Tonight I decided to leak test the right tank. It has been well over the Van’s recommended 48 hours to allow the sealant to cure properly.
I did this in much the same way as I did the left tank. Except that this time I connected a cheap Amazon digital manometer to the tank to measure pressure. The water method is OK and works fine but I’m a sucker for gadgets!
The hardest part of this process was adapting the clear 12mm hose attached to the tank to the 4mm fitting that was on the digital manometer. I tried all sorts of ways to adapt the fitting with what I had available. I finally settled on a shed load of PTFE tape around the fitting with the hose fitted by hand.
Once that was secure I used a normal bicycle pump to inflate the fuel tank through the drain valve using the Schrader Valve adapter that I purchased from Van’s.
I put the tank as close to 1 PSI as I dare go. It creaked a little as it inflated. Just like the left tank it deflated slightly with each inflation. My thoughts drifted between leak and air balancing inside the tank.
At about 1 PSI I disconnected bicycle pump and left the manometer to settle. It did at 0.963 PSI. I watched it for 5 minutes and it seemed to hold steady. After 10 minutes or so I noticed the pressure increasing! So I moved a thermometer near the test so I could see what was happening with temperature at the same time.
The rise in pressure seemed to correlate to the rise in temperature of the workshop. I also checked the regional air pressure and was stunned to see it at 1034 mb. That’s pretty high pressure for where we are.
I wrote the figures on the tank and decided to have a clear up of the ‘shop while I waited for more news on the tank. While cleaning up the workshop I also, accidentally, started riveting the most outboard ribs of the two leading edges to the wing spars. This was fairly easily done using the hand squeezer but it took a ton of hand strength for some reason.
After about 45 minutes I checked on the tank again and was delighted to see that the air pressure inside the tank had risen to 0.984 PSI. That’s a fantastic start to the leak test. I wrote the figures on the tank for reference and called it a night.
Fingers crossed that holds pressure for a few days.