Fuel Bladder Hanging in the Breeze?

[Kit Bays]

Building a 1/2A for AMA classic and would like to avoid it hanging down like it needs a jock strap. Is there a vacuum-formable plastic that resists nitro?

Kit

[Glenn Schneider]

Bladders in the breeze are an abomination! Nothing is less aerodynamic. All mine go inside, even the Country Boy has a built up front fuselage with a space inside (lined with epoxy) and a simple hole for the fuel line to come out and the bladder to go in. Added advantage is it keeps the bladder out of the sunlight. Disadvantage is you cant tell how much fuel is in it, so I empty it each time and refill it the same amount each time. Thermals, Glenn

[gos]

Why not put a hard tank in it and run it on pressure?
Yeah I know, I'll get shot down but I find bladders a pain, and find the hard tank so much more friendly.

[Glenn Schneider]

To answer the hard tank question,two words: foamy fuel -nuf sed. Gos, while I've got your attention, I replaced the greenhead 35 with a small case Johnson 35. Its a 1956 engine as your rules require, only weighs a 1/4 ounce more than a Fox stunt and for my money has much more grunt than the K&B. I'm having much better luck with it hanging together too. Thought you might be interested. Thermals, Glenn

[gos]

Thanks Glen,
Will stay with the K&B at this stage though......looks really nice in the Playboy.

Foamy fuel you say. I can't say I've ever had the problem. I have made the tanks since the mid '70s, have the flood off line at the very rear and feed line a litle ahead, so if the tank for some reason is low on fuel it should still flood off.
I have used bladders way back.....the best were the good old genuine black pen bladders that seem to be long gone now. I built and lost a couple of Kit's Laser Chaser's in the early '70s, "with KSB shutoff timers, and even a couple of Rossi F1C's, but I just find the hard tank filling so much easier and not as messy.....not that I'm a clean freak. LOL.

To each his own of course.

[gos]

On from my last post, last weekend we were messing about looking at old photos with our Grand kids, and this one was taken in early 1974.
The model was a Kit Bays Laser Chaser blown up X 5 from the plan in the magazine and Rossi MK2 powered on a pen bladder tank. It flew okay and was F1C legal but ended up folding it's wings.
The other model has grown up with the kids that were here last weekend. Kit may be also interested to know the Grand kids were born in NC.

[Bruce]

I'm with Glenn all the way,yes bladders can be a pain so do like the F1C guys do make it as simple as possible.You get a much better needle with a bladder,no sag at launch and if it's set up right once its set you almost don't need to touch the needle again.Inside is also the way to go just a little glass and epoxy and your set.

[flydean]

Internal bladders are the way to go. Usually a compartment sealed with epoxy as mentioned earlier works really well.

Genuine black pen bladders are still available, however. Go to pendemonium.com for a huge selection. I use #12 for 1/2A engines, and #14 for anything larger. A penny balloon goes round the whole thing to provide a bit of protection as well.

I have had bladder tanks made with these bladders last a whole contest season.

[gos]

Pendamonium....what a great site. Thanks Dean for the info. Will keep it in mind if I have the need.

[marauderbomber]

Greetings Kit,

What 1/2A are you building?

[Kit Bays]

Thanks Guys, that's good information.

Gos, I like the picture of your big Laser Chaser. Sweet. And if you ever get to eastern North Carolina you should look me up.

Kenny, I'm preparing the final version of the Laser Chaser for classic. Compared to the published one it had a slightly higher aspect ratio wing, a smaller stab, and a boom fuselage. Plan to recover the original wing and stab which still have processing stamps from the 1973 NATS at Oshkoh, which I believe was the last contest in which I flew it. Will build a HyrdoStar-type fuselage (there were problems with the boom fus) and fit it with a set of Taibi's floats for ROW. I will post before and after pictures when complete.

Kit

[marauderbomber]

I like it. Sounds like it will be a lot of fun. I love that unique wing and stab design.

Good luck,

[gos]

Hi Kit,

Good to hear Laser Chaser lives again. The third 1/2A one I built that I still have, was built in 1973. It's in the bottom box of old models, and when you post pics of yours I'll get it out and do the same. For what it's worth I did always think the stab. was very big for the model, but it still went okay like that. Good construction design on the stab. too.
I'll need to check your classic rules.....I'm not au fait with them, but guess 60s or 70s models must fit in?????

Would love to come back to the east side of US. We did spend a lot of time there in the late '90s and loved it. Charlotte was our base but we travelled up to Boston, down to Savannah with a lot of points in between, including to the Outer Banks to see the Wright Kitty Hawk area......very touching indeed, and what a sensational part of the world. When we were there then our dollar was about 1/2 the value of yours, but now with ours at $1.05 to yours we should make the effort.....will have to talk to the financial guru here and see if I can talk her into it as it would be great to chew the fat as such.

Keep us updated please. Cheers.