rust removal from cast iron

[Lance]

I wholly agree with Tom on the use of electrolysis . It is non toxic ,has very little smell , definitely does work and is cheap . All you need is a  charger , some washing soda and water . People are always amazed when I show them the results . The longer you leave it the better it gets and can be used over and over .

[Bill Gauch #23121]

I agree that electrolysis would be the way to go on something that is rusty on the outside. My problem is that my pump housing is rusty on the inside. I have read that you need to have a sort-of line-of-sight to the rust from the electrode. I have no idea why for sure, but I would guess its some sort of skin effect the same way lightning cant hurt you inside a car. I would never risk a short putting a metal electrode inside the narrow tube of the housing.

[Tom Beaver CLC 22002]

Bill - You are right that the electrons like to travel pretty much in a straight line between the electrode and the rust so for the interior of parts you need to place an electrode such that it can "see" the inside.  Just fasten/clamp an insulator with an attached electrode (a piece of wood or plastic will do it doesnt have to be fancy) to the part such that the electrode sticks inside, connect all of the electrodes together and hook it all up to a battery charger.  Most battery chargers are protected from shorts such that they will just trip off if that happens.  However, all you really need to do is watch the ammeter when you plug it in.  If it goes off-scale just unplug it and go check your connections.  I used this procedure for the water pump from my 38 LaSalle and had no problems with removing the rust from both inside and out.

[Mike Josephic #3877]

Guys:

Ive read through all of the posts of the ways to
remove the rust.  However, have you considered the effect
on the pump bearings if you soak them in these kind
of solutions?  A solution of phosphoric acid will remove
the rust, but if it were my pump I would have it
professonally rebuilt by somebody who will replace the
packing, bearing, etc.  Aurthur Gould has been doing this
for about 50 years and he does great work.  Hes in Hemmings
every month.  He rebuilt my pump and it came back "as new".
The cost was about $150 a few years back (for a 55 Cad).
You need a bearing press and the know how to do this.

All this business of building tanks and soaking in molassas
etc. that Ive read about is simply not cost effective.  
Mike

[Bill Gauch #23121]

I agree, building a tank for this wouldnt work. I just used a random plastic bucket and purchased chemicals. I fully disassembled the pump parts from the housing before derusting. Getting the bearing and packing assembly out was a pain, but other than that, it went pretty smoothly. Im just not happy about the rust removal from the inside and my rattle-can paint job. For me its not about the cost/effort. Actually, cost is a bit of a factor to a point. Personally, I want the experience of rebuilding/restoring this car to fine working order. I like working with my hands. I like tools. I like mechanical things, especially old cars. And, I like the knowledge and skills I have gained. Going back to cost, I can get the rebuild kit for $50 and am pretty sure that $150 was the rate that I saw for a rebuild. While the end result wont be perfect, it will be better than it was before and definitely functional. Also, as I said, I get the experience of knowing that I did it myself.

[Geoff Newcombe #4719]

A-HA!! And BINGO!!  Checkbook restorations are OK, but part of this hobby to me is LEARNING and the satisfaction of doing as much as you can yourself.

[Mike Josephic #3877]

Guys:

I certainly was not trying of offend anyone -- just offer a simpler method and my nickels worth of advice.  I do not
think sending out a water pump for rebuild is a "check-book"
restoration -- just a way of farming out some small items
that can take alot of time and by farming them out perhaps
can help speed things along.  I have done it both ways, from doing everything myself on one car to having a near total restoration done at a shop on another.  Therfore, I can see
both sides of the coin as it were.

I enjoy working on these cars as well, and my hat is off to those who have the skills and patience to do it all themselves.  Mike