Casting tips from the past

[Morpar]

My kids and I just returned from the Children's Museum of Indianapolis about an hour ago, and I saw the coolest idea for making molds. The museum has recently opened a large exhibit about dinosaurs, and part of the exhibit is a working palentology lab. I knew that a lot of the dinosaurs on display were actually castings and not real fossils, but I never thought about how they would make the castings. In the lab, there was a guy cleaning a fossil to prepare it for use as a master. The strange thing was that there was a large stack of Legos on his, and every other, workbench. As I moved on down the lab the reason was made clear. They use the Legos to make the outer form to pour rubber into to make a mold, and as the keys to align the molds! In all the information I have seen on casting, they recommend making these outer forms from .060" styrene. I have done that and it works well, but now I have these forms that are useless for anything else. The thing I started doing was to try and make 1 large form that will cover most all my needs. The bad thing about that is then there is either a lot of area that is just wasted rubber, or putting up with the hassle of trying to temporarily subdivide the inner space. Using Legos would allow a person to make their form only as big as it needs to be, with no waste! I am lucky that I have 2 kids that have a bunch of Legos, because the next time I am making a mold I will be using their Legos for the forms! Hope that this will be as helpful to someone else as it is to me. Good luck.

[Anonymous]

Outstanding idea. Pushing legos together sure seems easier than gluing up a bunch of styrene! For those that don't have kids, or kids without legos it might be difficult to get the needed blocks as today's sets seem to be geared towards constructing a specific object, not just plain blocks. I've seen listings on ebay for legos gathered together in lots of a specific color, size and even the bases.

[dehusman]

Legos are used a lot by casters, several articles on casting RR equipment and several posts on the Casting Yahoo Group have mentioned using Legos for making the mold form.

Dave H.

[Morpar]

My oldest son has ordered plain Lego bricks from www.lego.com in the past. They were the 4X2 bricks and he was able to get them all the same color and size. I haven't looked at the site myself, so I can't be any more help than that.

[deltamech]

Another good source of used Legos is a yard sale. I have a friend who collects Legos and he has good luck at yard sales. He says that he finds a good variety and cheap prices.

Richard M