Re: [Paddlewise] aluminum and salt water (was:blown out footpeg)

From: Gabriel L Romeu <romeug_at_erols.com>
Date: Tue, 26 Jan 1999 00:23:02 -0500
rdiaz_at_ix.netcom.com wrote:
> 
> DANJW_at_aol.com wrote:
> >
> > All this talk of metals and saltwater and corrosion causes me to wonder what
> > the metallic frames of folding kayaks are made of , and how do they defeat the
> > corrosion problem?
> 
> I hope someone with more metallurgical knowledge that I have will pipe
> up on this.  Feathercraft uses two different types of aluminum.  The
> K-Light uses 6063-T832 extruded aluminum/magnesium whereas its bigger
> brothers use a heftier 6061-T6 aluminum/magnesium.  

additional information (though probably useless),
the 6000 series aluminum is an alloy of magnesium and silicon,
attributes being good formability (not stringy on cutters and stuff),
tempering (hardening) ability and good resistance to corrosion.  the
last two digits indicate the percentage in hundreths +99%- 99.(60)63% or
99.(60)61% aluminum, rest ('cept for trace impurities) magnesium
silicate.
The 2000 series uses copper and is subject to intergranular corrosion. 
Totally innappropriate for marine use.
The alloy generally used for marine application is a strictly magnesium
alloy, the 5000 series.  This alloy can develop stress corrosion in
operating temperatures over 150 degrees farenheit (due to the higher
magnesium content).  Might not be the thing for hot garage storage.  It
is not heat treatable, and care must be taken in cold work.
Probably the 606x series was a good all around material.  The anodizing,
especially if it is a deep anodize (done in a cool bath, a hard thing to
maintain in electrolysis), should help protect it.  
I know many people who anodize and also wax the pieces for additional
protection, but these wern't being used in a marine enviroment.
The t designation is for the hardening process, t6 is heat
treated(temper) and artificially aged, the 832 is heat treated, cold
worked, and artificially aged.

sorry if this was not applicable.



-- 
Gabriel L Romeu
http://users.aol.com/romeug   ------->   furniture
http://users.aol.com/romeugp  --->   paintings, prints, photos + stuff
http://members.xoom.com/gabrielR -->   a daily journal of observations

***************************************************************************
PaddleWise Paddling Mailing List
Submissions:     paddlewise_at_lists.intelenet.net
Subscriptions:   paddlewise-request_at_lists.intelenet.net
Website:         http://www.gasp-seakayak.net/paddlewise/
***************************************************************************
Received on Mon Jan 25 1999 - 21:26:43 PST

This archive was generated by hypermail 2.4.0 : Thu Aug 21 2025 - 16:30:03 PDT