I hope this is not too "caveman" like.

I come from a woodworking background. This idea is simple and cheep.

I could not put it in words correctly. A picture is worth a thousand. So
they say.

www.putfile.com/pic.php?img=5884634

That is a good idea. I'd probably be looking at a 1.5" diameter plywood circle at the top. I'm going to bevel it 45 degrees to get it more profiled. I really like the idea. I'm wondering if instead of the wooden dowels I can just drill holes in the nosecone and the slather epoxy on top and let the epoxy work like the 'dowels'

Edward

Your first idea with the allthread is what I done in the past. I've used ether 20 or 30 minute epoxy for the allthread. You have to remember to keep the nose cone is cool water while the epoxy sets, so the heat from the epoxy doesn't melt or deform the nose cone. On my next project I'm using allthread and then using small screws to keep the bulk plate form spinning or twisting.

Ron

To give your epoxy more bite in the nosecone, run some pins of small brass rod criss-crossed through the tip of the cone. After the epoxy is cured, clip them off and sand flush.

-Ken

I've ditched using epoxy in the nosecone and will go with PL Premium. It is a polyurethane construction glue. I was looking around and remembered that when I did water rockets I often would glue two 2L bottles to each other and PL would hold up to 125 psi - even without scoring the surfaces for bite. I would have bottles delaminate before the glue would fail. So, I'm going to use this and score the inside of the nosecone and it should all glue fine together.

Edward

I use that PL Polyurethane construction adhesive all the time in my business. Two recommendations: score the surface you intend to ahere to and make sure it's clean, and do a strength test after it's cured. I use it to glue plastic membrane to concrete and wood, and there are times when the plastic will peel away after cure. Usually this has to do with the plastic joint releasing, never the porous joint. If this happens the PL caulk will not hold it even if reapplied. At that point, I suck it up and pay for the Liquid Nails pure polyurethane (which is where you may want to start).