Anyone have any idea what happened to this airplane?

[dkkim73]

On 11/28/2024 at 6:30 AM, GeeBee said:

I use the quart bottles from MG chemicals on Amazon. About 10 bucks a quart. Be careful with it as it is really hard and tank sealant. I use a big syringe to measure it out and meter it in at the fuel nozzle for a good mix. 

Thanks for the source. What size syringe did you find convenient for typical fills? 

[Fly Boomer]

As I understand it, IPA is more attracted to water dissolved in fuel than it is to the fuel itself.  Once The IPA has found all the dissolved water, the new freezing point of the water/IPA mixture (when crystals can form) is -43 °C.  So, with our turbocharged birds, there are temperatures below which ice crystals can form even if the fuel was well-mixed with the IPA.

[dkkim73]

Interesting topic. As the alcohol would absorb water, it seems a (the most?) vulnerable period is when alcohol is in the tanks, sitting on the ground less than full-full. 

Ie. wide surface area communing with the atmosphere via the vents. 

So, maybe I could drop a heating element into the avgas? ok, joking. However, it made me wonder about the utility of drying the air. E.g. a dry air circuit like an engine dryer except going between the tank cap and the vent? Would have some fuel vapor to safely manage, but I imagine one could dry or keep dry fuel this way. 

@A64Pilot's comments on processing/testing/drying fuel made me think of this. 

[dkkim73]

I just added IPA to my tanks and the engine is running terribly. I think it's those new West Coast IPA's with the unreasonable amount of hops and weird aromatic fermentation by-products... 

[GeeBee]

1 hour ago, Fly Boomer said:

As I understand it, IPA is more attracted to water dissolved in fuel than it is to the fuel itself.  Once The IPA has found all the dissolved water, the new freezing point of the water/IPA mixture (when crystals can form) is -43 °C.  So, with our turbocharged birds, there are temperatures below which ice crystals can form even if the fuel was well-mixed with the IPA.

True, but if your fuel tank temp gets below -43, you got other problems. 

[GeeBee]

1 hour ago, dkkim73 said:

Thanks for the source. What size syringe did you find convenient for typical fills? 

https://www.amazon.com/Individually-Measurement-Scientific-Measuring-Applicator/dp/B0C1NBMHWM/ref=sr_1_5?crid=3U3ZVPVUMH2QJ&dib=eyJ2IjoiMSJ9.BakRLezekQvh3OqlrGgEzFDnFr6rjLYtnIy-swIT3oUNH_c3eKLhLJRnIYk30cIxH8zHgKtDPhZcW63IfC6eHWQwTWZIfQgYDY03pvwMSzpRYfDEgmdtUtRsUGv6NyvienWmzzVoLNB4LJC3UxVqMNzOcPZmeTZ_DhrmMN_T5vaovmO6np6PNnSbVG4Mv_2nWcdbx_OcQZDlNSa9eHc5owb2zPAgZxYNNbQ6cvy4tzM.DZVuOcaxzFFmrj3D6qcLVfdCXGbYu12THoXazm-mxVU&dib_tag=se&keywords=syringe&qid=1732994552&sprefix=syrin%2Caps%2C143&sr=8-5

[N201MKTurbo]

I just read about using silica gel desiccant to dehydrate a gas tank. It seems feasible, with caveats.

The gel will absorb water much more aggressively. Until the gel gets saturated with water, then it will start absorbing fuel vapor.

[Pinecone]

For measuring, syringe is pretty small.  1% is 1 gallon per 100 gallons.  So even a 34 gallon tank, you are putting in more than a quart.

As I understand it, adding IPA is not for water dissolved in the fuel, but for liquid water that gets trapped in nooks and crannies.

And that water is not a problem at sub 0C temps, as it is then frozen.

Water dissolved in the fuel is the source for ice crystals.  If the fuel is fully saturated, as it cools, the ability to hold water is less.  So the water precipitates out and immediately freezes as ice crystals.  The problem with ethanol containing fuels is the large amount of alcohol draws water out of the atmosphere into the fuel.  And when the fuel has more water, the more likely you will get precipitation ice crystals when the fuel cools.

IMO, using IPA could cause more issues with ice crystals.   I would only use it if I thought that some liquid water got in (heavy rain with plane outside).

[Sue Bon]

On 11/29/2024 at 7:58 PM, AME LLC said:

I fly and maintain an A26 here in Seattle called Sexy Sue.

Love that plane. Love that name!  

[neilpilot]

7 hours ago, Pinecone said:

As I understand it, adding IPA is not for water dissolved in the fuel, but for liquid water that gets trapped in nooks and crannies.

And that water is not a problem at sub 0C temps, as it is then frozen.

Water dissolved in the fuel is the source for ice crystals.  If the fuel is fully saturated, as it cools, the ability to hold water is less.  So the water precipitates out and immediately freezes as ice crystals. 

That's very different from my understanding.

As I understand the process, IPA is specifically intended to address dissolved (or, more correctly, soluble) water in the fuel.  Water solubility in fuel is decreased at the much lower temperatures experienced at altitude, and if no IPA is present to keep it in solution those very fine ice crystals can then form and block fuel flow.

[GeeBee]

7 hours ago, Pinecone said:

For measuring, syringe is pretty small.  1% is 1 gallon per 100 gallons.  So even a 34 gallon tank, you are putting in more than a quart.

As I understand it, adding IPA is not for water dissolved in the fuel, but for liquid water that gets trapped in nooks and crannies.

And that water is not a problem at sub 0C temps, as it is then frozen.

