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<DIV><FONT size=2 face=Arial>Alec,</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>It's the length of line and the slope. The
aft tank is the bigger problem. I'm sure a larger diameter tube would
be better also. All it takes is one lower part with water in it to stop
the air flow. The shorter length of tubing on a K-250 would be less likely
to block. </FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>Dan H.</FONT></DIV>
<BLOCKQUOTE
style="BORDER-LEFT: #000000 2px solid; PADDING-LEFT: 5px; PADDING-RIGHT: 0px; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="FONT: 10pt arial; BACKGROUND: #e4e4e4; font-color: black"><B>From:</B>
<A title=personal_submersibles@psubs.org
href="mailto:personal_submersibles@psubs.org">Alec Smyth via
Personal_Submersibles</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=personal_submersibles@psubs.org
href="mailto:personal_submersibles@psubs.org">Personal Submersibles General
Discussion</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Thursday, June 12, 2014 12:11
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [PSUBS-MAILIST]
Bouyancy</DIV>
<DIV><BR></DIV>
<DIV dir=ltr>I find all this trouble with water blocking curious. I've never
experienced one, either with the original thin tubing nor with the current
tubing. Even at extreme angles, venting just one tank, nothing blocks. I
presume this is just a matter of how much the lines slope up to the valves, or
maybe the K250 just has shorter lines and its easier to keep it sloping.</DIV>
<DIV class=gmail_extra><BR><BR>
<DIV class=gmail_quote>On Thu, Jun 12, 2014 at 11:03 AM, Dan H. via
Personal_Submersibles <SPAN dir=ltr><<A
href="mailto:personal_submersibles@psubs.org"
target=_blank>personal_submersibles@psubs.org</A>></SPAN> wrote:<BR>
<BLOCKQUOTE
style="BORDER-LEFT: #ccc 1px solid; MARGIN: 0px 0px 0px 0.8ex; PADDING-LEFT: 1ex"
class=gmail_quote><U></U>
<DIV bgcolor="#ffffff">
<DIV><FONT face=Arial>Scott, </FONT></DIV>
<DIV><FONT face=Arial>To clear the lines, I screwed a T onto each of the
through hulls that feed air to the MBTs. (on the open end under the
MBTs) Then I fashioned a piece of copper tubing that directs a stream
of air right into the MBT vent line but not actually connected to
it. I put a restriction in the other end of the T to create
enough back pressure so the tubing emits a pretty good blast of air directed
at the vent port. </FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>To vent the MBTs, I open the conning tower vent valves
then give the tank blow valve a turn till I see the water blow up and out
the vents. That seems to clear the lines and then it vents
properly. </FONT></DIV>
<DIV><FONT face=Arial> It's not a great fix but it works.</FONT></DIV>
<BLOCKQUOTE
style="BORDER-LEFT: #000000 2px solid; PADDING-LEFT: 5px; PADDING-RIGHT: 0px; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px">
<DIV>
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV style="FONT: 10pt arial; BACKGROUND: #e4e4e4"><B>From:</B> <A
title=personal_submersibles@psubs.org
href="mailto:personal_submersibles@psubs.org" target=_blank>swaters via
Personal_Submersibles</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=personal_submersibles@psubs.org
href="mailto:personal_submersibles@psubs.org" target=_blank>Personal
Submersibles General Discussion</A> </DIV></DIV>
<DIV>
<DIV class=h5>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Wednesday, June 11, 2014 10:37
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [PSUBS-MAILIST]
Bouyancy</DIV>
<DIV><BR></DIV>
<DIV>Dan,</DIV>
<DIV>I have the exact same problem with hydrolocking in the vents. I have
to open the hatch and blow the water out with my mouth. Pain in the
butt.</DIV>
<DIV>Thanks,</DIV>
<DIV>Scott Waters</DIV>
<DIV><BR></DIV>
<DIV><BR></DIV>
<DIV><BR></DIV>
<DIV><BR></DIV>
<DIV>
<DIV style="COLOR: #575757; FONT-SIZE: 75%">Sent from my U.S. Cellular©
Smartphone</DIV></DIV><BR>"Dan H. via Personal_Submersibles" <<A
href="mailto:personal_submersibles@psubs.org"
target=_blank>personal_submersibles@psubs.org</A>> wrote:<BR>
<DIV>If I were to do mine over again, I wouldn't vent it as it is in
the plans. Instead of running piping from the MBTs to the conning
tower, I would run linkage, and have the actual valves mounted on the
MBT. </DIV>
<DIV> </DIV>
<DIV>Besides slow venting, my biggest problem is getting water in the
piping that won't escape to let the air come through when venting. A
homemade mushroom valves made from bathroom sink drains controlled
by linkage going to the conning tower, or anywhere easy to reach in
the hull, would solve all the problems. </DIV>
<DIV> </DIV>
<DIV>My thought, Dan H.</DIV>
<BLOCKQUOTE
