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LarryH57

Frosts POR15 Petrol Tank Sealant

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Guys have any of you had any issues with Frosts or other brands fuel tank sealant?

A friend of mine said a mate of his had the sealant peal away and it blocked the fuel supply.

Would that be a common thing or perhaps a fault of the person who applied it. What stops it pealing off?

Also if the tank I have sourced  had rust inside 'cured' do I even need to use Sealant?

Apparently Fulltilt fixed a hole with a coin araldited to the inside of the tank!

Edited by LarryH57

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On 7/3/2020 at 7:30 PM, LarryH57 said:

I suppose the real question is Fuel Tank sealant necessary for every replacement Tank?

With E5 (and E10 to come) a real corrosion problem is oxidation + galvanic caused by getting water in the tank , technical - the added corrosion problem is due to ethanol blended petrol absorbing water from the atmosphere,  more serious is LIQUID water entering, water droplets sitting in the same place corrode a hole in the base of the tank because water containing ethanol is highly corrosive (to carb float chamber as well).   As I see it - a Land Rover with underseat fill tanks is less of a problem than neck fill , you can remove the cap and observe for beads of water rolling under the petrol.  Also there should be less danger of water entry than with a neck fill.   You can get bad fills of petrol with some water content - that is what to watch for. So in short your tanks are almost as good as car plastic tanks.    You could have a scoop device to remove, or a pump suction hose, if the worst comes to the worse you can drain the tank & remove the water easy (providing you do the job in open-air & have containers and keep smokers well clear.   The worst problem is a metal tank you can't see into  !       Winter storage , run one tank dry after running the other low (say 1 gall = 20 miles  LoL) , then run the other tank dry ,  spray some Triple T in tank ,  next season - be prepared as change over tap may need a new cork gasket,  ISTR instructions with a new cork - a smear of Vaseline helps ,,

You could also run the carb dry , you could remove the top cover of 36IV and mop out + check the ethanol has not got at the float.  I have had top gaskets for carburettor  dry out , totally cream crackered , not one piece bigger than 1/4" x 1/4".

Keep tank slosh sealer treatments for non top fill tanks.

A word of extra-warning - have wife handy with Fairey Liquid , I have had my hand well stuck removing water !

btw - I have a proper intrinsically safe torch when peering inside.

Edited by ruxy
spelin

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Hi Larry

This is coincidence as I 'was' just about to seal one of my FV432 diesel fuel tanks with POR15, and was a little concerned...

I have cleaned both tanks out with milkstone remover which I sell for descaling milking parlour stainless steel milk pipes, this I left to soak for 24hrs and has cleaned the little rust  away , I had in one tank with well.

I happened to speak to the owner of Tank school yesterday and he mentioned that he had sealed one fuel tank and it pealed off and caused no end of problems, so I am just going to thoroughly rinse out and put the tank back in.

The POR15 could cause a few health problems if you happen to breath the vapours in without the correct face masks.

Richard

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On 6/29/2020 at 1:23 PM, LarryH57 said:

Guys have any of you had any issues with Frosts or other brands fuel tank sealant?

A friend of mine said a mate of his had the sealant peal away and it blocked the fuel supply.

Would that be a common thing or perhaps a fault of the person who applied it. What stops it pealing off?

 

Following the instructions to the letter and using the stuff provided in the appropriate measures stops it peeling off.

If the tank isn’t degreased thoroughly and cleaned with acid properly, the sealant won’t adhere or cure, pure and simple. It’s actually in the instructions which come with the stuff.

Most probably, the degreaser and acid weren’t applied properly and for long enough and/or weren’t removed totally before putting the sealant in. When the sealant cures, it’s so hard that you can’t even break it with a sledge hammer (yes, I tried), and forms a tank within the tank. 

I have done five tanks with no issues so far and all to be used with fuel that has 10% minimum of ethanol in it. The one tank I didn’t do with POR15 was too far gone and had holes the size of 10p pieces appearing when I started using the acid, and therefore discarded and replaced with a new tank. 

This is not second hand information, but first hand so you can take MY word for it.

With regards to your question as to whether all tanks need POR15, the answer is no. As in the case Richardfv432 stated above, if the rust is gone after the first cleaning, and there are no holes, then you’re sorted. Had a Bentley T1 tank the other day, just steam cleaned it, and it came up pristine, so it went back in after blowing out all the fuel lines and replacing the flexible hoses to get rid of the crud in there. 

Edited by ltwtbarmy

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Larry  -  specifically with the Lightweight / military underseat fill tanks, first you need to identify.    Talking 'genuine' tanks  :-

Early tanks - these were made from  Terne steel  (steel coated with a alloy of tin & lead) , You should spot the folded side-plate seams easy , the give away is the tank top soldered seam.  This often cracks , I  re-solder quick heat in out (otherwise the folded lap-joint moves) - using a propane torch & nozzle a bit bigger than micro-bore.  First I wash out with Fairey Liquid & boiling water , then I steam with lance of a wall-paper stripper.    I have my doubts if ethanol will attack terne ,  Rolls Royce used it and I believe many cheap production cars - never heard of ethanol problems when Cleveland Discol was available & it was probably nearer E10 than E5.

Later tanks - these are welded , the bead runs to me seem gas welded , I doubt if they would use any coated steel such as Zintec , you should easy identify.  These tanks  - probably will get attacked from inside.

btw  -  the tank I repaired with a coin & Araldite (original long setting time) , I was caravan towing in Wales - early 1980's.  19FM65 , would be original tanks. I laid it up Y2K  (with time I would like to restore , have new vent panel & Les. Crome footwells) chassis is VGC and body is mint - just needs another respray with cellulose.   I drained the tanks & poured 1/2  gallon of diesel in both - that Araldite repair has held for coming up 40 years  !

There are other resin products , for boats - I have uses West stuff.  I would consider for slosh.

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Attached are photos of the tank that is to replace the one on the Lwt that is weeping fuel around the drain plug. This replacement tank matches the one on the vehicle, which I guess is original from 1980.

The inside of my replacement tank has a few spot of rust but these have been given the rust cure liquid to turn them black, though since last year a few more spots have appeared. Still, I think it is good enough not to need Frosts POR15. I bought this tank for £30 about 10 years ago. It has been cleared up and repainted on the outside with three coats of undercoat rust protection and two of black. The current tank is painted with underseal over the bottom and sides.

Incidentally the original tank looks to be in NATO Green under the dirt, so perhaps my black is not the right colour!

 

1530974627_FuelTank(1).thumb.jpg.6b7daffdb6ff0c9197c58eedc643ae79.jpg

Fuel Tank  (2).jpg

Edited by LarryH57

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That is a welded tank , from abt. early 1980's  the cradle is probably secured like early with solder plugs (would have to check). 

The mud trap at front fixings area to outrigger tends to get hosed - not a great problem , perforation from outside seems problem near rear mounting as only the keen hose there. Never known the side panels rust through.

A good degreaser is meths because it is 100%  spirit (ethanol) and £ cheap.

Actually ancient dried up petrol can look like rust on tank bottom, I have had this on a very old Honda genny set I purchased , only because it is a collectors item and mint. The tank is now perfectly clean but tinged brown.  I kept using WD40 to soak in thinking it was rust , came out like coffee !

I can't see the point of using slosh sealer on these tanks other for bottom and  1" to 2" up sides .  The ethanol danger is when the water settles on bottom & you could do a pair for £ of one - bogoff  !

Thicker sheet steel commercial tanks , after de-rust , you could get areas of high wastage checked with a NDT ultrasonic thickness tester. Modern electronic ones are now probably quite common.

Edited by ruxy

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