Re: [PSUBS-MAILIST] Seals again

[s_lindblom@conknet.com (Steve Lindblom)]

Pat, we were having a constructive, useful discussion here about seals,
when you made the mistake of saying a very dumb thing, and I made the
mistake of correcting it.

Since then, instead of just slapping your forhead and saying "Geez, what
could I have been thinking, you've flipped off into an nutball total-war
mode where you simply cannot seem to say enough bad about me. You distort
then contradict every single word I say, cast veiled insinuations, ad
hominems, and out and out insults, then when cornered, fall back on your
ultimate clincher, that you have a boat and I don't.

I try to follow a no-flame policy, and just plod along talking the issues.
But you have been so excessive that I feel I have to try to set the record
straight. However, rather than just flame away, to keep it strictly factual
I'll do it using your own words.

First of all, though, could why don't you show us where I said:

Redundancy is a bad thing.

Pressure compensation is always a bad thing

Pressure compensation doesn't work.


Now let's look at your record:

When I pointed out your pressure compensation system didn't offer reduancy
because you were using stock 1 ata seals you said:

>Who says we don't use good seals?  We just also use pressure compensation
>because we know it affords benefits seals alone cannot provide.  How many
>times do I have to say it before you understand?

and

>What's odd here is the fact that you don't know anything about my systems,
>what backups I have, or how I operate my boat; yet you keep talking smack.

Yet not too long ago you posted here:

>First, the Techs at MK tell me their seals will hold integrity for "about
>one additional atmosphere of pressure."  That says to me I should be able to
>dive my lower-end (motor) unit to about 33 feet (give-or-take) before she
>floods.  Now, even if she does flood, the motor will still continue to run:
>but the brushes will wear down at a much faster rate; so obviously I want to
>avoid that.

and

>OK.  In my explaination above, I'm talking about the stock seal that came
>with my MK-4HP.  I have not experimented with the other seals people have
>mentioned.

and

>As long as I keep the gauge-indicated air pressure in the motor-compensation
>system close to what's showing on the outside depth-pressure gauge, I'm OK
>and she shouldn't leak.  In practice, that's not extremely difficult to do,
>either.  A one-atmosphere seal-integrity range gives us a variable of about
>15 PSI to play with.

So you clearly are using the standard 1 ata seal, and hence I was correct
in saying you do not have redundancy below 33' since your seals alone are
inadequate at depth.

It seems I can't do anything right! One minute you accuse me of endangering
the poor people on this list:

>Regarding the present thread: encouraging others to forego long-established
>and well-proven methods is as irresponsible as sport-jumping out of an
>airplane from 12,500 feet AGL with only one parachute.  Feel free to do it,
>but don't advise others that it is safe to do the same.

and the next you get mad at me of trying to protect them!

>What are you trying to do, anyway, protect us from ourselves?  We don't need
>it!

The funniest thing is, if we follow your posts that followeda the one where
I pointed out your error on how external pressure effects drive mechanism,
we can see a progression of you first ignoring it in stunned silence, then
hedging by talking around the subject as if to show how you were right in
so many other ways that it didn't matter, and finally, to claim that you
were talking about something altogether different!

I wrote:

"The pressure on the armature/shaft at depth is going to be equal to the
area of the shaft where it comes through the seal, times the pressure."

Your replied:
> Wrong.  It's at least going to equal the pressure exerted
on the area of the prop hub.
>Given a prop hub diameter of 4", the pressure exerted internally on the
thrust bearing will be a lot more than the figure you've come up with.  I
have to go to work in a few minutes, I don't have my calculator handy, and
don't have time to do the math for you right now.

But now you'd have us believe:

>No you didn't and no it's not!  The particular motor/prop designs we were
>describing were different, that's all.   I understand the physics involved a
>lot better than you want to believe I do; and that's proven by the
>successful submarine sitting in my shop right now.  (What kind of submarine
>YOU got, Steve?)

Finally you conclude with;

>I'll tell you something, Lindblom.  There's a lot of guys at PSUBS who are
>qualified to offer educated criticisms about my boat: guys who have built a
>submarine, taken it under water, and faced the moment of truth wherein they
>proved  their understanding of theories and technologies was correct.   But
>you aint one of them!

You seem to be saying that the list is all on your side. But while I don't
notice many people jumping in to take my side, I don't see anyone coming in
on your side either. I think most of them are standing uncomfortably aside,
embarassed and maybe a bit cowed, while they watch you try to bludgeon into
submission another poor fool who made the mistake of trying to discuss psub
issues on the psub list without paying proper deference to your
preconceptions.

Well, it works. You've worn me out. Everything that can be said has been
said, and so I'm butting out of this catfight. Tell you what - I'll let you
storm and thunder your way through a few more posts on the subject
unchallenged, so you can feel properly victorious and vindicated.

You'll probably think over what I said, realize I was right about no
redundancy, quietly upgrade your seals, have a safer sub, and we'll all
have profited from this exchange!