Aluminium.What grade?

[seabug]

http://www.batsman.se/Hytt_inne.html

With the recent discussion re corrosion of tinnies,it is interesting that
Batsman boats(link above) are using 4120 spec. Alum. and are giving a 5 year warranty..

Regards
seabug

[revs57]

G'day bugman!

I'm not aware of the 4120 spec...I thought most tinnies were built out of a 5052 marine grade or something similar.

Is this a new spec? I don't spek franchies either so it was a bit hard to get the gist of their comment

Cheers

rhys

[finga]

Gees you need sunnies for the inside of those boats...click on the pommy flag and you get English.
These boats are from the home of Volvo's...Sweden

[Kerry]

Maybe they might have to up their standards then? as if that is 4000 series grade (not temper) alloy then it is not as good as far as corrosion is concerned as the 5000 series alloy most boats here are built with?

[seabug]

http://www.suppliersonline.com/propertypages/2024.asp

Alum. 4120 is listed under 2024 under Specifications.

Shows tech. data.

Regards
seabug

[Kerry]

Seabug,

Would you like a alloy boat built out of that grade/temper?

[seabug]

Seabug,

Would you like a alloy boat built out of that grade/temper?

Hi Kerry,
Would not have a clue,that is why I put up the thread.

I just wondered why Sweden use that spec.

On another tech site it says that it widely available and commonly used in Sweden.
Q. is WHY.

Regards
seabug

[Owen]

Not sure how you link 4120 to 2024
The former is unfamiliar to me, but the numbers suggest a high silicon alloy.
(4043 & 4047 are common welding allows with 5% & 10% silicon respectively).
This would make it form easily, but the strength in a boat building context would be a worry.

2024 seems to be an architectural grade.

Let's Compare some info

2024

Welding http://www.suppliersonline.com/images/transpix.gif
Welding may be done by use of resistance welding or inert gas consumable electrode arc method. However it must be noted that, in general, welding by any means is NOT recommended for this alloy because of the degradation of corrosion resistance that occurs as a result of weld heat. A repeat heat treatment should be done if welded.
http://www.suppliersonline.com/images/transpix.gif
5083

Welding
Weldability of this alloy is very good by conventional means. When filler rod is required it should be the same alloy, 5083.

http://www.suppliersonline.com/images/transpix.gif
http://www.suppliersonline.com/images/transpix.gif On this basis alone, I can't see 2024 being used on a boat.

[seabug]

[quote=Owen;660280]Not sure how you link 4120 to 2024

Hi Owen,
The spec below is from the link in my earlier post.


http://www.suppliersonline.com/propertypages/2024.asp
Specifications

The following specifications cover Aluminum 2024

AMS 4037
AMS 4120
>>>>>I am not suggesting it is better or worse.
Just wondering why it is used in Sweden.

From the Batsman website


Båtarna säljs i fyra basutförande!
En 12 fots (http://www.batsman.se/f12.htm), en 14 fots (http://www.batsman.se/f14.html), en 16 fots (http://www.batsman.se/f16.html) samt en 18 fots (http://www.batsman.se/f18.html) modell. Dessa kan förses med en mängd olika tillbehör (http://www.batsman.se/tillb.html).

Alla modellerna tillverkas i saltvattenbeständig marinaluminium 4120.


Modell 12f och 14f med en plåttjocklek av fyra millimeter i botten och tre millimeter i sidan samt 16f och 18f med hela fyra millimeter i både botten och sida.
Storlekar och modeller kan anpassas

Regards
seabug