Stretching a Tonneau ???

I had the good fortune to purchase a factory tonneau thru an E Bay vendor this summer. After cleaning it up and trying to fit same I realise that it had shrunk about one inch over all.
I hung it in my garage all summer with weights suspended from it to try to stretch it back into size. I was somewhat successfull but man, it's just a little shy of being the right size.
As I need to replace the zipper can anyone offer suggestions about a replacement zipper and the thought of adding an inch using asome extra material? Anyone know of a source for the black with white canvas backed material as well as the zipper?
The only other option thjat I can think of is cutting the tonneau and stitching in a body coloured insert material similar to a racing stripe. In this case a red cross strip into a black tonneau. (not my favorite option btw)

Thanks in advance!

My advice would be to just buy a new one. That 40-year old vinyl isn't going to hold up long anyway.

Or, if you really have the resources to replace the zipper yourself, just make a new one.

I couldn't get mine on until I attached the front by the windshield first and worked back to the rear deck. Much easier.

The same upholsterer that installed my seats and top looked at the tonneau and advised me that there is no way to stretch it. He did install a new plastic zipper replacing the original metal one. The zipper is great. What I did to make up for the shrinkage is looped in plastic ties to catch the dash hooks. Not great but it allows me to use the tonneau the few times that I park the car for a period of time and wish to leave the top down, such as at the golf course.

Yes, they just shrink over time. Then, because they also loose elasticity, they tend to tear at a clip or the zip. You will find that they are more pliable in hot weather. I put my top up in winter to try and stop it shrinking.

The tonneau cover on my TR3A is original. I leave it on all the time. In the last 18 years, I would guess that I've had the top up or the hood stick cover on for less than a few hours - mostly at TRA, VTR or other car shows. Because the cover is always snapped into place on the car, across the back, there is no shrinkage there. When I park in a public place, I close the doors, pull the cover up from behind the seats and snap it along the top of the dash. It's a tight fit and I have to pull it a bit, but it goes. Then I snap it closed along the doors.

Because it's tight at the rear and on the TR all the time (see photo), I feel that this may be the solution.

I had a new zipper sewn in a few years ago but when it rains, the tonneau cover would sag down in the middle and water would leak through the zipper and soak the carpet and seats beneath. So I asked the same shop to sew a piece of vinyl along one side (passenger's side) full length of the zipper. This piece is about 2" wide and lays over the zipper. Then I seal it down with Velcro that he sewed all along this side of the zipper. Now it won't leak.

TR3driver said:

My advice would be to just buy a new one...

Click to expand...

I agree, old tonneaus & tops are hard to work with. But know too that the replacements available are often pretty tight fits themselves (esp in the case of my TR4 tonneau). There was simply not enough material to reach front to back without putting the fasteners right to the seams and then stretching til your fingers bleed. In cold weather it became hopeless.

I finally remade that metal plate that holds the 2 male snaps at the front/center of the dash. Made one that positioned the snaps about a half inch aft and all was well.

I sometimes wonder if they make their patterns using NOS originals that have shrunk whilst sitting on the shelf.

Sorry for my thickness Geo but were these snaps extanded towards the rear to allow for the shrinkage?
The top is in new condition and for the number of times that I will likely use it I don't want to buy a new one. This is especially true due to the cost of this vs the cost of a whole new top. Supply and demand I guess ...

Tomster: I've done everything suggested by all of the others above, and still never got the tonneau cover to fit/look right, until I drilled out & removed all of the female snaps, & removed the front peg rings. I reinstalled the hardware at the proper locations, and now the tonneau fits like a glove. Its not perfect looking (original holes are visible), but its very servicable, and I use it often now. Bob H.

Tomster said:

Sorry for my thickness Geo but were these snaps extanded towards the rear to allow for the shrinkage?...

Click to expand...

That's right, though in my case it was to allow for the very tight fit of a new tonneau.

The modified snap plate (this is a TR4, I do not know if the front/center connection is the same on a 4A):

THANK YOU for a brilliant solution
MAN you win the award this week !!