![]()
Navigation
|
Billhooks and sickles
|
![]() Evolution of the sickle (Tresemer) |
![]() Scythe -- a highly evolved tool developed over millennia |
![]() |
![]() |
Iron and steel don't exist in nature in pure form and are not stable, quickly decomposing with air and moisture into iron oxide -- rust.
Badly rusted wood chisels ...
Steel tools that cut plants and bite into soil contact plenty of moisture and must be kept clean to prevent rust.
We've found biodiesel to be an excellent cleaner and lubricator -- unlike mineral oils, it's not toxic, ideal for organic growers. It protects against rust to an extent, but linseed oil gives better protection. Apply regularly.
Here's a good way to remove all rust from steel tools. We've used it a lot in restoring old tools deeply pitted with rust.
... cleaned with lye and electricity
You need an ordinary car battery charger, lye (Red Devil or any caustic soda -- sodium hydroxide) and a plastic bath -- a standard 25-litre plastic container with one side cut off makes a good bath.
Work outside -- the process emits some fumes. WARNING: Lye is highly corrosive, even though this is a weak mixture -- wear rubber gloves, keep clean water handy.
This old hoe is made of fine English steel, worth saving
Mix two tablespoons of lye with 10 litres of water in the bath. Attach the positive (red) terminal of the battery charger to a spare stainless steel kitchen knife or spoon and put it in the bath. Attach the negative (black) terminal to the rusted tool -- scrape some of the rust off first to make sure it makes good contact. Put the tool in the bath on a stone, not touching the knife.
Switch on the charger -- the rusty tool (and maybe the knife) should begin to send off streams of tiny bubbles. Leave it on for 24 hours. If it's a large tool, take it out after 12 hours and attach the terminal to the opposite end to spread the effect.
The hoe derusted, ready for re-edging
After 24 hours a lot of the rust will have flaked off, and the rest will have been converted to oily black stuff that can easily be scrubbed off in hot, soapy water. The tool emerges clean, all rust removed or converted, even into the deepest pinholes of corrosion.
Old Chinese logsplitter, folded and heat-welded by a blacksmith, crude but effective -- thoroughly cleaned by the electric treatment
Kevin Halgren wrote to explain the composition of the oily black deposit left on the tools -- and offered a better de-rusting method:
What you are seeing is the result of the electrolytic cleaning converting some of the rust, especially that most closely bonded to the surface of the iron, from conventional red iron oxide rust (Fe2O3) to black iron oxide, magnetite (Fe3O4). Because the red oxide is not truly bonded to the iron, the black oxide forms as a very fine film on the surface of the iron. The water and lye will combine with the magnetite in solution to give it the oily appearance and feel.
The electrolytic process can be performed equally effectively and more safely with washing soda (sodium carbonate, not to be confused with the very similar cooking ingredient sodium bicarbonate) instead of lye. Washing soda can be found in many stores near the clothes-washing detergents. I have performed electrolytic cleaning like you described with washing soda and have been able to safely place my unprotected hand in the solution and handle the iron while the current is live -- though I wouldn't recommend it because of the chance of a shock. But I can tell you that the solution itself is quite safe.
The electrolytic process, whether with lye or washing soda, generates hydrogen gas. That is the content of the bubbles coming off the iron. Ensure that there is plenty of ventilation so that there is no risk of explosion or fire. I usually do this outside.
-- Kevin
Appropriate technology
Appropriate technology resources
- Agriculture resources
- Wood resources
Blacksmithing
Wood fires that fit
Houses that fit
Water-powered water pumps
Journey to Forever and AT
- Chinese watering cans
- Handmade Projects watering can plans
- Hoe for victory!
- Billhooks and sickles
A better rat trap
- Rats and owls
- Chinese rat trap
- How to make a Chinese rat trap
- Bucket rat trap
Appropriate technology subjects
Community development | Rural development
City farms | Organic gardening | Composting | Small farms | Biofuel | Solar box cookers
Trees, soil and water | Seeds of the world | Appropriate technology | Project vehicles
Home | What people are saying about us | About Handmade Projects
Projects | Internet | Schools projects | Sitemap | Site Search | Donations | Contact us
© Copyright of all original material on this website is the property of Keith Addison, unless otherwise stated. It may not be copied or distributed without the explicit permission of the copyright holder. All material is provided "as is" without guarantees or warranty of any kind, either expressed or implied.