E: Engine Fuel tank needs cleaning

richardb

Forum User
Non-VOC Member
First off don’t use caustic soda it will remove your paint. Phosphoric acid will convert the surface rust to iron phosphate and will then prevent further penetration to lower layers of rust.

Get the tank renew kit from Bilt Hamber
https://www.bilthamber.com/
Get a large rubber bung from ebay
Local plumbing shop for two 1/4 BSP plugs for the fuel tap holes fit fibre washers to them

Follow the instruction in the pack from bilt hamber. I used 10% strength derust and threw in a hand full of small screws which I shook around for a few minutes everyso often. The derust soak was overnight and was started with hot water.

The treatment is totally paint friendly which is a big bonus.

Before and after pictures of the tank clean are attached

Don’t use a sealer just put some anti corrosion additive in the fuel you use. Sealers can cause more trouble than they are worth, and if you get a tank like this who needs them !


6B6166F6-6DD4-4416-913F-C36750DB1B3A.jpeg
BDFEFD6C-DB35-4AA3-9BE4-ABE01AD04C10.jpeg
 

Chris.R

Well Known and Active Forum User
VOC Member
Hi guys.
I have now started on the tank which I have flushed through with a combination of Central heating cleaner, Spirits of salts and Kettle de-scaler. also with lead shot to rattle around. The result has been after two days allowing the solution to lay stirring occasionally and then draining shaking out the shot and flushing with cold clear water, the garden hose a much cleaner tank but alas not clean enough, the crevices in the bottom around the welded seams are still filled with trapped crud, today I went on the hunt for more chemical, I used to be a plumber so am familiar with strong acids, I was refused Hydrochloric, Caustic Soda is discontinued due to some EU regulation and could not be served Killed Spirits either, I gather that on 1st of July and after a council licence is needed to buy any highly caustic acid product, the licence costs £38.00 valid for three years. I went to B&Q who did not seem to know the new rule and bought two litres while I could before they catch up. I am now going to try this drain cleaner in the bottom of the tank then get out the pressure washer, it is unfortunate I cannot see inside the other half of the tank. Just mentioning the wheels again as I really do need to know the way forward re- chroming, paint, spokes and red/black lining, can I rebuild them myself or should I have that done and by who, I am in the Croydon area south of London.
Carshalton Chris
 

Chris.R

Well Known and Active Forum User
VOC Member
First off don’t use caustic soda it will remove your paint. Phosphoric acid will convert the surface rust to iron phosphate and will then prevent further penetration to lower layers of rust.

Get the tank renew kit from Bilt Hamber
https://www.bilthamber.com/
Get a large rubber bung from ebay
Local plumbing shop for two 1/4 BSP plugs for the fuel tap holes fit fibre washers to them

Follow the instruction in the pack from bilt hamber. I used 10% strength derust and threw in a hand full of small screws which I shook around for a few minutes everyso often. The derust soak was overnight and was started with hot water.

The treatment is totally paint friendly which is a big bonus.

Before and after pictures of the tank clean are attached

Don’t use a sealer just put some anti corrosion additive in the fuel you use. Sealers can cause more trouble than they are worth, and if you get a tank like this who needs them !


View attachment 22706View attachment 22707
Thanks for that suggestion Richard.
The inside is looking better but still has crud in the weld crevice's those that I can see. I am going to sheet the tank up and put the b.s.p., plugs back in this afternoon and try sulphuric acid very, very, carefully this afternoon. I used to be a plumber so understand chemicals well.

I see you have lettering on your oil cap and assume the petrol cap would be the same, mine have no markings for a 1954 should they have the markings, the caps I have certainly look as if they have been around a long time.
Carshalton Chris
 

richardb

Forum User
Non-VOC Member
Thanks for that suggestion Richard.
The inside is looking better but still has crud in the weld crevice's those that I can see. I am going to sheet the tank up and put the b.s.p., plugs back in this afternoon and try sulphuric acid very, very, carefully this afternoon. I used to be a plumber so understand chemicals well.

