For starters, you could simply put a piece of duct tape on the back side of it to keep it from tearing any more. Beyond that, there are several companies who make vinyl repair kits. I think it's basically a liquid that solidifies and attaches itself to the existing vinyl to make it a permanent repair. You can find these online or in any auto parts store or even Walmart for $5-20 or so. Follow directions, let it cure, all done!

 

A repair that big is a tough one to patch. I have had some luck repairing smaller tears in vinyl with a product called "Brush on Electrical Tape". You can sometimes find it in big box stores or Amazon.com for about $7.00 a can. It comes in black and red.

Maybe try a combination of Ian's suggestion of the duct tape on the bottom of the tear and this stuff around the tear itself to try and glue the sections back together.

You will need to apply pressure to the repaired area while the liquid tape cures so what I do is prop a flat piece of wood larger than the tear underneath the area you are going to be working on. Then put a 5 gallon bucket (if you are going to perform the repair with the cover still on the truck) or something that will support some weight underneath the wood. You don't want the tonneau to flex or sag very much while the repair is drying. You will see why next.

Next brush on the liquid VERY sparingly (a little goes a long way) to the torn sections then place a piece of plastic wrap (like Saran wrap) or wax paper over the repair to keep it from sticking. On top of the Saran wrap place a smooth item like a piece of plexiglass. On top of the plexi place a relatively heavy weight (5 lbs) over the entire repair area. Park it in the warm (not too hot) sun while the electrical tape cures and you should be good to go!

Remember to be careful to not use too much liquid for two reasons:

1) When you put the weight on the tear to sandwich the repair together it will just spread out WAY too much. You want just enough to cover the rip but not globs of the stuff oozing out all over the place.

2) The vinyl has a "leather like" texture to it. When you put the Saran wrap on top of that you are going to make a flat smooth line where the repair is so the neater you are the less noticeable the repair will be.

This is a relatively inexpensive attempt to save yourself a few bucks. Worst case scenario is if this doesn't work you can always take the entire frame to an upholsterer who should be able to re-wrap the entire thing relatively cheaply as it is just a square of vinyl (unless you want a tuck and roll :act024

Good luck!

Manny

 

I repaired a small hole with some RV goop and a vinyl patch from underneath....over a year later and still holding.