Do you clean the old Fluid Film off before reapplying?

I coated my frame last fall with FF, worked great and I inspected the other day and still has a nice film on it in most areas. I will do it again this summer but just wondering if it's a good idea to clean off the grit or not worry about it. I noticed inside the frame rails on my 2015 it has collected and holds grit but it seams to be moist with FF.
I was thinking about a mixture of dawn and warm water in a pump sprayer, spray it real good and hose it off, let it dry and reapply the FF. good idea or no? I'm just concerned the grit will eventually hold water and road grime and contribute to rust.

 

I would just do a touchless carwash with the underbody spray. then re-FF it. Wouldn't worry about it.

 

If it is light grit then I would just cover it with the new Fluid Film. Some people recommend driving on a dirt road afterwords to help thicken the oil.

Hope this helps,
Charlie

 

I've had good sucess with Fluid Film by just giving the underneath a couple good coats every year. One can per application does it for me.

 

Is there any long term photo documentation of a second gen getting fluid film or similar sprayed annually since new?

 

mine looks like new and has been fluid filmed since day new (used to live in Chicago)...I do one touch up a year with 1-2 cans. I spray of the frame (lightly) with a pressure washer and just cover over the little bit of grime that's left with Fluid Film

 

Ok, It seems that the way to go is just touch up a bit. That will be easy. Thanks everyone.

 

Maybe I'll lay off the undercarriage washes to one every 2 months perhaps, rather than every couple days.

 

LOL, well I think I went overboard also. I made one of those PVC undercarriage sprayers that hook up to a hose. During the winter I was washing off all the road salt. I also turned my driveway into an ice skating rink.