Join Date: Feb 2008
Location: St. Petersburg Florida
Let me address some of these questions as someone who has done a lot of tanks with POR.
First, the POR product requires a process which includes a very intense cleaning using a specific cleaner (including using boiling water) in multiple steps, second using a phosphoric acid etching compound, then engaging in a multiple step rinsing process. Afterwards it requires a forced air drying period in which the interior must be absolutely dry. Then, and only then, do you use the interior coating material.
To do it properly you don not just "slosh around" the material. We have a fixture which clamps the tank and then we rotate the tank through all three geometric planes for about 30 or 40 minutes. We also utilize this fixture during the cleaning and etching phases. This rotational motion is the same process by which many fiberglass and other resin-based shapes are created using a positive pour-in molding process. After the elapsed rotational time the remaining material is drained and discarded. The tank is allowed to dry for at least a week in our shop.
No internal coating will fix significant leaks. That is not what is intended to do. If a tank has a leak we fix the leak first before we do any coating - we fix leaks by either welding (if visible) or with epoxy if they are just "pin" holes. We don't use POR to fix leaks - it is used to coat the tank not fix the leaks. We also blast, brush or strip the exteriors and then use a POR15 external coating to protect the exterior of the tank. It is a very labor intensive process. I believe used properly it is a good product - and there are other products out there for refinishing fuel tanks which are probably equally good.
I think that if you haven't used the product or had experience refinishing fuel tanks using this general technique you should probably not offer an opinion based on your imagination, or based on the experience of others who may not have followed the proper protocol in using the material.
I always advocate to those who have serious fuel tank issues to simply replace the tanks. That is the best option in my view. For many folks on a tight budget that is not always an option. If you need to conserve your resources then the use of POR or a similar product is a viable and in my experience a good option. But be aware that the amount of labor is very significant. And if you shortcut the protocol then you risk having the tanks deteriorate more rapidly. I have priced out what a professional refinishing company charges for refurbishing tanks for an Esprit. With shipping it is so expensive you might as well buy new tanks since the cost is about the same.
Like every other aspect of coating - from painting your Esprit to painting your house - 90% the work is in the preparation. If you do the prep properly re-coating will work well. If you don't, then it will be disappointing.
1989 Esprit Turbo