How-To: No-Weld Rusty Floors


Wingback73

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I did this same style repair in a couple locations on my driver front and rear floor last summer after doing a TON of research to decide if I needed to learn how to weld.

The thing to know is that the rivets are NOT structural - they are simply there to clamp the panel in place while the adhesive dries. If you can find another way to do so, then by all means do - I couldn't.

The panel adhesive itself has a hold strength great enough that several vehicles now produced using just the adhesive and no welds.

Welding won't go away since this, of course, requires a lap joint while welding can create a butt joint, but in situations where you can overlap the panels this is an excellent, permanet substitute.

d-
 

chuck47

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Not quote sure yet. I am going to start with mats and see if its too hot/cold. Hopefully I wont need the carpet because the carpet I have is trashed.
Running with no carpet is just fine IMO. Just be careful if you have shorts on, you can burn your leg if your not careful.
 

Jackman

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I’m getting ready to do this as well. Looks like I also need a rocker panel for the driver side though... should be able to make a weekend project of it.
 

Wingback73

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I’m getting ready to do this as well. Looks like I also need a rocker panel for the driver side though... should be able to make a weekend project of it.
Expect to need to use Bondo or other filler to give yourself a smooth surface to paint afterward. Remember - these require a lap joint, so there is no such thing as "smooth" afterward as you WILL have a seam.

That said, if you are a bit handy, you can always put a slight bend in (using seaming pliers or the like) to minimize the portion that is raised, and if you do it right, you can put that part on the inside, giving you an almost smooth surface to play with once you grind down your rivets.

It would look like this from the side. Obviously, you rivet through the overlapped part.
__________
________/ __________________

If the bottom of the picture is the out/visible side then you simply fill the seam. If the top is the out/visible side, then you'll need to feather that ridge, which will be substantial since you used 14-18 gauge metal...

d-
 
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Zukey14

Zukey14

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Just wanted to post a follow up. Its been almost 3 years now and I just got under and inspected everything. No changes from the day I finished the project. Really happy with how everything has held up.
 

Vtx531

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Just wanted to post a follow up. Its been almost 3 years now and I just got under and inspected everything. No changes from the day I finished the project. Really happy with how everything has held up.

Great to hear that. I am going back through all the similar threads as I prepare to do mine. I was planning on replicating the factory spot welds (plug weld with a mig) but the more I think about, the more I like the idea of the pop rivets.

Right now, that’s the way I‘m leaning. 3/16” rivets but will not be doing the panel bonding adhesive. I don’t think it is necessary if you use enough rivets.

Everything about rivets makes sense in this situation:
- easy
- cheap equipment
- can even do it outside without worrying about shielding gas and wind
- makes a tight clamp on the entire piece
- no worry about sparks or burning anything inside
- easily removable if the floor pans need replacing again in the future
- can paint the pieces before joining and have superior corrosion protection inside the lap joint, no burning it off with the welding

That final bullet point is the big one for me. I think corrosion protection between the flanges/lap joint is a major drawback for welding.

If I go this route, I would use more rivets than you did (same as number of factory spot welds?) but I really think that is a great idea. Will still use welding as the method where any rivets would show on the outside of the body though. (Rocker panels?)

The only reasons I can think of to use spot welds would be cost and speed in production on the assembly line. Also that is a very tightly controlled environment for the quality of the welds and no consumables ( again…cost, sourcing, logistics, quality control)

I really don’t think strength is an issue. Rivets work well enough for aircraft, bridges, and buildings. Especially for a backyard DIYer, welding strength can vary greatly on operator skill and specific conditions but a rivet is going to have a consistent quality.

540lb shear strength and 680lb tensile strength for a 3/16 steel rivet on Fastenall’s website. Add up 50-100 of them and I’m not seeing any problem with strength there.

I would love to hear other opinions though before I get started but I am excited to get this issue fixed on my Jeep finally.
 
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Vtx531

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And some questions if you can help me:

The rear floor pans - do they have a flange on the back of them to go under the rear existing body piece and rivet where the factory spot welds are?

How about under the wheel tub?

It looks like the front pans go all the way under up front in the factory location too?

I am still waiting for mine to ship but looking at photos I am hoping the only side that require cutting are the side toward the center and toward the support piece that goes all the way across under the front seats. Looks like all the rest can be cut out at the spot welds?

55FDE2E8-264B-463A-AD45-A65B575B3162.jpeg
 
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Zukey14

Zukey14

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And some questions if you can help me:

The rear floor pans - do they have a flange on the back of them to go under the rear existing body piece and rivet where the factory spot welds are?

How about under the wheel tub?

It looks like the front pans go all the way under up front in the factory location too?

I am still waiting for mine to ship but looking at photos I am hoping the only side that require cutting are the side toward the center and toward the support piece that goes all the way across under the front seats. Looks like all the rest can be cut out at the spot welds?

View attachment 276721
If I understand you correctly the spots you have circled in yellow are spot welded and if you remove the spot welds you will not have to cut there which is what I did. I did have to cut the center and I cut on the sides that butted up to the outside body panels as I did not want rivets on the side of the jeep and that area was still good. So I left a flange and cut the new panels to fit so they overlapped and riveted under the jeep where no one can see,
 

Wingback73

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I personally wouldn't go with just rivets since you will be creating a water storage pocket (your lap joint) that will rust eventually no matter how well painted it is. That is why, in the repair the OP and I did, the rivets are only there to hold the joint while the adhesive dries. The adhesive itself is a rust inhibitor, and therefore you have no fear that your lap joint will trap water and rust since it is totally sealed. Your call, but I think you'll find that a huge number of rivets, especially if you go SS, will be about the same cost as doing it with adhesive, except that the adhesive has substantial benefits (including significantly higher strength ratings)
 
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Vtx531

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Thanks for the replies

Maybe a dumb question but I’ll ask anyway- Did you guys apply adhesive first and then drill through the adhesive for the rivets or did you align all the panels and predrill holes before applying the adhesive?

Is cleaning the paint off to bare metal a requirement for the adhesive or something extra you did just to make sure?
 

Wingback73

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No dumb questions...

Here is what you need to know:
1. The adhesive is stronger than a weld or and much stronger than the rivets
2. The rivets are only there to hold the 2 panels together while the adhesive cures
3. The adhesive requires bare metal, but is also a rust inhibitor
4. You apply the adhesive to both panels, spread it to cover all exposed metal (on both pieces), place it, then pop-rivet in place quickly before the adhesive cures (you have about 60 minutes)

Therefore, test fit the panel and drill holes FIRST, since you won't have time to do so and still get your pop rivets in place

Hope that helps!

d-
 
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