    
Bob UK
Unregistered guest
Posted From: 94.197.122.86
| | Posted on Friday, 09 January, 2015 - 09:50: |    |
I love working with brass, it's a shame that more brass is not used on cars. It's so easy to machine and it solders well and gives strong joints however brass has its limitations.
Brass is not as strong as steel and heavier than aluminum. So one must be careful where it is used.
Machining is easy it cuts fast will high speed steel tooling. Brass likes normal water soluble cutting oils. Brass is kind to SHARP tools. When machining brass the swarf splinters and flys so goggles is best.
It files easy, use blackboard chalk on the file. To get flat surfaces truely flat it's easy to scrap.
Brass also polishs well and is about the easiest metal to polish. It is also the best metal for chrome plating.
I can machine and polish steel and because steel is harder it will polish with more effort even better than brass but the oxygen in the air is trying to oxidize the steel as is being polished and within hours it's degrading. Even a fingerprint damages it.
Brass is different it polished fast and stays like it for days. It then oxidizes which protects the brass and gives it a dull bronzy look which looks ok, but a quick splash of brasso and it's shinny.
I keep any bits of brass, some of the bits for a boats electics were made from a brass door handle.
For stuff like electrical distribution boards brass is simply king. Brass holds screw threads well especially BA threads which are designed for brass. Do not use soldered joints on things like buzz bars.
Brass casts well. Old brass plumbing fittings work well.
A way of casting brass is to make a pattern allowing for shrinkage from hard candle wax. Then dip the wax pattern in ceramic slip many times until it's nice and thick then dry it then fire the pattern and ceramic together the wax burns off. Then with the ceramic mould still hot pour in molten brass. Allow a few hours for cooling then break the ceramic mould. Instance brass door handle for a 40hp RR. This is called the lost wax casting method.
Other ways if a lump of brass is need for machining is and open mould made from ceramic (clay) This works well with plumbing fittings. For details Google it.
I have seen some smashing stuff made from brass.
Bearings and bushes.
Brass is very good on light stuff like a bush in a wiper motor. But there is brass and there is brass, some brasses such as plumbing fittings are good for handles and electrical but make poor bearings. I wouldn't for instance make a gearbox bush from plumbing fittings. I would get phosphor bronze or sintered bronze.
Brass is a very useful material. It's also an immortal copper based alloy.
Note the word alloy is misused to describe aluminum alloy. Most metals used are alloys. Alloy means a mixture of two or more metals. Solder is an alloy and so is steel. Copper and gold are common pure metals. Ironically aluminum isn't an alloy unless mixed with an another metal.
Ironically also so because cast iron is an alloy.
(Message approved by david_gore) |