Can't See Fuel on Dipstick!

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Airmaster23

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Hi,

The dipstick on our club Cessna 150 is made out of a paint stir stick.

I made my own out of a paint stick from Lowes.

The problem is that it is very difficult to see which part of the stick is wet and which is dry when I dip the tanks. I have this problem for both dipsticks.

Can I paint the stick to make it easier to see the fuel? It's 100LL.

Is there a concern of the paint flicking off and contaminating the fuel?

Thanks for any suggestions.
 
I don't have any trouble spotting the wet part with an unfinished paint stick.

But the plastic straw type fuel sticks aren't very expensive and come pre calibrated for a few common aircraft, including a 150/152.
 
MAKG1 said:
I don't have any trouble spotting the wet part with an unfinished paint stick.

But the plastic straw type fuel sticks aren't very expensive and come pre calibrated for a few common aircraft, including a 150/152.
Click to expand...
http://www.mypilotstore.com/mypilotstore/sep/1174

This one is made for a 152.

I can't remember if there is a difference in the bottom shape of the fuel tanks in a 150 and 152. I think the zero mark might be slightly off depending on that.
 
Airmaster23 said:
The problem is that it is very difficult to see which part of the stick is wet and which is dry when I dip the tanks. I have this problem for both dipsticks.
Click to expand...

The problem with very slick prefinished wood is that the fuel has to slightly soak into the wood to be able to see the fuel line. Fuel just runs off of slick wood before it has a chance to soak in.

Do a little sanding with a moderately rough sandpaper, say an 80 or 100 grit, clean the sanding grit and crap off of the stick with paint thinner and see if that doesn't help.

Just for ship and grins, CAREFULLY see if there is ANY way that the paint stick can be dropped into the tank at any angle or configuration. Do not EVER use a dipstick that can find its way into the tank under any conditions.

As somebody else noted, clear plastic tubes precalibrated for the aircraft model are available or made from clear plastic tubing and calibrated by the age-old method of draining the tank and then adding fuel by the liter or gallon and marking your tubing accordingly.

Or you can use the redneck method and strap a lit match to a string and lower it into the tank to see the fuel level :goofy:


Jim
 
Last edited:
"Just for ship and grins, CAREFULLY see if there is ANY way that the paint stick can be dropped into the tank at any angle or configuration. Do not EVER use a dipstick that can find its way into the tank under any conditions."

Tie a string to the stick while doing this , keep the non-stick end in your pocket
 
There is a pink fuel finder paste available from fuel equipment suppliers. You use your finger to smear some up and down the stick. It becomes a darker color when wetted by fuel. We use it all the time to stick our fuel farm storage tanks.
 
weirdjim said:
As somebody else noted, clear plastic tubes precalibrated for the aircraft model are available or made from clear plastic tubing and calibrated by the age-old method of draining the tank and then adding fuel by the liter or gallon and marking your tubing accordingly.
Click to expand...

Like this, just use a cheap engraver.
 

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Matthew said:
http://www.mypilotstore.com/mypilotstore/sep/1174

This one is made for a 152.

I can't remember if there is a difference in the bottom shape of the fuel tanks in a 150 and 152. I think the zero mark might be slightly off depending on that.
Click to expand...

I use that for my 150. I don't know if the tanks are shaped differently, but I always try to be a good pilot and have more than enough gas. Got too close one time and vowed to never let it happen again.
 
So if you use the plastic straw method and you drop it into the tank you can use a coat hanger and bend about 1 inch on the end with a 90 degree bend and use that to slide it into the end to the straw and lift it up. On a 95 degree day on a ramp in the middle of Ohio it will only take you about 1/2 hour to retrieve the straw. It will take you about 3 second to vow to never drop it again.
 
When the mechanics open a rental or flight school airplane they often find several of the dip tubes. One had a screwdriver.
 
JB1842 said:
I use that for my 150. I don't know if the tanks are shaped differently, but I always try to be a good pilot and have more than enough gas. Got too close one time and vowed to never let it happen again.
Click to expand...

