| Success or otherwise in your hobby foundry will | | | | timber comes from the Philippines, I don't know |
| depend to a large degree on your skills & ability to | | | | whether it is from plantation timber, or old growth |
| create simple patterns, i.e. | | | | forests, but it is great to turn on a lathe, or shape and |
| Patterns that are easy to mould, lift or separate from | | | | carve with sharp hand tools.Some of the other pattern |
| the sand | | | | timbers in use are cherry wood, mahogany, maple, |
| mould after a gentle rap.A pattern that has incorrect | | | | white pine, and many others.Quite often a master |
| draft on vertical surfaces, badly finished corner fillets, | | | | pattern can be made from timber, and then a replica |
| or a pattern that has not been finished to an ultra | | | | mould is made using RTV 585 silicone, this is a quick |
| smooth finish will be difficult to work with.Pattern | | | | method to remake replica production patterns.The |
| making is an art in itself, pattern making | | | | replica patterns can then be mounted onto a match |
| apprenticeships take around three or four years to | | | | plate along with the runners & gates, this method will |
| complete, before you are given your "Trade | | | | enable you to mould & cast multiple parts at the same |
| Ticket".The average hobby foundry worker most likely | | | | time.With a little practise you will soon know enough to |
| won't have the time, or the patience to get involved | | | | make reasonable quality patterns that create good |
| with the art of pattern making to that extent.But the | | | | sand moulds.There is one important pattern making |
| basic skills are worth the effort to learn, because | | | | tool that will make you wince when you purchase, but |
| without them you wont get far with your hobby | | | | it is an important tool to have if you want to make |
| foundrywork, unless you PAY to have all of your | | | | accurate patterns where shrinkage rates are |
| patterns made for you, but that would take all of the | | | | concerned.The tool is the "Pattern Makers Rule", this is |
| fun out of it, and also cost you a sizeable amount of | | | | a ruler about 500mm (20")long. Made by Rabone Of |
| money.Construction costs of professional pattern | | | | England. No B5. And the graduations are marked as: 1 |
| making can vary from a few hundred dollars for | | | | 30-1/40-1/60-1/80,The graduations represent the |
| simple patterns, up to several thousand dollars for | | | | amount of shrinkage allowance for different types of |
| complicated pattern designs.I happen to a know a | | | | metals. The pattern makers ruler provides a built in |
| pattern maker who designs and builds patterns & core | | | | shrinkage percentage, which means you don't have to |
| boxes to make alloy & cast iron cylinder heads, it is not | | | | calculate the final measurement or size of your |
| unusual for pattern & core costs to be around | | | | pattern, you simply take your measurement from your |
| $20,000.00 AU before you even think about melting & | | | | shrink rule, and transfer the measurement to the |
| pouring any metal.If you are a legacy of the old tech | | | | pattern being made.The system is quite clever in the |
| school system of the sixties | | | | way it's all been calculated.For a quick example, the 1 |
| & seventies, there is a good chance that you still | | | | 30 scale measurement seems to give |
| remember how to skilfully use woodwork hand | | | | the correct result with patterns used for cast |
| tools.Some of the finest foundry patterns were made | | | | aluminium items.Machining allowance on specific parts |
| using basic hand tools. More than likely you still have a | | | | of a given pattern may also need to be considered, |
| chisel set tucked away in a drawer, or a spoke shave, | | | | generally your own judgement can be used to judge |
| wood plane & handsaw, plus | | | | that.Pattern making can be quite a challenge for the |
| a host of other tools that could be used to make | | | | hobby foundry worker, but once you learn the basics |
| excellent patterns in the home hobby shop.And if they | | | | and develop your skills, with a little practice your |
| happen to be a bit rusty, then get them out again and | | | | patterns will get better and so will the overall casting |
| bring them back to life, re-grind the cutting edges and | | | | quality.If you intend on making lots of patterns, the |
| hone | | | | investment in a shrink rule is well worth the money.And |
| them with an oil stone.Remember what your trade | | | | while you're at it buy a good book on pattern making, it |
| teacher always told you; "sharp tools | | | | deserves a study all on it's own, but it forms an integral |
| give the best results."Do the same with the wood | | | | part of foundry work, and because you're the boss of |
| plane and any other tools, such as a small set of | | | | your own workshop, you have to learn to wear the |
| carving chisels you could use to carve intricate shapes | | | | hat of the pattern maker & that of the sand moulder & |
| in wood.You'll need some good pattern timber or | | | | founder.Sounds like a whole lot of work doesn't it, but |
| lumber as it's called in the states... doesn't matter, it's all | | | | you'll soon learn what will work best for you. Spend |
| wood isn't it. There are many types of timber suitable | | | | the time to learn all you can, and you'll be rewarded |
| for pattern making, but, you'll probably be limited to | | | | with encouraging results.Col Croucher.To find out more |
| what's available in your area or region. | | | | about hobby metal crafts and how you can employ |
| Quality pattern timber is expensive to buy, so ask for | | | | the methods & techniques to build & create your own |
| off cuts at the local timber merchant, which you may | | | | unique projects, visit our web site to download a free |
| get for a considerable discountYou'll be looking for a | | | | ebook to begin your understanding of foundry metal |
| soft timber that doesn't splinter, has a straight grain, is | | | | craft. This article is available for ezine publishing as long |
| easy to work or carve, and finishes to an ultra smooth | | | | as reference is given to the source. |
| finish.One of the easiest timbers to use is jelutong, this | | | | |