Home Made Hand Tools For Hobby Foundry Work

If you have been thinking about making a start in hobby foundry work in your home workshop, you may be forgiven for thinking that the tools and equipment are going to cost you an arm and a leg, this need not be. Sure, you could trot off to the downtown industrial tools supplier and take home an arm full of expensive tools.

But if you take a good look at some of the tools, you'll discover that the design principles and fabrication could well be undertaken in the home workshop if you have metal fabrication skills and a reasonable amount of basic metal working equipment.

Take for instance "crucible lifting tongs", once you understand how these tools operate; you could quite easily make a set or two over a weekend. The basic design action operates on the "scissor principle" but they don't cut anything, they are designed to "clamp securely" onto the crucible to lift it out of the furnace when the metal has melted. Great caution needs to be taken while carrying out this operation, as one slip due to faulty or badly designed tongs, and you could have a disaster on your hands.

The best way to design and build a set of tongs is to copy a well made set, or to follow directions set out in a textbook or ebook downloaded from the net, we'll give you some links a little further on in this article.

Some of the most frequently used basic tools you'll need in the hobby foundry are; Bench ramming moulders tool - Tube sprue cutter - turned wood sprues - slick & oval spoon - hand riddle or sand sieve - draw pins, screws & hooks - rapping bar and spike - gate cutter - strike off bar - sand carving tools (made from old hacksaw blades).

The tools mentioned above seem to be the ones that will be most used in your hobby foundry... and all of them can be home made if you have metal & wood working skills, it will take time and effort to make the tools required but they wont cost you a red cent if you make them from scrap materials, and if you are like most hobbyists you will know where to "scrounge stuff".

You may have to experiment with different ideas before you arrive at the most satisfactory design, but you will learn a great deal about why things have to be made in certain ways.

Do you own a wood lathe? Even a most basic machine will suffice in the home workshop, you could even make your own if you were keen enough,I guarrantee there are tens of thousands of home made wood lathes sitting in hobby workshops the world over. A wood lathe will repay itself many times over when you start to make patterns for your hobby foundry.

Your bench-ramming tool can be quickly turned to shape on your wood lathe, in fact, while you're at it, make two or three of them in different shapes & sizes, they will all come in handy when ramming and moulding patterns of differing sizes, you could get away with a single tool, but you wont regret making extra tools.

After a pattern has been completely rammed in a sand mould, and before the metal is poured, the pattern has to be removed without disturbing any of the surrounding sand. Draw pins and spikes are used to remove timber patterns from sand moulds.

Simple draw pins can easily be fabricated from long slender wood screws, particleboard screws are ideal. The easiest way to convert woodscrews into draw pins is to braze-weld a short length of 1/4" dia mild steel rod onto the head of the screw...that is all you need to do... make a set of them with different gauge screws as well long and short ones and you should have the field covered as far as lifting pins or draw spikes go... simple isn't it.

Blunt hacksaw blades are usually thrown in the bin, from now on you should save them, as many useful little hobby foundry tools can be made from old saw blades, quite often small sand carving tools can be quickly made by grinding and shaping using a normal bench grinder.

By being resourceful and thinking how you can use scrap materials, you should see now that there is absolutely no need to spend large amounts of money to get the tools and things you need for your hobby. If you are not sure about your own building & fabricating abilities then you should always ask advice.

Basic Pattern Making In The Hobby Foundry

Success or otherwise in your hobby foundry will depend to a large degree on your skills & ability to create simple patterns, i.e.

Patterns that are easy to mould, lift or separate from the sand

mould after a gentle rap.

A pattern that has incorrect draft on vertical surfaces, badly finished corner fillets, or a pattern that has not been finished to an ultra smooth finish will be difficult to work with.

Pattern making is an art in itself, pattern making

apprenticeships take around three or four years to complete, before you are given your "Trade Ticket".

The average hobby foundry worker most likely won't have the time, or the patience to get involved with the art of pattern making to that extent.

But the basic skills are worth the effort to learn, because

without them you wont get far with your hobby foundrywork, unless you PAY to have all of your patterns made for you, but that would take all of the fun out of it, and also cost you a sizeable amount of money.

Construction costs of professional pattern making can vary from a few hundred dollars for simple patterns, up to several thousand dollars for complicated pattern designs.

I happen to a know a pattern maker who designs and builds patterns & core boxes to make alloy & cast iron cylinder heads, it is not unusual for pattern & core costs to be around $20,000.00 AU before you even think about melting & pouring any metal.

If you are a legacy of the old tech school system of the sixties

& seventies, there is a good chance that you still remember how to skilfully use woodwork hand tools.

Some of the finest foundry patterns were made using basic hand tools. More than likely you still have a chisel set tucked away in a drawer, or a spoke shave, wood plane & handsaw, plus

a host of other tools that could be used to make excellent patterns in the home hobby shop.

And if they happen to be a bit rusty, then get them out again and bring them back to life, re-grind the cutting edges and hone

them with an oil stone.

Remember what your trade teacher always told you; "sharp tools

give the best results."

Do the same with the wood plane and any other tools, such as a small set of carving chisels you could use to carve intricate shapes in wood.

You'll need some good pattern timber or lumber as it's called in the states... doesn't matter, it's all wood isn't it. There are many types of timber suitable for pattern making, but, you'll probably be limited to what's available in your area or region.

Quality pattern timber is expensive to buy, so ask for off cuts at the local timber merchant, which you may get for a considerable discount

You'll be looking for a soft timber that doesn't splinter, has a straight grain, is easy to work or carve, and finishes to an ultra smooth finish.

One of the easiest timbers to use is jelutong, this timber comes from the Philippines, I don't know whether it is from plantation timber, or old growth forests, but it is great to turn on a lathe, or shape and carve with sharp hand tools.

Some of the other pattern timbers in use are cherry wood, mahogany, maple, white pine, and many others.

Quite often a master pattern can be made from timber, and then a replica mould is made using RTV 585 silicone, this is a quick method to remake replica production patterns.The replica patterns can then be mounted onto a match plate along with the runners & gates, this method will enable you to mould & cast multiple parts at the same time.

With a little practise you will soon know enough to make reasonable quality patterns that create good sand moulds.

There is one important pattern making tool that will make you wince when you purchase, but it is an important tool to have if you want to make accurate patterns where shrinkage rates are concerned.

The tool is the "Pattern Makers Rule", this is a ruler about 500mm (20")long. Made by Rabone Of England. No B5. And the graduations are marked as: 1/30-1/40-1/60-1/80,

The graduations represent the amount of shrinkage allowance for different types of metals. The pattern makers ruler provides a built in shrinkage percentage, which means you don't have to calculate the final measurement or size of your pattern, you simply take your measurement from your shrink rule, and transfer the measurement to the pattern being made.

The system is quite clever in the way it's all been calculated.

For a quick example, the 1/30 scale measurement seems to give

the correct result with patterns used for cast aluminium items.

Machining allowance on specific parts of a given pattern may also need to be considered, generally your own judgement can be used to judge that.

Pattern making can be quite a challenge for the hobby foundry worker, but once you learn the basics and develop your skills, with a little practice your patterns will get better and so will the overall casting quality.

If you intend on making lots of patterns, the investment in a shrink rule is well worth the money.

And while you're at it buy a good book on pattern making, it deserves a study all on it's own, but it forms an integral part of foundry work, and because you're the boss of your own workshop, you have to learn to wear the hat of the pattern maker & that of the sand moulder & founder.

Sounds like a whole lot of work doesn't it, but you'll soon learn what will work best for you. Spend the time to learn all you can, and you'll be rewarded with encouraging results.