Recent fuel tank patch - now fuel contamination - normal?

[nightmoves]

Hi everybody.

About 2 months ago I started getting the lovely smell of fuel in the cabin after my M20F sat for any period of time and our on-field A&P immediately located the lovely blue streak near the wing root. Interestingly this wing had been "completely sealed" not 9 months ago (I purchased the plane 6 months ago). Well, once inside the tank we found where the new sealant stopped in the area near the fuselage and only super old, crusty sealant was in place. The A&P spent hours removing all that old stuff and applying the new sealant (not the quick-dry version, took 3 days or so to set). Afterwards we gassed it up, flew it around, landed and let it sit for a few days and when I returned, no smell!!! So, that problem is fixed but now I'm noticing that every time I sump during preflight I get a sample with small red/brown flakes. If I sump 2-3 times it clears up. I go fly, land and sump again and the fuel is clear. I come back a few days later after it's sat, there are flakes again.

TLDR:

Is this considered normal for a tank that just received a patch sealant? Is it dangerous? Will the fuel screen catch anything large enough to cause a problem? I tried to get a picture of said screening but my camera didn't want to focus. The fakes ranges from brine shrimp size to very, very tiny.  Any input is appreciated.

 

[Bartman]

I had some flakes after I had my tanks resealed, but it was definitely a complete reseal and not a patch.  It cleared up after a few flights, but I did get one injector that was partially clogged about 15 hours later and no problems for about 500hrs since, but I think that was just coincidence due to tank and finger screens in place should catch that.  If the flakes are only after it sits then maybe there is a lot in suspension and you only get what settles out near the sump.  I have no special knowledge beyond being the caretaker of a J for 10 years and what I have picked up here, but if it were mine and I was concerned I would drain and strain the fuel after short flight to agitate and then use that in my lawn mower and refill with new fuel.

[RobertGary1]

I've seen this after patching too.  Pull the collator and you'll see some on the screen.

Might go ahead and pull the servo screen just to check it. Also, most of us have a "secret" screen that can clog just after the electric pump. This gets forgotten since its not known by most A&Ps.

 

-Robert

Edited December 14, 2017 by RobertGary1