Diesel Tank Painting

[DeepFrz]

This doesn't really seem to be the ideal steel coating, as expensive as it may be.

This material is designed for fillet sealing of fuel
tanks and other aircraft fuselage sealing applications.

PR-1776M Class B is a two-part, manganese dioxide cured
Permapol® P-5 modified polysulfide. The uncured material is a low
sag, thixotropic paste suitable for application by extrusion gun or
spatula. It cures at room temperature to form a resilient sealant
having excellent adhesion to common aircraft substrates.

Aircraft substrates. Steel?

[Don1500]

"Aircraft substrates. Steel?"

Aluminum
But it will work on steel or plastic.

[brankin]

Don1500 is 100% correct. I had welds on my aluminum tank that had daylight showing through. I glued new skins on to the exterior of my tanks with a product from a different manufacturer (but the same stuff) and it pressure tested for a week. I don't think it will ever leak again.
my 2 cents

[dpons]

Call the people at HEMPEL (Hempel) and ask them for advise. They really know their stuff and have boat/tank paints for all uses.

[EqPierre]

Don't know if this post is still active, but I'll try it anyway. The tanks in my steel sailboat never contained fuel. When I just bought the boat, I could only access the first part of the tank, which was half filled with water. Now, after removing all interior timber, I opened the second part too. It was still soaking wet inside. The upper inside and walls of the tank seem to be painted. There are some marks on the bottom and walls that look like some algae has been growing there. Please take a look at the pictures and give me some doable advice about how to go on with these tanks? I also opened the 2 lateral water tanks, and they seem in rather good condition. They are painted black, a thick layer of it. I understand this is a product that is no longer been used or sold. Have to find a solution for these tanks too. Does somebody know what the black liner is called? If the stuff is sticking well, maybe I can grind it and apply a modern liner on top?

[boden36]

I would not paint them inside. No paint lasts forever, and eventually it will cause a problem that will be hard to fix.
Also, if you have voids in your weld, these will cause a perfect corrosion cell which will bubble and destroy the paint in the very area you were needing it.

Our tank is over 30 yrs old, unpainted and does not show significant corrosion. (but has thick walls as is part of the keel).
To clean it after construction I filled it with a dilute mixture of phosphoric acid and water and left it for a week or so. This cleaned it to bright steel but it flash rusted after being hosed out.

If you are worried about leaks, lightly pressurize the tank with air and then paint the welds on the outside with a foamy mix of water and washing up detergent. You will soon see any bubbles.
If you are building a tank, it is a good idea to research specific welding techniques peculiar to tank construction.



Regards,
Richard.