Cary wrote:FWIW, I have the well-type fuel caps on my P172D (no flapper covers like early 180s/182s have), which were standard on earlier 172s. Whenever I park her outside for awhile, I put these guys on, which keeps water out of the well and out of the fuel cap vents:



They work pretty well--in the 11 years I've had my airplane, I haven't had any water in either tank. So that I won't forget to take them off, I extended the "Remove Before Flight" tags which were on them (and easy to miss during pre-flight) with cords, which I drape over the leading edge and loop around the struts.

Cary

FYI, Monarch has a very simple collar that covers the well on the 170 fillers, and replaces the caps. I installed on my 170 which sat outside on floats all summer. Before, I always got some water out of my tanks from sumps. After this simple mod, I never got any water out. I presume they have a kit for the 172.....maybe. A good kit in any case, and well worth doing.

MTV

Thanks for the info. I was wrong.

We had one 180 with the flush doors. One side was always flooded, the other side drained fine. Good idea on the use of canned air to blow out the drain frequently.

Another 180 had the doors again but they were raised not flush. Never a drop.

corefile wrote: ....it can become a well to hold water. What I do is use a can of keyboard cleaner (compressed air) and I blow out the drains every other fuel stop or so. ..........

I assume you're talking about blowing out the drain hole in the well? Others have mentioned this feature also, but my airplane doesn't seem to have them. I'll have to take a closer look, maybe they've been painted over or something.

IMHO it's not a great idea to drain water down into the inside of the wing anyways ...seems like you're just asking for corrosion issues.

The wrinkles are the real issue. A lot of people with bladders will have wrinkles at some point IMHO. They are a pain to get out, and even when a mechanic does it, is is often the case they come back soon to some degree. I think a whole lot of water could hide in the wrinkles I've sen in bladders.

Gaskets for the raised caps are a few bucks and easy to find/make. I like them because they are easy to get on and off- I don't use a stool to fuel with. They are easier to check on the walk around to see they are twisted on all the way as well. I've had the flush caps be fickle about sealing and not being obvious without actually unlatching them and relatching them to be sure. A loose seal will give you "full tank syndrome"...the bladders pull off the hook points and collapse, and the indicator will read full...until it doesn't any more. It will also dump fuel overboard. Not common, but it happens. Yourplane will seem mighty fuel efficient when you only have to add 15 gallons to your tank to top them off from empty the next time.

Used conversions are available for a few hundred on Ebay,and they are not the end of the world to install if you want the added convenience.

Gramps had the flat style cover with the well and filer neck for 30 plus years on his ’55 180. He, Grandma and the 180 would winter in Florida. I think was 19 when first time I did the preflight inspection after a big Florida rain, I just about crapped. I informed Gramps that we had a BIG problem with the wells being full of water. He told me not to worry about it because when we got airborne the water would suck right out. When we landed I check the wells, low and behold he was right all of the water was gone. BTW, no water was in the tanks when I drained them during the preflight. We were going to the Monarch caps but sold the plane before we got the chance to. One of the big reasons that he wanted to put them on was because he could see that the caps were on without having to climb back up there to double check , he was in his 80’s by then. Another reason was if you did leave a cap off, Monarch claimed that very little fuel would leak out due to the flap. The last feature was you can't get Jet A in the Monarch cap.

Now forward to the past year to current I have been working on 2 different 180’s , one a 54 and the other a 55. Both of these fine aircraft had the dome style cover. The ’54 had to have the blatters replaced so we opted to put on the Monarch’s at that time because it did not cost us anything extra. Now the ’55 is having the blatters replaced and the Monarch aux tanks installed and we are putting on the Monarch caps. Same deal here as well not an extra cost to put them on. If the blatters were not going to be replaced we were eventually going to add them within a year of ownership of the planes.

The Monarch is a better design overall for safety than the Cessna or the other company that make the flat style cover.