may leave an oily film that helps with lubrication but will then get dirty quickly.

The gold plating on the balls will be smooth and any high spots will get smoothed out quickly. It will wear the gold away unevenly and no longer run quite as smoothly as when new and result in lots of repeat sales.

• It could easily be a cosmetic thing, but maybe the gold's malleability is good for wearing down small bumps in the balls and the surface. Probably not though. There isn't a lot of pressure put on yoyo bearings compared to other uses. Low friction is a big concern, and ceramic bearings are the best I've found. The gold bearing spun for a long time when I got it, but it's degraded a bit. I'm using dry cleaning fluid right now, and it works as well as hexane. They probably aren't good for the gold bearings though, what do you think? – Lumify Mar 8 '16 at 19:12