Mooney Bladder Fuel Stick

[MoonFlyer68]

I am not about to start up the great bladder vs sealant debate, but I wanted to pass along something I got from Griggs up in PA.  After my install at an MSC, I started to develop some leaks when the bladders were filled to the top.  Rather than just have anybody look at them, I took them back to the people that produce the bladders so I could get the best care possible.  The people up at Griggs were great and the job went pretty quick finding the fittings that came loose and were causing my leaks.  They also identified a couple issues from the original install and corrected them.  One thing I was not expecting was they made a custom fuel stick for my plane including having my tail number stamped into the metal.

I make no guarantees so use this information at your own risk.  My plane is a 1968 F with the 64 gallon bladders installed.  Here are the measurements of the fuel stick they made for me. If anyone else with bladders was wanting to make a fuel stick, this could be a good starting point.  Enjoy

[BDPetersen]

Very nice. I wish I had that for my 54 gallon C installation.

[The Other Red Baron]

10 hours ago, BDPetersen said:

Very nice. I wish I had that for my 54 gallon C installation.

I copied these measurements and they seem to be in good enough territory for me.  90% of my trips I'm filling the tanks up every chance I get any way.

 

 

[Pinecone]

The July issue of Mooney Flyer has an article about calibrating commercial sticks, and can be used for making your own.

[A64Pilot]

On 7/29/2023 at 7:17 AM, BDPetersen said:

Very nice. I wish I had that for my 54 gallon C installation.

This is my 54 gl J, but as I think the wings are the same it ought not matter?

After dropping a commercial fuel stick into the bladder on a C-210 and having not just a little difficulty retrieving it, I decided to make my own that you can’t drop into the tank, so I stole one of the Wife’s wooden whatever this is. Wide part won’t fit in the opening, it’s too big. I think it’s actually bamboo, the top mark on the 15 gls is the actual mark, I wasn’t pushing down on the stick on the first one and the bladder either compresses slightly or more likely wasn’t laying perfectly flat.

Interesting is the distance between 25 and 27 gls, it’s done every 5 gls, but the first 5 didn’t wet the stick.

Just fly around until the engine quits, change tank of course and put in 5 gls at a time and mark stick, let it sit a little while just in case it has to level out between the bladders, didn’t seem to make much difference but I waited a couple of minutes anyway.

 

Edited July 30, 2023 by A64Pilot

[BDPetersen]

Thanks, I’ll check it out. Tried to make a stick on initial fueling post bladder installation, but the results were unusual. Haven’t revisited the project.

[Pinecone]

I like the wooden spoon.

But they do make a device to keep from dropping the plastic tube type into the tank.

https://www.sportys.com/the-fuel-stop.html

 

[A64Pilot]

Before I hit on the wooden spatula thing I used a wooden dowel on the 210 that was too long to drop in, after of course dropping in one of the plastic straw tubes

I like something that gets wet because then you can see the fuel mark, the bamboo dries completely in seconds too, and being a CB is cheap.

I was using it to press a bearing in with my vise, the bamboo is strong but won’t mark steel and thought why not?

Results being “unusual” is I think normal, the quantity per distance isn’t linear, which is I think one thing that makes fuel gauges so tough to be accurate, and why I think you have to have multiple calibration points or it’s not going to work.

Edited July 31, 2023 by A64Pilot

[catchman86]

On 7/29/2023 at 7:17 AM, BDPetersen said:

Very nice. I wish I had that for my 54 gallon C installation.

Hey brother, I think I have you covered. I have a '62 M20C with bladders and I just did a custom Fuel Stik for my plane. I used a siphon plus a 2 gallon gas can and measured out two gallon increments to get accurate numbers. I don't have an engine monitor but have tested the burn based on power settings over 10 flights since measuring and the numbers come out within about a half gallon or so of where I predicted. If you'd like to buy a stick from Fuelstik.com, Sportys, Aircraft Spruce, etc., then you should be able to use this scale.

 

By the way, I cleared up a bit of a mystery when I was working on this project about the true fuel volume of the bladders. My '62C when built had only 48 gallon tanks according to the owners manual. My aircraft and STC records only reference bladders added and their serials without stating the fuel capacity, so I reached out to Griggs who confirmed that my tanks were indeed expanded to 54.8 gallons total with the bladders because that bladder 27.4 gallon bladder (each) size corresponds with their part number. So now I know for certain that my tank capacity is indeed higher thanks to the bladder STC. I cannot recommend Griggs enough based on the level of help they provided in pursuit of answering my burning question. I will not hesitate to work with them if needed in the future.

Printable Mooney M20C 27.4 Gal N6475U 6-16-23.pdf

[Buckeyechuck]

Been looking for something like this ever since having bladders installed. Thanks. This is great.