Clean the inside of a tank with Caustic soda

[Trigger]

Someone posted a thing about using caustic soda to clean the inside of a tank. I use caustic soda to soak carbs, that have come in from the states, so did not have to run out and buy some.
Had two tanks to do which were very rusty inside. Filled one up with a strong mix of caustic just to see if it would work. After 5 days is soak it had loosened some of the rust, but was nowhere near to what my standards are. I think this may work on flash rust.
Went back to my old way of 500g of ball bearings in the tank, and in the tumble dryer for 15 minutes. It was totally spotless in side as always.
For some reason i had a bag of small stone that they use in fish tanks. So thought on the second tank i would give that a try as it would be cheap for any members that had to do this job. Placed 2kg of fish tank stones and 3 liters of water, 15 minutes in the tumble dryer. The results were very good. Only one small problem was getting all the stones out of the tank.
When using ball bearing i just empty out what i can and the rest with a magnet.
When using a tumble dryer for this job, you have to wrap the tank in a blanket and pack the dryer out with pillows so the tank does not touch the side. 
Triggers Top Tip for Today     

[UK Pete]

Great tip trigg, i used a cement mixer and pea shingle, FFFFF me thats awkward to get out the fine stuff it leaves behind
pete

[Trigger]

Try ball bearings next time Pete. A lot easier to remove

[Lobo]

Aye... great tip... the simple methods are often the best. Who dreams up these things - tumble driers with bearings, laying your bike on its side to drop the engine etc etc.

Alas no tumble drier in Brunei... bloody 32 degs all day / every day.. this method sounds far easier than electrolysis.

BUT, when we eventually return home I can see I'll have to lug a tank into Currys to 'help' Mrs Lobo choose said tumble drier with a cavernous opening; and a 750 SOHC block into John Lewis to select  the oven, whilst ensuring of course, they have a special on a dishwasher which can swallow the gearbox + all internals.

Oh, we'll need a garden too... sufficient to lay my old Hondas down.

She'll be so excited...

[Paull]

Hi Trigger,

I used caustic soda but as you say, it was a new tank with flash rust and it cleaned it well.

Then i stopped the caustic from working with spirit of salts.

Then lined it with por15.

Worked very well two years later its still good to go.

PaulL

[Nurse Julie]

I posted an item on here from a Classic Bike mag about tank cleaning with Caustic Soda etc. Link attached again for anyone that's interested.
http://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&frm=1&source=web&cd=4&cad=rja&uact=8&ved=0CDMQFjAD&url=http%3A%2F%2Fwww.realclassic.co.uk%2Ftechfiles%2Fpetrol_tank_cleaning_and_rust_removal.html&ei=tdlAVKqrHKKV7Aat3oDAAQ&usg=AFQjCNGGMi_nGGEIVjflu4uzqR39N7QniA

[Trigger]

Aye... great tip... the simple methods are often the best. Who dreams up these things - tumble driers with bearings, laying your bike on its side to drop the engine etc etc.

Alas no tumble drier in Brunei... bloody 32 degs all day / every day.. this method sounds far easier than electrolysis.

BUT, when we eventually return home I can see I'll have to lug a tank into Currys to 'help' Mrs Lobo choose said tumble drier with a cavernous opening; and a 750 SOHC block into John Lewis to select  the oven, whilst ensuring of course, they have a special on a dishwasher which can swallow the gearbox + all internals.

Oh, we'll need a garden too... sufficient to lay my old Hondas dow

She'll be so excited...

Old tumble dryer Lobo. One with the heater not working. Love to see someone walking round John Lewis with a engine block, trying to fit it into a oven

Paull, I never line a tank with anything. If it has a small hole it can be fixed. Big hole in the bin.

[Trigger]

That was the one Nurse. Mixed 100g  to one litre . Must point out that the tank was well rusted up and had sat on the bike since 1983, that bad that i had to burn the fuel tap off.

[Paull]

Hi Trigger,

I tend to build my own tanks, I do pressure test them but just for peace of mind, i line them.

I have had one leak i made and it made a right mess of the paint job.

PaulL

[Lobo]

Seriously Trig.... I'd have guessed ball bearings would just roll around and not give the rust a particularly hard time versus a hand full of good old hex nuts, bolts etc. What size bearings you using?

[Trigger]

Hi Trigger,

I tend to build my own tanks, I do pressure test them but just for peace of mind, i line them.

I have had one leak i made and it made a right mess of the paint job.

PaulL

Not worried about the paint. These tanks were pressure tested before i stated. Now they are filled with diesel, which will be drained off in a couple of months. Then i will blast the tank to the bare metal and resprayed.
On a restoration i leave the tank and panels till last, as this is the last parts fitted.

[Trigger]

Seriously Trig.... I'd have guessed ball bearings would just roll around and not give the rust a particularly hard time versus a hand full of good old hex nuts, bolts etc. What size bearings you using?

These are old balls that i have collected over the years, all different sizes and not smooth new ones. Have a mate that uses old fishing shot with good results.
Sand and water work well but, a sod to get out.

[Green1]

Great Tip Just one problem I don't want to go near caustic soda ever again.
Iv been stripping ornate cornices at work for a month now and tree days ago I got a massive dollop of a paint stripper made out of lime and sodium Hydroxide in my eye.F**k me does that smart Iv only just started to get my vision back.
You may think you don't need goggles but trust me you do.
Mick

[UK Pete]

Ouch i feel for you, i remember scrubbing paint stripper on to some paint with a tooth brush and it flicked into my eye it took two days for my eye to recover
pete

[Bitsa (Ralph Wright - RIP)]

Agreed fellas
If I do not know it glasses and protectors are in order friggin hurts otherwise.
Cheers
Bitsa