Well, yesterday was a nice day with temps in the upper 60s so I decided to do some work on my truck.
My floors had some pinholes and were more flexible than I would like them to be. They are still pretty solid so I decided to cut some metal for strengthening them up.
These pieces will be glued down to the floor with sheet metal adhesive and then covered with something, maybe fiberglass. The areas with the indentations seemed to be solid for the most part so that is why most of the metal is flat. I did have to bend some of it down in the the indentations but I'm glad I didn't have to do too much. It is kind of fun shaping metal but I don't really have the right tools and my outcome is far inferior to some of the work I've seen here.
The only big holes are where the cab mounts used to be. My cab is bolted directly to the frame rails with some belting in between. I'll be looking for some better fasteners than those bolts you see sticking up.
Layering metal on metal is just asking for bigger problems down the road...any gaps between the metal will allow condensation, and ultimately rust, to form and destroy what you were trying to save...add fiberglass or bondo to that mix and it'll get even worse since both will absorb moisture and hold it for later...the proper ways to do this are to cut the rotten parts out and butt weld a new panel in and then seal both sides of the welded seam with seam sealer...or...leave yourselve a 1" wide overlap all the way around the 4 edges of the patch panel after cutting out the existing floor, crimp an offset into the patch panel so that it fits flush with the existing floors and tightly spot (rosette) weld the new panel in every 2 inches and use seam sealer on both sides of the panel seams...I'm not trying to preach, but it bugs me to no end when I get a new project vehicle and I find someone else's butchered panel repairs that ALWAYS wind up making things worse than they had been before...
Heres what putting metal over metal will get you
Repaired right?
Not so much
Gotta love previous owners.
the Right way.
Cut "ALL" the rust out and replace with new metal.
Boons wrote:Heres what putting metal over metal will get you
Repaired right?
But you don't know what the floors looked like before the repairs. It is obvious that they only glued the edges down and not the center. Perhaps they never did any prep work to the floor.
I plan on covering the entire surface with adhesive and clamping it after I've prepped the floor and metal. Then I might grind the edges so it feathers into the existing floor. Perhaps that would be enough but it seems that the seams should be covered with something.
Some people look at things as having a right way and a wrong way. I like to explore all possibilities and find what works. To me it makes no sense to cut out a decent floor to weld in scrap metal. The existing floor isn't bad but just needs a little strengthening and has a few tiny holes. I could leave it as is and have no problems with it.
I also don't have a welder. I've thought about rivets but don't want to drill a bunch of holes in the floor. I'm trying to have fewer holes not more holes.
the reason fiberglass doesn't work is because it has a different coefficient of expansion than steel. when the temp drops the steel and fiberglass shrink at different rates, pulling themselves apart and breaking the bond between them. that being said, i have fiberglassed floor sections in my 74 w200 that have been in there for almost 20 years. not pretty, not firmly attached all the way around, but still plenty strong enough to stand on.
putting metal pieces against each other can cause electrolysis issues between the two pieces. they say that this applies to dissimilar metals, but if you really get into it, it seems there are seldom two batches of mild steel that are exactly the same composition. if you cant be certain that there will be no opportunity for moisture to get between the two, you might want to rethink.
btw, what is 'sheet metal adhesive'... is that something like jb weld? very dangerous to sand/grind/inhale.
just a thought... maybe house construction subfloor adhesive would work?
Panel adhesive can be found a decent body shop supply store.
I used this one to attach a roof skin.
Use's regular caulking gun ,mixing tube screw's on the end.
3M announces an unprecedented automotive adhesive, 3M™ Automix™ Panel Bonding Adhesive (PN 08115), so strong that it's guaranteed to perform to specifications for the life of the vehicle. The guarantee is just as strong. The lifetime guarantee covers all parts, materials, labor, and loss of use of the vehicle.
Never before has a company made such a guarantee! Using 3M™ Automix™ Panel Bonding Adhesive, body shops can now be assured that the adhesive repairs they make will equal or exceed the strength of welding. Car owners and body shop professionals alike can feel confident about the choice of bonding over welding. 3M™ Automix™ Panel Bonding Adhesive is for panel bonding only; it should not be used on structural components such as rails, rocker panels, core supports, etc.
Beyond its strength and guarantee, 3M™ Automix™ Panel Bonding Adhesive's advantages over welding include excellent corrosion protection, reduced grinding time, curing on demand with heat, and sealing and bonding in one application.
Moreover, with adhesive bonding, there's less fire danger to the technician, less danger of damaging adjacent panels, and no danger of heat warpage of sheet metal, as there can be with welding.
And, with its easy application and short learning curve, 3M™ Automix™ Panel Bonding Adhesive does not require the same specialized skills as welding.
Independent research has concluded that 3M™ Automix™ Panel Bonding Adhesive's bonding integrity is as strong as welding.* These impressive results did not compromise quality of workmanship. Researchers concluded that 3M's Panel Bonding Adhesive process "yields a finished repair that has the same aesthetic appearance as that seen on a factory installed panel."*
wally426ci wrote:Use Rust bullet or something on the metal(s) themselves.
Then, instead of sheet metal over the existing, I would seal the pinholes and then weld strips of angled steel to the bottom side of the floors.
What would you use to seal the pinholes?
Since I don't have a welder and don't really want a bunch of angle iron tacked to the bottom of my truck that seems a bit out there.
The place you buy the stuff from if local may have a loaner application gun for you to use. Just wire brush the crap out of it and get the metal clean, apply, clamp. It will look good from under neath, and the adheasive will fill all the holes.
Don't use angle iron. My "floorpans" are roof patch tin screwed to what was left of the original metal, braced with 1" angle iron. And chunks of 2x4 lumber to prop up where the floor pans separated (rotted away) from the sill plates... Someone's 10 cent fix is going to end up costing me around a grand to fix. And the door corners full of fiberglass, oh, the joy... When it fell out, the outer door skins came with it. My truck looks tolerable in pictures, but I wouldn't take it off the farm right now for love or money.
