|
|
|
|
|||||
|
||||||
From: Jim Donnelly (no email)
Date: Sun Jul 03 2005 - 20:23:14 EDT
1)
http://www.yachtsurvey.com/corrosion.htm has some excellent basic
explanations of corrosion in the marine environment.
2) I sell a lot of scrap stainless steel in 200 ton lots, and I needed a
quick and dirty test to tell the good stuff ( 316) from the junk.
2 junkmens tests are widely used - The magnet test ( it will NOT stick to
the really good stuff)
- the acid test with a 9 volt battery. You put a drop of acid (HCl works
fine) on the metal. With a 9 volt battery and 2 pieces of jumper wire-
you ground the negative side to the sample and just touch the positive wire
to the drop of acid. The acid will turn pink+ to red immediately if it is
high moly stainless. That makes it worth twice as much. In the Papermill
business we use mostly 316 due to its RELATIVE (but not absolute)
resistance to Chloride Stress Corrosion which leads to catastrophic cracks.
- you are much safer with good hot dip galvanized steel screws (not the
flash plated junk) than you are with any "stainless". Monel is good. But
hard to get small quantities in the sizes we use (14 x 2 1/2).
The name "Stainless Steel" is about as definitive as "Dog"
read this stuff: www.corrosion-doctors.org
. Silicon Bronze
is another subject- There has been a lot of trouble in the REAL ( wooden)
Boat Building and Repair industry with junk metal sold as Silicon Bronze.
(Dont Eat that, Elmer). This stuff has caused serious trouble with
snapping off during driving. Look at some back issues of Wooden Boat for
coverage on this. Also search on the web to read about Brasses and Bronzes.
Brass has no place at all in the marine environment, except as shiny
stuff.
Jim Donnelly
Troller Fan Isle
With the OPEN WIRELESS NODE
at Powell River BC
_______________________________________________
http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering
To unsubscribe send email to
with the word
UNSUBSCRIBE and nothing else in the subject or body of the message.
Trawlers & Trawlering and T&T are trademarks of Water World
Productions. Unauthorized use is prohibited.
|