Not all rubber fuel lines are created equal. I purchased a rather expensive electronic petrol sniffer and found that the fuel lines in my Savannah set the sniffer off quite easily. The plastic fuel tanks also set off the sniffer but not as mush as the fuel lines. After researching rubber fuel hose I discovered that most fuel hose has a rating of >10gms per sq m of permeability to aromatic vapours. However some purpose made fuel hose has a permeability of <1gm per sq m. The same US company makes both grades of hose so you need to have the correct grade to prevent that fuel smell from building up in the cabin when the plane is locked up in the hanger etc. The plastic tanks also emit fuel vapour but there is not a lot you can do except seal off the wing roots to prevent the vapour from entering the cabin. That still leaves the reserve tank which you can't do anything about except replace with a aluminium tank. However, not as much smell comes out of the plastic tanks as what comes out of standard rubber fuel hose so it is probably not worth worrying about. Spilling fuel around the fillers if they are not sealed against the top wing skin is also a big No No as it takes ages for the smell to evaporate out of the wings. And by the way there is a lot more to the yarn going round about the fuel smell in the factory Savannah at Broken Hill supposedly causing the owner to sell the aircraft. These forums seem to generate a heap of misinformation as well as the helpfull good stuff.
