grease for paint sprayers air motors

[nondairy]

Hello I am rebuilding paint sprayers and air motor for an industrial paint sprayer. The manual does not specify any particular grease though there is a mixture of materials nitrile, PTFE and viton o-rings and grommets. Housing usually a mixture of Aluminum and stainless steel. V or U seals with UHMWPE, PTFE and leather packings that need to be lubricated during assembly but do not need to be lubricated long term by grease. Most commercial grade pumps I just use multipurpose lithium during assembly of the fluid section but these air motors need to be in good working order for 5+ years. I believe this one made it 12 years before servicing.

Graco just specifies 'waterproof grease'. What to use? Is superlube better than white lithium in this case? Would be best If I can have one grease do everything for these pumps both air motor and during assembly of the fluid section meaning it should be easily cleaned out using lacquer thinner, hot detergent water or mineral spirits without contaminating any wetted parts with silicone.

Air motor: https://www.graco.com/content/dam/graco/tech_documents/manuals/307/307043/307043EN-ZAB.pdf
Pump: https://www.graco.com/content/dam/graco/tech_documents/manuals/308/308116/308116EN-V.pdf

 

[nondairy]

Tough crowd
Will just use white lithium for the next guy who works on them

 

[Foxtrot08]

I found the msds for Graco Pump grease. It is a moly grease.

We rebuild a lot of Graco pumps, but I’m not super familiar with that side of the company. I want to say we just use a normal lithium Ep2 grease. Probably with moly now that I see the product data sheet.

So I would find something with 3% moly or 1% moly in it.

 

[Foxtrot08]

Also, super lube grease - which is a ptfe based - would play fine too. However the “graco” branded, is just a moly grease. And I’m led to believe just a lithium grease.

You could probably play around with a calcium complex moly grease if you wanted to get fancy. It’s better at dealing with water than lithium of course.

 

[nondairy]

Also, super lube grease - which is a ptfe based - would play fine too. However the “graco” branded, is just a moly grease. And I’m led to believe just a lithium grease.

You could probably play around with a calcium complex moly grease if you wanted to get fancy. It’s better at dealing with water than lithium of course.

thank you for reply!
I considered a calcium grease but this pump 'shouldn't' ever see water. Very dry arid environment and lacquer only. I have super lube and they say in their datasheet its suitable for paint environment; I believe Kremlin uses something similar in their air motors a PTFE based grease. I looked up specs for the newer graco xtreme air motors and the manual specifies "Apply high quality lithium grease.".
I don't want to vary from that as I can't assume I will be the next person to work on them. I picked up some lubrimatic white lithium from ACE and will use them.

also many of the fluid sections I rebuild do see mainly water based materials so its advantageous for the grease to be easily washed away. Its just there to facilitate the installation of the piston rod and packings and not to function as a long term lubricant. Paint sprayer are lubricated during use with a special Throat Seal Liquid [Di(2-propylheptyl) phthalate] which functions as both a lubricant and plasticizer to keep material drying on the rod.

https://www.burwell.com.au/assets/volumes/downloads/Graco-Xtreme-XL-Air-Motor-Manual.pdf

 

[Foxtrot08]

All our pumps are grease and oil pumps. I’ll ask one of the guys that rebuilds them what we use later today.

That being said, you’re on the right track either way. I personally would just use a lithium moly grease. Pick your favorite brand. It’s inexpensive.


PTFE would be a “longer lasting” grease so to speak in the air motors. However, I don’t think the life cycle of the grease is the limiting factor for most air motors. Otherwise they would recommend something stupid like Krytox GPL 215. It’s not their money, why not? They already want $50-60 a tube for a tube of Graco branded grease.

For the assembly assistance, you could use the same grease and flush it out. Or just use an assembly grease - if you don’t mind two products - as the assembly lubricant is designed more to come off. Where as a lithium grease with moly may hang around longer. I’m not sure on those sprayers without seeing it - do those parts have contact with the paint product? As contamination would be my only concern there.

 

[Foxtrot08]

Update:
They use Lubriplate 105 grease for their assembly of the pumps.