Water dissolved in the fuel is the source for ice crystals.  If the fuel is fully saturated, as it cools, the ability to hold water is less.  So the water precipitates out and immediately freezes as ice crystals.  The problem with ethanol containing fuels is the large amount of alcohol draws water out of the atmosphere into the fuel.  And when the fuel has more water, the more likely you will get precipitation ice crystals when the fuel cools.

IMO, using IPA could cause more issues with ice crystals.   I would only use it if I thought that some liquid water got in (heavy rain with plane outside).

I order the 350 mil (11.835 oz) size syringe which treats 9.2 gallons. So while you are fueling at least for me on a 44 gallon tank which I do not empty, I might have to load the syringe 3 times at 1%. Personally I only use 0.5%.

[Pinecone]

1 hour ago, GeeBee said:

I order the 350 mil (11.835 oz) size syringe which treats 9.2 gallons. So while you are fueling at least for me on a 44 gallon tank which I do not empty, I might have to load the syringe 3 times at 1%. Personally I only use 0.5%.

Or make it easier and add 2 pints/1 quart per tank.  

Versus measuring out 28.16 ounces.

0.568% versus 0.5%.

Measure with a micrometer, mark with a crayon, cut with an axe.

[Jim Peace]

Just live in Florida.........problem solved

[N201MKTurbo]

5 minutes ago, Jim Peace said:

Just live in Florida.........problem solved

If you don’t go anywhere….

[GeeBee]

1 hour ago, Pinecone said:

Or make it easier and add 2 pints/1 quart per tank.  

Versus measuring out 28.16 ounces.

0.568% versus 0.5%.

Measure with a micrometer, mark with a crayon, cut with an axe.

Yes but the problem with bulk loading is getting a good mix. The stuff is really hard on tank sealant. I prefer to meter it in at the nozzle stream like you do with Prist on JetA. The syringe allows you to do that.

[Pinecone]

13 hours ago, GeeBee said:

Yes but the problem with bulk loading is getting a good mix. The stuff is really hard on tank sealant. I prefer to meter it in at the nozzle stream like you do with Prist on JetA. The syringe allows you to do that.

As long as there is fuel in the tank, I don't see it eating tank sealant in a couple of minutes.  Otherwise the tank reseal guys would use it.

 

[Jim Peace]

16 hours ago, N201MKTurbo said:

If you don’t go anywhere….

Flying in the winter with no palm tress around?  Thats just plane crazy.......

[GeeBee]

3 hours ago, Pinecone said:

As long as there is fuel in the tank, I don't see it eating tank sealant in a couple of minutes.  Otherwise the tank reseal guys would use it.

 

It sits in your tank for a long time. Think about it.

[dkkim73]

5 hours ago, Jim Peace said:

Flying in the winter with no palm tress around?  Thats just plane crazy.......

Somewhere, up above, Jimmy Buffett is smiling at you. 

[dkkim73]

4 hours ago, GeeBee said:

It sits in your tank for a long time. Think about it.

Yeah, I wonder. I think the take-home I have from the last couple pages of posts is to think ahead about fill cycles (bigger fill for XC alone, smaller fills for taking people locally, etc) and try to decrease dwell time. 

 

[Pinecone]

22 hours ago, GeeBee said:

It sits in your tank for a long time. Think about it.

Yes, but the final concentration is the same.  You were saying you wanted to inject it into the fuel stream from the pump.  

Even if you dump it into an empty tank then fill, it is only in contact with the sealant, at high concentration, for a minute or two.   If you are worried about that, fill the tank to 1/2, add the IPA, then top off.  The fuel coming in will mix the IPA with the fuel.

[GeeBee]

1 hour ago, Pinecone said:

Yes, but the final concentration is the same.  You were saying you wanted to inject it into the fuel stream from the pump.  

Even if you dump it into an empty tank then fill, it is only in contact with the sealant, at high concentration, for a minute or two.   If you are worried about that, fill the tank to 1/2, add the IPA, then top off.  The fuel coming in will mix the IPA with the fuel.

Do you have experience in using the product?

[Pinecone]

19 hours ago, GeeBee said:

Do you have experience in using the product?

I have some on my shelf, but have not had a need to use it.

But again, if adding a couple of quarts to a half full tank and filling damages the sealant, it will flat strip the sealant off in minutes in an empty tank.  And the tank reseal shops would be using it.  Polygon stripper contains NO IPA.

Just found a reference where polysulfide and butyl O-rings are specifically recommended for environments with IPA.  https://www.efunda.com/designstandards /oring/oring_chemical.cfm?SM=none&SC=Isopropanol

[GeeBee]

2 minutes ago, Pinecone said:

I have some on my shelf, but have not had a need to use it.

But again, if adding a couple of quarts to a half full tank and filling damages the sealant, it will flat strip the sealant off in minutes in an empty tank.  And the tank reseal shops would be using it.  Polygon stripper contains NO IPA.

Just found a reference where polysulfide and butyl O-rings are specifically recommended for environments with IPA.  https://www.efunda.com/designstandards /oring/oring_chemical.cfm?SM=none&SC=Isopropanol

I can tell you I have a lot of experience using it since my college days in Alaska. I have seen it take out tank sealants, I have seen it take out sender gaskets when not well mixed or where it sits for a long time. Most recently after using it, my 15 year old tank sealant started to leak, guess where? On the plate below the filler. I have placed some in a GATTs jar with fuel. Without agitation it does not readily mix. This is why iinsertion requires adding to the stream.

The reason why it is not used in tank stripping is safety and evaporation rate. It is highly flammable much more so than Polygon and it evaporates quickly from any mix.

[Pinecone]

Interesting.  Thanks.