style="BORDER-LEFT: #000000 2px solid; PADDING-LEFT: 5px; PADDING-RIGHT: 0px; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV style="FONT: 10pt arial; BACKGROUND: #e4e4e4"><B>From:</B> <A
title=personal_submersibles@psubs.org
href="mailto:personal_submersibles@psubs.org" target=_blank>via
Personal_Submersibles</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=personal_submersibles@psubs.org
href="mailto:personal_submersibles@psubs.org"
target=_blank>personal_submersibles@psubs.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Wednesday, June 11, 2014 9:53
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [PSUBS-MAILIST]
Bouyancy</DIV>
<DIV><BR></DIV><FONT color=#000000 face=Arial>
<DIV><FONT size=3>Scott, Alec, Vance, and all,</FONT></DIV>
<DIV><FONT size=3></FONT> </DIV>
<DIV><FONT size=3>A 3/4" vent is going to be about 2.25 times as big in
cross section as the 1/2" vent. A 1" vent would be about 4 times
as big as the 1/2". What are your thoughts/comments on 3/4",
1" or any other size vent vs another?</FONT></DIV>
<DIV> </DIV>
<DIV><FONT size=3>Thanks,</FONT></DIV>
<DIV><FONT size=3>Jim </FONT></DIV>
<DIV> </DIV>
<DIV>
<DIV>In a message dated 6/11/2014 5:45:10 P.M. Central Daylight Time, <A
href="mailto:personal_submersibles@psubs.org"
target=_blank>personal_submersibles@psubs.org</A> writes:</DIV>
<BLOCKQUOTE
style="BORDER-LEFT: blue 2px solid; PADDING-LEFT: 5px; MARGIN-LEFT: 5px"><FONT
style="BACKGROUND-COLOR: transparent" color=#000000 face=Arial>
<DIV>James,</DIV>
<DIV>I totally agree with you on the 1/2 inch vents being way to
small. Eventually I am going to switch mine out to 3/4"</DIV>
<DIV>Thanks,</DIV>
<DIV>Scott Waters</DIV>
<DIV><BR></DIV>
<DIV><BR></DIV>
<DIV><BR></DIV>
<DIV><BR></DIV>
<DIV>
<DIV style="COLOR: #575757; FONT-SIZE: 75%">Sent from my U.S.
Cellular© Smartphone</DIV></DIV><BR>James Frankland via
Personal_Submersibles <<A
href="mailto:personal_submersibles@psubs.org"
target=_blank>personal_submersibles@psubs.org</A>> wrote:<BR>
<DIV>Hi All,</DIV>
<DIV> </DIV>
<DIV>A member has asked me to post a description of what was going on
with bouyancy on my dive. Which was as follows:</DIV>
<DIV> </DIV>
<DIV>I'd asked the crane driver to be prepared for the first dive to
hold me just below the surface as i was expecting to be a little out
of control. </DIV>
<DIV> </DIV>
<DIV>At first, i got a bubble stuck in the forward tank. Ive put
quite a large lip on the inside of the tanks in an attempt to cope
with Guernsey seas. I could see the bubble stuck through the
forward dome and i squished myself right up into the front to try
and force it a bit more level so it could escape out of the
vent. It didnt make any difference and then all the lead i had
inside, slid along the deck right to the back, making the entire
situation worse. Closed vents, blew mains and re-surfaced.</DIV>
<DIV> </DIV>
<DIV>Next attempt, i got the bubble stuck in the aft tank. This
wasnt as bad because the motor cut away allows air to escape so i got
under a little further, but not enough. I flooded the variable
in an attempt to get under. Still no good, so i asked the divers
to shove on the back. This got the boat under, but then because
of the total lack of air in any tanks, i sank to the bottom like a
stone. Depth was 6m (20ft). I expected to stop on the
crane ropes, but the driver must have misunderstood me and before i
knew it, the bottom was in sight and then i was down with a gentle
bump. </DIV>
<DIV> </DIV>
<DIV>I sat for a bit talking to my brother on the radio and then shut
the variable vent and pumped a little air into the tank. I
slowely started to rise. Flooded it again and started to
sink. Really quite straight forward. </DIV>
<DIV> </DIV>
<DIV>Blowing the VBT completely brought me up fairly quickly until i
seemed to be just awash with the surface. Filling the mains then
brought me right out. </DIV>
<DIV> </DIV>
<DIV>I did several more test dives after that and as long as i evened
out the venting of the main tanks to avoid the bubbles, i could dive
without the divers assistance. </DIV>
<DIV> </DIV>
<DIV>I next got the boat neutral just off the bottom and then used the
motors to drive up and down. I was not aware at the time that one
motor was not working but it still seemed quite responsive and i could
drive all the way up to the top or down to the bottom, stopping
anywhere in between.</DIV>
<DIV> </DIV>
<DIV>I need to add some extra vents to the main tanks to prevent the
air pocket from occuring again, and also those half inch vents are far
too small. It takes forever to vent the main tanks. Thats
one for a winter modification.</DIV>
<DIV> </DIV>
<DIV>I think that was it.</DIV>
<DIV>Regards</DIV>
<DIV>James</DIV>
<DIV> </DIV>
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