Baloon tanks

[Ken Burdick]

I'm about to make a tin tank for the WDZ I'm building, but.....
I saw on RSM that they sell a balloon tank for 1/2A. Anybody try one?


Thanks

Ken

[riley wooten]

Ken, just go to party store or perhaps Dollar Tree, etc. and find size you need.  They are cheap and easy to make.. Pick up tube can be anywhere, just suck out all air and fill.. NO AIR and they work great!!
RW

[Curare]

Yep, the old slack bladder tank works well. Use a decent size balloon, and like Riley says, you want NO air in the tank. When I did mine I used a T peice in the line, as getting the pipe back on the nipple of reedies is impossible, and filled the bladder with a syringe.

To fuel up pinch the line forward of the T, so you're not sucking air through the venturi and suck the bladder down to nothing. All the air bubbles will rise through the fuel in the syringe if the nipple is downwards, and you then fill with nothing but fuel. When ready to go, unpinch the line and away you go.

No need for clunks, muffler pressure or anything!

I had mine in a cavity behind the motor, but it just lived in there, it wasn't attached to anything. Hope that helps!

[RknRusty]

Yeah, as long as it reasonably can't flop around like when you go inverted it works fine. I extend a piece of plastic tube or fuel tube perforated with holes through the inside of the balloon. Forget the piece of tube on the tail end, it won't stay on after a bonk. I bought a bunch of silly straws for those.
Rusty

[RknRusty]

Oops, Duplicate

[Chancey Chorney]

Well, I was just posting about this yesterday on another forum. I had made and used a couple this year and they worked great. If you do a 'Google' search for balloon tank, there will be many pictures and tutorials. A quick overview for the way I make mine.

1. Get your balloon, fuel line, brass tubing (3/32 o.d.) and small cable tie/ty wrap.
2. Make a series of holes/notches down the length of your tubing, mine tubing goes from the front of my 'tank' right to the back. My notches start approximately 1" from the front.
3. Put approximately a 1" piece of the copper tubing in the end of the hose that is in the front.
4. Put the hose assembly into the balloon, and tie it up very snugly. The reason for the brass is that while tying up the front, it does not crush the tubing.

I had also read that a finger from a rubber glove works as well. I have one made, but not yet tried. Also, we are now sticking the whole assembly into a single stem flower vial for securing it down.

[Chancey Chorney]

Forgot to add. I have seen and read about sucking out the air prior to filling. I got a big syringe for that, 60 cc, but have not yet done it. I fill my balloon more than needed, then upon disconnecting it from the syringe, I let my air out then before hooking it up to my engine. I always make sure to see fuel coming out on its own. Lastly, you do NOT want to pressurize the balloon. Just fill it up till full, but not as to 'expand' the balloon.

[John Rist]

Search Balloon tank in 1/2 A section.  Many posts with lots of pictures.  I use medicine (Rx) bottles to hold the balloon. PS Balloon is spelled with two L.

[phil c]

Maybe not so important in Half A, but the tank should go into a compartment that is not too wide, 1-1-1/4 in or less.  If it is in a wide compartment it will lean out during the flight.  The longer it  flys the leaner the engine gets.  The balloon has to be slack too.  Any kind of pressure wll give an initial rich run.

[Ken Burdick]

thanks for the information and spelling corrrectionas.
Like Riley's backwards propeller, when I was a kid, I saw my first pen bladder set up....I thought it was a balloon. Got engine OS 35 to run in my sneaker but too low a pressure for flying. One of the older guys later told me the balloon went OVER, the bladder.

I'll give it a try as I only need 2 ounces in a 1.5 x 2 x 2 compartment.


Ken

[Chancey Chorney]

So, what you're saying is that you'll need a bigger balloon.