I want to share my experience for a waterproof rust proof paint that I have used over the years to cover steel car sections like floor and inside doors which doesn't cost the earth and is very resilient. It is particularly good for floors which occasionally get wet.
Use it if you like and see how it goes but of course no responsibility for me. But it works.
I learned this on the worst rust car that Holden ever produced, the HD/HR Holden which leaked like a sieve and had rust installed as a free accessory during manufacture. These cars predate most of you but some on the forum will attest to the standard of mid 60's Australian cars when it came to water tightness and rust protection.
Treat the rust with phosphoric acid/rust converter, neutralise if required by the manufacturer's instructions etc then prime with standard steel red primer making sure you get it into the hidden bits. This is pretty easy. For simplicity I just used to use things like Killrust converter and primer.
Buy black bituminous paint used for sealing gutters like Ormonoid or the really thick paste like material that you spatula on from the same manufacturer and cover everything you want treated. Of course this stuff smells is terribly sticky and this process is more for vehicles being restored than for daily drivers but if you can stand the smell and can put some paper down you can do it and drive. Make sure you wear disposable gloves.
Leave it to dry until reasonably tack free. Depending on the temperature this can take a week or so, or longer.
When you think it is reasonably dry add the magic ingredient. Buy some Estapol 2 part floor varnish like 7008 then liberally apply over the bitumen paint, pouring it where possible into door seams etc to get the full covering. This serves to seal the stickiness and provide a rock hard impact resistant and waterproof layer(s).
I've tried both one part and 2 part and both work but 2 part is more resilient. I guess it is moisture cured polyurethane like POR15 and is very tough. Re coat to your heart's content. It goes a little glassy and yellow the more coats you add and you can get quite a thickness up. It dries pretty quick and can be recoated as per Estapol's instructions. I just laid tacky coat over tacky coat and had no problems.
When hard you can hit it with a hammer and not crack it. I have not had any crack and flake off despite how much flex there is in the body or floor pan. Admittedly I haven't used it near exhaust etc but it is perfect for VW floor pans that are treated and not requiring say a POR15 treatment.
I have just found an old HR door treated and left under the house over 30 years ago and the inside of the door is like the day I did it but the outside is showing external mild corrosion. This is what has prompted me to write this up.
Of course if you don't treat the underlying rust issue it will grow rust underneath. But this process will ensure you can have moisture and sweating and not worry about the water penetrating to the substrate.
As they say in the blurbs "try it out on a hidden piece first to see if it does not cause an allergic reaction".
Cost is not bad, you can mix only what you need and you can buy all you need in the next trip to one of the monopolising retail hardware giants. Adding the bituminous paint and Estapol provides a degree of sound proofing by removing druminess as well.
Enjoy.
viiking
viiking Officially Full-On Dubber
253 posts · joined May 2012 ·
