Best carbon removal methods?

Technical questions and Maintenance advice post in here please
Post Reply
User avatar
Demetri
Posts: 41
Joined: Fri Oct 07, 2016 8:27 pm
Location: Nicosia, Cyprus

Best carbon removal methods?

Post by Demetri »

Ok, this might be a newbie question, but I'll ask it anyway as the carbon buildup behind all four of my inlet valve seats it's incredible. It consumes the valve stem in two of the ports, to the point that you can only see a hole. My cylinder head is on my beach and completely stripped down.

Before you shout at me, I HAVE researched this question both on here and on Google, and everyone seems to have their own methods and solutions. I am not concerned with damaging the paint because it is going to be repainted anyway. I was just wondering what the general consensus would be here..... amongst friends :wink:
Image
1956 A30 Countryman
* 1 owner - recovered from dry basement where it sat for 30+ years *
Dave Clark
Posts: 5896
Joined: Mon Apr 21, 2008 1:00 pm
Location: High Wycombe, Bucks

Re: Best carbon removal methods?

Post by Dave Clark »

Caustic soda - but be very careful with it and wear gloves and eye protection/
User avatar
Demetri
Posts: 41
Joined: Fri Oct 07, 2016 8:27 pm
Location: Nicosia, Cyprus

Re: Best carbon removal methods?

Post by Demetri »

Dave Clark wrote:Caustic soda - but be very careful with it and wear gloves and eye protection/
It dosent damage the metal at all? Do I submerse it in a bath of Caustic Soda?
1956 A30 Countryman
* 1 owner - recovered from dry basement where it sat for 30+ years *
User avatar
Demetri
Posts: 41
Joined: Fri Oct 07, 2016 8:27 pm
Location: Nicosia, Cyprus

Re: Best carbon removal methods?

Post by Demetri »

Has anyone tried Methyl Chloride Paint Thinners?
1956 A30 Countryman
* 1 owner - recovered from dry basement where it sat for 30+ years *
Alan
Posts: 3511
Joined: Sat May 23, 2009 5:10 pm
Committee Role: A30 Registrar
Location: Surrey/West Sussex

Re: Best carbon removal methods?

Post by Alan »

I used brake cleaner.
Modified 1963 AV8 A35 Van
Modified 1972 Rover P6 3500s

Austin A30 Owners club registrar
User avatar
Demetri
Posts: 41
Joined: Fri Oct 07, 2016 8:27 pm
Location: Nicosia, Cyprus

Re: Best carbon removal methods?

Post by Demetri »

Alan wrote:I used brake cleaner.
I tried that but it wasn't so affective... maybe because of the 50 years of thick crud :|
1956 A30 Countryman
* 1 owner - recovered from dry basement where it sat for 30+ years *
User avatar
gazza82
Site Admin
Posts: 5585
Joined: Sun Nov 24, 2013 3:39 pm
Committee Role: WebEditor
Location: Buckinghamshire
x 2
x 17
Contact:

Re: Best carbon removal methods?

Post by gazza82 »

Chip most of it out with an old screwdriver or similar. Small brass wire brush in a drill?

Given the amount and it will respond better to chemicals if there is less.
"If you're driving on the edge ... you're leaving too much room!"

Club WebEditor.

Cars: "Project 757" '59 A35 2-door bought in 1971 & Subaru BRZ SE LUX Auto plus "family fleet": Alfa MiTo, Peugeot 206, (Ex '98 Alfa Romeo 156 2.0 TS)
Dave Clark
Posts: 5896
Joined: Mon Apr 21, 2008 1:00 pm
Location: High Wycombe, Bucks

Re: Best carbon removal methods?

Post by Dave Clark »

:iagree: Then immerse in caustic soda

Never go anywhere near methyl chloride. As far as I am aware this is now a banned substance in the EU.
User avatar
Demetri
Posts: 41
Joined: Fri Oct 07, 2016 8:27 pm
Location: Nicosia, Cyprus

Re: Best carbon removal methods?

Post by Demetri »

OK... well the oven cleaner didn't do a thing... I tried reverting back to scraping it off with a screwdriver, but it's hard as a rock... so no go. I tried soaking it in diesel, heavy duty degreaser... couldn't find any phosphoric acid in the shops, or lacquer thinners...

So now its sitting in a vat of caustic soda solution. I haven't a clue of the required ratio, but judging by the fact that the solution only got slightly warm i'm guessing I need more soda crystals. Neither am I sure how long I'm supposed to leave the cylinder head immersed before any damage is potentially done.

My ratio was 15 litres of water to 1 kilogram of caustic soda. I poured the crystals right into the ports as it was laying with the machined surface facing up. Let's see if it does anything by tomorrow... :roll:
1956 A30 Countryman
* 1 owner - recovered from dry basement where it sat for 30+ years *
User avatar
Demetri
Posts: 41
Joined: Fri Oct 07, 2016 8:27 pm
Location: Nicosia, Cyprus

Re: Best carbon removal methods?

Post by Demetri »

One day later and there's not a great deal of action taking place... it didn't even dissolve the WD40 that I'd sprayed it with after I washed it. Which makes me wonder if caustic soda even affects mineral deposits at all.

Anyway, I placed 3 house bricks into the solution to decrease the volume of liquid, poured the excess away to just above the cylinder head, and poured another 2kgs of soda crystals directly into the ports.

I'm not sure how long it's supposed to take, but if i don't see any progress by tomorrow, I might try dropping it from a very high building... :roll:
1956 A30 Countryman
* 1 owner - recovered from dry basement where it sat for 30+ years *
Post Reply