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RE: [PSUBS-MAILIST] Hot-galvanize stainless steel ?
What's wrong with just using a sacrificial anode on your drop weight? So
long as you keep it active, shouldn't that prevent your corrosion
problem?
Ron
-----Original Message-----
From: owner-personal_submersibles@psubs.org
[mailto:owner-personal_submersibles@psubs.org] On Behalf Of Carsten
Standfuß
Sent: January 24, 2002 9:56 AM
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] Hot-galvanize stainless steel ?
Alec - during diving in the baltic I found the wreck of a
modern sailboat maybe just 2 years underwater.
I salvage a rigging terminal made from unpainted stainless steel.
It has very bad big corrosion holes in many parts..
Is there a material I can put between the both - key and hole
which is :
- not metal
- can be loaded with the weight pressure of the keel
(load area is 3600 mm2 with a load of 3 N/mm2)
- is just 1-2 mm in tickness ?
see you - Carsten
Alec Smyth schrieb:
>
> Carsten, maybe I'm misunderstanding it, but as I understand your
> description you would have:
>
> - A stainless shaft (or "key")
> - A stainless insert for it welded into a dropweight of plain steel
>
> If you galvanize the drop weight (with the insert already welded of
> course) then the key and the key-hole would be of different metals so
> the corrosion problem would be worse than if they were both just SS.
> Wouldn't it be enough to just paint the drop weight like the rest of
> the sub for corrosion protection purposes, but leave the key-hole
> unpainted? If you wanted to get really fancy, you could sleeve the
> shaft in plastic like nylon or teflon, to prevent it from sticking
> after a year in the water.
>
> rgds,
>
> - Alec
>
> -----Original Message-----
> From: MerlinSub@t-online.de [mailto:MerlinSub@t-online.de]
> Sent: Thursday, January 24, 2002 11:49 AM
> To: personal_submersibles@psubs.org
> Subject: Re: [PSUBS-MAILIST] Hot-galvanize stainless steel ?
>
> "Dan H." schrieb:
> >
> > Carsten,
> >
> > Why not just weld in a stainless steel plate with your key way
> > already in it into a hole cut in your steel weights. Instead of
> > cutting out the key in the actual steel weight, weld in a piece of
> > stainless for the key to fit into.
>
> That it exact was I want to do. Maybe my description was a little
> short.
>
> > Even if you had the whole thing galvanized and it didn't take well
> > to the stainless it wouldn't matter. Actually, the part of the key
> > way in contact with the key will probably wear through the galvanize
> > in time anyway just from rocking back and forth in use, won't it?
>
> That is exact the question - would the galvanize hold on the stainless
> - or not ? I think that if the zinc gives way from the key-hole - we
> have a direkt contact from two parts of Stainless steel with a very
> little gap filled with saltwater between them - all the time in
> seawater - maybe
> the hole year. That should generate maybe a corrosion problem - and if
> one of the key-hole surface has to much structure on it - the key will
> not turn.
>
> Maybe it would be better to make the key-hole-plate from normal
> carbon steel. I am not affraid that the zinc gives way during "Using
> the key". If I use it - the drop weights gives way and the sub is not
> longer able to dive - so the weight will be lost and will not
> repaint..
>
> >
> > Just a question; why didn't you use lead for your drop weight?
> > There's so much more weight for the area it takes up. A ton of old
> > tire weights doesn't make that big of a pile.
> >
> Maybe I will do it - a drop weight build from 1/3 inch strong steel
> plates as a box - and than filled with lead. It will be depents on the
> final weight calclulation - some month before CSSX contact the water
> in our river.
>
> Carsten
>
> > Dan H.
> >
> > Carsten Standfuß wrote:
> >
> > > Hi submadmans and ironheads,
> > >
> > > One question about metalurgy :
> > >
> > > Is it possible to Hot-galvanize stainless steel ?
> > >
> > > I want to build the drop-weights from normal mild
> > > and cheap steel and hot-galvanize it.
> > > The release-key will be made from stainless steel (SS).
> > >
> > > For the reason that the welded key-hole inside the dropweight can
> > > be made easy from the same plate as the key and with the same
> > > waterjet cut - I ask this unuseual question.
> > >
> > > drawing without scale : (and below 40 KB :-) )
> > >
> > > I = Stainless steel release key
> > > O = Stainless s. hot galv.? key hole
> > > = = mild steel hot galv.drop weight
> > >
> > > _____________________________________
> > >
> > > IIIIIIIturn90°
> > > I
> > > ========= I ========
> > > ==========OOO I OOO==========
> > > =========== IIIII ===========
> > >
> > > _________________________CS-1/2002___
> > >
> > > And please - I know that a full SS drop weight will fit the
> > > problem.. .. but I have three weights of 1,3 ts - means it
> > > generate another one..
> > >
> > > regards - Carsten