Pietenpol-List: Fuel Site Gauge
Posted: Mon May 05, 1997 12:00 pm
Original Posted By: Jack
You probably have seen my pleas for infomation on a site gauge for thewing tank on the Air Camper. Well I just finished my tank and wanted toshare this success story with you.Anyone looking in Aircaft Spurce for the Stearman site gauge is out ofluck. They won't have any in stock acording to the order takers for 2years! I couldn't wait that long even thoug it is nearly a perfect fitfor about $30. Instead I built my own for about $5. It is based on thetank indicator in the 2nd Issue of the Buckeye Pietenpol Newsletter.For those who don't have that issue (it was in 85' or so) I willexplain.I build the wing tank out of .040 aluminum from our local sheet metalshop. I bent up the bottom tray and prosealed the sides and bafflesin. The sight gauge had me stimmied for a while until I came up with asolution involving copper pipe fittings and vinyl tubing. Here is amaterial list:6 inches of 1/2" copper pipe (usually used for water plumbing)1ea 1/2" copper pipe sleeve joint1ea 1/8" NPT hose fitting1ea large hardware store washer hole should be enlargeable to 5/8" dia6" of fuel resistant vinyl hose1 large corka few rivetsa few square inches of scrap aluminum36" of 1/16" wire (I used welding rod)1 small lead fishing weightspecial tools include:1/8" NPT tapSafty wire pliersSilver soldering tools (torch, solder, flux, etc)Inside the tank I made a bracket and that held a length of the 1/16"wire near the top of the tank such that it would hinge to the backwall. I fastened the float to the other end of the wire so that itwould be in the deepest part of the tank ~ 16 inches or so from the backwall of the tank. About 8 inches from the back I bent a 360 degree loopin the wire which would be the location of the indicator that would passthrough the bottom of the tank. Next I cut a shorter lenght ~12" or soas the indicator and bent it through the loop. I drilled a hole in thebottom of the tank for the indicator to pass through. Cut the indicatorwire to length such that at full cork travel the indicator remainsoutside the tank at least 3/4". At this point you have an indicator,now you have to make it fuel proof since although accurate at thispoint, your tank has been comprimised. (I.E. you've got a nice hole inthe bottom of your tank.) Here is where the creativity comes in. Tostrengthen the inside of the tank and to have material to anchor thefittings I made a 1/4" aluminum disk 2" in diameter. Tap a hole in thecenter to 1/8" pipe threads. I found a brass hose fitting at the autoparts store with matching threads to fit. This fitting screws into thebottom of the tank through which the indicator passes. Pinch the leadsinker to the bottom of the indicator and then slide the vinyl tubingover the indicator and safety wire to the nipple of the fitting. Put abolt in the bottom end to seal the tube and safety wire it tight. Ifound that a little gasket sealer is helpful to prevent leaks. In mytank I put a quick drain in the bottom of the vinyl instead of a bolt.It has come in handy several times already. At this point you have afuel tight tank, but the indicator gets stuck in the tubing due to thecurve the vinyl retains having been on a roll all its life. The finalstep is to encase the vinyl tube in the length of copper tubing toprotect it and keep it straight. To do this, I drilled out the flatwasher to accept the copper pipe sleeve and soldered it on about halfway up on the sleeve. Cut one side of the sleeve off flush with thewasher. Drill four mounting holes in the washer and through to thealuminum disk in the tank. This fitting will hold the copper tubing inplace firmly on the tank. Apply Proseal to the disk, tank bottom andwasher fittings, making sure not to clog the opening or restrictingmovement of the indicator and bolt tight the whole assembly. Next cutthe copper tubing to lenght and cut out a window slightly longer thanthe travel of the indicator. You may choose to cap one end or leave itopen if you have a quick drain. Clean all edges and paint the inside ofthe window with white paint. To finish the install, slide the coppertubing over the vinyl tubing making sure not to bend the indicator andalign the window towards the pilot. My sleeve fits very snuggly overthe vinyl and the safety wire making a clean solid sight gaugeinstallation. Works great!I'll post some pictures with this article on my web sight in a few days.Hope this is of some help to someone!Steve Eldredge________________________________________________________________________________
