Cleaning Block Waterways

[Martin Baker]

I am having to get a block re-bored following the seizure of the engine in our Pearl on the way to David Nightingale. I thought I would take the opportunity to de-rust the water jacket. I am considering using  Bilt Hamber - Deox-C. Does anyone have any experience or alternative suggestions?
Martin

[Charles P]

My solution is a sodium hydride bath. Not a domestic process but very, very good.
These people do it
https://lentontreatments.co.uk/

[Dennis Nicholas]

I have used the Deox-c. It works well removing all corrosion.  The solution can be used again and again untill it no longer works - check with a small rusty off cut.  I think that using a strong solution rather than a weaker one would be best.  It took several days to get my bits cleaned up enough and as suggested fairly frequent agitating helps as well as scrubbing the surface with a wire or other brush to remove the black deposite from the chemical action to reveal shiny clean surface.  You can make up enough solution in a large enough plastic bowl to put the whole block in fully immersed which would do the outside as well. Once satisfactorily cleaned the piece can be just washed off with clean water. The bottle of powder goes a long way, making up lots of solution.
Several members of my Reliant Scimitar club have also cleaned out their V6 3litre engines and radiators using neat Coca-Cola, but of course it is not re-usable afterwards  .
During use the solution gets progressively blacker.  With more gentle use on something not too badly corroded the remaining solution can be drained through a filter (coffee filter) into a container for storage till next needed.

 Th

Dennis

[Dave Mann]

Be aware that Deox C does remove a small amount of parent metal and I make sure all threaded holes have greased studs fitted and I do it with the old valve guides in and yes it does a good job. The last one I did with the head on and and pumped circulation    

[Chris Garner]

Lenton Treatments are a +1 from me. Excellent company. Used by many vehicle restorers including one of our own.

[Nick Lettington]

I took a suggestion from this forum and used oxalic acid.

The COSHH sheet made interesting reading!

[Chris KC]

I've used citric acid before, with reasonable success - it's readily obtained in powder form for de-scaling kettles etc.
Perhaps slower, but a lot less nasty than oxalic.
As some trace will inevitably remain after flushing, it may be wise to neutralise it with an alkaline rinse.

Nowadays I'd be inclined to use a professional service, such as Lenton suggested above.

[dickie65]

I have always found Oxalic acid to be one of the milder ones to use.
I have never tried to use it on car parts but have used it on boat timber work and GRP hulls for years.
I get it in a tub from my local GRP suppliers although my last tub went to work as they needed some to use on some Titanium.

[Parazine]

Anybody tried Acetic acid? 

Reasonably easily available and not too aggressive for home use I guess.

[JohnD]

a short length of curtain wire, bicycle brake cable outer with the plastic off it or similar poked about and connected to an electric drill will knock off some of the flakey hard to get to bits between the cylinders