Frame rails

[Tradewind59]

So I am getting ready to start wrapping the belly pan. As a victim of Mainframe rail rot I'm finding myself very apprehensive to rivet or make any holes into the main frame rails. I assume this is unreasonable. I also assume most people are using the frame rails and not strictly the cross members and out riggers to rivet the belly pan down? Thought about trying to overlap sheets enough to avoid it where possible . Probably a dumb question. But the headaches that the rot in the frame rails caused linger. Thanks for the help

[Bubba L]

I think drilling holes in the main frame member has always been done and possibly contributes to the rust buildup. You could drill in the frame and cleco. When you’re ready to rivet, squirt a dab of polyurethane caulk in the hole the rivet. Where you join the edges of two sheets, don’t caulk so any accumulation of moisture can leach out. When we were rebuilding our 55 chassis, I modified a small 1/2 gallon sprayer with a longer hose. I poured some Por 15 Metal Prep in the sprayer and slid the hose as far as I could from both ends of the 2
“X4” frame and sprayed. Later I sprayed with primer. Maybe I didn’t get the inside all painted, but some was better than none. Just a thought.

[Belegedhel]

I had a lot of rust, rot, and corrosion on my frame rails, crossmembers and outriggers. I don't think the holes made much of a difference in terms of accelerating the rust, it is more a matter of galvanic corrosion between the steel and aluminum sheet, and just the fact that water gets trapped in that interface and takes longer to dry. When I was reassembling mine, I considered putting some kind of spacer between the skin and the frame at every rivet, just to create a little air and help dry things out. I eventually talked myself out of it, as I expect there are some unintended consequences of such a change. Afterall, the original configuration lasted over 50 years, so although it may not be the best, it was good enough.

good luck!

[Tradewind59]

Thanks for the responses.

I appreciate it. We have moved forward after the gentle nudge. The fear of putting holes in something new was real even if unwarranted. Thanks again

[CRH]

Consider putting Fluid Film inside the frame rails.

[Bubba L]

Originally Posted by CRH

Consider putting Fluid Film inside the frame rails.

I read about Fluid Film. That seems like an ideal material for just about everything. I think if you use that on the inside of the main frame members, then weld caps on the ends to seal the frame, it should last forever. Thanks

[CRH]

I live where the roads are salt treated in the winter. I buy Fluid Film/Woolwax by the gallon. I spray it in the frame rails and on everything steel under my vehicles. I've treated our cattle trailer, snowblower, mower decks, farm equipment,.ect. It's done a good job keeping rust at bay.

[57Vintage]

I was also concerned with corrosion and did two things.

Installed the belly pans from back to front with overlap so the seams aren't pointing forward. Less chance of infiltration going down the road.

I also put high density polyethylene tape between the steel of the frame and the aluminum skins to reduce the chance of galvanic damage. It comes in several thicknesses. I used the 5 mil.

You could also get a product that is used by the auto industry to coat the interior of rocker panels, B pillars, etc.

https://www.amazon.com/gp/product/B0...5249a71bd1a066

https://www.amazon.com/gp/product/B0...e1c6a83a2603dc

[Tradewind59]

Thanks for the responses everyone.

Great ideas all around. Getting ready to start for the day here. 32 degrees to start the day out there. So I will definitely be overlapping back to front. Decided to get some polyethylene tape. Frame is new and sealed. The only holes in it now are the bolts for the axle mounting and the bellypan he's I have started. It will be either fluid film or eastwoods inside frame spray going in through the holes I drill. Game time decision there. With the Temps outside fluidfilm is probably the better choice. And I have both on hand. Wet rivet the belly on as well with a dab of vulkum on the hole before the rivet. Suppose to get up to 60 both days this weekend. Hopefully we can get this bellypan wrapped up.

Thanks everyone