The International Hobby Metal Casting ezine.
Brought To You By:
Col Croucher: www.myhomefoundry.com
Australia.
Number: 75: February 2010.
Well it's been awhile since you have been able to read the ezine... sorry about that, life is pretty hectic these days, and seems like I am running out of time to plan - write and edit the ezine, as I have said in the past if you have something you would like to share then send some pics and a short story about your project... would like to see what you have been up to.
Judging by the global news bulletins we hear that much of the USA & Canada has been covered in very heavy snowfalls, while here in Australia we are just about near the end of the Hot Summer period and we will soon be welcoming Autumn, or fall as you guys up north call it... bring it on I say. Autumn (Followed closely by spring) is just the best part of our seasons.
But the winter also brings snow to the Alpine country close by, and it's also the time when I really enjoy metal casting, I just find it much more comfortable.
It Is Official: We are going to have a Casting Party weekend. It is scheduled for the middle of May In Western Australia; so far we have several people who have put their hands up to say they will attend. One of our WA clients, Mr John Harmes who lives at Tambellup, will be hosting the party at his workshop. We are looking forward to the casting meet. It will be a weekend of learning and sharing and catching up with others over a few beers.
After the WA casting party announcement went out to the list, I had a couple of clients from Northern New South Wales and Queensland ask when we are going to organise one in that region... well, it's on my mind in thought only, we will see what happens in the later part of the year.... but to put some feelers out now, it would be based in the Northern Rivers region of NSW, say, Lismore or close by.
We always enjoy receiving emails from people, the following email arrived at our inbox just the other day: (If you are reading this John I hope you don’t mind me using your email)
---
Message:
Hi Col, by accident I find you live in VIC and here I am communicating with the US and they link back to you. I am in Tallygaroopna, VIC. New to casting, no equipment as yet but have a 1927 Hudson I am restoring and need to try and fabricate some bits and pieces. Quite a lot of what I need I could cast.... once I know how.
The reason I am looking at casting is exactly the ones you describe. being able to make those obsolete, rare fittings I need. Funny how things turn out. I will keep in contact because I am so new to casting. Brand new. Many thanks for your quick reply.
Regards.
John K.
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Emails just like this one from John arrive fairly frequently from people scattered all around the globe, the DIY metal hobby casting renaissance just keeps on rolling along. Jump on board now to get a head start on your projects.
Col.
Perhaps you are thinking that the time is not quite right.
But, when Is it right?
Tomorrow - Next Week - Next Month - Next Year?
Procrastination Has Killed Many a Hobby!
Just One Click Here Will Get You Started With The Basics.
Another Click Here Will Get You All Of The Info You Will Need For:
Tomorrow - Next Week - Next Month - Next Year & The Year After That...
Metal Casting Treasure.
Would you
not agree that a chunk of scrap alluminium like this is like gold to a
hobby metal caster, well it is, this old V8 inlet manifold I found at
home recently after sorting through a pile of old bricks and other
rubbish. Soon it will be cleaned, melted & poured into ingot stock
ready for future casting projects.
Convert Your Scrap Into
Ingots.
The ingots are the
stock you will use to make your valuable finished castings... but
it gets better.
What Do You Want To Cast?
Door
Handles for a vintage - classic car or truck, can be done... even in
greensand.
Unique Shape wingnuts.
Threaded
shanks are embedded in the wing nut casting, easy to do and all
are cast in greensand. These are but two examples of what you could
make using your casting skills.
You really could make an endless list of things and easily cast them in
greensand or resin bonded sand for that matter, all it takes is the
desire to: Learn - Practise - Perfect your skills, and you are away.
What is the old saying:
Give a
man a fish - Feed him for a day. Teach a man to fish - He will
feed himself for life!
Way back in the early eighties when I was just beginning to explore the hobby of home metal casting, I had no clues on what I should do, or where to find info, I did not know about gas fired furnaces, did not know about how to sand cast.... did not know about a whole lot of other things.... but all I wanted to do was to melt some metal (Aluminium).
