That house foam for lost foam casting can get pricey, especially for the thicker sheets. I was at the White Water Center yesterday for the "build your own boat" contest. It was a great event. Basically, groups of people built boats out of the list of approved materials and try to navigate the channel. There were about 50 boats including a Barbie car, a Roman chariot with horses a few airplanes etc. Many of these boats use house foam and some are using the 4" foam. At the end of the event there is are several dumpsters full of this debris. It's free for the taking. I scored a nice sheet for myself. If you are regional to Charlotte this may be of interest. You could get a lifetime supply of foam! The event is always mid October.
Would you happen to know the cubic density? Plays a very large roll in casting success for LF. Good idea though!
The piece I got is Kingspan Greengard Type IV XPS 2" thick. Density 1.45 lb/cubic foot. Other brands were floating around-literally. What is the optimal density? The Octoberfest boat was a lot of foam!
I'm sure that's pretty much identical to the Owens Corning (Pink) Foamular 250. Foamular 150 is suposed to be 1.3lbs/ft3, but.......I have very accurately weighed and measured do sample it's density and found it to be be nearly identical to Foamular at 1.5lbs/ft3. Commercial LF casting may mold patterns as low as 1lb/ft3, but in general the answer is the lowest density that's strong enough for distortion free molded patterns. For hobby work and more delicate thin walled patterns that is usually too weak. I think 1.3-1.5lb/ft3 is a nice compromise between (low) density, strength, and workability/machinability. I recently was able to acquire some 4" thick planks of Owens Corning NGX 250 which is an HFC reduced more eco friendly version of Foamular 250. I have a big project going with it right now but I expect it to peform the same as their Foamular products. Best, Kelly
That boat does look like fun...beers look a little undrinkable... Given that density looks like you scored big time!
