Unfortunately, the Chapin 4 Gallon Backpack Sprayer Euro Style (61400/61500) is not meant for use in applying stains or anything other than insecticides, fungicides and herbicides. Doing so could damage the sprayer beyond repair.
No, the pump handle for the Chapin Backpack Sprayer 61400/61500 is not interchangeable. Most other Chapin backpack sprayers can be assembled with the pump on either side of the tank.
It is fine to use different products out of the same sprayer such as the Chapin 4 Gallon Backpack Sprayer Euro Style (61400/61500), as long as you triple rinse the sprayer and wash it out thoroughly. You should always triple rinse the sprayer if you are changing the product that you are using. Triple rinse means to rinse out the inside of the sprayer 3 times, and also fill it with water and run clean water through the hose for at least 1 minute to make sure that there is no residual left in the hose in addition to the tank. We also sell tank cleaners that are excellent for removing any possible residual from your sprayer.
The Chapin 4 Gallon Backpack Sprayer Euro Style will only reach about 10-15 feet depending on the PSI. We do not currently carry any backpack sprayers that will spray any further than that.
Chapin does not go by mesh size. They refer to filters. They did recommend when using Isoxaben in the the Chapin 4 Gallon Backpack Sprayer Euro Style (61400/61500) to pre mix and then pour into sprayer.