3mm aluminum composite board

[ChicagoGraphics]

Does anyone know if 3mm aluminum composite board can be submerged in water for long periods of time without falling apart.

Thanks in advance

 

[TimToad]

How long is "long periods of time" and is it fresh water or salt water?

 

[bannertime]

Interesting. I've got some drops that I may try this with.

 

[ChicagoGraphics]

Fresh water, will be 2 miles offshore in a lake, so it wont always be submerged, more like if waves hit it.

 

[equippaint]

Id use 080 marine grade aluminum sheet like 5083 or 5052 but I would ask a local sheet metal distributor for their input. I dont think 3mm acm would even be strong enough to stand up to waves let alone last in the water.

 

[TimToad]

Fresh water, will be 2 miles offshore in a lake, so it wont always be submerged, more like if waves hit it.

If its "the lake" and as a former Chicagoan, we know which one one we're talking about, I'd think it would be fine until whatever acidity or alkalinity there is in the water starts corroding the aluminum. I think the core is thermally fused to the skins, so I can't see that failing until the aluminum starts corroding throughout.

Just make sure they use a similar fastener or the electrolysis between the steel fasteners and aluminum will speed up the corrosion.

 

[Gino]

If its "the lake" and as a former Chicagoan, we know which one one we're talking about, I'd think it would be fine until whatever acidity or alkalinity there is in the water starts corroding the aluminum. I think the core is thermally fused to the skins, so I can't see that failing until the aluminum starts corroding throughout.

Just make sure they use a similar fastener or the electrolysis between the steel fasteners and aluminum will speed up the corrosion.

He's located in China. The name is where he used to live.

ACM won't even hold up to a brisk wind, let alone a wave which has some punch behind it. I'd do as mentioned and go with .080 aluminum. What's the finished size ?? That could have some bearing and if it's mounted to one pole or two...... or to whatever ??

 

[eahicks]

He's located in China. The name is where he used to live.

ACM won't even hold up to a brisk wind, let alone a wave which has some punch behind it. I'd do as mentioned and go with .080 aluminum. What's the finished size ?? That could have some bearing and if it's mounted to one pole or two...... or to whatever ??

I'd go one step further and use 1/8" Aluminum.

 

[ChicagoGraphics]

Th

He's located in China. The name is where he used to live.

ACM won't even hold up to a brisk wind, let alone a wave which has some punch behind it. I'd do as mentioned and go with .080 aluminum. What's the finished size ?? That could have some bearing and if it's mounted to one pole or two...... or to whatever ??

This sign will be put up in Chicago, Tim knows where the sign is going. It will be installed on a wall, size is 48"x24"

He's located in China. The name is where he used to live.

ACM won't even hold up to a brisk wind, let alone a wave which has some punch behind it. I'd do as mentioned and go with .080 aluminum. What's the finished size ?? That could have some bearing and if it's mounted to one pole or two...... or to whatever ??

 

[signbrad]

ACM is probably not a good choice. The more expensive brands, like Alupanel, will fare better than the cheap ones, especially if the paint finish is PVDF instead of polyurethane or polyester paint. Though not intended to be submerged in water, these high-end brands are designed to be used as rain cladding on buildings. But since the aluminum skin is so thin on an ACM and the panel is not superstrong structurally, I would expect delamination at some point from constant water contact. Just my opinion, of course.

To elaborate on what Tim T said about dissimilar metals in contact with each other, there is a definite galvanic reaction between stainless steel and aluminum. It works like a battery. One metal is the anode and the other is the cathode. When there is contact, the weaker metal is attacked by the stronger metal and corrodes it. The reaction is accelerated by the presence of moisture.

When both metals have substantial thickness, the galvanic reaction may not be a big issue. Even so, engineers often require nylon insulating washers or bushings to separate stainless and aluminum as a safety precaution, say, when heavy heating and air units are suspended in indoor pool areas using aluminum brackets and stainless bolts. Aluminum corrosion from contact with stainless steel in a moist chlorine-saturated environment can be a danger.

Over ten years ago I had ACM panels ruined by contact with 1/4x20 stainless bolts. The thin aluminum skin corroded under the paint, starting at the point of contact with the fastener and radiating outward. In a matter of weeks, the panels looked terrible. The problem is easily solved with a nylon washer, or, a nylon or aluminum fastener.
Still, I don't think I would trust an ACM panel in the middle of the lake where it would be regularly buffeted by waves.

1/8-inch aluminum is what I would use, painted with the toughest paint you can get. Better yet, some of the prepainted aluminum is available finished with PVDF, which will hold up better than polyurethane, polyester, or epoxy. At least one sign blank company I know of uses PVDF-finished aluminum for their products.

Brad in Kansas City

...................

Off topic.
After the Streator, Ill., Walldogs festival, we went to see a show in Chicago. Lots of cool sign work in Chicago, along with some not so cool. The Cadillac Theater in the Loop has upper and lower case letters vertically stacked on a tall projecting sign. I was visually disturbed. Unattractive, awkward-looking. The letter style choice made it even worse. The client must have insisted on the look and I felt bad for whichever sign company had to do the deed, especially considering how beautiful this theater is on the inside. However, after a couple of Manhattans made by a creative bartender after the show, it didn't bother me as much.

 

[signmania]

Interesting--I have found that barrel-aged imperial beers tend to increase my appreciation of poorly-executed signs.

 

[ChicagoGraphics]

I ended up going with 0.80 aluminum, hopefully it doesn't fall apart in the first year.