floorboard repair - part II

[JHZR2]

So Ive been going after the floorboard, getting the thing to a point where I can paint and seal from rust, have a weldable surface if I go that route, a good surface to seal to if I do pop riveting, etc. I also wanted to ensure that I had a good feel of what the extent of the rust was, so I could add structure wherever necessary.

Attached are pictures. Im currently planning on priming and painting, using galvanized to repair (as large a set of sheets as possible perhaps some galvanized support strips like are sold at the HD for hanging decks, etc. too. All pop rivited in place, sealed, etc.

But what are your thoughts based upon the pics?


Thanks!

 

[JHZR2]

 

[TooManyWheels]

It is hard to tell exactly how bad that it is, but it might not be very significant. Some places seem to be double thickness at least, with lots left still. You need a real grinder/brush to actually reveal what is happening there.

Is this moisture coming from the inside?

 

[JHZR2]

It was. There was a leak, and that is where the water pooled. THere is pretty extensive sound deadening, and the water would sit under the seam.

Ive hit with a hammer around, ground with aluminum oxide as well as a steel brush on a dremmel, and am at pretty solid metal. Most of the areas past what I show in pictures grinds to shiny silver metal now. I don't want to do that because everything else there is nicely painted, coated, etc.

I figured that if I was to weld, Id grind off all paint to silver metal and clean right before doing it... and if Im just riveting, I want to leave as much protection as possible.

Im leaning towards riviting, there is heavy metal that seems OK to me. It is solid, so I think it is best if we use an anti-rust encapsulation paint, then ultimately coat in a waxy spray that will keep water out and maintain itself.

My thoughts with the metal are as follows:

Put a big piece that not only covers the issue places, but also stretches far out in order to add extra support. I'm not sure if this is smart or dumb, as forming it would be really tough... Would laying it flat over the current floorboard, assuming I seal it, be OK, or should I just go not too far out into the center of the floorboard? How many inches overlap should I have?

For the two spots, Id do it as follows:

Hope this makes sense. Id rivet it at regular intervals by drilling the holes, painting an anti-rust paint in the holes, coating in the holes with a spray wax rust preventer, then putting in the rivet. Closer to the rust, Id perhaps do a few more into solid metal to support it better (or am I better off doing fewer to protect the metal structure???).

Thoughts???

Thanks!

 

[jcwit]

Looks like you're on the right track. I'd use some split tubing or split clear plastic tubing to cover the wires at least where the new metal ends. Will prevent it from wearing thru the insulation in time. Myself I'd use a butul (rubber) type of roof coating which will seal better than the wax form of coating. The wax is great for preventing rust but of little use for sealing. The butul (rubber) coating will remain flexiable, and not dry out and crack at least for the life of this old car.

Again use something to protect those wires.

 

[sciphi]

I JB-welded the living daylights out of a panel like that on two areas of my car. Seems to work.

Forming steel is very, very hard without the proper tools. What about fiberglassing? Seal it well enough and it's good to go for years.

 

[johnd]

On my 1962 Pontiac Catalina I had a trunk issue that looked like that. I chipped off all the surface rust, treated with phosphate and fixed leak to prevent future problems, and covered the small holes with fiberglass mat and resin. I thought it was a pretty good repair and conformed nicely to the existing pan. Sure was a lot less work than redoing all the sheet metal.

 

[andyd]

I spent 10 months of spare time repairing crash and rust damage in my current 528e. I have no formal sheetmetal experience and few tools. I used computer cases and metal shelving for steel. I have no clue as what type of steel it was, except that it was free and thicker than most of the stuff it replaced. I found that smaller pieces worked better than larger. I used 1/8 x 3/8 and 3/16 x 1/2 steel rivets. I bought them from Grainger. Get drill bitts there also. The shorter bitts last longer

 

[TooManyWheels]

Originally Posted By: sciphi
I JB-welded the living daylights out of a panel like that on two areas of my car. Seems to work.

Forming steel is very, very hard without the proper tools. What about fiberglassing? Seal it well enough and it's good to go for years.


At the risk of sounding like a hack, I'll say that, after seeing the area, my thoughts lie along this line.

With the (apparently) limited scope of rust, I would not actually want to disturb the surrounding area much. I would want to just grind off the surface stuff and tar over the areas that have a layer left underneath. For any gaping areas, make individual patches, as small as possible. To me, this would be much more workmanlike than a large homemade patch.

