I would like to know when you use ball bearings as a tool to mix paint with,does the ball bearings contaminate the paint in the long run?
Thank you.

316 Stainless would be preferred over 304 stainless. If they're Steel they'll likely rust.

I have a tube of BBs I've been using for years, haven't noticed any rust or contamination.

316 sea grade stainless steel and you cant go wrong,i buy the 7mm size

Matt,
So your saying that the 316 sea grade stainless will work fine for mixing paints? Now what about acrylic paints such as the life color brand?
where would you get this type of bearings?
Thanks

any color brand,if they are made to be safe in sea salty water any paint can't rust them,i get them from the marina...i dont steal bearings for boat!...i know the engenier work there,but write in google "316 sea grade stainless steel bearing balls" and you can find planty of sellers

I've seen bb's rust in acrylics and discolor some enamels. In a moment of desperation I used small pieces of glass aquarium gravel. If you have any concern about rusting put the bearings/bbs/shaker balls/ in a dish of salt water for several days. If there is any sign of discoloration or corrosion don't put them in your paint.

AK Interactive and MIG both have agitator balls.

My son the WarHammer figure painter just shared this idea with me two days ago.

Michael's Art Store sells bags of small clear glass marbles to put in glass planter vases. The bag is about as big as a Foster's can. He has been using these glass balls for the past several years and each bottle of paint gets one just as soon as enough paint has been used up to allow for the volume of the glass marble without over-flowing.

Glass,Hematite or ceramic they are all good substitutes but the only problem is the weight, a little too light

Glass marble is about five times the diameter of a small ball bearing so weight is approximately the same.

When you shake the bottle you hear the marble knocking around inside. That means it is moving paint around and that is all that matters.

This works for him. I am going to try it since my paint bottles are physically larger and hold more than his do.

I drop two stainless BBs into every bottle of paint I have as soon as I open it. I have never had an issue with rusting or tainting the paint. They work great to mix the paint up as well.

Word to the wise! Don't buy cheap on these. You'll either get low grade stainless that might corrode, or you'll get someone substituting steel that will corrode. You get what you pay for. And remember to scavange the agitators when the bottle is empty. I tend to forget and by the time I remember it's too late the trash is gone.

You need to be careful about using ball bearings or marbles in larger glass paint bottles. I had a bottle of Alclad Black Primer and Microporefiller which comes in a large glass bottle. I added a small stainless bearing, because Alclad has a tendency to settle. I paint at a special workstation in my 3 car garage. I was shaking the Microporefiller bottle vigorously at my workbench, when the ball bearing inside sheared right through the shoulder of the bottle, and a stream of black Primer shot out across my garage, hit the ceiling, and came down across the hoods of two cars, in a perfect black line about 1/2 inch wide! It was quite a mess to clean up. It was also across my hand, sleeve and workbench. Fortunately, the bottle didn't shatter in my hand, it just had a round hole the size of a dime in the shoulder of the bottle! I notice now that Alclad includes ball bearings in its Microporefillers. Instead of shaking paint by hand, I always use my Robart paint shaker-- it does a better job of mixing than ball bearings.
VR, Russ

I've had that happen with large bottles of Pactra enamels. The larger the bottles the thinner the glass. After the first time I put the smallest agitators I could find in the bottles, put the lids on tight, put the bottles in a ziplock baggie then used my Robards shaker. A couple more brake but they were in the bag so I didn't paint my workshop by accident.

Many years ago, I had that happen to me at work. Paint shot out all over the window column and my arm — luckily not on my drawing! I haven’t used that method since. Note: The bottle was a small one, and the glass was relatively thick.

—mike

I use Nut Standard Pitch A2 Stainless Steel M3 (A2-70 cold-worked Stainless Steel, also known as 18-8 or 304 Stainless Steel)

500 for UKP£4.50, way cheaper than Marine BB's in the UK

9 surfaces to agitate the paint instead of 1, drop 3-4 in every Vallejo bottle & 6-ish in large primer bottles.

No problems yet with discolouration or rust yet, but I only salt the ones I'm about to use