Thread: Do I have to paint cast iron bench to stop rust?

With cast iron there's a good chance that it will rusr a bit then no more,can be a good look,let it go and see how you like the finish,if not there are plenty of "stop rust "type products around.

Hi Vegemitegirl,
Wow, cleaning a cast iron bench seat with a dremel has got to be some sort of herculean effort, I shudder to think how many of those little brushes you went through.

Unfortunately WD-40 won't help much, you can try something a bit more durable like Inox or one of the lanoline based products but even that will only delay the inevitable.
I know of old engines that stay clean by being constantly soaked in oil but that is probably not all that useful on a seat unless you never plan to actually sit on it.

Probably the only thing that might work is to spray the seat with a clear coat laquer.
It might be worth a visit to your local paint shop and check with them.
Cheers,
Greg.

You could let a light film of rust develop - shouldn't take long - then paint with a phosphoric acid-based rust converter. Lots of different ones around. One example is Wattyl Rusteater. This will convert the rust to a dark, hard surface, sort of purpley-browny-black. It's not really meant to be a finish but seems to hold up pretty well.

look into these three brands they may help you sweetie... por15, kbs,3m rust

you wont ever stop cast iron from rusting, it's in the structure of the iron it's self, think of it this way, when you have pits or holes for water to sit in wether it in the form of condensation or water as we know it cast has all the poperties that attract and holds moisture. try and polish cast, you never will get a mirror finnish, the structure of the molecules will never allow a mirror finish, so in saying that to acheive a finish that will never rust you need to clean it and remove all atmospheric impurities ( most particles carrie some degree of C02) and finish it in an environment that depleets it off all oxygen.never the less, you can't polish a pourous rock.

i would say its a pipe dream and that you should embrace the beauty of the ageing cast.

Well said Kraits,you put into words what I said earlier but much better

Do you intend to sit on it or look at it?

If you can heat it up (no wooden bits), you can wipe it down with linseed oil at the stage when it is hot enough that the oil smokes (not so hot that it bursts into flames) and the oil will effectively bake into the porous structure of the iron - that will work if its kept out of the weather. You can also melt parafin (modern candle) wax on, similarly to linseed oil mentioned above, which will give an even more durable finish than linseed oil, but it tends to look plastic.

You have two options to keep rust at bay on cast iron - paint it with a clear finish, or paint it with an opaque finish.

Probably the most durable clear for a cast iron would be an automotive lacquer, but that will end up as a gloss coat (I'm not sure if you can get them in a satin finish, but you can probably fake it with a few dry coats). Clear finishes break down faster than opaque ones, so you may only get a few years protection before needing to repaint

After that, you are looking at a black or steel grey colour in an epoxy paint like Killrust, which you can get in a satin finish.

If you want to be really different, you could try one of the industrial micaceous iron oxide finishes that'll make it look like the harbour bridge.

You could paint it with penetrol

The Flood Company Australia » Paint Additives » penetrol