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Thread: Cast Iron
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25th Apr 2011, 10:18 PM #1
Cast Iron
Hi All,
I'm upgrading my furnace to be able to handle cast iron, what I'm wondering is what is the way of identifying suitable raw material for casting... we have a pretty good local scrap dealer, but they just call everything cast iron.
I'm aware of the following grades.
Grey Iron 2P A grey cast iron exibiting good strength and wear resistance
Ductile Iron 3D A speroidal graphite cast iron that possesses high elasticity and resistance to impact. Suitable for applications involving thermal and mechanical shock.
Grey Iron 4E A free machining grey cast iron, not suitable in applications where surface wear resistance is required.
My question is, what's the best way of identifying a bit of unknown cast iron?
The way it breaks? Maybe filing a corner to see how it files?
Regards
Ray
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25th Apr 2011, 10:24 PM #2Dave J Guest
Hi Ray,
I think the person to speak to would be Rob Wilson that joined here a little while ago and is also a Mod over on Madmodder.
He is experienced and does his own castings often.
Dave
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25th Apr 2011, 10:34 PM #3Dave J Guest
Here is his new furnace.
New Furnace Build ,,, Cupola
Dave
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25th Apr 2011, 11:42 PM #4
Hi Dave,
Thanks for that link, that's a forum, I've not spent much time on, that cupola looks like a good project. There's a guy down Gippsland somewhere that fires up one of those every so often.. I'd just get a bit edgy with so much molten iron on tap...
Regards
Ray
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26th Apr 2011, 12:07 AM #5Dave J Guest
I think you will find he will answer your questions. He has always been really helpful to everyone.
Dave
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26th Apr 2011, 12:24 AM #6Most Valued Member
- Join Date
- Oct 2010
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- melbourne, laverton
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- 1,910
you could always do a spark test. that will identify them for you. each one will have a different spark.
if you cant find the info on here i can send you a photo copy
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26th Apr 2011, 12:37 AM #7Most Valued Member
- Join Date
- Jul 2010
- Location
- Melbourne
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- 9,088
Ray,
One idea I came across while reading up on this sort of thing was to use scrap of the same sort of thing you want to make. Of course this wont always help.
I wonder how much remelting, degassing etc will change the cast anyway? So of the books I have read talk about adding some of this or that to make up for what you loose.
Good luck with your casting, keep your feet out of the way.
Stuart
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26th Apr 2011, 02:00 AM #8
Hi Stuart,
Thanks for that, I plan on going scrounging at the scrap yard later this week, from what I remember from the last time I was there, a lot of the cast iron scrap was old farm implements and broken cooking pots. I'm hoping to find that there's an old cast iron mill/lathe or similar with cracked castings
Hi Azzrock,
Thanks for the tip. After a bit of googling I found this info on spark patterns for different types of cast
Handbook-Appendices
Regards
Ray
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26th Apr 2011, 02:05 AM #9
I'll post the spark test information here, others might find it handy
From: Handbook-Appendices
Regards
Ray
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26th Apr 2011, 02:11 AM #10Dave J Guest
Thanks for that Ray, I will file it away for future use.
Dave
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26th Apr 2011, 07:31 AM #11
Hi,
Theres four groups of basic CI but you probably are aware of them by now.
Grey - cookwear and general cheapy stuff
Ductile - SG nodular graphite iron Holden crankshafts - from 179 on I think
White - Very hard and brittle-Impeller wheels and that sort of application
Malleable - Some plumbing fittings were made from it...
The grind test should be ok if you don't have a electro static spectrograph handy but you will have to watch out for stuff like :
Meehanite iron which is a process thats applied to diffrent grades of cast iron making some of it unsuitable for recasting.
Its applied to some high quality machine castningsfor rigidity and lack of warping.Some brake hubs too are also Meehanite,
heres a good read about it
Meehanite and the unflat table......
I also have a book from Mars machine tool company in Brisbane solely written about Meehanite metal,of which there are 6 sub types.
Just as an interest ,what will you produce ?.
Maybe lathe cross slides that have the tee slots unlike my metal master lathe which does not.
Cheers
Grahame
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26th Apr 2011, 09:55 AM #12
Hi Graeme,
No I wasn't all that aware of the 4 different types, thanks for that. I'll do some reading up on meehanite.
I'll dig out some pictures tonight of the patterns I'm casting.
Regards
Ray
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26th Apr 2011, 10:49 AM #13.
- Join Date
- Nov 2008
- Location
- Perth WA
- Age
- 71
- Posts
- 6,458
Shame I haven't saved all my 4E swarf for you over the years Ray. I buy my steel and cast bar from Bohler Uddeholm's Steel Store over here. They have a skip filled with bar ends. Most are colour coded. Something 4 inches long might be scrap to them but real useful to me. Could be a source of identifiable iron for you.
I am looking forward to the pattern photos.
There is something about casting that has a visceral, primeval appeal. As a kid my alltime favourite thing at the Perth Royal Show was to visit the WAGR pavillion. They had foundrymen casting in aluminium. The smell of the sand and the molten metal is still with me nearly half a century on. The closest I got to it was melting lead on Mum's stove for which I received a good belting. The lead had been indiscreetly removed from the chimney flashing!
Bob.
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27th Apr 2011, 02:32 AM #14
Hi Bob,
I've been down in Melbourne for the day, following up a friend's tip-off of a factory clearance.
There was some nice stuff, that I'll put in a seperate post when I get organized. A big saw doctors anvil, numerous specialist saw doctors hammers, a fly press, and a nice Parkin belt grinder. Plus a few choice odds and ends.
These are the parts I'm going to attempt to cast, they are the parts for the HM52 cnc Z axis quill conversion.
And this picture shows how the bits will go together.
Since the original design, I've got a few modifications to the patterns that I'll make before casting.
Late night, long trip in the ute loaded with heavy machinery.. very happy to finally get everything home in one piece
Regards
Ray
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30th Apr 2011, 04:57 AM #15Most Valued Member
- Join Date
- Oct 2010
- Location
- melbourne, laverton
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- 1,910
a quike guide
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