Red 69

My passenger side t-top has a gap you can see the liner through, so rain water has no problem leaking in. It is not a daily driver, so It doesn't see rain often, but a fix is called for. The warpage creates the largest gap half way around the forward curved section and continues about 10 inches toward the t-bar. The top fits perfectly in all other areas but a visual gap difference can be seen when comparing the two sides. The latch adjustment on this side is about as tight as it can go, so making it tighter is not an option. The warped fiberglass needs to be put back in proper form. Has anyone dealt with this issue successfully, if yes, How?

Red 69

I already know how to buy a new t-top, the question was, "has anyone successfully repaired a warped t-top?"

71 Vert LS1

Any pics?

CraigH

Pictures would be great.

if you remove all the t-top fittings and just lay it on that will show best how bad it may be. The fittings can exacerbate issues.

kanvasman

On my 78 there are shims that can be purchased that go under the points that fit into the center part of the roof. There are 2 of these pieces and you can add shims as necessary to pull the t top down, then readjust the latching points on the outside edges, fore and aft. Not sure what year you are working on.

Red 69

Thanks for the suggestions on my 79 model! I use the word warped because when I push down with the heel of my hand, the front does down, but no upward movement is seen or felt anywhere else. I will keep an open mind and when I get a chance, I will remove the top and play with moving shims around and see if it makes a difference. I'm hoping suggestions are correct and an adjustment will make my top fit properly. I'd like to fix this top, as the inner liner and outer paint are perfect, except for the poor fit and resulting rain leak. Adjusting a t-top is about the only part of a C-3 that I have not tackled. I will post my results after trying shim adjusting to fix the gap issue.

doorgunner

You can remove everything from the T-Top...
place it on saw-horses in the sun outside...
position it in such a way that the "High Area" is unsupported...
use furniture assembly clamps with thick cloth to hold the "Good Sides" against the sawhorses....
measure the distance from the driveway to the High Area...
place a thick cloth on top of the Top...
SLOWLY add weight until there is a 1/2" "sag" at the high spot...
leave the set-up in the sum all day...
EVERY 2-3 HRS REMOVE THE WEIGHT-ONLY AND REMEASURE THE HIGH SPOT TO SEE IF IT HAS SETTLED INTO PLACE.

This method worked on the 3/4" high bulge on left center edge of my hood AND the arched centers of my Door Panels.

JUST BE CAREFUL TO NOT CRACK THE FIBERGLASS/NO GUARANTEES.

ukjohn

Is this the sort of warping you mean? If so I have the same problem. Doorgunner is this what you fixed?

Red 69

Yes-ukjohn, this is the kind of warping I am referring to, but yours appears worse than mine, but they are warped on the same side and area, though. In response to other suggestions, I took everything apart today and shimming will not resolve my issue. I may try doorgunner's approach and let it sit in the Florida sun with clamping pressure for a day and see what happens. We are in the rainy season now, so either wait for a clear forecast, or monitor closely. Keep suggestions coming, maybe someone has a magic wand! :-))

calwldlife

Damn, that sucks.
I would have to see how much force to straiten and try the heat thing.
Hell, could have to scarf cut areas to allow flexing an maybe epoxy a brace?
Sorry to hear another vette issue that can rear up.

Red 69

Yes, I have considered a similar method of making cuts, open with pressure and fill the cuts with JB Weld, but the fiberglass is not thick enough for the JB Weld to do any good. T-top warping might be avoided by unlatching the top when parked in a garage. But then, you better remember to latch the top before hitting the street!

doorgunner

AS we speak I am having to De-Arch my door panels which have a 1 & 1/2" Negative warp in each.
If you decide/need to do the work in the garage because of rain...place a halogen shop light on the floor under the sawhorses so the heat will rise up to the clamped fiberglass.


MONITOR the heat on the fiberglass with an infrared gun...don't go above 130*F.
After a few hours take the weight off the T-Top at the "High Spot" to see if it is beginning to De-Warp.
See my last post in my thread for a general idea.

stevedinino

Crazy how threads pop up when you need them. I was going to start one with a title almost exactly the same as this.

My t-tops are also warped, but in a different direction - along the back edge where they should seal against the halo bar. I can see 1/4” of daylight through the gap. No amount of shimming or adjusting helps, and I’ve fiddled with it a lot. Seals are new.

I am encouraged by the suggestion that it’s reversible. If I have any luck I’ll post it. Thanks for sharing.

