The hatch rings don't need to be made from Stainless Steel. But if you use steel it is a normal practice to make them thicker so that you'll have a corrosion allowance. And if you keep them painted they will work. But Stainless is better. DJB
I think I may have made an error when designing this hatch. My plan
was to build just the hatch and then seal off the bottom part and then
take off our coast here and drop it down to about 1200' or( 365 meters)
to see if it would hold together. I'm mainly curious about the acrylic
dounut. Origionally I was thinking that the whole assembly would be
the hatch but upon further thought that seemed like it would be too heavy
to handle so I decided to split the hatch above the acrylic dounut so
just the top steel hemisphere would open. This is the drawing I posted
a while back
http://www.prismnet.com/~moki/20040309.103505/hatchXdrawing.jpg . The
bummer part is that I just ordered a ring 24" OD by 20" ID and .75
thick A516 - 70 which I was planning to weld onto the 20" (508mm)
hemisphere. Since when that ring gets welded onto the hemisphere there is
going to be a lot of warping of the ring and it will have to be machined
flat so it seems like you would need enough metal so!
that once you're done machining it is still thick enough to be
strong. If I had to use stainless steel for that ring I bet that would be
really expensive. The 24" od by 20" id by .75" thick is going to run
me $156.00 would it be possible to weld a piece of 1/4" stainless
onto the thicker piece or would you still have the problem of warping ?
Brian
----- Original Message -----
From: "Carsten Standfuss" <
MerlinSub@t-online.de>
To: <
personal_submersibles@psubs.org>
Sent: Wednesday, April 07, 2004 2:06 PM
Subject: Re: [PSUBS-MAILIST] hatch rings
> I would say: Yes.
>
> In the year 2004 hatches rings and troughull connetors should be made
> from stainless steel. Corrosion on this parts can be really expensive
> over the years. Maintance time is also an issue.
>
> regards Carsten
>
> > Brian Cox schrieb:
> >
> > Do the hatch rings need to be stainless