The Griggs/O&N bladder fuel system

[Gilt]

Griggs installed the B800 8-bag 64 gal system in my 1963 M20C. Went from 48 gal to 64gal !  Right at a week turn around. I’m very impressed with their skills . They did a great job!

[steingar]

I have the main bladders.  I want the extra.  Some day, when I have coin...

[Marauder]

The folks at Grigg's are decent people. When we upgraded my original bladder filler caps to the new style, one of the caps leaked when the tank got pressurized a bit. Called them up and with a simple explanation what was going on, sent me a complete set of O rings for the cap.

[carusoam]

Great pirep for the Grigs people!

64 gallons will be great for hauling two people long distances!

Best regards,

-a-

[Jim Peace]

I have a 64C.  I have newer CIES fuel senders.  If I were to do the 64 gallons do you know if I could just use the same senders? Would I need an additional pair?

What did you do?

Did Griggs calibrate your fuel senders/gauges?

did they suggest you keep a certain level of fuel in it when not flying?

total cost out the door if you would like to share.....

looks great.....

[RobertGary1]

How much weight did it gain?

[Gilt]

(1) same senders .. i have (2)EI senders.

(2) yes Griggs calibrated my CGR30C.

(3) forgot to ask if i should keep it a certain level of fuel... but ill keep it topped off.  

(4) ~$15,600 out the door. 

(5) 36.90 lbs     (useful load 955.64).

 

Edited January 26, 2022 by Gilt

[carusoam]

To fill, or not to fill…. And why….?

 

1) Do sealants and polymers ‘dry out’?

No, if they absorbed any fuel… they would swell and that would cause more challenges than drying out….

2) What is the biggest enemy of sealants and polymers?

Heat, the top surface of the wing on a really hot day in the sun, you can cook your breakfast on it…

 

3) How does filling the tanks protect the sealant from overheating?

Air in the empty tank, pretty much works as an insulator and doesn’t take much heat away from the top surface…

Fuel in the tank in contact with the heated surface has the ability to adsorb a lot of heat, thus keeping the temps nicely moderated….

 

4) What’s the difference between a sealed tank and one with bladders?

Bladders don’t have the intimate contact with the heated surface, for the most part….

Sealants are glued intimately to the heated surfaces…

5) What to avoid for the long term health of the fuel tanks….

Avoiding empty tanks, when left out in the sun… makes the most sense for both systems….

 

6) Where do we see the most heat damage to tank sealant?

screws on access panels on the wing’s top surface…

Popular leak… screws under the walkway… it gets both heat and physical stress…

 

The sun hates polymeric materials… 

In this case… UV rays don’t even enter the equation….  
 

PP thoughts only, not a tank man…

-a-

[Gilt]

“The manufacturer recommends keeping fuel in them on a regular basis .they don’t want them to sit dry for a long period of time it will cause dry rot…If by any chance this should happen the bladders can be reconditioned” …   
 

Griggs Aircraft.

 

[David Lloyd]

One of the former Bonanza gurus said to keep some fuel in the bladder tanks to keep from drying out, never leave them empty.  He said a cup of fuel was adequate, they need not be full.

Partial tanks for a few weeks at a time should not be a big deal.  Five years on the ramp in Tuscon with empty tanks will be.

[A64Pilot]

From Cessna’s and Beechcraft, you want to keep bladders full if possible, bladders almost always rot out on the top, not the bottom. It’s often argued if this is because of heat from being outside in the sun or not being wet with fuel. Maybe being wet keeps them cool?

Either way it’s usually 15 or 20 years before it’s a problem, but hangered airplanes I’ve seen with 40 yr old bladders with no issues, so maybe it’s heat moreso?

Call the manufacturer and ask what they want.

I keep my bladders full, but I only hold 27.4 a side I think.

Edited January 26, 2022 by A64Pilot

[67 m20F chump]

I am replacing the wing on my F and put in the bladders.  Griggs was so easy to deal with and would always pick up the phone if I had questions.  I’m happy with them.

[kris_adams]

Looks great.  Love mine as well.  I had them installed at O&N just before being bought by Griggs.  Couldn't be happier. 

Gorgeous plane btw!

[Marauder]

From Cessna’s and Beechcraft, you want to keep bladders full if possible, bladders almost always rot out on the top, not the bottom. It’s often argued if this is because of heat from being outside in the sun or not being wet with fuel. Maybe being wet keeps them cool?
Either way it’s usually 15 or 20 years before it’s a problem, but hangered airplanes I’ve seen with 40 yr old bladders with no issues, so maybe it’s heat moreso?
Call the manufacturer and ask what they want.
I keep my bladders full, but I only hold 27.4 a side I think.

I was told by Ollie (the O in O&N) to try to keep the tanks full if possible. Since I’ve owned them, I have always kept them full. 31 years since installation.

When I installed the new caps and CiES senders, I got a good look at them with my borescope. They looked pretty good for their length of service.


Sent from my iPhone using Tapatalk Pro

[A64Pilot]

I’m 99% sure the bladders in the 76 C-210 I used to fly a lot were original, only issue was the left tank apparently had a wrinkle, which showed up when the fuel cap leaked and the aircraft was left outside.

You could sump that wing and get no water, but rock the wings vigorously and then you would get water.

I used to get black granules in the fuel strainer and was sure that was the bladders breaking down, but it turned out to be the fuel liners.

Bladders are also claimed to be safer in a crash as there is less chance of a fire, but I’ve not seen official data that supports that, but it seems likely.

[RobertGary1]

I took off in my F with full fuel the other day. Probably been close to 10 years since I did that. Wow it turns a sports car into a dog. But useful for those times you need very long legs. 

[A64Pilot]

I had a silver car once, silver is impossible to match because starting from the first day the sunlight bleaches it out.

Silver used to be Mercedes color and they weren’t any better

Paint has come off of my covers, almost like they were SS ?

 

Edited January 27, 2022 by A64Pilot