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How-To: No-Weld Rusty Floors

Zukey14

Member
Dec 6, 2018
30
Lambertville Michigan
New to the forum and thought I would share my floor pan and torque box repair. Just purchased a 97 Jeep Wrangler Sahara with 135k for very cheap to be used as an off road toy. Being that its spent its entire life in Southern Michigan it has been salted to near death. My frame is still solid but rusty, no soft spots however all three body mounts on both torque boxes were completely rusted through as were the floor pans front and rear on both sides. Probably would have been easier to get a new tub however there are some significant headaches with that I had no idea how to tackle, like how to move an entire tub by yourself.

These are the front pan:
IMG_0278[1].JPGIMG_0755[1].JPG
These are the rear pan: (Yes that's the body mount)
IMG_0757[1].JPGIMG_0759[1].JPG
What's left of the drivers torque box:
IMG_0277[1].JPG

I have only done the drivers side so far but to repair it I cut off everything that was rusted, drilled out all the spot welds and ordered new pans and the torque box from amazon.

Torque box
https://www.amazon.com/gp/product/B01MS4UGFV/?tag=wranglerorg-20

Front Pan
https://www.amazon.com/gp/product/B00ZBBDXC0/?tag=wranglerorg-20

Rear pan: Key parts from Quadratec

No floor:
IMG_0767[1].JPG

After removing all the rust I cut my new pans to have a +1" overlap to the holes in the front and rear floor, placed the new pans and sanded all the overlap on the new pans and old floor down to bare metal. I liberally applied 3M body adhesive to the overlap and placed the pans in. Then used 3/16 stainless rivets to attach the pans. Once the pans were in and riveted I smoothed out the push out from the 3m adhesive to seal the seam on the inside and outside. I used an entire bottle for the pans, which was probably a bit excessive but it sealed up nicely and is solid. After letting the pans cure I used the same process with the torque box.

Front pan:
IMG_0779[1].JPG
Rear Pan:
IMG_0780[1].JPG
Torque box:
IMG_0810[1].JPGIMG_0811[1].JPGIMG_0812[1].JPG

Pop Rivets used:
https://www.amazon.com/gp/product/B00FAUF1SQ/?tag=wranglerorg-20

3m Adhesive and applicator:
https://www.amazon.com/gp/product/B00KSF9TCW/?tag=wranglerorg-20

New body Mounts:
https://www.amazon.com/gp/product/B01C62R1PQ/?tag=wranglerorg-20

I know this is not the traditional repair but being that I don't know how to weld it was the best repair option for me. The combination of the 3M adhesive and rivets on paper should be stronger than the tack welds but I am not going to try and convince anyone. I am not recommending this to anyone just sharing my experience in trying to bring a rust bucket back to life.

IMG_0278[1].JPG


IMG_0277[1].JPG


IMG_0767[1].JPG


IMG_0755[1].JPG


IMG_0757[1].JPG


IMG_0759[1].JPG


IMG_0810[1].JPG


IMG_0779[1].JPG


IMG_0811[1].JPG


IMG_0780[1].JPG


IMG_0812[1].JPG
 

JEEPCJTJ

TJ Enthusiast
Supporting Member
That seems like a very good improvement.

You'll probably hear about how it should have been welded or the tub totally replaced and maybe even a whole new frame while you're at it but I've lived with worse cars and Jeeps and did various repairs, some better some not so great.

I'm not sure if your off road toy will be driven on the road to get off road but I wouldn't have a problem with it if it was.
 

Chris

Administrator
Staff Member
Sep 28, 2015
38,128
Salem, Oregon
Well that looks night and day better! Do you think rivets will present a problem versus being welded in? I wouldn't think so.
 
OP
Zukey14

Zukey14

Member
Dec 6, 2018
30
Lambertville Michigan
Thanks for the positive feedback! I sort of expect the negative comments but I thought it was worth sharing. I use the Jeep on the road sometimes in the summer when I can cruise with the top off but mainly its just driving to the off road park. Its the back up vehicle if something happened to my truck or my wife's car.

