Pro-seal Guidance

I am going to start the cleanup and repair of my left tank.

My question,Can the new MC-236 Fuel Tank Sealant be used over the old Pro-Seal?

The situation is, that the new sealant will overlap some of the old sealant on the inside of the tank. will the new and old sealant play nice? or fight?

What surface treatment, should be done to the Aluminum inside the tank before new sealant?

What should be used to cleanup after the Polygone Gel?

The Polygone Manufacture doesn't know anything about the MC-236.

The Flamemaster Manufacture doesn't know anything about the MC-236 product. (at least on Fri pm)

What are you trying to accomplish?

Hi Bill,
Please give a bit more info on what you are trying to repair with your fuel tank. Are the tanks built completely and leaking? Is the rear tank baffle removed? Are you trying to remove "flaking off" sealant? Are you referring to sealant AC-236?

To answer one of your questions, AC-236 will be compatible and bond with the old pro seal granted its completely clean. AC-236 is the same just a different manufacture.

Surface treatment under the sealant

If the inside of the tank is accessible the ideal surface treatment for the sealant to stick properly is to etch with a scotch brite pad. and then alodine the etched area to prevent corrosion.

kevinsrv7.com said:

If the inside of the tank is accessible the ideal surface treatment for the sealant to stick properly is to etch with a scotch brite pad. and then alodine the etched area to prevent corrosion.

Click to expand...

Yes you can apply new sealant over old, clean up old sealant good with MEK before applying.
(remove any old sealant that shows signs of deterioration or peeling)

"Etching" is actually a chemical treatment prior to alodine.
But yes, typically the ideal process is:

rough up surface
etch
alodine
clean with MEK
apply sealant

Sorry for the confusion, I had two threads on this subject, split into tank issues and Tank sealant issues. Probably should have been one.

The situation currently is, I was able to remove the Tank Access Plate without removing the Tank.

I found the leak in the Tank Access Plate. The leak was through the two rivets mounting the Anti Rotation Bracket to the Tank Access Plate. The rivets were standard pop rivets and had not been ProSealed inside the tank. This left two straight channels from the fuel to the outside. The Fuel pickup fitting exiting the Tank Access Plate had a lot of ProSeal around the fuel fitting on the outside of the tank access plate. This layer of ProSeal covered the exterior ends of the pop rivets, concealing them very well. The exterior ProSeal held the fuel in for about 8 years, till now.

The ProSeal issues I have now are two.
1.The Angle bracket on the inside of the tank is unfinished AL with a fillet of ProSeal around the base. The top surface of the angle and the pop rivets are clear of ProSeal. I can sand them to scuff them, then coat all the surfaces with a new coat of ProSeal. This will cover the old fillet of ProSeal. OK?

2. The Tank Access Plate is being cleaned with the Polysulfide Sealant Remover stocked by Vans. What other treatment should be used to clean the Tank Access Plate to remove the Polysulfide Sealant Remover and any other contaminants ?
Before applying the new ProSeal?

I would guess the right tank will start leaking next........