What is this stuff in my gascolator?

[Vance Harral]

15-20 *inch* pounds is the torque spec on the gascolator.  It's very light.  Use caution, I broke my fuel selector last year after mis-understanding the torque spec, and finding a replacement was a saga.

You can undo the rod on the nose gear door.  Or, if your airplane is more workhorse than beauty queen, a long-shaft phillips screwdriver with a bit of flex in the shaft, and a willingness to bend and rub on the gear door during the deed, can also get the job done.

We don't necessarily replace the gasket every year, I will re-use it a second year if it appears to be in good shape.  LASAR does indeed sell the gasket and fancy washer, but be aware they sold me a faulty gasket last year.  I'm not saying it's their fault, necessarily - they just stock parts from Mooney.  But it was definitely bad.  You can read about it here: https://mooneyspace.com/topic/34307-fuel-selector-woes/?do=findComment&comment=584949

[Mcstealth]

I like the idea of taking a sample of fuel and allowing it to evaporate. 

[AH-1 Cobra Pilot]

On 4/8/2021 at 8:08 AM, A64Pilot said:

Does anything grow in Avgas? I don’t think anything does?

Something does. 

 

[AH-1 Cobra Pilot]

Do you have access to a good microscope?  You can learn a lot by looking at something on the micro-scale.  If you do not, you can send a piece to me.  PM me if so.

[philiplane]

I see plenty of white fuzz on the inlet side of fuel bowl screens, it comes from fuel dispensers. How yours got on the other side is a mystery though.

[A64Pilot]

40 minutes ago, AH-1 Cobra Pilot said:

Something does. 

 

Looking at that takes me back. We ran a training mission on night in Tx, went to the FAARP, no truck, so of course we shut down and waited, the Col got on the phone and was giving the LT Hell about where is the truck. Well a couple of hours later the truck show up and starts refueling the aircraft. when he was done we all got in and began starting up to leave, well the  Blackhawk had its APU”s shut down in a couple of minutes, all the Apache guys laughed at him and we left.

‘Turned out the truck had been in the motor pool for some work and I guess the procedure is to empty the truck and “purge” it with some kind of purging fluid, and they didn’t get all the fluid out in the rush get the truck back into service, the Blackhawk was fueled first and got a shot of the fluid, all the Aqua glow testing and recirculating fuel etc was skipped because the Col was giving them Hell.

So I wonder if anything was growing or was it some kind of contaminant?

Ref “bugs” growing in Jet-A and requiring liquid water to grow, first it’s bacteria and not algae etc like you may hear and while it certainly love’s a water / fuel interface it will grow in fuel without liquid water, just not as well. Fuel has water dissolved in it, even gasoline, especially if the gasoline has any alcohol in it, but I was unaware of anything that could grow in gasoline.

‘If any if you are curious, look up APPL jelly, sometimes it’s not just as simple as removing the water.

Edited April 9, 2021 by A64Pilot

[Vance Harral]

Pulled the fuel servo inlet screen today and found more junk.  Cleaned and flushed with solvent.  Still no smoking gun as to exactly what's causing this.

 

 

 

[A64Pilot]

Touch some of it with a soldering iron, see if it will melt. I think that may point to a plastic, if it chars I think that may point towards something like cotton?

As I said if it’s organic, I believe bleach will make it change color.

I think I would get a 55 gl barrel and using the boost pump, pump the tanks dry, put an inline filter in the line, you can use cheap vinyl plastic hose you get at home depot, no pressure and your not using it for long, plus of a slug of anything goes though, you’ll see it.

Inspect the inside of the tanks and using an inexpensive electric fuel pump, pump the fuel back in, again going through an inline filter.

That ought to get you back to clean fuel.

‘I’m betting the person that said it came from a filter on the truck breaking down, called it.

‘Bond everything together and connect to a ground of course, don’t let the fuel air drop into the drum, put the hose to the bottom of the drum

[FlyingDude]

On 4/8/2021 at 1:08 AM, Vance Harral said:

Weldon boost pump

Hey, I have a weldon, too. Do they have any screens, filters, whatnot to clean? Thanks.

[PT20J]

14 hours ago, FlyingDude said:

Hey, I have a weldon, too. Do they have any screens, filters, whatnot to clean? Thanks.

The filter was only a retrofit for aircraft with a Dukes pump per SB M20-222A. So, unless you originally had a Dukes pump and a filter was installed, your airplane shouldn’t have one.

Skip

[FlyingDude]

Yeah, I'm ok with that part. They even annotated it among the list of ADs that were complied with.

What I wondered was if there's a screen, filter, etc "built into" the weldon pump. 

Thank you

[bradp]

There are examples of material bypassing a filter to reaggregate beyond.  

[FlyingDude]

2 hours ago, bradp said:

There are examples of material bypassing a filter to reaggregate beyond.  

I worked on throttle bodies whose job was to create turbulence such that recirculated exhaust gas mixed better with clean air. We did see some coagulation of dirt downstream of the throttles... So here, I would speculate that the turbulence downstream of the screen mesh made tiny threads that alone were to small to pass through the screen holes recombine. And the low pressure generated by the vortices kept them there.

Who has Ansys license and can simulate this? Man, it would be so much fun to figure this out

 

[EricJ]

6 hours ago, FlyingDude said:

Yeah, I'm ok with that part. They even annotated it among the list of ADs that were complied with.

What I wondered was if there's a screen, filter, etc "built into" the weldon pump. 

Thank you

No, but there should be one in the fuel selector/gascolator.