one shot drain cleaner - de-rusting

[JonE]

do you need to heat the molasses solution to let it disperse, or will it naturally do it over time?

[Howard Wright]

Hi Jon

Just naturally over time but it doesn’t work as well over winter. 

I went to our local agricultural suppliers and bought a huge horse feeding bucket.  The molasses is about £8 for 5 litres again from the agricultural supplier (horse feed!). Dilute it 9 to 1 with water and put it somewhere where you don’t mind the smell!  It tends to go mouldy (surface crust).  In the summer it took about 3 weeks to strip a wheel to bare steel.  Make sure you wash thoroughly and dry quickly before painting as surface rust tends to form.

Cheers

Howard

[Parazine]

Here are before and after pics from the Top Hat engine electrolytic de-rusting:

Block before:

   


And after:

   


This bucket of sick is actually the electrolysis bath working:

   

The head came out like this (no before I'm afraid):

   

[JonE]

out of interest, did you find that you got "pores" on the dressed face underneath the head, or did you reface anyway?

[Hedd_Jones]

https://www.constructionchemicals.co.uk/...NDEALw_wcB

[Bruce Nicholls]

I use oxalic acid to clean the rust stains from anchor chains etc off our boat deck. Can vouch for its efficacy.

[Parazine]

out of interest, did you find that you got "pores" on the dressed face underneath the head, or did you reface anyway?

Hi Jon, no the uncorroded metal comes out of the bath just as it went in!

[JonE]

Oxalic axid users - I'm gradually getting up to the right strength to use. Hedd mentioned that it leaves a nice grey colour when its finished working.
A few questions for chemists:
1. will the oxalic-ised (grey areas) have any more protection than over bare steel, for new corrosion?
2. The solution appears to make a greeny yellow - almost lemon - coloured dust/slurry which presumably is the byproduct of the iron oxide.
If this is removed by settlement, should the remaining solution still be the same strength as one started with?
One wants to be as efficient as possible with the stuff, just for what one throws down the drains or onto waste ground...

[Bob Olive]

I'm with Parazine on this topic, the electrolytic system using washing soda is as safe (and as cheap) as it gets. One solution will last for ages, years even, with just top-ups of water and a quick scrape of the scum off the top. You can't overdo it, so you can leave it for hours, days or even weeks in very difficult cases, though I have never had to. Just try it...

[Robert Foreman]

Parazine and Bob, 
    what ratio of washing soda to water do you use?