Anyone know about solvents and sticky stuff?  I have my 78 fuel tank out and replacements are not available.  The tank has a rubber bladder and the bladder has large cracks.  Like 3 inches by 1/4 inch on each end.  This is allowing rust to form and clog the strainer on the metering unit.

I purchased the POR 15 fuel tank repair kit from Corvette Central and I'm wondering if any of the solvents, or solutions will negatively attack the rubber bladder.  I hope I can use the kit as directed and just make sure to clean, prep and seal both ends where the cracks are in order to seal the exposed steel. 

Any ideas or suggestions?

Wil, I would suggest you remove the bladder, and then seal the tank. Cut the top part of the bladder off, to use as the gasket for the sending unit, and re-install without the bladder.

Thanks for the suggestion Joel.  I'm really struggling with cutting that bladder.  It's ridgid and there is only a 4 inch dia hole to work through.  I'm considering just putting it back in the 78 as is and wait and see how fast the condition gets worse.  I'm hopeful that someone will offer these tanks in the future.

Just an idea.  Is there a gas additive that prevents or inhibits rust?

[QUOTE=wil_burkholder]

...Just an idea.  Is there a gas additive that prevents or inhibits rust?

[/QUOTE]

Sure.....engine oil!
Truthfully, I don't think so.

[QUOTE=Adams' Apple] [QUOTE=wil_burkholder]

...Just an idea.  Is there a gas additive that prevents or inhibits rust?

[/QUOTE]

Sure.....engine oil!
Truthfully, I don't think so. [/QUOTE]

Is there a vast difference in shape of the tank between 77 and 78?

 

cthulhu38942.4330092593

I think the tanks are way different. The '78s have the sending unit on the top of the tank, not the bottom, like the older cars. The shapes are different, also, due to the change of the rear bulkhead for the "fastback" glass. You could probably hang an earlier tank in there, but......I don't know ...

Upon further investigation...
The '75-'77 tanks are interchangable, and do have the large hole in the top, for the bladder install.
                                       LQQK!!!
I just don't believe the earlier tanks will physically fit. Adams' Apple38941.8486921296

There are some liquid tank sealants on the market that might work to prohibit the rust. I used one from NAPA some years back on my Jeep Cj. It didn't hold but the CJ tank had some severe rust going on under the tanks straps.
Your vette tank probally didn't see mudd every weekend so I'm betting it to be in much better condition.
I still like Joel's idea best. even if this requires taking the bladder apart in sections through the opening.
If I had the tank out I would'nt put it back without some surgery even if it was minor. Tank removal isn't enough fun for me to want to be skilled at it!

Some gas tank repair shops will have the tank fiberglassed.  Fiberglass is fuel proof.   They spray the old tank inside and out with fiberglass to seal it.  You may have them just spray the inside.  Just a thought to check out.

Fiberglass my not be the way to go if you put the ethenol addative in your tank. It eats fiberglsss, just ask a any boat owner.

Alan

I emailed POR15 about their fuel tank repair kit.  Cleaning solvent, Metal prep solvent, Sealant.  They said the solvent will react with the bladder and suggested the same thing as Joel, remove the bladder.  Sorry guys, I must be chicken hearted.  I  just couldn't bring my self to cut it.  That is one of those burn the bridges solutions, there's no way back.  I just cleaned it (new strainer) and put it back in.  I'll probably end up redoing it when I get more time (and nerve) over the winter.  Right now I want to drive it, so I'll live with a temporary solution.  Thanks for the suggestions.

Wil