Notatestpilot
Pre-takeoff checklist
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Notatestpilot
Don't use it. As Nauga says, you can't monitor it or drain it before flight.Nope!
My RV6....thanks.
I don't think anybody makes a clear bowl gascolator for airplanes any more, might have been an AD to replace the glass with a metal tube? Only glass ones I've seen in recent years are for small engines and antique cars, with no drain.Transparent lower container on most models, to see the water or debris, some are metal, must be drained to see what is there, or, not there
Integral drain to remove contaminants
Outlet at the top to the engine, will not pass water until filled
In the rv’s, you’re gonna find any water in the fuel when you sump the tanks. Beyond that, gascolators are a really good way to add heat to your fuel and cause hard hot start and other warm fuel problems.Interesting so many use this sort of filter. I'm a big fan of experimental but apart from a few aforementioned specific use cases, why divert from the well trodden path in such a critical component?
They are common on the sonex line of aircraft. A gascolator doesn’t work with the aerocarb because the aerocarb needs to be the lowest point in the fuel system with a straight downward sloping line from the tank or else vapor bubbles cause the engine to stumble. These in line filters are the only thing that works in the limited space available and are what the factory uses instead of a gascolator now. Standard practice is to replace them every annual. There is also a tank finger strainer before the fuel gets to the filter. Some have also used the ones with a clear housing that can be inspected before flight but they are not made as well. The sonex is a pure gravity fed system so if you have a fuel pump on your RV then your experience may be different. If a gascolator works in the standard RV setup I also wouldn’t recommend deviating from it unless there is a really good reason.
My comments were specific to the aerocarb. A marvel Schebler carb has a float bowl that allows for any air bubbles to not interupt the engine. The aerocarb has no float bowl so any interruption in fuel flow, even a small vapor bubble interrupts the engine and makes it stumble. I don’t recommend it for an RV but that is why many Sonex use that inline filter instead of a gascolator.I just wanted to put in my 00.02 to say that my particular gravity fed aircraft with a Marvel Schebler carb has a gascolator ...
My comments were specific to the aerocarb. A marvel Schebler carb has a float bowl that allows for any air bubbles to not interupt the engine. The aerocarb has no float bowl so any interruption in fuel flow, even a small vapor bubble interrupts the engine and makes it stumble. I don’t recommend it for an RV but that is why many Sonex use that inline filter instead of a gascolator.
I have one. It came off my Jodel. That glass cylinder was 1/4" thick but I still didn't trust it. The head was cast zinc, so the total weight was not airplane-friendly. They were meant for tractors of the 1930s and '40s. I machined an aluminum gasolator for the airplane.I don't think anybody makes a clear bowl gascolator for airplanes any more, might have been an AD to replace the glass with a metal tube? Only glass ones I've seen in recent years are for small engines and antique cars, with no drain.
Some say there is, but I have seen stainless sheet riveted to aluminum, chiefly as firewall sheet to aluminum fuselage. After many decades it's still there in every airplane I've worked on. I've also seen stainless fuel fittings used in aluminum bulkhead fittings in large-aircraft tanks. Then, of course, there are the many stainless exhaust systems bolted to aluminum cylinder heads. Sometimes the flange gaskets are stainless, too. In Lycomings, the spark plug threads are a stainless Helicoil in that aluminum head.Any concern with SS bolt into aluminum threads? Galling? Galvanic corrosion? Or is there a threaded fitting in the top?
Any concern with SS bolt into aluminum threads?
But the critical time when the gascolator is needed is when the airplane is NOT in gorund attitude. That's when the fuel is flowing from the tanks to the engine, and the gascolator does indeed trap moisture and debris. As a mechanic and commercial pilot I've seen it often enough.i have been using the summit version of that for 22 years, never found more than a few specks in it when i clean it. a gascolator on a tailwheel aircraft is just a heat sink. it does no good, as it is not at the low point of the system.
On all of the [tailwheel] airplanes I've owned (Taylorcraft, Kolb, Fisher 404, Starduster, Hatz, Parakeet), the gascolator was indeed the low point of the system, both in flight and on the ground.a gascolator on a tailwheel aircraft is just a heat sink. it does no good, as it is not at the low point of the system.
