Dave - I suppose you could use RV anti freeze (LOL! I didn't feel right typing RV-AF! ) if you have it.
(I don't want anything with ethelyne glycol in it around my hounds.)
Since I don't have any real use for the RV stuff, I'd just use mineral spirits - since I do have a use for that.
The whole idea is to keep something "oily" on the insides of the pump & gun.
Some of the positive displacement Graco pumps also have leather packings on the piston & throat seal. The "oily" stuff keeps the leather from drying out and/or expanding due to moisture.
I haven't looked at either one of those. The pump is not as important as the gun. If both have the same gun, get the cheaper one
Same gun on both.
Same gun you get on the more expensive units also.
Actually - the pump is critical.
The low end unit is a disposable. The one a step above can be rebuilt over and over and over again by just replacing the pump assembly. Go a couple steps up and you can buy kits to repair the packings in the pump.
Last edited by Rich Engelhardt; 07-30-2019 at 6:36 AM.
My granddad always said, :As one door closes, another opens".
Wonderful man, terrible cabinet maker...