[SEL] Re: Electrolysis - Summary of Responses

[Peter A Forbes]

Thanks to everyone who replied on and off-list, the information has been really
useful, especially the personal experiences with different electrodes etc. I
have condensed the replies here for brevity:

The stainless steel electrode question seems to be significant, and Orrin's use
of Graphite looks to be a good way of going if the cost is not too high for
coninued usage. I do remember the discussion about Chomates on the Lists, and
will steer away from that method.

Power requirements seem to be very modest, with pretty much any small DC supply
being suitable, and current draw depending more on distance between the anodes
and objects being descaled than almost anything else.

Electrolyte seems to last well, only water loss through electrolytic breakdown
and evaporation being noted.

Disposal of the remaining electrolyte looks to be fairly easy, I have checked
with our own local water authority and there is no problem with just soda
solution as long as any metallic solids have been taken out.

Paint and grease removal surprised me a little, but I assume that the
electrolysis gets at rust underneath these deposits and loosens them off, rather
than the solution/process getting at them directly?

Speed of rust formation after rust removal has been quoted as a problem, and
Sodium Silicate mentioned as a solution. More information on this would be
appreciated.

Craig Matthews made the following comment:

"One note, make sure there is no other metals in the solution besides cast iron,
steel or sheet metal, brass, copper, aluminum and babbit will stop the process
and make a mess (from experience) "

That is a bit ambiguous :-))  I read the intended text as: "Nothing but Cast
Iron or Steel" ?  If not, could Craig correct the punctuation so it reads
"right" please?

Andy Nicholson used a 28V supply, running at about 6amps on his setup, and Bill
Dickerson's trailer chassis example on his website used an 80V welder power
source, so voltage is not too critical. Use of excessive current just warms up
the solution and causes more gassing, with no apparent increase in the rust
removal rate.

I think that covers most of the points made. 

Thanks again guys, if there are any more items that we need to know about,
please let us know.

Peter 
--
Peter & Rita Forbes
Email Address:
diesel at easynet.co.uk
Web Pages for Engine Preservation:
http://www.oldengine.org/members/diesel