The reason “low point in the system” matters is because it gives you head pressure when you sump the gascolator. No head pressure = no flow. The important things about a gascolator are the screen and the fact that the bowl acts as a small reservoir and allows water to precipitate out to the bottom of the bowl where it will not be picked up and sucked (or pushed) downstream.On all of the [tailwheel] airplanes I've owned (Taylorcraft, Kolb, Fisher 404, Starduster, Hatz, Parakeet), the gascolator was indeed the low point of the system, both in flight and on the ground.
Not a gascolator quality problem. It was either lousy maintenance practices, or a gascolator that was well past its best-before date.I lost any love for gascolators when the top of mine came loose and the engine began sputtering and gasping. I had a field repair done using safety wire to tighten the top of the bowl.
gasolator top loose video
The real reason it matters is that water and dirt are heavier than gasoline, and will settle in low spots. A fuel line with a low spot can accumulate water until the flow is enough to suddenly shove it farther downstream. Or it can accumulate there and freeze and restrict fuel flow.The reason “low point in the system” matters is because it gives you head pressure when you sump the gascolator.
Exactly. You need a “local” low point to capture the bad stuff. But you need a systemic low spot so gravity allows you to drain it. Put that gascolator up high and it’ll still catch the stuff. But it ain’t gonna drain very well.The real reason it matters is that water and dirt are heavier than gasoline, and will settle in low spots. A fuel line with a low spot can accumulate water until the flow is enough to suddenly shove it farther downstream. Or it can accumulate there and freeze and restrict fuel flow.
There are system drains that are very high. We see examples in nearly every fuel tank: the sump drains, and they work fine.Exactly. You need a “local” low point to capture the bad stuff. But you need a systemic low spot so gravity allows you to drain it. Put that gascolator up high and it’ll still catch the stuff. But it ain’t gonna drain very well.
I have been learning from Dan the last 4-5 years. I have often thought/wish I could capture his knowledge and store it somewhere other than in my weak mind.Dan, you have an amazing reference library.
Speaking from the point of view of one who had one, in a different field, and has recently down sized, do you have a recipient picked out to be the next owner?
Are they enough younger than you to get a lot of use before they retire?
They can end up in the trash if you do not haver a plan in place, well before your self reliance slides.
I transferred my collection of manuals, instruction books and notes in three stages, in my 80's. at 89, when we moved out of our house, the remaining material went into paper recycling. 40 years of work reports, some with complex diagrams of how things worked, went out. I will miss occasionaly pulling one at random, and relive some of my history. No value to any one else, so trash.
You need to find that, or those people now, while your mind is sharp, and be sure they know they are going to receive it. The list should be with your will.
Clear hindsight from 90 years old, but, fortunately, still active, to a limited degree.
Define "soon".Not a gascolator quality problem. It was either lousy maintenance practices, or a gascolator that was well past its best-before date.
Run without a gascolator and you soon realize why it's there.
It only takes one bit of contaminated fuel. If you are using Mogas, it will usually have ethanol in it, which absorbs water and disperses it so it flows through. 100LL won't do that.Define "soon".
I've run without a gascolator for 10 years. Haven't had any problems. I personally know about a dozen planes without a gascolator that have been flying for over 20 (some at 30 years) without any problems.
Once again, define "soon".It only takes one bit of contaminated fuel. If you are using Mogas, it will usually have ethanol in it, which absorbs water and disperses it so it flows through. 100LL won't do that.
Leaky fuel caps are responsible for much water in systems.
Thanks, I had never used the hotkey to access this. It's a Windows facility, certainly in Win 10.Windows Alt-Shift-S combination, holing them down and selecting the section I want with the mouse.
That's it. I mistakenly called out the Alt key instead of the Windows key. I don't even look at them. Alt gets used for a lot of ASCII characters that aren't on the keyboard.Thanks, I had never used the hotkey to access this. It's a Windows facility, certainly in Win 10.
It seems to be WindowsKey-Shift-S. This starts the Snip & Sketch application but without the sketch bit available. There is no need to hold anything down after it has launched.
After starting with WindowsKey-Shift-S you can "upgrade" to get the sketch facility by clicking on "Snip & Sketch".
View attachment 131863
I have Snip & Sketch on the task bar. Maybe I will try the hot key. I do use the sketch bit quite a lot though to highlight relevant parts of the screenshot as shown above.
I’m working on assembling a document with Dan’s and Magman’s posts, plus a few others. It’ll be a fair amount of work, but will be a great maintenance bible.I have been learning from Dan the last 4-5 years. I have often thought/wish I could capture his knowledge and store it somewhere other than in my weak mind.
At least some of it is here in POA.
Thanks Dan.