Choosing an agitation system for your new pressure pot requires some thought. First of all, do you need an agitator? I would recommend that you use an agitator if you will be spraying coatings with heavy particulates, such as organic or inorganic zincs. If you don’t agitate these coatings, the zinc will quickly settle out. You should also consider using an agitator if you are planning to leave coatings in the pot between uses and you want to mix it prior to each use.
If you determine that you need an agitator, you’ll need to choose between a direct drive or gear reduced unit. On Binks models, the direct drive agitator is like a small propellor on a boat motor. It can turn very quickly, but its small size may limit its effectiveness for agitating the entire pot. Direct drive models are usually very suitable for thin coatings. If you use a direct drive unit regularly with thick coatings, you’ll probably burn out the motor eventually. Unfortunately, replacement motors aren’t cheap. These units may also require oiling, so check the user’s manual to determine if that is necessary.
Binks gear reduced agitation systems use a rotating paddle, similar to a drywall mud mixer. Because the motor is gear reduced, it is well equipped for repeated use with thick liquids because of the low stress on the motor. This system also does a better job of mixing the entire pot at low speeds. These units cost considerably more than direct drive units.
When adjusting the speed of either type of agitation motor, use the lowest speed that will effectively keep the coating in suspension. Especially with direct drive units, it is possible to whip air into the coating and make a mess inside your pot if the air is turned up too much. If your gun is spitting air, check to see that a mixer on high speed isn’t the cause. You may want to take the lid off while adjusting the speed so you can see how fast the mixer is turning. If you are spraying a coating that doesn’t require agitation and you plan to spray down to the bottom of the pot, consider turning the agitator off.