Aluminum stiffener

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fallguy1000
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Aluminum stiffener

Post by fallguy1000 »

So, I have a piece of 5052 Al.

It is too flimsy and could kink.

I can't find 5052 Al angle.

Can I just bond some 60xx Al angle on this with 5200?

Sort of want to avoid the expense of welding and a piece of 5052 Al is like $250 to get made.
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Fuzz
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Re: Aluminum stiffener

Post by Fuzz »

Try a test and see. You could always bolt the angle to it if you do not trust the 5200. That stuff will bond ice to ell shit so it might work just fine.

fallguy1000
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Re: Aluminum stiffener

Post by fallguy1000 »

Any chance of galvanics?
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Fuzz
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Re: Aluminum stiffener

Post by Fuzz »

fallguy1000 wrote: Wed Jun 17, 2020 9:33 pm Any chance of galvanics?
Out of my wheelhouse,sorry

OneWayTraffic
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Re: Aluminum stiffener

Post by OneWayTraffic »

I read that with aluminium water vapour will eventually find its way into the joint. The oxygen will react with the Al, reducing bond strength over time. Have you considered taking it to a shop to get it bent to shape?

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OrangeQuest
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Re: Aluminum stiffener

Post by OrangeQuest »

I found this chart on the subject of corrosion.
6901

You could use the 5200 and use aluminum blots to make sure it holds.
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LarryA
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Re: Aluminum stiffener

Post by LarryA »

"5200 to Aluminum" shear strength is about 1/3 the shear strength when compared to gelcoat (which is where it is most commonly used) and most common woods. I would not recommend it.

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cape man
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Re: Aluminum stiffener

Post by cape man »

What are you doing with it?
The world always seems brighter when you've just made something that wasn't there before - Neil Gaiman

fallguy1000
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Re: Aluminum stiffener

Post by fallguy1000 »

Aluminum angle 6061 on aluminum plate 5052 as a stiffener.

The plate is 3/16ths, so welding might deform or mess with the appearance. I plan to paint someday.

I could rivet, but that would show a bit.

It is a plate to close the beam notch to the sea.
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Evan_Gatehouse
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Re: Aluminum stiffener

Post by Evan_Gatehouse »

6061 is welded to 5000 plate all the time. No issue with corrosion. Almost all extruded sections are 6061 or 6063. You can't extrude the 5000 series alum.

Bonding alum to alum is HARD. Not to do initially but to have the bond survive for years. Eventually moisture gets under the edges and weakens the bond.

Welding will leave a line but it won't be too bad on 3/16 if the welder is good. Easy enough to fair and paint.

You could also lay up some flat polyester/glass panels with a few foam stiffeners (from offcuts) on the underside of the panel.
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