You can find all sorts of things for sale on the net. I have recently discovered "foundry patterns" for sale. All sorts of patterns pop up. Take a look at this one. Is it really for light bulbs? There are a number of similar ones for sale. Interesting design. How was it made/cast? The design is a lot like some core boxes I need to make. I guess the holes are for air evacuation. https://www.ebay.com/itm/2-Piece-Cast-Iron-Foundry-Incandescant-Light-Bulb-Mold-Industrial-History/112398502077?_trkparms=aid=777001&algo=DISCO.FEED&ao=1&asc=49451&meid=6066893a35a847cb8a72c26a1670c9b7&pid=100651&rk=1&rkt=1&&_trksid=p2481888.c100651.m4497&_trkparms=pageci%3Ae9bea4d2-dd10-11e7-b999-74dbd1802416%7Cparentrq%3A3c974d221600a9c4d750fa36fff2d9dc%7Ciid%3A1 Some nice metal letters with draft. A little too large, but a nice design. https://www.ebay.com/itm/Vintage-Fo...605967?hash=item4d68cad88f:g:6CQAAOSw2xRYRaVR Frying pan. https://www.ebay.com/itm/Vintage-Fo...884105?hash=item35f9016209:g:eFUAAMXQDnpTbRHI
I ran across these letters a few years ago, and did not buy them because I could not find them locally, and I don't like paying currency conversion fees, taxes, etc. But I have searched for a long time for good local small foundry letters, and the only thing I found was for letter board signs, and the letters had tabs on the back that had to be removed, one letter at a time. I finally broke down and bought some of these. They are very nice letters I must say, and I notice that they appear to be the ones used by Myfordboy and I am sure others here. I don't think they have any draft, but they appear to be flat on the back, and not too thick, so I think they will pull nicely from the sand. I think they were designed for the model railroad hobby. https://slatersplastikard.com/plastikard/alphabets.php
I don't get it. Are they dies meant for blowing glass bulbs? I've noticed a few old sand casting patterns up for sale on eBay tagged with 'steampunk' before. When people who like to dress up in funny costumes become interested in something, it can only drive up the prices... Jeff
Exactly, the bulb molds are for glass. Saw this operation once (a long time ago) at an Owens plant that was making our baby food jars.
Yep, they are blow moulding shells. A glob of molton glass is preformed with a neck then while hot the shells clamp over it and compressed air is blasted in to expand to the form.
A nice little crankshaft pattern. https://www.ebay.com/itm/Vintage-So...554226?hash=item213515fcf2:g:g~oAAOSwH-daMc2Y
Nice find. Looks like a split pattern, other than none of the 8 pix showing it in two pieces. But you can see a seam that looks like the parting line very clearly in a few of them. Jeff
I have seen a number of commercial foundry patterns that are one-piece, and that practice seems much more common than two piece patterns (from the few I have seen). I have started making all my patterns (when feasible) one-piece. The two piece are not as stable as far as warpage, and are sometime prone to breaking, or one half getting misplaced, miss-aligned, etc. Sometimes I use a follower, and sometimes I just ram the mold and dig down to the part. Either way works well. Greatly simplifies making a pattern, and eliminates all alignment issues with mold halves too. Some people seem to make two-piece patterns without really having a good reason to do so, perhaps from habit or whatever. Adding complexity to an already complex process seems counter intuitive but I guess we all have methods to our own particular madness. The only time I would consider using a two-piece pattern is if I were going to use matchplate construction, or if I needed to use the interior of the pattern as a corebox. I see the same thing with coreboxes made from pvc pipe. Instead of slitting the pipe down one side and leaving it as a one-piece corebox (works great), people cut the pipe in half, and then make pieces to hold it all together, thus lots of pieces to make and get lost. There seems to be a two-piece mindset that is difficult to shake.