I don't think the rivets will cause any issues except maybe a way for water to get in, but it would be minimal if any plus I don't have the plugs in either so that would be the main source of water if I got that deep. I plan to monsta-line the inside which will seal them and I truck bed lined the underside so that sealed the bottom ones. I have seen pans riveted in before and the only downside vs welding I have heard is the cosmetics since they aren't smooth.
 

Mike_H

Rust Belt Heavyweight
Supporting Member
Feb 28, 2017
4,436
Grand Rapids, MI, United States
I'm gonna say Kudos for thinking outside the box. I think your method of repair for the floors will work out great. However, the torque box is a structural part of the body...I don't know enough about that body adhesive to know if it will hold or not. What is it's shear strength? The rivets alone won't do it.

Welding is recommended because people understand it, and say negative things about what they DON'T understand.
 

59 wagon man

TJ Enthusiast
Supporting Member
Nov 15, 2017
424
Hollywood, FL, United States
the 2 part adhesives are great. there is a guy on the tv car shows named kevin tetz I believe, he did a video series about bodywork and highly recommends it for body panels but as stated for structural it doesn't pass. for the floor pans it is great and it does look good
 
OP
Zukey14

Zukey14

Member
Dec 6, 2018
30
Lambertville Michigan
I'm gonna say Kudos for thinking outside the box. I think your method of repair for the floors will work out great. However, the torque box is a structural part of the body...I don't know enough about that body adhesive to know if it will hold or not. What is it's shear strength? The rivets alone won't do it.

Welding is recommended because people understand it, and say negative things about what they DON'T understand.

Thanks, I was concerned about using it for the torque box as well. 3m's data shows the shear strength is 3935psi with a 10mil thick application to 18 gauge steel, which the steel and adhesive will fail together. The Jeep uses 16 gauge steel so it would potentially be higher. It performs as well or better than tack welds and has a uniform load distribution vs tack welds which are localized, except for the peel test. The rivets are all additional to this and will perform similarly in shear and peel as tack welds. Rivets are more expensive and not cosmetically appealing so they are not used but mechanically they perform similarly to tack welds if used correctly. But again this is a garage repair and I am not an auto body engineer but I do know that before the repair I had no torque box and the body mounts were literally sticking through the floor so its better and safer than it was.
 
This looks great to me! If you have any buddies that weld, or you learn yourself, you can always add a few inches of weld anywhere you want all the way around the repair panels to have to best of both worlds. Or take it to an exhaust shop, I'll bet if you get to the right shop they'd put some weld down and not charge you too much.
 

jeepins

TJ Enthusiast
Supporting Member
Mar 28, 2018
348
Houston, TX, USA
Excellent work! I wouldn't have used rivets myself since I have welding capabilities but the combination of the rivets and the adhesive that you're doing is looking good. Unless you're really dogging that thing through the mud and over rocks afterwards, it's perfectly fine and you're doing a great job of installing it.
 
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RussTJ

TJ Enthusiast
Nov 22, 2017
435
Bridgewater, MA, USA
Nice job. I've had a lot of vehicles over the years and they're all different. Some are new, shiny and you want to keep them that way. Others are for rougher use, whether that's work, fun or just beater transportation. You've made a small investment and put some hard work into it and you're gonna have a great time. Have fun.
 
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Tranz Zam

Member
Jan 13, 2019
94
MA
Nice work!

The 3M panel bonding adhesive is strong. In fact a panel bonded around the perimeter is as strong, or stronger, that traditional welding.

I've used it plenty of times on various sheet metal repairs across all different types of vehicles, and it works incredible.
 
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OP
Zukey14

Zukey14

Member
Dec 6, 2018
30
Lambertville Michigan
Nice work!

The 3M panel bonding adhesive is strong. In fact a panel bonded around the perimeter is as strong, or stronger, that traditional welding.

I've used it plenty of times on various sheet metal repairs across all different types of vehicles, and it works incredible.

Good to hear, I read several reviews like this. So far everything is holding up very well, no complaints at all except my "stainless steel" rivets have some surface rust on them... Michigan winters suck.
 

