Yup, they work well. Mine are made from poly bags and I seal them to shape with a $30 food sealer if they need modification, just like LF mentioned.

Polyethylene is impervious to anything we use. It also has about zero surface energy and doesn't bond with anything we use either, so heal sealing or pressure + elastomers are the two practical choices for sealing.

Apart from working on a couple of prop molds myself (slowly) I've ordered some D speed props from Steve Wilk. I'll have the combo on the test stand about as soon as the props get here.

There is an article at least 30 years old in an RCM I was thumbing through the other day, describing making tanks from lost wax molds. Lost foam should work great for custom tanks.. make tank shape from foam, add nice smooth bits to form neck, glass over it purty-like, then dissolve out the foam. Well, I make it sound quick and easy anyway.

At a recent jet rally, I noticed how many people use pop bottles to satisfy the rigid fuel tank requirement. They are so tough that they apparently often outperform the composite tanks in drop tests - PET is really, really tough stuff to tear apart.

Today I was distracted by another project - I need to finish machine the motor plate before I can carry on anyhow - and that project I am sad to admit is a lekkie Demon. The saddest part is the biggest baddest motor I own is not worthy, but it will make a nice analog to a light .32 powered Delta though, and should hum around north of 100 anyway. At least I can fly it in the community centre behind my house.. gimme a break, I gotta keep those thumbs sharp for the real RC airplanes, right?

MJD