need a metal tank for my 1/2a Pathfinder

[Andrew Borgogna]

Anybody out there in cyber space know if somebody makes a 1oz metal uniflo tank for 1/2a use.  I am planning to add pressure to my Norvell for better consistency but that requires a metal tank.  I tried RSM and Brodak and nothing there.  I am beginning to think I will have to make one myself.
Andy

[Tim Wescott]

Bigger engines use pressure with plastic tanks -- or do you mean you can't use the motor's plastic tank?

If you could figure out how to make the plug, you could use an eyedropper bottle or similar for a tank.

[ray copeland]

Andrew, my Hyper Viper rebuild uses a Hayes 2 oz. clunk (actually holds about 1 3/4 oz.) with muffler pressure from a Norvel .061, runs great. As always with 1/2a's, make sure the distance of the fuel feed hose is as short as possible for consistent runs thru the entire tank.   

[Andrew Borgogna]

Ray
I have opted to go with your setup, but I still plan to run crankcase pressure.  We have been doing quite a bit of experimenting with the AP Wasp and the Norvell using uniflo, balloon and pressure setups.  The crankcase pressure seems to give us the best and most consistent runs.  Surprisingly uniflo un-pressured seems to be the least effective, but uniflo with pressure works best.  The balloon tank as designed by Larry Renger is also very good, but in my opinion not quite as good as crankcase pressure.  I have used the DuBro pressure fitting with an inline piece of brass tubing that has been squeezed around a piece of .008 flying wire to create a pressure limiter.  I have a one way check valve but have yet to use it.  We run the pressure hose to the tank overflow tube that is above the fuel level, this prevents fuel from being sucked back into the crankcase.   I now have a pair of ST pressure fittings I am going to try, one on my Norvell the other on my second AP Wasp.

The tanks vertical dimension seems to have a big impact as well, tall tanks are a real problem with short tanks being better.  And your point about keeping the fuel line length to a minimum is very true.  We now have four fliers in our club flying 1/2a stunt with more coming online.  We are mostly using 1/2a Magicians, but there are several of us getting 1/2a Pathfinders ready for competition.  Thanks for you input.
Andy

[Stan Tyler]

Andy,

The tanks I use on my twin are standard vented 1 1/4 oz tanks (Brodak PN BH-472) with the pickup tube re-sized and rerouted to clear the cylinders and the standard venting re-plumbed as uniflo. The tubing in the tanks is 1/8" od and is fine for using 3/32 ID fuel line, but for 1/2As it really needs to be sized for small fuel line, so I replaced the pickup with 3/32 OD copper tube.

Later,
Stan
 

[John_Craig]

Having an old folks moment.  Model Aviation had an article about a high performance 1/2A stunt plane a few years back. Loss foam wing, wing angled forward. Fox fire?? Renger??  It had an easy to build light metal tank.  Do the full pattern