I saw some online POH copies:

A '68 150 POH says:
26 gal total 22.5 usable 3.5 unusable
(13 per side 11.25 1.75)

An '80 152 POH says:
26 gal total 24.5 usable 1.5 unusable
(13 per side 12.25 .75)

The FuelHawk dip tubes are calibrated so that the zero mark falls on the level of the unusable fuel. So when they read 10 gal, they mean "10 gal usable". And when they read zero (even though there is fuel inside the diptube) they mean "zero".

I zip-tied a USB thumb drive lanyard to the top end of my Fuelhawk so it's wrapped around my wrist when I use it.
 
Flat black paint is the best to use on hard to read dipsticks, but I second getting a tube type.
 
jtheune said:
So if you use the plastic straw method and you drop it into the tank you can use a coat hanger and bend about 1 inch on the end with a 90 degree bend and use that to slide it into the end to the straw and lift it up. On a 95 degree day on a ramp in the middle of Ohio it will only take you about 1/2 hour to retrieve the straw. It will take you about 3 second to vow to never drop it again.
Click to expand...

... or poke a hole through a tennis ball and stuff the top end of your straw (or paint stick) into it to keep it from dropping in the tank in the first place!
 
Matthew said:
I saw some online POH copies:

A '68 150 POH says:
26 gal total 22.5 usable 3.5 unusable
(13 per side 11.25 1.75)

An '80 152 POH says:
26 gal total 24.5 usable 1.5 unusable
(13 per side 12.25 .75)

The FuelHawk dip tubes are calibrated so that the zero mark falls on the level of the unusable fuel. So when they read 10 gal, they mean "10 gal usable". And when they read zero (even though there is fuel inside the diptube) they mean "zero".

I zip-tied a USB thumb drive lanyard to the top end of my Fuelhawk so it's wrapped around my wrist when I use it.
Click to expand...

Thanks for the info. I'm going to have to look into that more. I take the unusable off the markings. If it says 20 gallons total for both tanks, I plan on only having 16.5 usable.
 
ElPaso Pilot said:
... or poke a hole through a tennis ball and stuff the top end of your straw (or paint stick) into it to keep it from dropping in the tank in the first place!
Click to expand...

I made a stick for my Cherokee 140 that is exactly twice the required length (and it's still only a foot or so long). Anyway, it works no matter which end I stick in there, and being long, it is very hard to drop into the tank.

Tim
 
I have the straw type calibrated to my fuel tanks, great tool for fuel and weight calculations. I have used mine for several years, haven't dropped it in yet.
 
JB1842 said:
Thanks for the info. I'm going to have to look into that more. I take the unusable off the markings. If it says 20 gallons total for both tanks, I plan on only having 16.5 usable.
Click to expand...

From what I've seen, they only make a 152 stick. And the usable fuel differs from the 152 and 150.

At zero on the tube, the 152 will have .75 gal in the tank. What I don't know is what the the 150 will have in the tank - you'd think 1.75. So if the fuel tanks are shaped the same and the pickups have just been moved farther down, that same tube used on a 150 might indicate you still have one gallon left even though it's unusable. That's another reason to be careful at low levels.
 
Matthew said:
From what I've seen, they only make a 152 stick. And the usable fuel differs from the 152 and 150.

At zero on the tube, the 152 will have .75 gal in the tank. What I don't know is what the the 150 will have in the tank - you'd think 1.75. So if the fuel tanks are shaped the same and the pickups have just been moved farther down, that same tube used on a 150 might indicate you still have one gallon left even though it's unusable. That's another reason to be careful at low levels.
Click to expand...

Yeah. I try not to let it get that low. Almost bit me once, so I take extra care to plan accordingly.
 
I use this one. If you are worried about the paint just buy this one. It's like 10 bucks.
 
JB1842 said:
Thanks for the info. I'm going to have to look into that more. I take the unusable off the markings. If it says 20 gallons total for both tanks, I plan on only having 16.5 usable.
Click to expand...

