Diesel Tank Painting

[Gerry Courtney]

Any suggestions for repainting the inside of steel diesel tanks please?

[perchance]

Google G E Glyptal. They have products for this application.

[DeepFrz]

Yes. My suggestion is don't do it.

[lorenzo b]

Second that, it's not done on fishing boats.

[GordMay]

Greetings and welcome aboard the CF, Gerry.

Why do you want to paint the inside of your fuel tank?

Originally Posted by perchance

Google G E Glyptal. They have products for this application.

Which of these Glyptal products would you recommend for coating the inside of a fuel tank?
➥ Glyptal Product Info

[Matt sachs]

I dont know enough about this to say if you should do it or should not, but if you are going to, this is how I am doing it. Needle scale it then sand blast it till its clean. (at this point you can fill it with fuel and forget about the next steps)
Any place you think its not exactly clean apply phospho to convert any left over iron oxide to iron phosphate. Follow that with 4 coats of PPG 90HS. ( however its on back order currently and I am waiting patiently)

[perchance]

1201 used for painting the inside of hydraulic reservoirs or contact the supplier for recommendations.

[minaret]

Why paint the inside of a diesel tank? You will be sad if the paint fails and clogs up your fuel system. Also, how would you paint all the baffles inside the tank through a regular inspection plate? Unless it's a tank so small it has no baffles, or so big that you can climb right in, I don't see it being possible. Unless you cut off the top of the tank for painting and then re-weld it. But that would defeat the purpose, as well as being silly....

[lorenzo b]

I think the best thing to do is to wire brush or sand the steel as clean as you can, completely vacuum up the dust, and wipe it down will diesel soaked rags. Hard to imagine getting a needle gun or sand blasting nozzle into a fuel tank, just welding the inside seams was a nightmare, and my tanks are 1500 gallons each with hatches you can climb through. If the tank is 200 gallons, how are you going to look inside to see what your doing?

[Matt sachs]

I gave it a lot of thought. The reason I decided to do it was my lack of faith in my welding ability. The welds were inspected (and passed), but on the other side of the weld is my potable water. One side of the weld is inside the fuel tank, and will be coated with the PPG 90hs, on the other side is potable water and its coated with PPG amerloc2.
Basically I divided the unused aft section of the keel for additional tankage. I can access both sides of each baffel for inspection.
If it dosent work out like I plan, then I will be left with what I started with, unused aft keel (but now its not rusty on the inside)

[sdowney717]

Sanitred permaflex can seal this as well as water tanks.
This is a paint on polyurethane coating.
only 2 things to ensure success
1. make absolutely sure no oil is left on the metal before you coat.
2. wash off between dried coats with dish soap and rinse with water.
If you recoat before it is cured you dont have to do that.
I would do it anyway.

PermaFlex Technical Data, Deck Coating & Repair, Wet Basement Waterproofing Product

PermaFlex CHEMICAL RESISTANCE

Salt Water

No Effect

Distilled Water

No Effect

5% Detergent Solution

No Effect

Anti Freeze

No Effect

Hydrochloric Acid 36%

No Effect (higher testing not required)

Sodium Hydroxide 50% Solution

No Effect (higher testing not required)

Sulfuric Acid 60% Solution

No Effect (higher testing not required)

H²S (Hydrogen Sulfide) 30 Day Immersion

No Effect

Sulfuric Acid 5% Solution 30 Day Immersion

No Effect

Sulfuric Acid 10% Solution 30 Day Immersion

No Effect

Caustics

No Limit – No Effect

Ammonium Hydroxide

No Limit – No Effect

Nitric Acid 50% Solution

Up To 50% - No Effect

Hydrogen Peroxide 50% Solution

No Limit – No Effect

Hydrogen Fluoride

No Limit – No Effect

Hydrogen Sulfide

No Limit – No Effect

Calcium Hydroxide

No Limit – No Effect

Gasoline

Slight Stain

Motor Oil

Slight Stain

Hydraulic Brake Fluid

Slight Bleaching

Diesel Fuel

No Effect

JP - 4

No Effect

JP - 5

No Effect

JP - 7

No Effect

JP - 8

No Effect

[lorenzo b]

To test your welds they make dyes you spay on the inside [red] and outside [white] and if there is a pinhole the red will show through.
To test steel fuel tanks before filling, close off the vent and pressurize the tank a little with a water column you can mark and walk away. Come back another day and see if the pressure is holding.

[Matt sachs]

Originally Posted by lorenzo b

To test your welds they make dyes you spay on the inside [red] and outside [white] and if there is a pinhole the red will show through.
To test steel fuel tanks before filling, close off the vent and pressurize the tank a little with a water column you can mark and walk away. Come back another day and see if the pressure is holding.

Thanks, gonna do that too...

[Don1500]

If you really want to do it, this is the BEST stuff you can use. Not Cheap. $77/pt in lots of 16 pints. This is what is used to paint and seal fuel tanks on aircraft. Use it correctly and you will NEVER have to worry about fule leaking from inside corrosion. Paint the outside and it will also be protected.

Using this stuff you could have screwed the tank together and it would never leak.

PR-1776M

Buy PR1776M-B2 | PR-1776M-B2 SEALANT PINT KIT

[sdowney717]

I have used a lot of permaflex
here is something else cheaper than PR-1776M
perhaps that expensive aircraft sealant has to work in extreme cold of high altitudes which a boat would never experience.

ALCOHOL RESISTANT <br>GAS TANK SEALER from Aircraft Spruce

This is impervious to all fuel types. Over 2,000,000 sold to date. It is the best way to repair and restore your fuel tank. Simple application, includes extensive application information and product information sheet. Will seal pinhole leaks and prevent rusting. 1 Pint will seal a 10-12 gallon tank. Good for all fuel types. Works well with all metal and fiberglass tanks.