There was an article in Flying Models within the last 5 years or so, about making tanks from various things, including plastic 35mm film "cans" and plastic bottles. The guy drilled holes, pushed silicon fuel hose in, then pushed metal tubing through. The silicon fuel tube worked as a grommet or o-ring sorta thang. No reason it wouldn't work for a 1/2a or .09. There weren't any actual diagrams of where tubes should go, and of course, it was really all about arcee.  Steve

Contact MinnesotaModeler.  He posts on here and I think he was the first.  Don't trust my memory tho.

Ray does use the film can, but IIRC, he uses a balloon inside of it, now.  The balloon is not *pressurized, just a *floppy* balloon.  The can is for protection now, I guess!   (and it works great on 1/2A's!

Big Bear

I seem to be a little late to this party, but here's some pix of a "hard" tank made from a canister, alum. tubing, and Goop. The silicone fuel line is forced through a slightly smaller hole, if sized right it seals up fine. This one is set up as a uniflow clunk.  It worked fine for a couple of years in an .061-powered stunter now crashed, repaired and retired.

I've done several other configurations, with round canisters as well as this oval one, fixed lines as well as clunk.  Made some oversize ones (my .061s are thirsty) by cutting out the bottom of one and splicing it to another, gooped together.

Couple of caveats: Choose a canister with a tight-fitting lid (they vary).  Rough up the plastic with sandpaper before applying Goop.  Let the stuff cure for a week or more before exposing to fuel. 

Love the Hornet...I don't spose you've got an extra laying around, huh?

Any for sale?  That was my dream engine as a young teen.

Yes, well documented here.  Do a search on balloon tanks, and it is all layed out for you in detail with photos.  Several times, actually.