JEG

Member
Feb 24, 2019
30
New Hampshire
I had done this on a CJ-7 that I owned back in the 90s. I didn’t have panel adhesive so I used whatever construction adhesive I could find. Once I was done I bed line the whole inside of the tub. I didn’t have any body mounts that were affected but it worked great and I had zero issues from it. After the bed-lining no body could tell they were ever replaced (as long as they didn’t look underneath).
 
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chino1969

TJ Enthusiast
Supporting Member
Apr 14, 2019
259
Oxford, PA
For someone without any welding experience you've done a very good job. If it were mine I would look for someone to weld any structural part in the future but see how your repair(s) hold up and then decide.
 

K0LCB

TJ Enthusiast
Supporting Member
Mar 31, 2019
208
Los Fresnos, Texas
New to the forum and thought I would share my floor pan and torque box repair. Just purchased a 97 Jeep Wrangler Sahara with 135k for very cheap to be used as an off road toy. Being that its spent its entire life in Southern Michigan it has been salted to near death. My frame is still solid but rusty, no soft spots however all three body mounts on both torque boxes were completely rusted through as were the floor pans front and rear on both sides. Probably would have been easier to get a new tub however there are some significant headaches with that I had no idea how to tackle, like how to move an entire tub by yourself.

These are the front pan:
View attachment 66619View attachment 66622
These are the rear pan: (Yes that's the body mount)
View attachment 66623View attachment 66624
What's left of the drivers torque box:
View attachment 66620

I have only done the drivers side so far but to repair it I cut off everything that was rusted, drilled out all the spot welds and ordered new pans and the torque box from amazon.

Torque box
https://www.amazon.com/gp/product/B01MS4UGFV/?tag=wranglerorg-20

Front Pan
https://www.amazon.com/gp/product/B00ZBBDXC0/?tag=wranglerorg-20

Rear pan: Key parts from Quadratec

No floor:
View attachment 66621

After removing all the rust I cut my new pans to have a +1" overlap to the holes in the front and rear floor, placed the new pans and sanded all the overlap on the new pans and old floor down to bare metal. I liberally applied 3M body adhesive to the overlap and placed the pans in. Then used 3/16 stainless rivets to attach the pans. Once the pans were in and riveted I smoothed out the push out from the 3m adhesive to seal the seam on the inside and outside. I used an entire bottle for the pans, which was probably a bit excessive but it sealed up nicely and is solid. After letting the pans cure I used the same process with the torque box.

Front pan:
View attachment 66627
Rear Pan:
View attachment 66629
Torque box:
View attachment 66626View attachment 66628View attachment 66630

Pop Rivets used:
https://www.amazon.com/gp/product/B00FAUF1SQ/?tag=wranglerorg-20

3m Adhesive and applicator:
https://www.amazon.com/gp/product/B00KSF9TCW/?tag=wranglerorg-20

New body Mounts:
https://www.amazon.com/gp/product/B01C62R1PQ/?tag=wranglerorg-20

I know this is not the traditional repair but being that I don't know how to weld it was the best repair option for me. The combination of the 3M adhesive and rivets on paper should be stronger than the tack welds but I am not going to try and convince anyone. I am not recommending this to anyone just sharing my experience in trying to bring a rust bucket back to life.

View attachment 66619

View attachment 66620

View attachment 66621

View attachment 66622

View attachment 66623

View attachment 66624

View attachment 66626

View attachment 66627

View attachment 66628

View attachment 66629

View attachment 66630
If it works for you, that’s a great improvement
 
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Zukey14

Zukey14

Member
Dec 6, 2018
30
Lambertville Michigan
Any update on how this is holding up? I was planning on doing this exact same thing tomorrow. :)

Its holding up very well other than a couple of my "stainless steel" rivets had some rust on them after the Michigan salt got on them. It cleaned off easy enough and I painted the bottom but other than that it looks exactly the same other than the paint. At first I was unsure of the rivets in the floor but they actually grew on me and I like the little bit of character it added inside (reminds me I fixed it myself) since I don't run carpet. I will probably bedline the interior at some point but its not high on the to do list.
 
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