Aluminium Grades

[HiltonSteve]

For flood coolant what about using a pond fountain pump like this one -

http://www.diy.com/diy/jsp/bq/nav.js...&isSearch=true

I bought one for leak testing a job we did for the m.o.d., just threw it in a bucket of water and left it pumping water onto a bearing for 2 days. Worked a treat! Plugged a hose pipe onto the top were the fountain attachment usually goes.

They have a flow adjustment built in as well.

Michael - I have one in my garage if you want to give it a go.

[Ross77]

That is a bloody good mister Kip, wonder how well a fuel injector would work with a fuel pump, They create a good mist. Easy to control coolant quantity etc.

Michael

Hi Michael
The fuel pump idea should work, A friend uses them on most of his machines. not used as misting though, just constant flow which is recirculated.

[John S]

Diesel injection pump isn't really suitable, the clearances inside required to get up to 115 bar to 280 bar - 1700 psi to 4,000 psi means the slightest lack of lubrication or grit and it's toast.

Going slightly off topic but whilst looking up these pressures which I had forgotten [ past life ] I found out that the latest diesel with high pressure common rail systems use pressures up to 2,000 Bar or 29,400 psi.

Home made water jet anyone ?

[John S]

They are even more fragile....Some reduce engine power and even cut the engine to "not" run out of fuel....kills the pumps.

Right, Didn't know that not had the pleasure of owning / running one of these our two vehicles are on the last of the mechanically injected engines with no brain etc.

Hate to loose this independence.

On topic I did tell Michael T6 machined OK

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[michael]

Right, Didn't know that not had the pleasure of owning / running one of these our two vehicles are on the last of the mechanically injected engines with no brain etc.

Hate to loose this independence.

On topic I did tell Michael T6 machined OK

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Yes you did mate!

Michael
:clap:

[Ross77]

How easy is it to cast alui. did it years ago at college but always ended up looking like an aero lol bubbles bubbles......

Do you need main gas? definatly interested in getting in to it.

Sorry to be off topic again

[Ross77]

I'd suspect your aero would have been caused by too wet a sand/clay mix (clay bonded brown sand?) if using petrobond you get none of that.


I'll be building 2 new furnaces this year, one for cast iron and another tilting furnace for Al.

I'll take some pictures and might break a habit and write about it :)

As for off topic....it's about Al so it's on topic [/quote]
:clap:Yeah it was a brown sand and i seem to remember it had to be preety wet to retain the shape, Cheers! the poor finish has always put my off doing it again, but like you said the posibilites and time saved in milling from billet would be well worth the effort.

Look forward to the pics and demo.

Are alloy wheels a good supply for melting down?

[HiltonSteve]

I feel a need to share some of my experiences with cast aluminium, this will be only personal views, not aimed at anyone or trying to spoil anyones fun in trying to make your own as I am all for having a go at something and f@&king it up and trying again as sometimes this is the best way to learn!

Cast aluminium will always be full of aero holes, I once tried to water cool a vacuum forming tool that was made out of 20 chocolate box female aluminium castings which were cast by a foundry that specialized in aluminium. After 40 hours of drilling 1mm holes and then linking all the holes by back drilling the castings then free hand milling all the tracks to link the holes and then mounting them on a nice solid 1" aly plate found out that after I had water tested it that I had made myslef a very expensive and very large water sprinkler!

Threw it straight in the scrap bin and started again, tried it a couple of times again with different grades and methods of cast aly with same results. In the end I gave up and watercooled the 1" extruded aly back plate by drilling and plugging, never bothered with water cooling the castings again.

Personally I don't think you can cast ally without aero bubbles, I may be wrong but would take a lot of convincing!

By the way just bought some T6 aly plate today - £39.70 for a piece of 550x300x20mm. I have not had the fun of making it but can have more fun machining it and for £40 I know what I would rather be doing.....

Still interested to see your results though.

[HiltonSteve]

Aw crap....my cylinder head on my car is Al.....And the casting for the Xcalibre hydraulic drill handle I did last year is doomed...@ 120Bar too ....Hand held

Nice cheap piece of plate!

Heat treatment and temperature control all play a part in casting Al....What was the structure (crystalline) of the Al like?

I see "Ali" and "ally" but the periodic table has it as Al.....shorter too :)

Like I said, inetrested to see what people results people get, not saying I'm right or wrong as nobody ever is!

Ali, ally, al who gives a f$ck, what do you expect after drinking a bottle and a half of wine.

Good point about the cylinder head though, never thought of that one before....

[John S]

I think is down to method.
Just sticking a few lumps of alloy in an old pot, melting it and pouring into another old pot will get you anything, good bad or indifferent.
For a start iron is soluble in molten aluminium and the gasses cause bubbles.

You also need ge gassing tablets to throw in that cause all the dross, shit , crap and German routers to come to the top so it can be scooped off and thrown at next doors cat.

Material also plays a part just because you stuff one grade in it doesn't meant you get that grade out as it changes in the melt.
professional smelters melt a charge, run a test to see what's in it or more important what's missing and then lob in ear of bat, tongue of newt to make up.

Things like pistons when melted contain most of the original metal plus carbon from the burnt oil and deposits which doesn't help, clean alloy is hard to get in quantities.

One of the best grades is LM25 which is available in ingot form but rare to find as scrap items, when heat treated this is closed grained, machines nice and can even be bent slightly proving how ductile a casting can be.

Unfortunately to make good casting it then becomes another hobby at the expense of others.

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