Bubbleless fuel tanks

[Peter Ferguson]

I was looking through the Central Hobbies site and I saw that Tettra is offering bubbless fuel tanks. My previous experience with Tettra products has all been very good.  I believe they are a plastic  clunk tank with a bladder. They come in 3oz sizes and up. I presume you pressurize the outside of the bladder. The advantages seem obvious, less air to mix with the fuel,  what would be the expected disadvantages of this system? Whats been the experience with this type of system ? (surely it been done before)

http://www.centralhobbies.com/Fuel/fueltnk2.html

[Steve Helmick]

Rod Claus and Tom Strom have used them in the PNW...probably Dirty Dan, too. They work fine, but are a bit of a pain in the rump to prep (empty) & fill. Not sure if run time is a problem or not, but I could see how there might be some variations if you're not really careful. I think Rod liked the Tettra tank but stopped using them. Haven't seen Tom out flying stunt in several years. Generally, simpler is better.  Steve