rusty petrol tank

[oldmodern]

Have just successfully de-rusted the inside of my petrol tank using brick cleaner!
Toolstation have a product, Bostic mortar and brick cleaner. Product code 98902. Has a 10 to 20 percent hydrochloric acid content and costs £5.98 a gallon.
Bought two gallons, topped up with water until tank brimming full, left overnight 12 hrs.
Drained, then flushed with baking powder solution to neutralise the acid.
Shiny tank! Have sloshed oil around it to avoid flash rusting but filling with fuel would also work. Surprised at the amount of rust that flushed out!
Ron

[spookefoote1956]

I'd line it with grey Slosh for a bit of belt and braces

[39speedtwin]

Don't line it, as it cannot be repaired later. Pressure test it no more than 5psi.

[oldmodern]

Many years ago, I had expanded polystyrene insulation pumped into my wall cavities. Ever since I have avoided processes that are difficult to reverse. I will try to keep the tank topped up to avoid the rust returning and keep an eye on it.
Never thought of pressure testing, I will give it a go.
Ron

[Stan Palmer]

Make sure you strap across the fixing holes. Even at 5psi tanks will spread.
Stan

[Group Leader]

If you are going to pressure test it you should do it hydraulically not pneumatically.

If the tank fails catastrophically when tested pneumatically it will effectively turn into a bomb due to the stored energy in the compressed gas and you wouldn't want to be near it! On the contrary, fluid is incompressible and therefore stores very little energy and should the specimen fail, the liquid will leak out like an expert (Drip under Pressure ... ). I spent some time in my early career pressure testing vessels of various sorts from the aerospace industry (containers not boats!) the largest of which was an aircraft fuselage.

Alan

[Mick D]

If you are going to pressure test it you should do it hydraulically not pneumatically.

Hmm!

Whilst I agree with the physics I think most people test fuel tanks etc. by raising the internal pressure a little whilst immersed in water or sprayed with soapy solution to look for escaping gas bubbles. Personally, I would limit the pressure to 2 or 3 psi and not be concerned about the bomb squad turning up on my door step.

Regards Mick

[oldmodern]

My thoughts on pressure testing was to fit a long tube to a petrol inlet, hang the tube up the wall and top up with water. 3metres of tube should return about four psi.
Although my attentions have now been turned towards the carb which has a cracked body and weeping fuel.
The bike and biking is new to me but these old girls do seem to be a never ending story!

[dave16mct]

What bike and carb have you got?
Dave.

[oldmodern]

Hello Dave
The bike is a "53" AJS 18s the carb is a 89B/1AK and has a 1 3/32 inch bore. have trawled the internet. only ones available look worse than mine. Our spares don't show one. Have e-mailed Amal for advice.
Bought the bike from the son of an old Jampot member who's no longer with us. From Worthing, E. Sx
The bike hasn't turned a wheel for 20 years so I expect a few surprises. Any advice on an alternative carb would be welcome.
Ron