Minor surface rusting on floor

[justin-311]

I’m replacing the crap seats someone put in my ‘67 and I went down the rabbit hole of repairing/redoing the floorpan as much as I can while I’m in there. I took out the carpet, padding and scraped off the original tar (?) that lined the floor. I’m seeing a small bit of surface rust that I am going to treat, likely with some Por-15 I have. I was then going to add some sound deadening material a friend had given me (forget the brand) to mimic the original tar coat. Does this sound like a sound decision (pun intended)? You can see the rust on the edges and middle belt.

[Habitat.pat]

Sounds good to me. I’d also check at least the surface rust areas to see if there are any pinholes. I used a scribe to push on the metal in places I thought could be thin. I also put a light under the car & looked for holes that way. I found a few using the light even though there wasn’t any visible rust on the inside.


Peace, Pat

[funkaholik]

This doesn't look too bad. Definitely try Pat's idea of putting a bright light under the car in a dark garage to make sure there is no rust-through. POR-15 does not treat rust. Their "paint over rust" slogan falls short as soon as you read their instructions, which call for you to mechanically remove as much rust as possible, treat the remaining rust with a converter, and then finally paint it with POR which seals the part from oxygen getting to it and creating any new rust. It's a multi-step process but will give you a nice finish if you follow all instructions closely.

For reference, you can see how my floors looked to start, during and after the whole POR process on page 3 of my build thread. I used a spray-on sound deadener, but the press-on tar type is great, too. Get one of the little wooden rollers that they sell to help press the deadener into all the valleys on these floors. Saves your fingers and makes the job much easier.

Link to page 3. Scroll down for floor pics:

viewtopic.php?t=19067&start=30

[funkaholik]

One more thing - I can't remember whether acetone or spray-on brake cleaner worked best for removing the residue from the tar, but you'll need to get all that off, as well as any dirt, grease, etc for the POR to stick like it should.

[justin-311]

Thanks Erik and Pat. I’ll try a couple things to get the tar off then get the converter; I just have the Por topcoat right now.

Did you use anything different for the seams by the rear wheel arches? I notice some of mine was flaking off and should like do that too.

[Stick]

I just went through the same process about 2 months ago. Your floor looks pretty good and similar to mine. I took some wire brushed to some of the heavier stuff around the straps that the seats go through and then lightly sanded the areas to remove as much as possible.
The Por-15 or rust encapsulations will take care of the rest. Then you can apply the sound deadening once it’s cured.

Below is a link to what mine looked like - pages 1 and 2

viewtopic.php?t=37878

[justin-311]

I just went through the same process about 2 months ago. Your floor looks pretty good and similar to mine. I took some wire brushed to some of the heavier stuff around the straps that the seats go through and then lightly sanded the areas to remove as much as possible.
The Por-15 or rust encapsulations will take care of the rest. Then you can apply the sound deadening once it’s cured.

Below is a link to what mine looked like - pages 1 and 2

viewtopic.php?t=37878

You say the straps the seats go through… I don’t have stock seats, should there be a piece of metal(?) running across under the lengthwise piece? Your ‘69 looks like a slightly different pan. Would be good to know for whatever seats I get. There are already a bunch of holes drilled for the seats the PO put in it and I’d like to not drill others if possible.

[justin-311]

This doesn't look too bad. Definitely try Pat's idea of putting a bright light under the car in a dark garage to make sure there is no rust-through. POR-15 does not treat rust. Their "paint over rust" slogan falls short as soon as you read their instructions, which call for you to mechanically remove as much rust as possible, treat the remaining rust with a converter, and then finally paint it with POR which seals the part from oxygen getting to it and creating any new rust. It's a multi-step process but will give you a nice finish if you follow all instructions closely.

For reference, you can see how my floors looked to start, during and after the whole POR process on page 3 of my build thread. I used a spray-on sound deadener, but the press-on tar type is great, too. Get one of the little wooden rollers that they sell to help press the deadener into all the valleys on these floors. Saves your fingers and makes the job much easier.

Link to page 3. Scroll down for floor pics:

viewtopic.php?t=19067&start=30

Since I don’t have stock seats, what are these studs for? I do have these studs on the passenger side.

[funkaholik]

Those are the four mounting holes for the parking brake center cantilever (at least that's what I call it). They are actually welded-on nuts. they look like studs because I have them taped up so they wouldn't get boogered up with sound deadener.

Here is what it looks like from underneath:

[funkaholik]

It also might look like this!



And, now that I look at these before and after photos again, I realize that I put mine in backwards. The horror!

[funkaholik]

Justin,

In response to your "seat straps" question, there should be two reinforcement strips of metal running front to back on each side of the floorplan, and this is where the stock seat mounting holes are located. In the closeup photo of my floor that you cropped and posted above, you can see the strip running pretty much down the middle, and one of the stock seat mount holes right about in the center of the photo. Hope that helps.

Actually, this photo from Greg's page shows both sets of seat mounting holes perfectly. there is a forward and rearward set of mounting holes, for you to use depending on how long your legs are.

[justin-311]

Justin,

In response to your "seat straps" question, there should be two reinforcement strips of metal running front to back on each side of the floorplan, and this is where the stock seat mounting holes are located. In the closeup photo of my floor that you cropped and posted above, you can see the strip running pretty much down the middle, and one of the stock seat mount holes right about in the center of the photo. Hope that helps.

Thanks for the brake piece!

If you look at the first pic of my pan it just has the one strap in the middle. The other groups of two holes is what I “though” were the original seat mounting location. Is it different between 1967 and 1969/1970? My car is a hodgepodge of parts it seems, so running down what should/shoudn’t be there is proving to be confusing and taking a little time.

Thanks again!

[funkaholik]

OH! I guess I could have just paid more attention when I was looking at your 1st photo. I'm going to blame it on the after-dinner martini I'm having right now. I've only seen the bare floors on '69 and '70 cars, and silly me for assuming that other years would be the same. After working on Datsuns I should know better.

Those hole sets of yours look pretty close to the same position as mine. I would suggest getting whatever seats you're going to use, setting them in the car to be sure you know where they should be to fit you, and seeing if they happen to line up with those holes. If not, and you need to make new holes, you want to do so before sealing everything up with POR (drilling new holes post-POR breaks the "encapsulator" seal) and adding sound deadener. Drilling through that tar sound deadener with a hot drill bit gets really messy. Ask me how I know.

[Stick]

Looks like your 67 floor is a bit different from the 69 I have but Erick summed it up well - sorry for the poor description of floor straps!

Does the earlier floor have reinforcement for seat mounting on the underside? It would seem like some reinforcement would be a good idea but it has also survived 55 years without any issues so far.

I would second Funkaholik’s suggestion about sound deadening around the holes. You don’t want that too close to any holes and suggest leaving at least a 1/2 inch of material clearance around the seat belt mounting holes or any other hole where you will be wrenching a bolt or screw back into. When I replaced the carpet and installed a seat belt mounting bolt it grabbed a little bit of carpet and some of the sound deadening and wrapped it all up on the bolt in a bit of a mess. Had to remove and clean the bolt and more of an installation hassle.

Also helped me to “map all of the holes in the pan to see what was used and unused. I covered o few unused holes and marked where mounting hardware went.

Yours will look fantastic when completed I’m sure!