Do you sump your gascolator?

[gasman]

I can't think of any model RV, that Van's designed their fuel valve below the wing sumps of the aircraft....
Therefore the lowest location of the fuel system is in the fuel tanks at the drain petcock.

The RV15 will be the first RV model that will benefit by having a gascolater installed and inspected before each flight.

Van's head of design for over 16 years, that brought us the RV 7, 8, 9, 10, 12, and 14, did not install a gascolater on his own RV6....... go figure.

[MacCool]

But if you have one, and it is the lowest point, you have to drain it.

..

[RV6_flyer]

I may have missed it but the electric boost pump must be on to get anything out of the gascolator on my airplane. Sumping the gascolator without the boost pump on, I get NOTHING out of my gascolator.

The first year of flying, I sumped the gascolator before 1st flight every day. On the RV-6, the wing tank sump is the lowest point in the fuel system. After lots of checking the first year and the only time I have ever seen any water was after flying through rain. My SOP has been to only sump the gascolator after flying through rain or any event that the airplane has been exposed to water.

Not saying others should do as I do as it is better to test and not need than to overlook a possible problem. I do not suggest skipping the sump of the gascolator till you are 100% certain that water does not get that far in your fuel system.

[Desert Rat]

I can envision an extremely unlikely scenario where a few drops of water get pumped through the fuel system and happily get shoved through the combustion chambers without issue, but on shutdown, whatever is in the gascolator settles to the bottom.

A few drops here, a few drops there...after a few months of that a guy could have a nice slug of water sloshing around in there.

I'm not putting a gascolator on my airplane, but if I had one, I would definitely be sumping it

[rvbuilder2002]

Originally Posted by gasman

I can't think of any model RV, that Van's designed their fuel valve below the wing sumps of the aircraft....
Therefore the lowest location of the fuel system is in the fuel tanks at the drain petcock.

The RV15 will be the first RV model that will benefit by having a gascolater installed and inspected before each flight.

Van's head of design for over 16 years, that brought us the RV 7, 8, 9, 10, 12, and 14, did not install a gascolater on his own RV6....... go figure.

Quite a few of those designs have had gascolators installed in the company airplanes, so I am not sure what you are saying……….

A gascator doesn’t have to be located at the low point in a fuel system to be effective. It is an artificial low point in the system, that used properly, can be an effective filtering system.

My current airplane has a gascolator. Do I sump it? Not during every preflight but I do pretty regularly.

[FireMedic_2009]

Originally Posted by rvbuilder2002

A gascator doesn’t have to be located at the low point in a fuel system to be effective. It is an artificial low point in the system, that used properly, can be an effective filtering system.

My current airplane has a gascolator. Do I sump it? Not during every preflight but I do pretty regularly.

Thanks Scott for your statement. I was going to ask why does everyone state the gascolator has to be at the lowest point. If the gascolator is designed to separate water and debris, what does it matter where the gascolator is mounted? The gascolator can be mounted on top of the cowling and it still should work the same if it were mounted on the gear leg. And if you have an inline filter the only real need for a gascolator is to catch water. And for FI, don’t all fuel servos have a finger strainer/filter? So if you don’t have a gascolator on a FI engine as long as you shake the wings before pre-flight to get any water in the wings to the lowest point and sump it you shouldn’t need a gascolator. And according to DanH, small amounts of water are not a problem for FI unlike for carbs where water can collect in the bowl.

And like someone mentioned in an earlier post, make sure you clean the carburetor bowl annually.

[gasman]

Scott, I do agree that a gascolator can provide a low spot in the fuel system. What I am saying is that it is not the lowest spot in the fuel system. That location remains as where Van's placed the tank sump.

In order for water to make it to the gascolator, you would have to pump it there. I can only think of two ways water can get into the gascolator.

1. You fly through rain and your fuel cap seals are so bad that more than 8oz (RV6 tank) leaks in and is picked up by the pump and delivered to the gascolator by first lifting it to the gas valve that is over 5 inches (guess!) above the fuel pick-up.

2. During your walkaround, you reach in and turn on the master, lower the flaps and flip on the fuel pump to go sump the gascolator. As you take your sample, the pump just sucked up any water that was in reach of the pick-up. That water will not make it to the gascolator during your sample, but will be there the next time you sample...... Sump Your Tanks First.

Should you install a gascolator on your RV....... YES. Do you need one? It all depends on what you do with your airplane. Is it the lowest point in the fuel system?.... NO. Will it trap water?.. YES, only if you fail to sump your tanks properly. Will it save your life if you are flying in a rain storm without fuel caps? YES, but only for about 5 more minutes......

[PaulvS]

The mesh screen in the gascolator that Vans supplied is finer than the mesh on the fuel tank pickup tubes, so it will help to trap any particles that may get through, in addition to any water that hasn't been drained from the tanks before it was picked up and pumped through.

[Snowflake]

Originally Posted by gasman

Therefore the lowest location of the fuel system is in the fuel tanks at the drain petcock.

Unless the tail is raised, ie. on an A model or a tailwheel model in flight. At that point, a gascolator (if properly installed) does become the lowest point in the system. Once the water is trapped there, it won't get out until you sump it.

I have found water in my gascolator. RV-6, and hangared as long as i've owned it. I sump before flight.

[FireMedic_2009]

I keep hearing the only way to suck water into the gascollator is by using a fuel pump which must be insinuating an electric fuel pump since all aircraft engines have a mechanical fuel pump. If the engine driven fuel pump is drawing fuel from the tanks it will also draw water as well. So what makes an electric fuel pump any more efficient to pull water into the fuel system than the engine driven fuel pump? The electric fuel pump is a back up in case the mechanical fuel pump fails.

I can’t imagine anyone not having an in-line fuel filter at the very least which has way more filter area than a gascolator to filter out way more debris. And we certainly aren’t considering the fuel pick up screen which is nothing more than filtering out large debris.

Again why does everyone keep stating the gascolator needs to be at the lowest point of the fuel system when the fuel is being filtered by the gascollator, and as stated by Scott, the gascolator provides an artificial low point in the system, thus separating the water (and debris for those of you who do not have an in-line filter) from the fuel??? Mechanically it shouldn’t matter where it’s mounted on the firewall. If you can come up with a logical explanation as to why the gascolator needs to be at the lowest point, I’d like to hear it.

This reminds me of a story I heard a long time ago. The mom tells her daughter when she cooks the ham to cut off the ends before putting it into the oven because it will make it taste better. The daughter asked why. The mom responses, because that’s what my mom did when she cooked the ham and it tasted so good. So the daughter tells her mom, let’s call grandma and ask her why cutting off the ends of the ham makes it taste better. So they call grandma and ask her. Grandma says, because back then we had really small ovens and the ham would not fit into the oven without cutting off the ends. Hmmmm, I think grandpa Scott is right.