I see you have lettering on your oil cap and assume the petrol cap would be the same, mine have no markings for a 1954 should they have the markings, the caps I have certainly look as if they have been around a long time.
Carshalton Chris



Hi
The “crud” you see in the weld depression is just fluid that I didn’t slosh about enough to clean out. I was a bit to keen to get the tank back on as I was to blow away by the result. I later removed the tank and sloshed about a bit more. My tank needed doing as it shed a very fine red rust which blocked the pilots on the carbs - so fine it got through all filters. Problem now solved after the treatment.

What I really like about the stuff from Bilt Hamber was not only that it did a really good job on the de rust but did not go after virgin metal. I did a test prior to the derust on some clean mild steel and could not find any mass loss when weighing with a chemical balance. This stuff has now become my go to for all derusting no more mechanical abrasion and messing about with phosphoric and wire brush heads. Just a big bucket of solution and when it’s gone a yellow/brown from clear it gets changed.

Petrol cap has no lettering, as far as I am aware they were plain for that period. I am a 1952.

Gosh you are just down the road from me.

Cheers
Richard
 

richardb

Forum User
Non-VOC Member
Hi guys.
I have now started on the tank which I have flushed through with a combination of Central heating cleaner, Spirits of salts and Kettle de-scaler. also with lead shot to rattle around. The result has been after two days allowing the solution to lay stirring occasionally and then draining shaking out the shot and flushing with cold clear water, the garden hose a much cleaner tank but alas not clean enough, the crevices in the bottom around the welded seams are still filled with trapped crud, today I went on the hunt for more chemical, I used to be a plumber so am familiar with strong acids, I was refused Hydrochloric, Caustic Soda is discontinued due to some EU regulation and could not be served Killed Spirits either, I gather that on 1st of July and after a council licence is needed to buy any highly caustic acid product, the licence costs £38.00 valid for three years. I went to B&Q who did not seem to know the new rule and bought two litres while I could before they catch up. I am now going to try this drain cleaner in the bottom of the tank then get out the pressure washer, it is unfortunate I cannot see inside the other half of the tank. Just mentioning the wheels again as I really do need to know the way forward re- chroming, paint, spokes and red/black lining, can I rebuild them myself or should I have that done and by who, I am in the Croydon area south of London.
Carshalton Chris


Hi Again
There is a wheel builder around your area, I will dig out his card.
Also there is a wheel builder who goes to Kempton - he will do all chrome work and central painting and red pinstripes - again I will dig out his card for you but by memory he is based West Country. But does not matter you can take and pick up from him at Kempton.

Will be after the weekend when I hunt for the cards.

Unless you have original Dunlop stamped rims may be cheaper, and won’t change the pedigree to get new rims from central wheel components. Chrome plate is getting expensive.
 

Chris.R

Well Known and Active Forum User
VOC Member
Hi
The “crud” you see in the weld depression is just fluid that I didn’t slosh about enough to clean out. I was a bit to keen to get the tank back on as I was to blow away by the result. I later removed the tank and sloshed about a bit more. My tank needed doing as it shed a very fine red rust which blocked the pilots on the carbs - so fine it got through all filters. Problem now solved after the treatment.

What I really like about the stuff from Bilt Hamber was not only that it did a really good job on the de rust but did not go after virgin metal. I did a test prior to the derust on some clean mild steel and could not find any mass loss when weighing with a chemical balance. This stuff has now become my go to for all derusting no more mechanical abrasion and messing about with phosphoric and wire brush heads. Just a big bucket of solution and when it’s gone a yellow/brown from clear it gets changed.

Petrol cap has no lettering, as far as I am aware they were plain for that period. I am a 1952.

Gosh you are just down the road from me.

Cheers
Richard
Perhaps we can meet up. I will start a conversation to give you my contact details. My rims are marked Dunlop 3.50 x 19".
I have no lettering on either cap. What do you ride?
Chris
 
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