I’m making an aircraft cover that will cover the fuel cap (I assume this is desirable to avoid water in the tank!). I’m planning to make it out of waterproof ripstop nylon but wonder if I need to consider some kind of vents around the fuel cap to avoid having the material attacked by the AVGAS fumes? Any thoughts?
Hm, rather uneducated, but I don’t think so. The filler caps should be really tight, otherwise water would get into the tank quickly. So there should be no fumes either.
However, is waterproof nylon the right material? We have a Bruce cover and it is deliberately not completely water proof, to avoid moisture beeing trapped between the cover and the aircraft skin. At least this is how it was advertized.
kwlf wrote:
waterproof ripstop nylon
Isn’t nylon prone to static electricity buildup?
It is very important for fuel caps to be sealed. I change the o-rings every year or two. Leaking caps are the major (many say 100%) source of water in fuel.
There is a problem with some filler cap designs (like mine 
) in that after any rain the gap around the cap fills up with water and when you open it to check the tank level, that water runs into the tank. It would be nice if one could avoid this… In these case I sometimes don’t open the caps, if I know I filled the tanks right up the day before, etc. Accurate fuel gauges would reveal if somebody drained some fuel out.
Thanks for the thoughts. There is a small hole in the cap – fuel gauge is a bit of wire on a cork. I’m not aware of other vents though there might be one somewhere.
This cover is just to protect the open cockpit for day trips and perhaps the odd overnight stay so I think something properly waterproof should be ok. The point re static is a good one.
Have you had water in the fuel Kwif?
My seals were changed by the previous owner as part of the pre-buy inspection 3 1/2 years ago and I have never had a drop of water in my fuel. I still check each time I fly though!
I have no doubt it is type specific, the PA28 has some nice chunky rubber type washers around the inside of the caps.
No, the rubber seal seems ok. My engine did stop in the air the other day, but I’m fairly sure it wasn’t due to water in the fuel. It’s a wood and fabric aircraft so it gets left in the rain as little as possible.
Peter wrote:
It is very important for fuel caps to be sealed.
I did not know this and will check the seals. I have never found any drop of water in the fuel.
Peter wrote:
It would be nice if one could avoid this
You can avoid this easily, I do carry always one of these:
Re the link above…………
I am not sure if the rolls of paper are for wiping water from the tops of the wings but in my case if “my engine did stop in the air the other day” then I’d definitely need the paper to wipe something else!!
I’ll write up an ‘ilafft’ when I have worked out what caused it to stop. Until that time it seems a bit premature!