I ended up building the most agricultural looking temporary charcoal fired furnace you could find anywhere... a three layered circle of ordinary house bricks with a pipe in the bottom (on the ground) for the air blast... and an old electrolux Vacuum cleaner (Set to blow - not suck) as the blower.... yes, this set up provided an incredibly basic, no frills melting set up.... but it worked... and better than you would imagine.
When using charcoal as a fuel... first you have to make your own... unless you know where to source it... not so easy these days.
PIONEER CHARCOAL.
The pioneers placed a high value on charcoal.It was the "basic fuel" required by the:
>> Local blacksmith.
>> Small foundry.
>> The farmer.
The pioneers used the following method to make high-grade charcoal. The great thing about living on the land is that you can make as much charcoal as you wish, as there is no shortage
of raw hardwood material.
Note:
This method is NOT recommended for residential areas, the smoke produced will really upset your neighbours. If you have friends or relatives who own some farm land you could ask them if you can use old scrap hardwood on their property to calcine or burn into charcoal.
Make your charcoal during the winter months, burning in the hotter months could start a bush or forest fire?
Charcoal Making Method 01.
Hollow out the ground about 10' X 4' X 6" inches deep.
Use different size pieces to pack the wood in as tight and close as possible. (Use short pieces for easier placement) Build each layer up on top of the other, and make each one smaller than the last. The idea is to make your woodpile the shape of a house roof ridge. (looking from the end)
At each end, make a good pile of light twigs and other fire lighting material to ignite the wood. Cover the entire stack with sods of damp or wet earth, with the grass on the outside.
Start the burning process by lighting the twigs. Do not cover the ends of the wood stack until the fire has a good hold of the wood stack.
Watch the wood stack for some time, to make sure that the sods of soil do not crumble and let air into the woodpile. Letting air into the woodpile will tend to hot burn the charcoal and reduce the amount of fuel made. You may have to sprinkle water onto the soil & sods if the heat dries it out too much.
Your wood will be calcined into charcoal in about four or five days. When the stack cools down, break open the soil cover, and bag your charcoal up.This is actually better charcoal than that made by the drum method. (beehive charcoal) Which will be explained next.
Note:
This pioneer method is a hard way to go about making charcoal, but you will get top quality fuel, you could dig the ditch with a backhoe, or something that takes the backbreaking work out of it.
Using this method will make a very substantial supply of charcoal; don't try this in a residential area, as you will smoke your neighbours out, do it out in the countryside somewhere.
Charcoal Making METHOD 02.
Here is a modified version of how to make charcoal with a large oil drum.
Burning or Calcining Charcoal:
Good quality Charcoal is made from old dry hardwood limbs and branches, it is possible to set up two or three drums and make quite a bit of charcoal at the same time.
Method.
Light a good fire in the drum; quickly cut the wood up with your chainsaw into small pieces 6 to 8 inches long. Split anything that is too large. (3"Dia or bigger) Pack as much wood into the drum as you can. When the fire starts to die down, block the air holes with a few shovels full of earth, & pop the lid on the drum, and put a heavy weight on it to make sure it stays on. "LEAVE IT FOR A DAY" and then return to bag
The charcoal up.
Warning:
Do not be tempted to lift the lid to take a look during the process; you could be met with an explosion, because the gases in the drum will mix with oxygen in the air!..The result...KaBOOM.
You have been warned!!
Preparing the Drums.
Find a good 40 Gallon drum with a tight fitting steel lid, cut two wedge shape holes down at the bottom rim opposite each other. Make the holes about 6" wide with about 2" or 3"
opening. The actual charcoal making process is started by lighting a fire in the drum with twigs and rubbish and some kero or diesel to hurry it up a bit (Be Careful).
Start by cutting up the limbs & branches into pieces about 6" to 8" Long, split any pieces larger than 3" or 4" dia. Throw them in as the fire starts to get bigger. The idea is to pack as much wood in the drum as possible, get the fire very hot. Keep adding wood as it burns away.
