N201MKTurbo Posted May 3, 2020 Report Share Posted May 3, 2020 It almost looks like someone cut their own gasket out of a sheet of gasket material that was not compatible with avgas. When I did my first annual back in '84 the mechanic showed me how to clean and inspect the gascolator. He said it needs to be done every year. I have done it every year sense and rarely find anything in it.. There was another discussion about the usefulness of draining the gascolator on every flight. Do you do that? If you do, it seems like it would flush that crud out before it had a chance to stick in there. 1 Quote Link to comment Share on other sites More sharing options...
MikeOH Posted May 3, 2020 Report Share Posted May 3, 2020 Would the chemical used to strip the tanks attack the gascolator seal? 1 Quote Link to comment Share on other sites More sharing options...
carusoam Posted May 3, 2020 Report Share Posted May 3, 2020 When using stripper... be very deliberate with what it goes on, or near... Like being a test pilot... you don’t want to accidentally become a test chemist either... An example of this comes from stripping tanks first, then doing paint work... as the tank stripper works too well on paint... Same goes with breathing the vapors... PP thoughts only, not a polymer chemist ... Best regards, -a- Quote Link to comment Share on other sites More sharing options...
Prior owner Posted May 3, 2020 Report Share Posted May 3, 2020 (edited) 2 hours ago, MikeOH said: Would the chemical used to strip the tanks attack the gascolator seal? Would depend  on what was used to strip the tank, I would think.  I think you might be onto something, though... when Polygon is used, it melts the sealant and creates a tan colored, milky solution that can flow and re-harden anywhere it ends up.  I think it is standard practice to remove the tank interconnect hoses though... to avoid anything getting into the lines or fuel valve.  Edited May 3, 2020 by PilotCoyote Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted May 3, 2020 Report Share Posted May 3, 2020 Lets think about this stripper scenario. Even with the sprinkler head arrangement spraying stripper into the tanks, it is sprayed up and runs down. The fuel pickup is at the bottom of the tank very near an access panel. The fuel pickup in the tank runs up hill for about 2 inches to the tank penetration. It is hard to imagine more than a trace of stripper getting up into the fuel lines even in this severe situation. Also it would have to flow through a couple of feet of fuel line and through the fuel selector, which should be off at this time to get to the gascolator. After stripping the tanks are washed down until they are squeaky clean before you apply new sealant. Any stripper in the fuel line would most likely evaporate at this time. After the tank repair is complete, you will fill the tank up with fuel and prime the fuel system. The first thing I do is pull the ring until a generous amount of fuel flows through to give the electric pump a fighting chance of priming. It is bad to run the electric pump dry, you want it to prime quickly. If it doesn't then you have to open the fuel line downstream of the electric pump and let it prime by gravity. Either way, if there was stripper in the fuel line it would be flushed through very quickly and wouldn't dwell in the gascolator. Personally, I would just clean it out, put a new gasket on it and inspect in in another 100 hours or so. 1 Quote Link to comment Share on other sites More sharing options...
Prior owner Posted May 3, 2020 Report Share Posted May 3, 2020 I wonder...  Polygone is often warmed when it is applied, so that it will work more effectively. If I remember correctly (I could be wrong), it also heats up on its own when it hits sealant. If there is enough in the tank to submerge the pickup screen, it is conceivable that enough tank pressure could develop (with a clogged vent) to force fluid up the fuel line. Also, if a plane was jacked by the main jackpoints to raise it slightly for better tank access while the nose wheel was left on the ground, the fuel lines aren’t so much of an uphill run anymore. Quote Link to comment Share on other sites More sharing options...
cferr59 Posted May 3, 2020 Author Report Share Posted May 3, 2020 Just now, PilotCoyote said: I wonder...  Polygone is often warmed when it is applied, so that it will work more effectively. If I remember correctly (I could be wrong), it also heats up on its own when it hits sealant. If there is enough in the tank to submerge the pickup screen, it is conceivable that enough tank pressure could develop (with a clogged vent) to force fluid up the fuel line. Also, if a plane was jacked by the main jackpoints to raise it slightly for better tank access while the nose wheel was left on the ground, the fuel lines aren’t so much of an uphill run anymore. That is an interesting theory.  I can't think of a good reason that someone would have painted the bottom of the gascolator with fuel tank sealant. It wouldn't prevent any types of leaks. Although, it seems like it would have required a lot of errant stripper to leave this much residue.  Quote Link to comment Share on other sites More sharing options...
