David, from the classic 1986 movie, had Max (the alien AI spaceship) attempt filling his brain with starcharts. When David asked how the experiment had gone, the answer was the same as an issue I had with the shed in today’s beating rain. It leaked.
To be fair, the vast majority of the shed was fine – such a relief not to be ankle deep in a river as was the (exaggerated) case from the previous shed. That one needed the ShopVac to suck as much of the free water up so it didn’t start lapping around the base of the tools sitting on wheeled bases.
The leak today was no more than a puddle forming on the floor of the mezzanine, directly under one of the windows in the eaves – rain was getting in around the rubber seals of the glass. Not ideal, but with a bit of glazier’s silicone, should be pretty easy to rectify. If that is the only leak I ever have to experience, I will be happy.
At least nothing was raining on the cast iron tools – I’ve had enough dealing with rust on tools. Tried some Killrust Rust-Eeter (sic) the other day, and although I am sure it did a good job in converting the rust, it is only suitable as a product when intending to paint over the surface afterwards. It left the surface completely black, as if it had been painted (which effectively is what it was).
It didn’t work as I was hoping – I just wanted to convert rust back to raw metal, or use something that cleaned rust off. Both on large surfaces, but also something I could set up as a bath to immerse smaller tools in to clean rust off.
Does anyone have a good product for doing this? I have some old tools that really need some of that TLC.
Filed under: Techniques, Tools | Tagged: Rust |
Stu's Shed 
Hi Stu. This stuff http://www.evapo-rust.com.au/ has good reviews for a bath but don’t think you can use it to wipe down larger surfaces. Have you used Top Saver for this?
I resorted to TopSaver just to get the surface I was working on back, but it isn’t for really rusted items I don’t think – better as a light restore and conditioner/protector.
I found Evaporust to be OK but expensive. A better alternative is “Electrolitic Rust Conversion”. I’ve used it to restore some vintage Stanley planes and the cast iron table from a vintage band saw to working order.
There are heaps of How To articles on the web (e.g. http://www.instructables.com/id/Electrolitic-Rust-Removal-aka-Magic.
Basically – A plastic container of suitable size filled with a mix of water and washing soda. A sacrifical steel cathode (or is it anode – forgotten which) in the plastic container. Place the component to be derusted in the plastic container – ensuring the it doesn’t touch the sacrifical plate.
I suspend my parts in the container.
Connect up a suitable DC power supply. Most people use a car battery charger. Caution- my modern battery charger has smart circuitry and whould not apply current when it detected not residual battery voltage. You need an older or cheaper ‘dumb’ battery charger. I ended up recycling and old 18 VDC 2.5 amp Laptop Computer charger. It works great, but for parts with larger surface area, the current flow will be higher, and you’ll need a bigger charger.
Caution: make sure you get the polarity right!. If you get it wrong, you will derust your sacrifical plate and destroy the tool you are trying to derust!
The process only attacks rust. It doesn’t attact clean steel or non-ferrous metals. The cleaned part will have a soft layer of black coating on it after the de-rusting. The blackcoating is the carbon that was in the rusted steel. Just scrub it off with scotchbrite. Make sure to protect the newly de-rusted surface with wd-40 or similar to prevent flash rusting.
Last caution: the electrolisys process causes hydrogen and oxygen to out-gas. Ventilate the area well at all times, etc. We don’t want Stu’s new shed to become Stu’s Hindenberg!
Maybe this would be a good topic for a StusShed video.
Regards,
Roy
Catalytic bath – that sounds like the best option. And more interesting to boot.
Stu’s Hindenberg – why does that sound vaguely tempting?!
I recall White Vinegar (acetic acid) being use as a soak treatment for Rust – it will help loosen rust but will need a scrub after treatment as well.
Also see (not that i have tried any of these) http://www.wikihow.com/Remove-Rust-from-Metal
Many of the commercial rust converters seem to be basically concentrated phosphoric acid and will convert rust to the black colour you have already mentioned. They work by converting the iron oxide to an iron phosphate which is relatively stable. The only way to get back to bare metal is abrasive of some kind. These can also be used for the soaking of small parts.
Interestingly the rust eeter MSDS/SDS suggests it is not based on this ingredient.
There is black, and there is a painted coating – Rust Eeter seems to do both, which is not what I am looking for. Happy to scrub off carbon. Not so keen having to scrub off a paint-like surface!
I think in this case your coating is at least partly rubber which is one of the ingredients in the rust eeter (with the rest of the ingredients seeming to be largely solvents) – hence the appearance of a painted surface. The black in the case of the phosphoric acid treatments is different in that it only appears where the rust was.
That’d make sense- I was expecting black where there was rust, not the whole surface.
Citric acid
available from your local supermarket
works well