Oh, okay, great, never mind then. I was replying to the OP's question, originally. I just picked up a truckload of sand today, and am going to try some LF casting with some of it after a very long period of wood pattern/greensamd casting.
So, first attempt at lost foam casting after a very long time. Basically a test run, and since it's being discussed, I thought I'd start out with using only Elmer's (Bordens) Rubber cement to see how far we can go with it. No POR, even though I have it on hand. The pattern is a combined water jacket heat sink for a hot air engine in aluminum. It's cut out with a homemade CNC hot wire cutter that I used in the past for making model airplane wings. The old software I'm using doesn't like non-airfoil shapes very well, so it took some doing to get this pattern cut. There's a piece of excess at the top, a bad lower left hand corner (defect in the scrap foam piece I was cutting from) and two gaps where the wire had to cut through to get to interior hollows. Those will all be plugged with glued foam bits, and a good test of the rubber cement.
Besides the wire-cut portion, this pattern also needs a back, for which I'm using what we call fanfold foam in model airplane jargon. I believe it's called Dow Protection board. It's about .25" thick and is unfortunately quite wavy. Again, a good test of the rubber cement. Properly, I should really just hot wire slice off the 1" thick Dow Blueboard I'm using for the main pattern. It would be much more uniform in thickness. Here's what the fanfold foam looks like:
Sprue added. This time I used hot melt glue. It just seemed proper for this type of joint. Otherwise the entire pattern was rubber cemented.
Might be better to start a separate thread. Also, you can upload and post more than one photo in a reply........no need for a reply for each photo. Best, Kelly
Okay, will post several photos together, although one time when I tried 4 photos here, the forum software errored with "post too long, please shorten" so I was avoiding that mistake again, I thought. I'll try a maximum of three in a post. The glue question is the only reason I've done this as an experiment w/ Elmer's rubber cement. Basically so the OP and others can judge whether it's useful for them or not. I've just finished casting this piece, and so I'll show the result here, and then stop posting here. I didn't have castable ceramic to make a pouring basin, and this was a quick test of the glue, so I just poured in a section of steel tubing. The mold seemed to fill, and it looked encouraging: Top view:
This is the casting with just the refractory flaked off, still warm, top: Bottom: And a detail of the corner where there was a foam patch and also the sprue fed in. You can see a small separation in the glue line due to fanfold uneveness probably, but also the tight glue seam along the side. It was sanded along the fanfold edge, the smoother surface of the hot wire-cut is obvious also. POR would have probably also kept the corner down, but would not probably have sanded as well. Well that's it, over and out. If this particular glue I use suits your purposes casters, it's widely available, inexpensive, very fast drying as a contact cement, sands well and does not melt foam. Up to you.
