out, damned rust!

[REG]

Would you not have to submerge it upright in you were to insert an anode into the tank?

Otherwise, the gases would collect in the tank and the electrolis would fail in those areas where the gas 'pools'.

 

A large anode 'outside' the tank would work??

 

Or mollases with a damned good clean afterwards?

[Jessie The Jeep]

Looked online and Sainsbury's stock it, £0.90/Kg - Soda Crystals

[fv1609]

I've an old charger, I'll stick a 21 watt bulb in series that should giove about 75 ohm.

 

How did you work that out Tony?

[Richard Farrant]

How did you work that out Tony?

 

mental calculation ?

[fv1609]

mental calculation ?

 

I always try & work it out with a pencil.

[Degsy]

I always try & work it out with a pencil.

 

And the correct answer is......

[fv1609]

And the correct answer is......

 

First of all make sure the pencil doesn't break off.

 

12v bulb rated at 21 watts, so current carried is 1.75 amps

 

Resistance of bulb = 12 divided by 1.75 = 6.8 ohms appx

[Kufra Kiwi]

Would you not have to submerge it upright in you were to insert an anode into the tank?

Otherwise, the gases would collect in the tank and the electrolis would fail in those areas where the gas 'pools'.

 

A large anode 'outside' the tank would work??

 

Or mollases with a damned good clean afterwards?

 

Thanks for that. Standing it upright is a good idea, but would an external anode work internally? On reflection perhaps a more practical solution is to replace it with a modern fuel tank of about the same dimensions. As its out of sight hidden under the seat no-one would ever know. Safer too.

[Tony B]

First of all make sure the pencil doesn't break off.

 

12v bulb rated at 21 watts, so current carried is 1.75 amps

 

Resistance of bulb = 12 divided by 1.75 = 6.8 ohms appx

Forgot the decimal point!.:blush: Did the rough brain calculation, rough being the operative word. the old nemonic is Ohm James, E, I , R sir. E= Voltage I= Ampaage R = Resistance in Ohms.

[fv1609]

Tony I thought you had been starring at coax cable when you replied as that commonly is 75 ohms impedance & somehow the figure transposed itself. Easily done at our age

[Tony B]

Tony I thought you had been starring at coax cable when you replied as that commonly is 75 ohms impedance & somehow the figure transposed itself. Easily done at our age [/quote

 

You're to kind!

[Tony B]

Anyone had any experience removing the rust from a petrol tank by electrolysis[ATTACH=CONFIG]56461[/ATTACH]? The petrol tank from our 1942 Chev truck is rusted inside and out. I have previously had good success with mollasses but for obvious reasons I don't want to introduce any kind of sugar into a petrol tank. I think with electrolysis the main difficulty would be getting a large enough anode inside the tank (and then out again) through the narrow filler neck?

 

You have got the gauge plate to remove. Stick the anode through an insulated plate and bolt in. I can't see the problem with mollases though, whatever you do it would need thourgh flushing afterwards, and probably a tank sealer.

Maybe something like this inserted into the old case? http://www.ahoycaptain.com/shop/flexiblefueltanks.html

[LongJohn]

Removing rust by electrolysis is line of sight only, so you can't derust the inside with the anode on the outside. When I did my motorcycle tank, I bunged up the outlet, mounted a shaped length of threaded rod on a piece of wood, and filled the tank with electrolyte. Obviously this only works if the tank is corroded but not leaking, a quite large non-metallic container would be required to completely submerge a leaky tank.

[Degsy]

First of all make sure the pencil doesn't break off.

 

12v bulb rated at 21 watts, so current carried is 1.75 amps

 

Resistance of bulb = 12 divided by 1.75 = 6.8 ohms appx

 

 

Thanks Clive, I don't have a problem with mental arithmetic...yet..... but I never could remember formulae so now I've got no chance:nut:

Edited January 29, 2012 by Degsy

[Tony B]

Thanks Clive, I don't have a problem with mental arithmetic...yet but I never could remember formulae so now I've got no chance:nut:

My excuse, I'm just mental.

