Originally Posted by
jetflyr
My tanks have a solid brass vent line going to the top of the tank. My fill/clunk line extends about 2 inches inside the tank, then Tygon to length allowing full swing of the clunk.
Since there is not a neck to worry about splitting on the tanks, I just used a Dubro cap and gas/kero bung. It hasn't leaked yet.....
As I mentioned, I plumbed mine in series - which is also the way the CARF Lightning and Flash is plumbed - the pump really doesn't care if the correct fuel line diameter is used.
The tanks are just secured to the fuse sides with a dab of silicone - you don't need much.
There was a lot more in my submission - but Jay edited it down for space in the print edition.
Hysol 9462 is VERY different from JB Weld, or 30min epoxy. Each has its place - and really shouldn't be substituted for each other. Micro-balloons do nothing for strength - and in fact make the joint weaker. Search the archives of JPO's Contrails for the article Lance Campbell (of the big SR 71) did on strength and compatibility of epoxy resins.
My guiding principle is KISS - and each aircraft has its own issues. I have yet to run a check valve on the vent since it vents outside the plane ... if I get fuel inside, it is from another source, not the vent.
My 2 cents -
Greg
Ha ha ha ha ha ha ha!! The joke is on me Greg. I had no idea jetflyr was the author of the F86D Model Aviation mag review! I looked back at my posts to see if I said anything offensive. Seems like I behaved myself.
OK, on to jets. I pressure tested my tanks to 1 psi and submerged them, one leaked and the other one did not. So I've been busy fixing it. I laid up fiberglass all around the seam hole and retested. It still leaked....the air just traveled to the side. This time, I pulled a vacuum on the tank and dribbled thinned resin over the area. The hope was the liquid sucked into the passageway. Then, I laid up a 2nd round of glass & resin over it. This time it held just fine. I ramped it up to 5psi and it still held. So, I'm past that little issue.
Greg, I need to clear up one thing. You've mentioned both you routed your tanks in series, but you also said you had vents in your tanks(S). Plural. so, I'm thinking a series tank setup should have one vent in the last tank? Otherwise, there's nothing to draw the fuel from the last tank into the first one. Was that just a typo? Or am I still missing something? Thanks for all the help and comments.