It's not meant for high accuracy, it's just there to confirm or deny what the gauge says. I really don't understand why every plane isn't fitted with a real fuel flow/totalizer.:nonod: If you want accurate info, that is how you get it. You just look in or stick the tanks to see if anyone siphoned you out. If you don't see a gross error, the totalizer will accurately tell you how much fuel remains. You then look at the gauges for distribution.
 
Henning said:
I really don't understand why every plane isn't fitted with a real fuel flow/totalizer.:nonod:
Click to expand...

Yeah, figure out how to do that in something like a J-3 or Aeronca. Some planes just don't need something like that.
 
Greg Bockelman said:
Yeah, figure out how to do that in something like a J-3 or Aeronca. Some planes just don't need something like that.
Click to expand...

Fine, I though about adding 'with an electrical system' but didn't really think I had to since they make up a tiny fraction of the GA fleet. Here would be an interesting one to find from the NTSB if they kept the records, what percentage of fuel exhaustion events were in planes with a fuel totalizer?
 
Henning said:
Fine, I though about adding 'with an electrical system' but didn't really think I had to since they make up a tiny fraction of the GA fleet.
Click to expand...

I had an EI FP-5L in my Cessna 195. It took some effort to get it set up so it was accurate. Having said that, it was still a "Garbage In - Garbage Out" instrument. In other words, it took some effort on each fill up to make sure it knew how much gas was onboard. If that wasn't done accurately, then one ran the risk of trusting it too much and still running out of fuel.

If one wanted to truly be able to rely on the instruments, what is need are fuel gauges that are accurate nearly 100% of the time. I don't see that happening with float type fuel gauges.
 
Greg Bockelman said:
I had an EI FP-5L in my Cessna 195. It took some effort to get it set up so it was accurate. Having said that, it was still a "Garbage In - Garbage Out" instrument. In other words, it took some effort on each fill up to make sure it knew how much gas was onboard. If that wasn't done accurately, then one ran the risk of trusting it too much and still running out of fuel.

If one wanted to truly be able to rely on the instruments, what is need are fuel gauges that are accurate nearly 100% of the time. I don't see that happening with float type fuel gauges.
Click to expand...

Nope, you would need at least a pneumo/Bourdon tube system.
 
Greg Bockelman said:
If one wanted to truly be able to rely on the instruments, what is need are fuel gauges that are accurate nearly 100% of the time. I don't see that happening with float type fuel gauges.
Click to expand...

Even the capacitance gauges in what I fly seem to be needing calibrated significantly more often than I would consider to be a good system.
 
archerdriver said:
"Just for ship and grins, CAREFULLY see if there is ANY way that the paint stick can be dropped into the tank at any angle or configuration. Do not EVER use a dipstick that can find its way into the tank under any conditions."

Tie a string to the stick while doing this , keep the non-stick end in your pocket
Click to expand...

Strings, like spaghetti, are really quite slippery when you lose your footing on the ladder and start grabbing for anything sturdy.

Jim
 
timrb said:
I made a stick for my Cherokee 140 that is exactly twice the required length (and it's still only a foot or so long). Anyway, it works no matter which end I stick in there, and being long, it is very hard to drop into the tank.

Tim
Click to expand...

Too sensible an answer! I've used a wooden paint stick from Sherman Williams for many years. ( the tall one used for five gallon buckets) . Plain wood, not painted. . Gas shows up on it perfectly. Very difficult to drop into tank I would think. Has worked perfectly on 195 Cessna, champ, cub, t craft, Luscombe, etc. fill the tank, dip it. Mark gas level full. Really simple.
 
Henning said:
It's not meant for high accuracy, it's just there to confirm or deny what the gauge says. I really don't understand why every plane isn't fitted with a real fuel flow/totalizer.:nonod: If you want accurate info, that is how you get it. You just look in or stick the tanks to see if anyone siphoned you out. If you don't see a gross error, the totalizer will accurately tell you how much fuel remains. You then look at the gauges for distribution.
Click to expand...

I don't trust the gauges very much, at least not to let me know how many gallons are left. As my instructor told me, they only need to be accurate when the tanks are empty.
 