 

Thanks Long John, a friend and I were discussing cleaning a Jaguar car tank earlier on.

[Degsy]

My excuse, I'm just mental.

 

 

 

:wow:Your voices have finally confirmed what we've been telling you for years have they? The nice men in the white coats with their yellow van will be calling soon;)

[Tony B]

So how do you explain walking round Tesco's with 20kg of Washing Soda and two dozen tins of Mollases then?

[Degsy]

So how do you explain walking round Tesco's with 20kg of Washing Soda and two dozen tins of Mollases then?

 

Dirty with a sweet tooth:rofl:

I do buy washing soda from Tesco but molasses comes in bulk, we've just taken delivery of 3 tonnes of the stuff, the truck was carrying about 18 tonnes and we share it around half a dozen farms.

[Tony B]

Dirty with a sweet tooth:rofl:

I do buy washing soda from Tesco but molasses comes in bulk, we've just taken delivery of 3 tonnes of the stuff, the truck was carrying about 18 tonnes and we share it around half a dozen farms.

 

So if we empty the clubhouse DUKW pond, and use you contacts... Who needes to strip the vehicle for de-rusting?

 

The local fish mongers sell off plastic bowls with tops for 10p each. What concentration of Mollases would you use? Surley neat would be so thick you'd never get stuff to sink ?

[Degsy]

Not as thick as you might think, it runs ok out of the tanks into containers with a ball fitted in the top which the animals lick.

[Kufra Kiwi]

I have had good results with six parts of water to one part of mollasses, but I understand you can dilute it further to 9:1 and still get good results. Don't be in a hurry though - at least two weeks immersion is necessary for 6:1 and probably 3 to 4 weeks for 9:1. Then waterblast after removal. It works quite well and there are no toxic fumes or voltage issues either.

[Kufra Kiwi]

Here is a floor panel from my 1942 Chev truck after the mollasses treatment at 6:1 mix. This panel was quite badly rusted and you can still see a bit of residual rust in top right hand corner. I tie the treated parts to an old bedstead for waterblasting.

[Tony B]

I have had good results with six parts of water to one part of mollasses, but I understand you can dilute it further to 9:1 and still get good results. Don't be in a hurry though - at least two weeks immersion is necessary for 6:1 and probably 3 to 4 weeks for 9:1. Then waterblast after removal. It works quite well and there are no toxic fumes or voltage issues either.

Thanks for that I was thinking 50:50 for some small stuff to start with, nuts bolts and some clasp knives that have rusted up. I have a nice little ultrasonic cleaner to deal with residue. I've got some old coins so be intresting to se ewhat happens with non ferrous as well.

[Rangie]

Regarding the petrol tank with the long spout:

 

You could take the sender out and dangle a large coil of iron rod down into it to cover the most surface area.

 

Or, as I did for a complicated water-pump casting, thread an iron rod down a small piece of alkethene or reinforced poly-pipe, used as an insulator, down and through into the tank. You would have to ensure the tank was submerged fully and the mixed solution was evenly distributed. Best to have the filler neck upright to release the gases/froth, so you may have to do it in a 200L drum with the top cut off

 

If you are making a lot of solution, dangle a lot of parts!!

 

Mind you, the more parts and the larger the surface area, the larger the amount of current is required to have a decent affect! :nut:

 

Enjoy!

 

Alec.

[Kufra Kiwi]

Thanks, I have just removed the guage cover ("sender"?) to look inside. I was surprised to see no rust, especially considering the outside of the tank is quite badly rusted. However as I can see only about 10% of the interior through such a small hole, I assume there will be rust in there somewhere. So some kind of treatment will be necessary if I am going to use it as a petrol tank in the truck. It has just occurred to me that buying a large enough plastic container for total immersion (in either mollasses or electrolyte) might be just as costly as having the tank acid-dipped by a professional.