Stainless Steel Rivets + Panel Adhesive?

[Yoda]

Hey guys I'm thinking through the process of replacing torque boxes on a TJ, specifically bonding the torque boxes to the floor pans. I'm not a body guy but have replaced my share of quarter panels and have always plug welded overlapping seems. I'm curious of a a couple other methods...

1. Panel Adhesive. Well....it generally isn't supposed to be used alone for structural applications. And clamping would be difficult.
2. Panel Adhesive + High Strength SS Rivet's. Grab some Stainless Steel 1/4" sealing blind rivets and use a back-up washer in the back and install every 3 inches or so. Use plenty of panel adhesive and the rivets and washers will apply the clamping force.

My main concern is corrosion. I would be drilling holes in clean sheet metal and there will be air in between the SS rivet and the steel. That may potentially be a source of future rust. Second, stainless steel is great but there will still be the potential for galvanic corrosion between the stainless steel and regular steel. The clamped panel adhesive may essentially rust proof it or it may not.

Or just plug weld the floor to the torque box and call it done. What's a good way to rust proof those seams? Will weld-thru primer be enough to seal out future corrosion? The main long term goal is corrosion prevention.

This isn't my thing but it is something that needs getting done so I am going to learn how to do it. Looking for some advice. Thanks!

 

[Vtx531]

Hi, I dont think long term corrosion protection is possible. Unless it is garage kept, non salt road driven.

Factory does lap joint/spot weld and then dips the body. There is no practical way to replicate this in a repair.

I saw you reference my thread about torque boxes and rusty floor pans in your thread about getting the super cheap project Jeep. My experience on only one Jeep (and no long term results) I would do (and did) regular steel rivets. Stainless would cause galvanic corrosion like you mentioned. Panel adhesive would be messy and hard to undo but probably better for corrosion protection. I think rivets would be better than welding because you can primer and paint everything beforehand and not burn through and destroy the paint when you weld it. Plus it is easier to do and cheaper for tools.

Best advice would be to GREATLY lower expectations and don't expect to get it like factory new for corrosion protection.

I think 1/4" rivets would be excessive in strength and a backing washer unnecessary. I did mine every 2".

If you decide to do the adhesive I would love to see how it goes! Just something I chose not to do.

Also, I am not a "body guy" so feel free to disregard anything I said.

 

[JEEPCJTJ]

I'm not an engineer of any type but I'd think the adhesive would be strong enough if done correctly.

I know clamping with real clamps would be almost impossible and I think just pushing on the flat bottom of a torque box could warp it and/or slide it out from where it should be but if the body is still right side up while doing the work you could probably rig up some various pieces of wood kinda like a mold and use that to push the flanges with adhesive up against the floor with a floor jack.

 

[mrblaine]

Hey guys I'm thinking through the process of replacing torque boxes on a TJ, specifically bonding the torque boxes to the floor pans. I'm not a body guy but have replaced my share of quarter panels and have always plug welded overlapping seems. I'm curious of a a couple other methods...

1. Panel Adhesive. Well....it generally isn't supposed to be used alone for structural applications. And clamping would be difficult.
2. Panel Adhesive + High Strength SS Rivet's. Grab some Stainless Steel 1/4" sealing blind rivets and use a back-up washer in the back and install every 3 inches or so. Use plenty of panel adhesive and the rivets and washers will apply the clamping force.

My main concern is corrosion. I would be drilling holes in clean sheet metal and there will be air in between the SS rivet and the steel. That may potentially be a source of future rust. Second, stainless steel is great but there will still be the potential for galvanic corrosion between the stainless steel and regular steel. The clamped panel adhesive may essentially rust proof it or it may not.

Or just plug weld the floor to the torque box and call it done. What's a good way to rust proof those seams? Will weld-thru primer be enough to seal out future corrosion? The main long term goal is corrosion prevention.

This isn't my thing but it is something that needs getting done so I am going to learn how to do it. Looking for some advice. Thanks!

Paint the underside of the seam overlap and the rivets with a urethane seam sealer. Similar thinner body version on top will effectively seal it as good or better than the factory did it.

 

[pagrey]

Good panel adhesive will do fine, it's used extensively in structural applications on new vehicles. Unfortunately, it is very expensive and the urethane and rivets will do the job.

 

[Yoda]

That's great news....thanks guys! I've had good results with Eastwood's seam sealer in a caulk tube. Anything better out there?

 

[someguysjeep]

i like the Eastwood brush-able sealer. lets you put down a thin wide lap over your seams and doesn't look any worse than the factory goo.

 

[tr21triton]

1/4 in rivets are too big, i would use 3/16 or even 1/8 diameter. 3/16 would be best .

 

[Yoda]

Thanks for the tips everyone! Sounds like rivets and seam sealing are a good way to go. Last couple questions:

1. Are stainless rivets a good idea or bad idea long term against corrosion?

2. Does anyone know of a brush-able or tube type seam sealer with an extended working time? Most of them see to be 10 minutes. I don't think I can coat all the seams on a torque box and have it rivetted in 10 minutes.

Fusor 123 and 231 seems like a good option, though I'm not familiar with it. It has a 45 or 60 minute working time and will bond to bare metal, e-coat, and pre-primed surfaces. Its a 2-part urethane.

Fusor 231 Link

Fusor 123 Link

 

[Vtx531]

As for #2 - Probably one of the most important parts of the job is getting everything lined up correctly. You don't want to rush this part and are absolutely right that it will take longer than 10 mins. Might even have to remove and reposition a few times.

