Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 24-09-2012, 07:21   #1
Registered User

Join Date: Mar 2010
Posts: 34
Aluminum alloy determination

Does anyone know of an easy way to determine the exact alloy of aluminum one is working with either through limited destructive or completely nondestructive techniques?

I need to know what type of welding wire and stock aluminum to purchase.

Thanks in advance....
__________________

__________________
anontrolus is offline   Reply With Quote
Old 24-09-2012, 07:59   #2
Moderator
 
noelex 77's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: Living on dirt waiting for our new yacht to be built.
Boat: Half built Bestevaer.
Posts: 10,619
Re: Aluminum alloy determination

Not sure if it will be any help, but if it's a boat, aluminium from reputable suppliers will be labeled with the aluminium type.
Below the waterline is generally not insulated or painted and if you poke around you should find a stamp somewhere with the aluminium type. My boat has severalsuch stamps from the original producer of the aluminium.

Destructive testing must be possible as I have seen forensic examination of boat structures.Notably in about 1996 when there was a defective batch of 5086 produced with some very expensive court cases where the alloy was shown to be the wrong composition for 5086.

However I would imagine such testing would be very expensive.

Generally substituting a suitable marine alloy is acceptable. The alloys are so close on the galvanic scale that there are no practical problems.

Most aluminim boats use different alloys for the extrusions (typically 6 series) and the plate (5 series) without any problems.
__________________

__________________
noelex 77 is offline   Reply With Quote
Old 24-09-2012, 08:00   #3
Registered User

Join Date: Nov 2011
Location: Fethiye Turkey
Boat: Lagoon 440
Posts: 3,164
Re: Aluminum alloy determination

If you strike 5083 or 5086# (that's not annealed) with a metal bar it rings plate is usually 5000 series and extrusions 6000 series with silicon to assist the extrusion process.

Really need to keep tabs on origin to be sure..'Tis a hard one!
__________________
"Political correctness is a creeping sickness that knows no boundaries"
Lagoon4us is offline   Reply With Quote
Old 24-09-2012, 08:02   #4
Registered User

Join Date: Nov 2011
Location: Fethiye Turkey
Boat: Lagoon 440
Posts: 3,164
Re: Aluminum alloy determination

Also the higher the magnesium content the more spatter balls you will see burning whilst you weld....5000 series is safe with 5%mag whilst castings 5 to 10% silicon....
__________________
"Political correctness is a creeping sickness that knows no boundaries"
Lagoon4us is offline   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 10:39.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.