JB1842 said:
I don't trust the gauges very much, at least not to let me know how many gallons are left. As my instructor told me, they only need to be accurate when the tanks are empty.
Click to expand...

Another aviation myth that crops up from time to time. See this:

§91.205 Powered civil aircraft with standard category U.S. airworthiness certificates: Instrument and equipment requirements.

(a) General. Except as provided in paragraphs (c)(3) and (e) of this section, no person may operate a powered civil aircraft with a standard category U.S. airworthiness certificate in any operation described in paragraphs (b) through (f) of this section unless that aircraft contains the instruments and equipment specified in those paragraphs (or FAA-approved equivalents) for that type of operation, and those instruments and items of equipment are in operable condition.



(9) Fuel gauge indicating the quantity of fuel in each tank.



____________________


Now, if the gauge is dead it's accurate when the tank is empty. But that's not what the reg requires. A dead gauge can't indicate the quantity of fuel in the tank.


Dan
 
Dan Thomas said:
Another aviation myth that crops up from time to time.
Now, if the gauge is dead it's accurate when the tank is empty. But that's not what the reg requires. A dead gauge can't indicate the quantity of fuel in the tank.
Click to expand...

The hiccup in the rule, of course, is the unstated tolerance. If it indicates dead nuts on when full and empty, but dead nuts on full for anything in between, is that within tolerance? Since it is not stated, I'd argue yes. But does it have to be perfectly linear? To what slope or tolerance?

JIm
 
Henning said:
Flat black paint is the best to use on hard to read dipsticks, but I second getting a tube type.
Click to expand...

I make dipsticks from aluminum, and either paint them with flat black high-heat paint (barbeque paint) and then cook it on with a torch so it stays put and doesn't dissolve in the fuel, or use a darker green epoxy primer. The epoxy is the best.

If the dipstick is made in a tee shape so that the tee bar rests on the tank filler neck, it can't fall in, and the stick can be trimmed to a length that doesn't quite touch the bottom of the tank. Important for bladders. I drain the tank completely, put in unuseable fuel and use that level for the zero mark. In many tanks it won't even show up on the dipstick.

Dan
 
Dan Thomas said:
Another aviation myth that crops up from time to time. See this:

§91.205 Powered civil aircraft with standard category U.S. airworthiness certificates: Instrument and equipment requirements.

(a) General. Except as provided in paragraphs (c)(3) and (e) of this section, no person may operate a powered civil aircraft with a standard category U.S. airworthiness certificate in any operation described in paragraphs (b) through (f) of this section unless that aircraft contains the instruments and equipment specified in those paragraphs (or FAA-approved equivalents) for that type of operation, and those instruments and items of equipment are in operable condition.



(9) Fuel gauge indicating the quantity of fuel in each tank.



____________________


Now, if the gauge is dead it's accurate when the tank is empty. But that's not what the reg requires. A dead gauge can't indicate the quantity of fuel in the tank.


Dan
Click to expand...

Thanks for pointing that out. I trust my gauges to give me a ballpark of how much fuel I have, but not down to the exact gallon.
 
Get a pipette. It is just a plastic tube with some calibration marks on it.
 
weirdjim said:
Or you can use the redneck method and strap a lit match to a string and lower it into the tank to see the fuel level :goofy:
Jim
Click to expand...

I'm concerned about the accuracy of this method. While it would give you an accurate initial reading, wouldn't the fuel level dramatically change as it catches on fire? It seems difficult to accurately account for the lost fuel. :nono:
 
I just bought a 1 inch wide dowel from depot, dremeled the markings on it after calibrating by adding 2gal at a time.

Works great and with the width it's easy to read and can't fall into the tank.
 
johnrweb said:
I'm concerned about the accuracy of this method. While it would give you an accurate initial reading, wouldn't the fuel level dramatically change as it catches on fire? It seems difficult to accurately account for the lost fuel. :nono:
Click to expand...

Trust me, neither the aircraft nor you will ever have to worry about accurate readings again . :yes:


Jim
 
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