Asg29 very slow water dumping issue (20+ minutes and wings still halffull or more)

On Wednesday, December 14, 2016 at 6:31:42 AM UTC-8, wrote:
On Wednesday, December 14, 2016 at 6:48:05 AM UTC-5, Sean wrote:
This has been a problem since late this summer. Asymmetric and or slow dumping.

After having the valves open today for (guessing) 20+ minutes (to be sure it was dry) I landed to find the wings with significant water (10-15 gallons a side) still on-board. Water flows thru the outboard panels so they are clear. The valves seem to be opening fine on the ground. We checked the outer panel for flow carefully this am before flying. Water flowed thru easily when the full wing was lowered slightly.

This is quite a mystery. It cost me significantly today. I thought I was empty but was still well over 10 lb/ft I'm guessing by the amount of water still in the wings when I had landed. It took 5-7 minutes for the water to dump AFTER I had landed.

Any ideas on what could be cuasing an excessively slow dump cycle? Anyone else having this problem? What else should I check for? What is the expected dump time for a 29? I use 6 minutes to be safe usually.

Maybe I was perceiving actual dump time wrong (need a stopwatch)? Maybe I thought only 3 minutes was 10-15? Maybe I was my using the fuselage tank valve handle accidentally and not the wing/tail? Even if this was the case it was 7-10 minutes from my last "thermal" to the ground and the water was flowing fine out of each wing valve when I landed. So the right valve handle was opened at this point. This should have emptied the wings alone easily, to say nothing if the 10-20 minutes the valves were open in occasional dumps before that point.

Thanks in advance for ideas...

Sincerely,

Sean

List of stuff to look at:
1- verify dump valves open fully
2- Make sure connector tubes from vents are not pinched. Easy to pinch if assembling quickly.
3- Verify that all vent lines are clear, both in tips and to inner tanks.
4- Use drilled fill caps(1/4 hole) , with check valve inside to allow air in but not out
As a diagnostic do dump test on the ground with caps off. It will differ from the air but not hugely.
My guess is poor venting from experience.
UH

Like others, my experience with this was the vent tube of one wing (for me, consistently the same one) but it hasn't made for a 20-minute drain time.
Need to find the right way to clean and possibly lubricate the tapered fitting on the inner panel so the outer panel tube slides on rather than kink.
ACF-50 works well on the TE probe, might be the thing here too.
My tank caps have one-way valves. I've heard air pressure equalising on removal of the outer panel after flying dry.
Now I always check the vent at the bottom of the winglet before taping the outer panel.
Jim