You probably have seen my pleas for infomation on a site gauge for thewing tank on the Air Camper. Well I just finished my tank and wanted toshare this success story with you.Anyone looking in Aircaft Spurce for the Stearman site gauge is out ofluck. They won't have any in stock acording to the order takers for 2years! I couldn't wait that long even thoug it is nearly a perfect fitfor about $30. Instead I built my own for about $5. It is based on thetank indicator in the 2nd Issue of the Buckeye Pietenpol Newsletter.For those who don't have that issue (it was in 85' or so) I willexplain.I build the wing tank out of .040 aluminum from our local sheet metalshop. I bent up the bottom tray and prosealed the sides and bafflesin. The sight gauge had me stimmied for a while until I came up with asolution involving copper pipe fittings and vinyl tubing. Here is amaterial list:6 inches of 1/2" copper pipe (usually used for water plumbing)1ea 1/2" copper pipe sleeve joint1ea 1/8" NPT hose fitting1ea large hardware store washer hole should be enlargeable to 5/8" dia6" of fuel resistant vinyl hose1 large corka few rivetsa few square inches of scrap aluminum36" of 1/16" wire (I used welding rod)1 small lead fishing weightspecial tools include:1/8" NPT tapSafty wire pliersSilver soldering tools (torch, solder, flux, etc)Inside the tank I made a bracket and that held a length of the 1/16"wire near the top of the tank such that it would hinge to the backwall. I fastened the float to the other end of the wire so that itwould be in the deepest part of the tank ~ 16 inches or so from the backwall of the tank. About 8 inches from the back I bent a 360 degree loopin the wire which would be the location of the indicator that would passthrough the bottom of the tank. Next I cut a shorter lenght ~12" or soas the indicator and bent it through the loop. I drilled a hole in thebottom of the tank for the indicator to pass through. Cut the indicatorwire to length such that at full cork travel the indicator remainsoutside the tank at least 3/4". At this point you have an indicator,now you have to make it fuel proof since although accurate at thispoint, your tank has been comprimised. (I.E. you've got a nice hole inthe bottom of your tank.) Here is where the creativity comes in. Tostrengthen the inside of the tank and to have material to anchor thefittings I made a 1/4" aluminum disk 2" in diameter. Tap a hole in thecenter to 1/8" pipe threads. I found a brass hose fitting at the autoparts store with matching threads to fit. This fitting screws into thebottom of the tank through which the indicator passes. Pinch the leadsinker to the bottom of the indicator and then slide the vinyl tubingover the indicator and safety wire to the nipple of the fitting. Put abolt in the bottom end to seal the tube and safety wire it tight. Ifound that a little gasket sealer is helpful to prevent leaks. In mytank I put a quick drain in the bottom of the vinyl instead of a bolt.It has come in handy several times already. At this point you have afuel tight tank, but the indicator gets stuck in the tubing due to thecurve the vinyl retains having been on a roll all its life. The finalstep is to encase the vinyl tube in the length of copper tubing toprotect it and keep it straight. To do this, I drilled out the flatwasher to accept the copper pipe sleeve and soldered it on about halfway up on the sleeve. Cut one side of the sleeve off flush with thewasher. Drill four mounting holes in the washer and through to thealuminum disk in the tank. This fitting will hold the copper tubing inplace firmly on the tank. Apply Proseal to the disk, tank bottom andwasher fittings, making sure not to clog the opening or restrictingmovement of the indicator and bolt tight the whole assembly. Next cutthe copper tubing to lenght and cut out a window slightly longer thanthe travel of the indicator. You may choose to cap one end or leave itopen if you have a quick drain. Clean all edges and paint the inside ofthe window with white paint. To finish the install, slide the coppertubing over the vinyl tubing making sure not to bend the indicator andalign the window towards the pilot. My sleeve fits very snuggly overthe vinyl and the safety wire making a clean solid sight gaugeinstallation. Works great!I'll post some pictures with this article on my web sight in a few days.Hope this is of some help to someone!Steve Eldredge________________________________________________________________________________