Well the idea for my first casting was to make some aluminum sides I could use for the moulding boxes. It seemed a good idea and I thought I would add the website name to see how easy it was to produce cast in letters. In the end it didn't work out too well. There was sand stuck between some of the letters and I put this down to the closeness between some of the characters. I did try to mould it again but without success so since this was a trial, first casting and non critical, I went on and made a melt.
The results were both good and bad. Good that the whole process went (other than the lettering) as it should. The calculator for estimating the amount of metal to melt ( produced in excel) I made proved very accurate on this first occasion and the finish on the casting was as good as the pattern allowed!. Download a copy here.
The letter failure will be explored further and I may well try just spacing them out or make a new set, perhaps from wood.
I do need to make an aide memoir since I keep forgetting to talc up! Also I need to produce 8 for each box and each different size and where and I going to get that much metal! It would seem to be more efficient to just use wood and make the set up to size as and when. If you have a large stock of scrap alloy then perhaps it may be worthwhile.
I intend to have a go at using foam for a pattern which is burnt away by the incoming metal.
Well the idea was to make some aluminum sides I could use for the moulding boxes. It seemed a good idea and I thought I would add the website name to see how easy it was to produce cast in letters. In the end it didn't work out too well. There was sand stuck between some of the letters and I put this down to the closeness between some of the characters. I did try to mould it again but without success so since this was a trial, first casting and non critical, I went on and made a melt.
The results were both good and bad. Good that the whole process went (other than the lettering) as it should. The calculator I produced in excel proved very accurate on this first occasion and the finish on the casting was as good as the pattern allowed!.
The letter failure will be explored further and I may well try just spacing them out or make a new set, perhaps from wood.I do need to make an aide memoir since I keep forgetting to talc up! Also I need to produce 8 for each box and each different size and where and I going to get that much metal! It would seem to be more efficient to just use wood and make the set up to size as and when. If you have a large stock of scrap alloy then perhaps it may be worthwhile.
I intend to have a go at using foam for a pattern which is burnt away by the incoming metal.
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- Made my own characters from foam card – needed to put further apart!
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- I knew the results would not be crisp but decided to make the first casting in anyhow
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- rear of the first castings
Mike, the letters look quite thick, perhaps you might want to taper them or make them thinner. You can also be very generous with the parting dust (talc seems to work for me) for single sided patterns like this as it does not need to hold upside down.
Stop press: I should have sloped the sides of the letters on my first casting and or made them much thinner (thanks to both David and Andy for there swift comments). David (Myfordboy) also suggested the use of dyno-tape for the relevant application, works well. One of the sets of Seal castings I am working on does indeed make use of dyno-tape to good effect.
Thats a great entry, thanks for writing it. I’ve bookmarked your website and will be eager to reading more!
Mike, great blog, always something interesting here!
have you come across this site:
http://www.buildyouridea.com/foundry/lost_foam_howto/lost_foam_howto.html
This guy coats foam patterns in drywall plaster, then just plants it in sand, no casting boxes, no part lines – seems to have some excellent results
Hello Alex, many many thanks for your link! It is very interesting to see yet another approach to castings. I was going to try lost foam myself quite soon but I do like the concept of the dry wall mixture and ordinary sand……..simples…………
Thanks for your comment Alex.
Kindest regards,
Mike
Mike, I shared your page with the Home Foundry and casting group,
http://groups.yahoo.com/group/HomeFoundry_and_Casting/
Gene’s response was
My take on the flask side and lettering is:
1.) all patterns rammed into sand need a bit of draft or taper so they pull out cleanly and crisply.
2.) I don’t recommend having the sprue, riser, vents etc right into the pattern as this tends to wash loose sand into the mould and may cause turbulance or other troubles. Also removal of large hunks from the finished casting is hard work and often causes marks or damage, etc.
3.) the lettering or finished side should be in the cope side for better results.
4.) go to Office Depot, Staples, etc and ask for the plastic lettering like used in sign boards, such as used in office buildings etc, -
( white plastic letters/ numbers with tabs to poke into the slots on the black sign board.) the tabs can be clipped off easily and a dab of glue or double stick tape to stick them on your pattern and walla nice lettering! I like the sizes above 3/4″ as they tend to make the more crisp detail I’m looking for!