When the drum is really super heated, and full of wood let the fire burn for a while. As the flames start to die down a little. Throw some small pieces into the drum to top it up, put your
leather gloves on and very carefully place the lid on the drum and put a weight on it (Bricks etc) to keep it on.
Block up the air holes with earth to stop the air entering the drum. Let it smoulder for a minimum of one full day, or overnight. Then return to bag up your fuel. Start the process all over again, if you wish to make some more Charcoal.
To make larger amounts of charcoal use two or three drums at the same time. This method will allow you to make as much charcoal as you need for your cupola, or charcoal fired furnace.
Further Warning.
Because of all the smoke you will produce with these methods, please do not try this in your backyard; your neighbours will most likely call the fire department. This is also a winter or springtime job; do not attempt this during the summer time when the bush and scrub are tinder
dry. Please take care when working with fire, wear your safety gear to prevent personal injury.
Note: Am I reccomending charcoal as a fuel.. NO... but I bet there are a few readers out there who might want to know how to make it, I use this fuel a every now and again in the old forge to heat metal or to do a small amount of melting, just for the heck ot it.
Foam Casting.
It has been said that foam casting is easy to do badly, but if you make the effort it is not that much harder to do well... as with all techniques lost foam has equal advantages as well as some disadvantages over conventional green sand or silicate casting.
Fun With Lost Foam Casting.
You will achieve far better results if you use the dense building grade foams, they are easy to cut & sand, they also produce a far better result. To achieve a fine/smooth casting finish, a coarse wet and dry paper used with water is hard to beat.
For rough casting where surface finish is not important, ordinary packaging foam can be used, but the big disadvantage is that it is coarse & porous, it should be covered with masking tape (Flat patterns) or something similar. Coating patterns made from packaging foam is a lot of work and really a waste of time, packing foam coated with plaster will soak into the pores & crevices of the foam, the surface finish on the resulting casting will be quite rough and require a lot of finishing work.
2. Constructing Patterns.
A hot wire cutter is the quickest & simplest way to cut and shape the foam. You can make a simple hot wire cutter from a PC power supply and a length of MIG welding wire if you can source these components.
Foam pattern sections are glued together using a LOW temp hot glue gun...
Coat any surfaces that are to be machined either with paper masking tape, or use plaster as outlined below.
Form your runners/risers from foam and glue them to the pattern/ Vents can be made by sticking drinking straws into the top of the pattern.
Put masking tape on the sides and bottom of the runner as that is where the sand most commonly washes into the mould from.
3. Sand.
Dry sand works fine... proper foundry sand works extremely well.. Either hand fill around the pattern in a suitable container or, if you are adventurous.. put your sand in a container, agitate it with an airline (gradually increase the pressure until the sand becomes fluidised.. don’t' try high pressure right off unless you want sand in your eyes !) lower the pattern into the sand and turn the air off.
4. Weights.
When the pattern is nicely surrounded by sand... put some blocks of metal, bricks etc on the top of the sand... things have a habit of moving about when you pour.
5. Pouring
You don't need hotter metal than normal... the energy needed to vaporise the polystyrene is negligible.. Pour fast... much faster than you might think... it just produces better castings
6. Coating.
For the best quality castings, you can't beat coating the foam patterns with a refractory wash.. Here in the UK I use a textured wall and ceiling wash called 'Artex' the main thing is that it is an
Air-drying material, not a gypsum type material... the chemically combined water in ordinary plaster will cause problems.
The wash should be runny and the best results are from dipping the pattern into it and leaving to air-dry for ages..
A nicely sanded dipped pattern will give almost a mirror finished casting.
............
Currently, I am just about to attempt to form my own polystyrene foam patterns by expanding the foam into my own moulds. There isn't much published on how to do this, but I am hoping it won't be too complicated..
Best of luck
Chris (-=Spiyda=-)
Note: This is a reprint article from a very early ezine, if you are reading this Chris what advances have you had with your foam casting projects.
Some Metal Casting Fun - Stone
Mountain - Georgia - USA.
Sean & Dave Casting Aluminium Waffles.
Col.