Gary Byrum
Overstable By Design
What about these:
https://www.generalplastics.com/products/tr-marine
These people have a great selection of foam products. One especially for tooling, (CNC and such) The 4500 series sounds like a great option and they will work with you on custom sizing. So I started to request a quote. That page tells you there's a $500 minimum for aerospace and certified foams and a $350 minimum for non-certified foams. That's going out of my affordability range. I have to consider the lack of storage space for bulky items also.
I also have fought the battle with glued-up foam boards. I usually have a hard core (1" dowel) running through the layers. I try to keep the glue on the dowel and the inner couple inches of the foam, avoiding the outside. This tends to leave small gaps on the outside, but they're easier to fill or cover with glass afterwards than to get the hard glue layer sanded evenly.
This is something I haven't tried yet. I thought about it though. I'm sure you had the same issue with glue layers not sanding down smoothly which led me to consider avoiding glue on the outer edges. The whole layering concept would be very nice to avoid altogether. My last effort was not as uniform as it should have been and I admit, I'm pretty new at this.
[/QUOTE]Another (untried!) approach which will probably be cheaper than trying to buy "big" blocks of foam is to make your own. Get a 6" concrete forming tube from Menards, line it with parchment paper, and fill ti with 2-part urethane foam. Then, peel and toss the cardboard. You could even cut centering rings and mount the central wooden dowel before you pour the foam. I think I'll try it on my next nose cone.[/QUOTE]
Why would you need a central dowel on a solid pour? I could see having a solid ply end cap of sorts on the shoulder end to attach to my lathe, and maybe a CR on the other end to make a nice round cylinder shape. This already sounds doable. Now if only I knew what kind of 2 part urethane foam to use. I'm sure there a variety of that to choose from. Particularly for density. Right?