The International Hobby Metal Casting ezine.
Brought To You By:
Col Croucher, administrator of: www.myhomefoundry.com
Australia.
Number: 83 October 2010.
Hi Fellow Metal Caster.
We are staring down the short barrel towards the end of the year, it'll roll around quicker than we think... time to get a move on and finish things before Christmas arrives.
Speaking of which, hows the projects going that you began at the beginning of the year? Have they all panned out for you the way you had hoped for?
With the big numbers of our ebook clients now spread around the globe, I often wonder how everyone is getting on, a big thank you if you have emailed some project photos to us... we
really enjoy learning about your progress & success.
To some people the metal casting craft comes easy... but to others, it's a bit more of a mystery, which means that more practise, learning and understanding is required about foundry work before the ah ha moment finally arrives.
Welcome to the new guys from South Africa, Europe and other far flung places around the globe, some of the foundry supply houses must wonder what the heck is going on at times with all of the new hobby casters now sourcing & looking for foundry supplies.
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Technique For Preserving Old Tools.
From: Tim Eggleton. Australia.
Message:
If you would like to long term preserve old tools I would suggest that you clean and polish them with steel wool and then dip them in molten paraffin/Candle wax. Unlike oil, waxes will not oxidise causing further decay. I have tools that are 200 hundred years old that have been preserved in this way & they still look brand new.
Thanks Tim for the tip.
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Big Steam Engines - Thousands of Hand Made Patterns - And It's All In Western Australia.
While visiting Western Australia back in May, one of the highlights was the visit to Yarloop Steam Workshops. This was purely a chance visit as the tourist signs out on the road don't really tell the while story to the casual passer by... but I am glad I made the effort to take a look.
The place was practically deserted on the day we visited... Entry was only $8.00 and you then step back many many decades to another era, there is far too much on display to describe it all here, but you can look at the photographs below to see what we mean... if you love foundry work you'll love to look around this place, if you are a died in the wool steam buff you will love the giant steam engines even more, they have engines that are fully restored and working, and others that are still under restoration.
The Yarloop workshops have a special day each month where the team fire up all of the old engines and run them for the public to relive a bygone era, there is something special about watching and listening to steam engines run... it matters little if they are miniatures, or big thumping & hissing giants, they can be quite mesmerising.
Read & learn more from the photos below.
You Do?
So What's Stopping You?
Now Is A Good Time For You To Make The Move.
But First You Gotta Learn The Ropes.
And You Can, Simply By Going Here.
Hand made timber foundry patterns.
Inside view of the Yarloop
workshops, with an old steam train and other workshop machines once
used for
rebuilding and manufacture of new parts.
The shear size of the machines can be visualised when you
see how small the rail carriage wheels look, the face plates/chucks are
over six foot in dia.
The two old flat bed lathes positioned along the wall
measured about 25" in length... a bit on the large size for the hobby
machinist!!
A bevel gear
& straight cut gear captured by soft window light, green sand
casting was all they used in the workshops to pour bronze & cast
(Grey) iron.
A steam engine under restoration, not sure of the make, a
dedicated team of steam enthusiasts work most weekends on these
projects.
Restored steam engine, the result of many hours of dedicated work &
team effort.
A wall of patterns, some of the thousands stored at the
Yarloop workshop & museum.
The Yarloop workshops, a big surprise
awaits the visitor, it is an adventure being transported back to
another era. To the first time visitor the workshops look like everyone
left on the Friday afternoon and never returned on the Monday!
Interested in making a large quantity of charcoal?.... I still use a small amount of charcoal, it is terrific fuel, but making it is hard work tp produce and it generates lots of smoke... don’t try making it in your back yard!! Check this link out below.
http://www.aussiebbq.info/wp/aussie-charcoal-from-riverina/#more-99
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Adding Strength To Aluminium Castings.
You may have read in past ezines that we manufacture various hard to get parts for little old English cars, well the other day we were casting a batch of door hinges and decided to experiment with the alloy mix.
The parts in question, have in the past, been cast from metal sourced from discarded aluminium cylinder heads, these cylinder heads are pretty big, they come from an Australian made straight si engine, the cyl heads do need to be cut up into small chunks in order to melt and pour into ingots... a bit of work involved, but hey, you should see the awesome quantity of metal they produce!
Anyway back to the subject of adding tensile strength to aluminium castings. While melting some scrap the other day I came across several old aluminium bicycle pedal cranks, chain wheels, seat pillars... old bike stuff that's not much use any more (My youngest son and I used to be involved in the road racing scene) the parts are left overs from a hectic sporting era... I still enjoy road riding purely for fitness and getting out in the fresh air... the best sport on two wheels!
Anyway, I decided to cut the worn out components up and throw them in the crucible furnace to melt for scrap.... after pouring the melt into the ingot mold and letting them cool, I discovered that this alloy was quite different to the normal head scrap I melt... for starters, it was a helluver lot more difficult to break and it had a high pitched ring to the metal when suspended and tapped.
So then I thought... why not put a small percentage of this high-grade alloy in the with the door hinges I was about to cast... no harm in trying I thought. The new ingots were melted under a skin of coverall 11 flux, then just before the pour, the melt was degassed with C19 Nitril compound, this stuff makes the melt bubble & froth like a witches brew in a cauldron... caused of course, by the gasses and impurities being expelled.... don’t let anyone tell you that degassing aluminium is a waste of time, if you compare degassed metal with non degassed there will be a vast difference in the quality produced... but then again, if the casting is just an ornament, or art casting and does not require great strenght, then there's probably little point in degassing.
As it turned out, the door hinge castings were of excellent quality and after some simple heat treatment, they were machined and finished ready to be shipped to the customer back in the UK...like selling coal to NewCastle as we say here in Aust.
You may ask the question, was the added strength worth the effort? the answer is yes, it was, and there was a significant difference to the quality of the metal.
A Cheap Source Of High Grade Metal - (Duralumin).
So if you want to find a cheap source of Duralumin... head straight for your local bicycle repair shop, ask the owner for any old cranks, chain wheels, seat posts that have been thrown out, when you get your Ally treasure back home, degrease and wash it, allow to dry, then cut up the parts - melt and pour into ingots... don't mix the metal up with other stuff, mark it with a texta marker so that you know what it is, then when you are ready to experiment with different percentage additions of the duralumin with your ordinary ingots. You'll be surprised at the results. Of course, you cant expect to what the alloy mix will be without having access to metallurgy testing gear... but you'll get close enough for your hobby work.
I just remembered another source... the horse racing industry use high tensile aluminium horse shoes on their thoroughbreds... John Harmes from Tambellup in Western Australia swears by them... and if you smile nicely you might get them for nothing. As the old folks used to say; "There's more than one way to skin a cat".
It matters liitle how you want to go about your metal casting - You can use: Greensand - Silicate Sand - Investment (Wax) casting - Lost Foam - Shell Moulding - As long as you are familiar and confident enough to understand how to get the best results - Learn the basics - advance your knowledge, and move on from there.
See you next time.
Col.