Aluminum Sheet

[ALAN GEDDES]

What is the minimum thickness for the aluminum and what type is it ? What is the adhesive to use and should the wood be sealed underneath ? AL G :

[Joseph]

Hey Al,

OK, here's the wisdom I have gathered over the past year. It is based on e-discussions (like this one) and on-line research rather than my own experience, which is minimal. (Note: experience = learning from the mistakes you have made. Wisdom = learning from the mistakes others have made.) :read2:

-The minimum aluminum thickness seems to be .032 though I believe most use .040.

-The glue you use to attach the aluminum doesn't matter because it's going to delaminate no matter what you do. Better to float the aluminum and secure it by the edge moulding.

-Sealing the wood is optional but recommended if you're not using marine plywood.

Hope this helps.

Joseph

[Jimbo]

Anyone ever consider using screws to secure the aluminum? If done uniformly, I think it would look good.

[Joseph]

Hey Jimbo,

Anyone ever consider using screws to secure the aluminum? If done uniformly, I think it would look good.

That's sort of what I'm talking about - the screws on the edge moulding secure it. The screws pass through the moulding, then the aluminum, then into the wood underneath.

If you're talking about screws horizontally across the width of the trailer, you can do that, but there's really no reason to if you do the edges right. There's also a good reason not to - every screw is a potential leak spot. Water between the aluminum and the wood underneath is a bad thing.

What I did was screw down my edge moulding to form the curve, then I removed it and ran a bead of Lexel (a rubber sealant) along the edge. Then I screwed the moulding down again and cleaned off the excess Lexel that squirted out the sides.

Joseph

[tdhombre]

I used .040 aluminum for the exterior of my teardrop although .032 would also work. I invested in the metal cutters that come with red, green and yellow handles that were very useful when cutting and shaping the profile curves.

I used my Skill saw with an appropriate blade to cut the shape(s) and the snips to cut to the final dimensions (after I had mounted the cut aluminum sheet on the trailer.)

I applied two coats of primer to the plywood exterior to guard against water getting under the aluminum. I doubt it will, but I don't want to take any chances.

I am going to let the siding "float" as the prospect of glueing it down is too daunting and my technical advisor (Peter Ward of Mac-Bilt) tells me its not necessary.

I am gong to use caulk tape under the edge trim to provide the water tight seal. It is a putty that comes in tape form and is an excellent way to provide the seal to the metal seams.

I would recommend against poking holes in the aluminum for screws. Just another hole for moisture to get inside.

Good luck!

[ALAN GEDDES]

Is $45 for a .040 4x10 mill finish a good price or should I shop around some more ? Only one place local. What is the best way to cur out door and window openings ? AL

[tdhombre]

I believe $45 for a 4'x10' sheet of .040 is a good price. Especially if it is from a local source. I paid $40 for 4'x8' as a benchmark.

As for cutting, I mounted the whole sheet on the side(s) using clamps then drew the profile of the teardrop on the aluminum using a Sharpie pen. Then it was back to the sawhorses with the sheet where I cut the profile out with a Skil saw using a metal cutting blade. Finally, I took the sheet back to the teardrop, clamped it on and used the aviation snips (the ones with red, green and yellow handles) and trimmed the sheet to the exact outside dimensions of the profile. (NOTE: cut the shape with a little excess left when doing the Skil saw step - like 1/8" or 1/4".)

Door and window openings were marked last after the final exterior was trimmed. Then it was back to the sawhorses with the sheet where I drilled holes in the corners of the door and window outlines. Then the Skill saw to "connect the dots" followed by the snips to cut the final openings.

By the way, I did NOT use adhesive to glue the aluminum to the sides. I believe that the doors and windows frames, once mounted, will hold the sheets in place very well (and the idea of that much glue was too imposing.)

It worked out really well for me. Hopefully, you will have good success as well.

[engled]

I payed around $150 for 3-4'x8' and 1-4'x12' .040. One thing that I haven't seen mentioned much is the alloy used, my plans called for 5052 .032 which is harder but cost a lot more (~350), I used 3030 .040 and it worked out well.

[Clancy Courtney]

Alan, I found sandwiching the aluminium between the side panels and cutting the the profile out to be the easiest for me. I used a jigsaw and it cut the 3/8" plywood and the Al with no problem. That way each piece was identical. You may be to far along for this method though.
Good luck,
Clancy