Fuel inlet splash guard

[scottmillhouse]

Legacy RV-12 without new plexiglass rear window. Looking for ideas for a splash guard to protect the Lexan rear window from crazing from fuel splashes. I’m sure they were posted in the past but i can not find in a search. Did not make it to Oshkosh with the fronts blocking the way North. About 7 hours now with bugs addressed, just needs the vinyl side stripes.

 

[DHeal]

In my experience, No.1 is to be very careful not to spill any fuel near or on the Lexan. This is especially difficult when using one of those huge B-17 sized fueling nozzles so prevalent at small GA airports. Fuel blow-back out the fuel port during refueling is a concern particularly if you have the older-style vented fuel cap system -- go slow with that nozzle's hair trigger. No. 2 is to be sure all of the edges of the Lexan ( e.g., cut edges around perimeter and within screw holes, etc.) are sealed with fuel tank sealant. No. 3 is to place a holed fuel-resistant rubber mat over the tank inlet during fueling operations -- just like they do at the classier FBOs. Despite your best efforts you will likely see some evidence of crazing in the Lexan material far away from any fuel spill areas -- it is apparently the nature of the beast.

 

[DaveWelch]

Agree with David’s recommendations, that’s what I do also.
Scott’s original question got me thinking…are any of the 3D printing resins resistant to gasoline and ethanol? If so how about a narrow “hooded funnel”? The spout would need to accommodate those ramp nozzles and also fit a bit snug in the filler neck so that any burps are directed up thru the device rather than around between the neck and spout. On the top end, the hood or shield would need to be tall enough to catch/stop fuel droplets and mist being ejected from the tank as air is displaced.

Now, keeping in mind the old adage “No problem is so simple that an engineer can’t develop a complex and expensive solution” (refer to design requirements above)…I’ve tried placing a clean rag around the nozzle and filler neck. Works well when the rag doesn’t blow off in wind. Other issue is I can’t hear the gurgling when tank is nearly full so fuel flows out onto the fuse skin. Now I have a fuel-soaked rag to dispose of. Grrr. Back to the high-tech approach…