carusoam Posted May 3, 2020 Report Share Posted May 3, 2020 Just now, cferr59 said: That is an interesting theory.  I can't think of a good reason that someone would have painted the bottom of the gascolator with fuel tank sealant. It wouldn't prevent any types of leaks. Although, it seems like it would have required a lot of errant stripper to leave this much residue.  Looks like somebody may have painted the sealant in there to seal where the bolt passes through the bottom in the center... The other seal is where the two halves of the separator come together... Followed by each compression fitting connecting the ins and outs.... Check the tank in lines to see if the sealant came in by accident... from the tanks. PP thoughts, not a mechanic... Best regards, -a- 1 Quote Link to comment Share on other sites More sharing options...
cferr59 Posted May 3, 2020 Author Report Share Posted May 3, 2020 8 minutes ago, carusoam said: Looks like somebody may have painted the sealant in there to seal where the bolt passes through the bottom in the center... The other seal is where the two halves of the separator come together... Followed by each compression fitting connecting the ins and outs.... Check the tank in lines to see if the sealant came in by accident... from the tanks. PP thoughts, not a mechanic... Best regards, -a- That is the only thing that would make any sense, but, if that was their goal, it seems like they failed to accomplish it. Quote Link to comment Share on other sites More sharing options...
Guest Posted May 3, 2020 Report Share Posted May 3, 2020 2 hours ago, cferr59 said: That is an interesting theory.  I can't think of a good reason that someone would have painted the bottom of the gascolator with fuel tank sealant. It wouldn't prevent any types of leaks. Although, it seems like it would have required a lot of errant stripper to leave this much residue.  My guess is that the bottom is corroded and pitted, so a layer of sealant was brushed on. Clarence Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted May 3, 2020 Report Share Posted May 3, 2020 If indeed that is sealant carried by stripper, I would inspect the whole fuel system. If it is true, I would make whoever did it pay to have it fixed. Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted May 3, 2020 Report Share Posted May 3, 2020 Just now, M20Doc said: My guess is that the bottom is corroded and pitted, so a layer of sealant was brushed on. Clarence If that is the case, they did a pretty poor job of it! 1 Quote Link to comment Share on other sites More sharing options...
MikeOH Posted May 3, 2020 Report Share Posted May 3, 2020 13 minutes ago, N201MKTurbo said: If indeed that is sealant carried by stripper, I would inspect the whole fuel system. If it is true, I would make whoever did it pay to have it fixed. While I appreciate the sentiment, establishing who did it and getting them to admit it is HIGHLY unlikely. The obvious SUSPECT is whoever did the strip and seal in 2018.  So, two years later the present owner is going to hunt down the PO's shop and get them to pay??? When I was younger I ran fools' errands and tilted windmills...not so much anymore Quote Link to comment Share on other sites More sharing options...
Oldguy Posted May 4, 2020 Report Share Posted May 4, 2020 17 hours ago, carusoam said: Looks like somebody may have painted the sealant in there to seal where the bolt passes through the bottom in the center... Â 15 hours ago, M20Doc said: My guess is that the bottom is corroded and pitted, so a layer of sealant was brushed on. Dumb owner-not-a-mechanic question: If this was done, would this be seen during the inspection of the gascolator and passed off by the mechanic as perfectly fine? Quote Link to comment Share on other sites More sharing options...
skykrawler Posted May 4, 2020 Report Share Posted May 4, 2020 When I helped with annuals on club aircraft (Cessnas) we always drained the low points in the fuel system, checked gasco, and Drained The Carburetor. Every year. Quote Link to comment Share on other sites More sharing options...
1964-M20E Posted May 6, 2020 Report Share Posted May 6, 2020 On 5/3/2020 at 6:17 AM, BDPetersen said: Just bought a supply of gaskets from Brown Aircraft Supply. About $8/ea. yes order the GL-30-HD (2" O.D. x 1/8" buna) but ask them to make it special out of 1/16" thick rubber  Quote Link to comment Share on other sites More sharing options...
cferr59 Posted May 6, 2020 Author Report Share Posted May 6, 2020 Thanks everyone for the parts information and thoughts on the issue. Parts have been ordered and I hope to have them this week. I should be able to get everything back together for the weekend. 1 Quote Link to comment Share on other sites More sharing options...
cferr59 Posted May 8, 2020 Author Report Share Posted May 8, 2020 So the screen did not shred the gasket. The existing gasket appears to be the wrong part, much thicker than the replacement gasket. 2 Quote Link to comment Share on other sites More sharing options...
carusoam Posted May 8, 2020 Report Share Posted May 8, 2020 cf, See if you can find the log entry where that seal got replaced... That will give you a hint of what else may have been done at the same time... PP thoughts only, not a mechanic... Best regards, -a- Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.