 

[yeti]

i've done many of these types of repairs over the years, mostly on friends' cars. cut out the bad metal, going at least an inch (where possible)into good metal. use around 20 ga. metal, and cut it to approx. 2" larger than needed, and do a rough fit with a ball pein hammer, cold chisel -- or whatever you choose for forming the metal. just keep fine tuning your fit, until it's ready to be fastened. we would use short cutter screws. when ready for fastening, apply fibrated roofing tar/patch on the floorpan, with a thick "bead" around the hole perimeter. this way, when fastening, the excess will be squashed out, providing an air/water tight seal. when done, paint over the job with the tar product -- on the underside as well.using this product will also act as a sound deadener. it's about 10 bucks for a gallon.

this job is not rocket science -- just tedious and time consuming. you don't need any expensive products. this repair will last many years. good luck, which ever way you decide to do the job.

 

[Jim 5]

Originally Posted By: yeti
i've done many of these types of repairs over the years, mostly on friends' cars. cut out the bad metal, going at least an inch (where possible)into good metal. use around 20 ga. metal, and cut it to approx. 2" larger than needed, and do a rough fit with a ball pein hammer, cold chisel -- or whatever you choose for forming the metal. just keep fine tuning your fit, until it's ready to be fastened. we would use short cutter screws. when ready for fastening, apply fibrated roofing tar/patch on the floorpan, with a thick "bead" around the hole perimeter. this way, when fastening, the excess will be squashed out, providing an air/water tight seal. when done, paint over the job with the tar product -- on the underside as well.using this product will also act as a sound deadener. it's about 10 bucks for a gallon.

this job is not rocket science -- just tedious and time consuming. you don't need any expensive products. this repair will last many years. good luck, which ever way you decide to do the job.


I did repairs almost identical to these (except far more extensive) on my early Bronco restoration project. I bought a good quality mig welder for the job. I would recommend that you do all of the above with the exception of the overlap. You want butt joints as perfectly fitted as possible. Then call a mobile welding truck (after everything is prepared) and the welder could mig-weld it all together in less than an hour. This will give you the best result at a pretty reasonable cost I'm guessing.

A good cutting tool for this job is an air operated chisel with a sheet metal cutting bit. The bit looks like a 3 pronged fork with the middle prong bent down. Sure, it will be a ton of work/time in cutting and fitting the part, but it will be worth it. If you choose to go down this path, feel free to PM me, as I spent about a year on the bronco project and had many successes and even more mistakes that had to be remediated at great expense of time.

Whatever you do, err on the side of thicker gauge replacement sheet metal for this job. Legs are strong and you'll feel the medium grade stuff buckle under your legs everytime you get in and out of the car. You can probably guess how I know this.

 

[JHZR2]

Originally Posted By: yeti
i've done many of these types of repairs over the years, mostly on friends' cars. cut out the bad metal, going at least an inch (where possible)into good metal. use around 20 ga. metal, and cut it to approx. 2" larger than needed, and do a rough fit with a ball pein hammer, cold chisel -- or whatever you choose for forming the metal. just keep fine tuning your fit, until it's ready to be fastened. we would use short cutter screws. when ready for fastening, apply fibrated roofing tar/patch on the floorpan, with a thick "bead" around the hole perimeter. this way, when fastening, the excess will be squashed out, providing an air/water tight seal. when done, paint over the job with the tar product -- on the underside as well.using this product will also act as a sound deadener. it's about 10 bucks for a gallon.

this job is not rocket science -- just tedious and time consuming. you don't need any expensive products. this repair will last many years. good luck, which ever way you decide to do the job.


so no riveting? WOuld super-short screws back out, or did it not matter once coated with tar?

Did the tar stink in the heat?

My thought was to not form the metal exactly... to every last feature of the floorpan, as I think that would be too tough. By getting it close and riveting in place, at least to some spots, with sealant in the gaps, Id think would work...

Or not???

 

[ATS-V]

If you rivet it in you'll invite a place for moisture to collect even if it's coated. The right was would be to cut it and weld it as suggested above.

Or for a half baked, but simple, repair grind it, coat it and use filler and then seal it. It won't last as long but probably longer than car.

My 2 cents