"Geoff Schultz" wrote in message
7...
I recently purchased a Questus self-leveling radar mount off of Ebay.
Unfortuantely this unit was designed to be mounted on a backstay, and my
boat (a Freedom 40/40 with a carbon fiber mast) doesn't have one. I've
designed an adapter for it, which I will machine out of 3" round Al stock.

It seems that there's primarily 2 types of Al stock available: T6511 and
6061. The part will be painted. Which of these (or some other varient)
should I use considering the salt water marine environment?

-- Thanks, Geoff

6061-T6 is about the commonest form of extrusion (such as pipe, channel,
T's, etc. - I guess 3" round bar is one of the extrusion forms
5086, 5052,5083 are the common forms of plate
5456 is pretty uncommon though it has higher "as welded" strength

Uhh, you're not planning to put this right on your mast are you Geoff?
Aluminum and carbon fiber get along like, well copper and aluminum.
Basically the potential for the aluminum to disappear is very high. If you
do this, make sure you insulate the two. One simple way is a couple light
layers of E-glass on the mast to isolate the CF.


--
Evan Gatehouse

you'll have to rewrite my email address to get to me
ceilydh AT 3web dot net
(fools the spammers)
You don't need to paint any of these alloys unless you want to.