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Discussion Starter #1 (Edited)
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A 355nation How To presented by
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Project Name
Rebuilding a waterlogged tonnea

Project Description
Rebuilding a waterlogged Checker (or similar) tonneau cover

Skill Level
Moderate

Project Vehicle
Make: Chevrolet
Model: Colorado
Year: 2007
Engine: 3.7L
Power windows: Yes
Sun Roof: No

Tools Needed
2x Foam Boards - Expaned Polystyrene - 4'x8'
Industrial strength Adhesive that will not react with styrofoam
A long, thin scraper of some sort
Rivet gun
Rivets
Drill w/drill bit to drill out rivets in the tonneau
Steel L bars


Project Time
48+ hours

Project Cost
Foam boards - $14 each
Adhesive (that I used) - $20
Steel L bars - $6 each


I purchased this tonneau after seeing it posted for sale nearby with the description of "changed it out because it's heavy." The tonneau looked just fine, though it was very heavy. It probably weighed about 100 lbs or so, which took some effort to lift it. This was also causing issues with my bed.

After doing some research and a tip from @rshadd about a run-in he had with a hot-tub cover he had years ago, I figured I would do some more digging.

First, I drilled out the rivets and pulled off the back section of the metal frame to see what was inside. As suspected, it was a foam core with a fiberglass sheet on the top and a fiberglass/plastic sheet on the bottom. The foam core was waterlogged.


Then I pulled the tonneau off the truck and laid it top side down. Then drilled out all the rivets and pulled off the frame, piece by piece.


Then I pealed the bottom fiberglass/plastic piece off in order to expose the foam. I tried sitting the foam in the sun/heat for a two days, but it did not dry out. FYI, after doing some research, it will not dry out for reasons I can explain if you are curious.


After that, I pulled it back into the garage and went to town removing the foam from the top piece of fiberglass. I did not want to rip the top piece or poke any holes so I used a saw I had that has a long thin, flexible blade. I slid the blade back and forth between the foam and the fiberglass sheet to separate the two. Then, once I couldn't get any further under the foam, I lifted it and broke it off, then repeated the process until complete.




This piece alone weighed twice the amount that two full pieces of 4'x8' foam weighed.


I attempted to use some contact cement, both spray and liquid, but it did not work.



At the suggestion of @DBNissan, I tried the Glidden Gripper. So far, it has worked out well. Unsure how it will hold up to the rain and heat/cold. This does not work with rains. The Gripper is a water based product and the rains will wash it out from inside the tonnuea, causing it to run down into the bed of the truck. Going to go back to the drawing board and try a different adhesive.


Then I laid Gripper across the section of the foam boards that would make contact with the top piece. I also spread it across the top and placed the top piece onto the foam. Be generous but don't leave puddles. Then I placed weight on it and let it dry for 24 hours.


After it was dry, I cut the foam board down to the size of the top piece. This would allow me to align the bottom fiberglass/plastic cover where it needs to be. I repeated the same steps as above and let it dry for 24 hours.


Then I sanded/straightened the pieces of the frame and painted them.


After everything was dry, I slowly pieced it all back together and used the rivets to secure it.


I also cut two pieces of steel L bars and riveted that to the frame for some structure since the foam I used didn't seem to have the strength the original did (or I just wanted more strength).


Now, I laid some paint down on it for a temporary solution to avoid it becoming water logged. This was just some satin black latex paint I picked up at Lowes. In order for it to be done properly, and to keep it from becoming waterlogged again, it needs a sealer/caulk used at the edge of the frame and fiberglass top as well as painted to keep the water from seeping through.



And, to test it, I was able to lift the tonneau easily on my own and place it on the truck. I also used the shocks that came with it, which wouldn't even come close to even thinking about holding it up previously...
Checker Tonneau Test
 

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Legen..wait4it..Dary!
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I read this is Boyd's sexy voice.
 

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Awesome job...looks great on the truck!
 

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Discussion Starter #5
Alright, a slight update.

I missed a section, or at least didn't do it well enough, on the top. It's about the size of my hand though hardly noticeable from what I have been told. Other than that, the thing holds up to 90+ in direct sunlight as well as up to 80 on the interstate.

I'll keep updating this as I see how it holds up.
 

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Discussion Starter #6
Okay, so I have to tear the tonneau cover back apart and redo the adhesive. Due to the nature of the Glidden Gripper product, rain/water will wash it away/out of the tonneau cover and it will not hold up, at least it isn't in this application.

I have a line on a 3M product that is used for polystyrene that I am going to try as that should be something that will work well... Should.

We will see. I will continue updating this until I figure out what is a tried and true adhesive.
 

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If I understand right, one of the problems you had/have is with the glue. I assume the problem you are having is it will eat the foam. From the RC model hobby industry, you need to look for 'foam safe glue'. The spray on stuff (3M or whatever brand) needs to be free of acetone, some of the old 3M Super 77 was this way, most stuff does have acetone. There is a glue called 'Foam-Tac' by Beacon, but it comes in small bottles, so cost????

Hope this helps.
 

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Discussion Starter #8
It does... and is still something I need to do. Haven't had time to fix this as it just sits there. Once I get some extra time and life isn't crazy, this will be fixed.
 
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