C3 Mini-Lathe Metalworking Beginners
It is important to anodise any metalworking you do with aluminium
Aluminium is a wonderful material to use in the home metalwork workshop. It is strong, yet light and easy to machine. It is an order of magnitude easier to make something from aluminium rather from steel. If we all used steel, we’d never make anything. It is very important to anodise almost everything you make in aluminium.
Because Aluminium is so easy to machine, it has one massive drawback. It is very soft. Whilst it is easy to score marking out marks and center punch marks with little effort on aluminium, the same softness comes to plague us after a while.
The softness of aluminium means that any nicely finished part soon becomes covered in nicks and scratches after seeing only short service. Some small but often handled part will soon pick up dings and scratches from every day handling. You can mark a nice finish on an aluminium part by simply scratching it with your finger nail. As soon as you drop it, or, more likely, bash it against some other part, it will pick up unsightly blemishes.
It is possible, with the application of a little elbow grease and sandpaper, to produce a fine and almost mirror finish on an aluminium part that we have made in the home metalworking workshop. As most of you know, this finish is extremely short lived. After a few days it will start looking knocked about and tatty.
Aluminium is a highly reactive metal. Over time, any finished part which is exposed to the elements will start to corrode. It will pick up a white coating of aluminium oxide, and look even more tatty and scruffy.
I always laugh at those books you read on home metalworking. The photos of parts are always superbly finishing and beautifully polished. We all know that this sort of finish lasts a few minutes. As soon as the part is handled, or gets knocked around on the work top, it starts to look poorly finished. By the way, what happens to all the swarf in those same photos?
Sometimes aluminium is just too soft. It is easy to tap a hole in aluminium to take a steel bolt. However, steel is much harder than aluminium, and if the bolt is often undone, it is only a matter of time before the thread cut in the aluminium starts to deteriorate.
All these problems result from the softness of aluminium alloy home metalworking materials. The solution is simple. Anodise. Anodising creates a thin hard coating on the aluminium that makes it impervious to scratches and dings. The finish is harder than steel. Almost glasslike. The sound of two anodised aluminium parts being knocked together is a joy!
Compare the parts on the right. The finished red part has been anodised and looks very nice, whereas the block of aluminium has been left in the garden for 6 months and has corroded badly.
Most people are scared of anodising. Pity. It is dead simple. All you are doing is dipping the aluminium part into some battery acid and attaching a car battery to it.
I have done a lot of home anodising of my aluminium parts and enjoy great success.
Another advantage of anodising is dye. You can use cheap commercial anodising dye to create fantastic colours on all your anodised parts. Anodising has two advantages, it makes things look pretty and it makes them hard and durable. No metalworking hobbyist has an excuse – you are a fool if you do not anodise the aluminium parts which you work so hard to create.
All images and articles copyright www.mini-lathe.org.uk
Hints and tips