 

[tr21triton]

I wouldn't use stainless steel, just use plain steel.

 

[mrblaine]

Thanks for the tips everyone! Sounds like rivets and seam sealing are a good way to go. Last couple questions:

1. Are stainless rivets a good idea or bad idea long term against corrosion?

2. Does anyone know of a brush-able or tube type seam sealer with an extended working time? Most of them see to be 10 minutes. I don't think I can coat all the seams on a torque box and have it rivetted in 10 minutes.

Fusor 123 and 231 seems like a good option, though I'm not familiar with it. It has a 45 or 60 minute working time and will bond to bare metal, e-coat, and pre-primed surfaces. Its a 2-part urethane.

Fusor 231 Link

Fusor 123 Link

The panel adhesive will seal the two mating surfaces. The seam sealer is to get what that misses after you have it fastened and glued.

You will have to get the TB in place, drill and bolt it to get all the holes done and ready for the rivets. If you don't have a Milwaukee M12 rivet tool, borrow or buy one.

 

[tr21triton]

Thanks for the tips everyone! Sounds like rivets and seam sealing are a good way to go. Last couple questions:

1. Are stainless rivets a good idea or bad idea long term against corrosion?

2. Does anyone know of a brush-able or tube type seam sealer with an extended working time? Most of them see to be 10 minutes. I don't think I can coat all the seams on a torque box and have it rivetted in 10 minutes.

Fusor 123 and 231 seems like a good option, though I'm not familiar with it. It has a 45 or 60 minute working time and will bond to bare metal, e-coat, and pre-primed surfaces. Its a 2-part urethane.

Fusor 231 Link

Fusor 123 Link

this is what we use on aircraft. it will do exactly what you need. has a 2 hour work time but it is expensive. dip the stem of your rivets in it before pulling them and brush the heads and tails with it after pulling them.
https://www.aircraftspruce.com/catalog/cspages/ppgsemkit09-04703.php

 

[Yoda]

Thanks everyone! My plan is to use 3M's panel adhesive. It is a two part epoxy with a working time of 90 minutes. That should do the trick. It is compatible with bare metal and e-coated panels.

I'll fasten the torque boxes and floor using 3/16 "Closed End" blind rivets. The closed end should prevent some corrosion as the body is sealed. I'm finding most sealed rivets are available as either Stainless Steel or Aluminum body and plain steel mandrel. Between the two I'd prefer stainless. I'll dip the rivet in the panel adhesive before installing it to prevent future corrosion.

After the panel adhesive is cured I'll go around with a good urethane seam sealer and seal everything up. Then I'll prime and paint and hopefully have a long lasting repair!

 

[mrblaine]

Thanks everyone! My plan is to use 3M's panel adhesive. It is a two part epoxy with a working time of 90 minutes. That should do the trick. It is compatible with bare metal and e-coated panels.

I'll fasten the torque boxes and floor using 3/16 "Closed End" blind rivets. The closed end should prevent some corrosion as the body is sealed. I'm finding most sealed rivets are available as either Stainless Steel or Aluminum body and plain steel mandrel. Between the two I'd prefer stainless. I'll dip the rivet in the panel adhesive before installing it to prevent future corrosion.

After the panel adhesive is cured I'll go around with a good urethane seam sealer and seal everything up. Then I'll prime and paint and hopefully have a long lasting repair!

The stainless rivet isn't going to rust inside the rivet body where the mandrel is so stop worrying about using closed end rivets. Stop with the dipping bullshit. The brushable seam sealer will cover and seal all of that so it doesn't matter.

Also be aware that most rivets don't suck down as tight with a rivet washer on them. Do some test pieces to figure out if they are doing what you need them to.

 

[tr21triton]

The stainless rivet isn't going to rust inside the rivet body where the mandrel is so stop worrying about using closed end rivets. Stop with the dipping bullshit. The brushable seam sealer will cover and seal all of that so it doesn't matter.

Also be aware that most rivets don't suck down as tight with a rivet washer on them. Do some test pieces to figure out if they are doing what you need them to.

the dipping is to put a coating between the steel and stainless to help reduce the dissimilar metals from touching. and it wont hurt as a extra layer of protection and will only use a thimble of sealer.

 

[mrblaine]

the dipping is to put a coating between the steel and stainless to help reduce the dissimilar metals from touching.

That isn't actually possible so knock it off.

 

[tr21triton]

That isn't actually possible so knock it off.

could you tell that to lockheed, boeing and airbus ? I'm sure there engineers would love to hear your logic on this !

 

[mrblaine]

could you tell that to lockheed, boeing and airbus ? I'm sure there engineers would love to hear your logic on this !

You are trying to convince me that you have a hole in two pieces of sheet metal and you can perfectly center a rivet in that hole without any of the barrel touching the bare edges of the steel and then you can make the panel adhesive fill in that small little perfect circle around the rivet barrel to prevent any dissimilar metal contact? Yeah, fuck right off and I don't give a shit who says to do it that way, it isn't possible.

 

[mrblaine]

Even better, I'll go one better. You get it all done with your perfect little dipping bullshit and I'll bet you 100 bucks I can take a multimeter, touch the head of any and all your rivets with one lead with it set on continuity with the other lead connected to the dash frame and it will show continuity between the rivet and the sheet metal body. Care to take me up on it?