Cracked acrylis top

Glide · 03-23-07, 10:58 AM

I have a crack in the Acrylic top of my 85. I wasn't too worried about it until I jacked the car up yesterday and saw how much flex these cars have. The crack opened up like the Red Sea when I jacked up the front right.

Upon doing a search I've seen two suggested fixes although the threads were very old (2001). One was some kind adhesive from 3M the other was a LORD adhesive. Does anybody know if they've come out with anything better in the last 5 years? What are current members using? Can you use heat to fuse the crack together, maybe from the inside where it wouldnt show?

I put a couple bids for tops on ebay but they don't end for a while and it's supposed to rain tomorrow.

gmhowe · 03-23-07, 04:14 PM

I have 2 cracks on my 85 both on each of the back corners, I actually used superglue and let it seep into the cracks, seems to be holding but if anybody has anyother ideas I am open to them, since Im not sure how long the super glue will hold since summer is coming here in Phoenix.

Glide · 03-23-07, 05:55 PM

I was looking at adhesives (actually looking for some clear epoxy) when a sales associate approached, we talked, and it came out that he too had a Corvette. He suggested silicone because of the flex. Then another associate approached, heard the problem and said Advanced Auto Parts carries a special adhesive for Corvette tops and other Auto Parts store might also. He knew this because he used to work there. Since we don't have an Advanced around here, I went to AutoZone. They didn't have a clue. I'll try Advanced this weekend when I go to Virginia.

Super Glue huh? Never had much luck with it although Gorilla Glue is very strong.

fatboyreyn · 03-23-07, 08:56 PM

I had a crack in my top before I replaced it, and had silicon caulk on the crack and it worked like a champ. Held off water and flexed with ease. It was ugly though because I used clear silicon. If you try this, make sure it is 100% silicon caulk. The cheap stuff won't hold good.

fatboyreyn · 03-23-07, 09:01 PM

Forgot to tell you, I just got a top off of (jgibson59) on ebay. It was 425 and 55 to ship and a 200 core deposit. The top is an excellent product mounted on original GM frame, and fits perfectly. I had purchased a cheaper one , but plastic was thinner, frame was lighter, and assembly was shabby, as was the fit.

1984C4 · 03-24-07, 08:31 PM

Don't forget to stop drill the crack first before you put silicone in it so the crack wont continue to grow. Thats what I did. I hate having the crack but I usually use the hard top anyway and replacements are not worth the money. They will crack also.

gmjunkie · 03-24-07, 10:11 PM

I have 1 Near Perfect (No Cracks,No crazing!!) Blue Tint, 84-86 1st design!! Perfect Rubbers!!

Actually Guy's I have decided not to Sell it!!! I will need it some day!! And at Todays Prices if I sell it it will cost me $844.00 to replace it without a Core and even then it won't be Original GM!!!

Sorry for any Inconvenince!!!

fatboyreyn · 03-25-07, 10:40 AM

I think as long as you remove top before jacking car up, and don't do any curb jumping, the top shouldn't crack. You just have to be aware of the terrain yoour on!!! I hope so anyway, cause I just invested $500 in a new one, and if it cracks anytime soon, I might go POSTAL!!!

pitt · 03-25-07, 01:33 PM

Quote:

Originally Posted by Glide

I have a crack in the Acrylic top of my 85. I wasn't too worried about it until I jacked the car up yesterday and saw how much flex these cars have. The crack opened up like the Red Sea when I jacked up the front right.

Upon doing a search I've seen two suggested fixes although the threads were very old (2001). One was some kind adhesive from 3M the other was a LORD adhesive. Does anybody know if they've come out with anything better in the last 5 years? What are current members using? Can you use heat to fuse the crack together, maybe from the inside where it wouldnt show?

I put a couple bids for tops on ebay but they don't end for a while and it's supposed to rain tomorrow.

I have a 94 with a crack (luckily ?) dead center down the middle front. I went to discount auto parts and got a roll of 6 inch white rally striping and put it down the center,car is white. then I went to wallmart and got some clear ductape and used that on the inside.It worked perfectly and I actually like the look!

Glide · 03-25-07, 09:22 PM

Junk - I sent you a PM

Glide · 03-25-07, 10:19 PM

Quote:

Originally Posted by 1984C4

Don't forget to stop drill the crack first before you put silicone in it so the crack wont continue to grow. Thats what I did. I hate having the crack but I usually use the hard top anyway and replacements are not worth the money. They will crack also.

What do you mean "drill the crack"? I was thinking of using a dremel to grind a small furrow along the crack , then filling it with epoxy?? Will this weaken the top?

I hope Junk comes through as I was outbid on ebay and I don't want to pay $500.

Zblast · 03-25-07, 10:29 PM

Junk, check your PM box.

1984C4 · 03-28-07, 07:20 PM

What do you mean "drill the crack"? I was thinking of using a dremel to grind a small furrow along the crack , then filling it with epoxy?? Will this weaken the top?

A crack will continue to grow with vibration and movement. You need to drill a small hole at the end of the crack to basicly stop it from growing. The round hole is now a new non cracked edge. We do this as a temporary repair on aircraft sheet metal all the time. The acrylic top drill very easily at high speed. Use about an 1/8'' bit. I did not furrow a groove in mine. I simply put tape on either side of the crack about an 1/8" and gooped it up then removedthe tape for a nice crisp weather tight repair. You will see it but you can learn to live with it.

Rabbit · 03-28-07, 09:06 PM

Quote:

Originally Posted by 1984C4

What do you mean "drill the crack"? I was thinking of using a dremel to grind a small furrow along the crack , then filling it with epoxy?? Will this weaken the top?

A crack will continue to grow with vibration and movement. You need to drill a small hole at the end of the crack to basicly stop it from growing. The round hole is now a new non cracked edge. We do this as a temporary repair on aircraft sheet metal all the time. The acrylic top drill very easily at high speed. Use about an 1/8'' bit. I did not furrow a groove in mine. I simply put tape on either side of the crack about an 1/8" and gooped it up then removedthe tape for a nice crisp weather tight repair. You will see it but you can learn to live with it.

Good advice

Glide · 03-29-07, 04:39 PM

I will try it! Thanks for the tips. One more question, can this be done on the inside where it won't show?