I bought a gallon of Fluid Film, that lanolin based rust preventative, a few weeks ago and I am just in from spraying the underbody of the van with the stuff. I had a bit of difficulty with the applicator I used, it did not spray the as thickly as I’d would have liked. But I think the multiple passes did the job ok. Well I have to confess, I found another applicator during the day and did a re-spray just before dark. I’ll take pics of the results when there is more light, but meanwhile here are pics of the can and the first applicator used. BTW, the consistency of the Fluid Film is a tad thicker than good quality latex paint. And yes, despite my best intentions, I ended up with the stuff everywhere. But is does make your hands baby bottom soft.

Have a look at this, a drop of Fluid Film (one of many around the workshop now) that fell onto the top of the new jerry can. I consider the grinding dust to be evidence of my hard work, not of sloppy housekeeping. Note the creeping wet spot.