Red 69

It will be interesting to find what results multiple efforts can have on correcting warped fiberglass. I am going to place a short section of 2X4 under and on top of my warped section of t-top, with a towel to protect the paint. A c-clamp on both ends of the wood will apply down pressure to correct the warp. The pressure will be increased over time and hopefully move the fiberglass back into proper form.

Update: A 1" x 2" length of wood over and under my top was much easier to work with than a 2X4. With a clamp on both ends protruding past my t-top, the warp has visually straightened in the intense heat of the Florida sun. I had to leave and while I was gone, a torrential rain storm ensued, drenching and cooling my top. It is still under pressure and I will return it to the suns heat for a few days before releasing the clamps pressure. When the experiment is over, I will post my results. The question remains, will a correction change in the warped fiberglass become permanent, that is what we are going to find out!

Red 69

For those interested, it is a rainy day here in FL and I grew impatient with my top still clamped under pressure, so I succumbed to the temptation and unclamped it. When I fitted it to the car, i discovered a significant improvement, so the warp was improved. When I placed a flashlight on the inside of the windshield frame, there was still a very small gap of light shining through. After considering possible options to close that small gap, I am now separating the weather seal from the fiberglass in the area of the small gap and consequential water leak. In resolving this issue, I am going to cut a 3/4 x 1/8 inch thick strip of rubber roofing material and use it to shim space the weather-strip from the fiberglass and see if it closes my small gap. It will be tested for results before any adhesive is used. When I get back to it, I will post my results either way. The good news is, as others have commented, the warped fiberglass tops can be corrected.
I returned home early and was able to apply the 1/8 inch thick piece of roofing rubber under the rubber top seal. Without any adhesive, the top was put in place and as hoped there is no flashlight seen between the windshield frame and rubber top seal, so the effort was a success.

In conclusion, the pressure to correct the warpage worked to correct/improve the problem and the rubber shim under the weather seal closed the tiny gap left that water might penetrate. If anyone else tries doing this, please post your results?

I must add a note of caution: as a result of the pressure on the towel used to protect the paint, the thread of the material is lightly imprinted in my paint. Maybe, if I placed some plastic wrap between the towel and paint it might have mitigated the printing effect.

stevedinino

I tried clamping mine as described above to see if i could flatten it out. Any change seems to be temporary - when I put the top back on, it bowed back up again. I'm giving up on this approach.

Instead, I am going the "enhanced weatherstrip" route. I had an extra hood seal, which is a pretty simple shape. Turns out the length is nearly perfect to go around the perimeter of the top, excluding the one side where the door glass goes. I glued the strip on and readjusted the mounts to account for the extra thickness. So far, so good - i can't see any daylight out the back of the top and the strip seems to be conforming to the shape of the roof nicely. If this works out, I'll get a second hood seal for the other top (about $8 plus shipping) and call it fixed.

I know this isn't the "right" way to fix it... but on a nearly 50 year old car, I accept that time and nature have taken a toll that can't be repaired short of buying a new t-top.

Red 69

Steve, sorry to hear you did not get the same result as I did. In my case, the two pieces of wood I used to apply clamping pressure were across the front of my top and in an ideal location to straighten my warpage. I did not stop applying clamping pressure until I could see the warp was gone. While in the FL sun, the ambient temp was 94*, but the top got hot enough you could not hold your hand on it. I did not put my heat gun on it to check the temp, but it must have been around the 130* that doorgunner described. I cannot say my top returned to factory spec, but most of my warpage is gone and the rubber shim under my weatherstrip sealed the deal. Don't expect to apply pressure and then release it and expect a change. In my case, the pressure remained over a couple days and under heat when the sun was out.

When I clamped mine, I became concerned that I might crack the fiberglass, but I continued to add more pressure and the wood became bowed. I kept the wood off thin areas of the fiberglass and kept on the strongest areas. Notice that there is a raised/reinforced area around parts of the top perimeter. If I had my support wood on the thin fiberglass outside this raised area, I might have cracked the top there. In my case, by keeping clamping pressure across the strongest areas of fiberglass, I could bear down with pressure and in conjunction of heat the warpage was reversed. Finding a suitable area to place the wood could be a challenge, but needs to be done to not damage the top. With the liner removed, blocks of wood could be used against the underside to support clamping wood, but keep it as long as possible, You don't want pressure on thin fiberglass in a small area, or damage could occur..