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Re: .040 aluminum panel edge trimming

PostPosted: Wed Sep 09, 2015 8:10 pm
by Gunguy05
I used the insert trim on my from curve it is a 24" radius. I bent it and screwed it down like Tony mentioned. Very, very, very easy. No hammer was required. If you do hit some spots where you think you need to hammer to make it sit a little flatter, just use a piece of 1/2 as a filler in the insert and bump that.

It is easy, I think they key is to measure, measure, cut, bend to fit, file and trim, and then seal and screw it down permanently. Just take your time and it will turn out fine.

Re: .040 aluminum panel edge trimming

PostPosted: Thu Sep 10, 2015 7:12 am
by noseoil
Thanks again guys, sounds like we can't possibly screw this one up. I'll just have to round up a few things prior to starting. Still need to decide on the skin color & do more work on the hatch, but we're getting there!

Re: .040 aluminum panel edge trimming

PostPosted: Thu Sep 10, 2015 4:18 pm
by dales133
Im going to bd using the insert type extrusion witch i picked up the other day.
Looks pretty bendy but i havnt played with it yet

Re: .040 aluminum panel edge trimming

PostPosted: Tue Sep 15, 2015 7:42 am
by noseoil
I've found a good deal on the sides (2 - 4' x 10' x .040" Ivy green @ $140 delivered) but I'm having a tough time finding the 5' wide stuff I need for the roof.

Best I've found is some 5052 H3 in 5' x 10' x .040" at $140 a sheet, I would need to buy 2 sheets for the roof & hatch. Any ideas about finding a better deal? The 5' wide stuff isn't readily available where I live & this price is from a dealer/fab shop which is marking up quite a bit. I could get it shipped in, but shipping is pretty expensive if I add it to the "cheap" price.....

Re: .040 aluminum panel edge trimming

PostPosted: Tue Sep 15, 2015 7:50 am
by dales133
Its hard to comeby here mate.
Im just using 8 x 4 sheets sideways across tge roof but mostly because i got them cheap.
Mines 1600 wide witch is over 5 foot so i was out of options anyway.
If you place the joints strategicly it shouldnt look bad or have any adverse effects.
Thats what im hoping anyway

Re: .040 aluminum panel expansion

PostPosted: Tue Sep 22, 2015 7:07 am
by noseoil
The 5' x 10' x .040" was delivered yesterday morning. Ended up costing right at $250 with shipping, for 2 sheets delivered where I work. Not too bad, but still a bit "spendy" for this type of material. It's 5052 H3 & looks pretty good.

I have a question about expansion on the roof. My "normal" temperatures will range for a low sometimes in winter of about 20f degrees to a high of about 110f. Add to the upper end of things by another 20-30 degrees when it's in full sun & I'm wondering about the effect this will have on the aluminum on the roof. I'll have a splice on the front at about 2' up from the lower edge at the front, so the overall length of the main roof panel will be about 8' long. Just ran the numbers & I think it may expand & contract about 3/16" in the extreme range of heat it will likely see over a year.

If it's .040" aluminum, does anyone think I'll see any "real" difference in the skin as it cycles in the heat? I'm thinking I'll put it on when it's about 90f outside, which is the normal temperature when I'm working. It will be fastened down at the back, where the hinge is screwed down at the last spar, at the vent opening in about the middle of the run, and then at the front edge where the air conditioner opening is located. It will overlap the front sheet from the top by about 1 1/2". The outside edges will be screwed down with some trim, which has butyl rubber tape under it. Thinking I'll bed the sheet at the edges with Osi Quad sealant to make a barrier against water.

Just curious about how it will look over time when it's hot & cold outside. With .040" I really shouldn't see any oil canning, right? Does this sound about right for putting things in place?

.040 aluminum panel edge trimming

PostPosted: Tue Sep 22, 2015 7:56 am
by aggie79
My 0.040 aluminum oil cans slightly in the summer. It wouldn't be noticeable except that you can see some distortion in the reflections. I did undercut the aluminum by 1/8" at the outer edges and drilled oversize fastener holes in the aluminum (but not the plywood substrate) so the aluminum would have room to move.

The oil canning goes away when the temperature cools down to 80 degrees or so.

Re: .040 aluminum panel edge trimming

PostPosted: Tue Sep 22, 2015 7:56 pm
by Gunguy05
I have some oil canning in mine as well, mainly on the top. My theory is that it is because of all the stuff that attaches on the top ( fan, moon window, seam attachment at a spar etc.) because of all the attachment points of the e aluminum in such a small space it wrinkles unevenly rather than just bubbling up slightly and evenly (less noticeable) .

On the sides it is very, very slight and almost unnoticed. I wouldn't sweat it there.

Sounds like you're have a plan! I think in the end the fewer attachment points you have of the aluminum in the middle, the less of an issue the oil canning will be.

Re: .040 aluminum panel edge trimming

PostPosted: Tue Sep 22, 2015 9:33 pm
by noseoil
Thanks Tom & Brian. I hadn't thought of using the larger holes in the skin, but it makes perfect sense to do it & that's what I'm planning on now.

There will be the vent in the middle & a solar panel mounted on the roof closer to the hinge, so it's going to have to work as best it can in the summer. Across the width it will only be growing about 3/32" from 20f to 140f & if I install it at 90f, this should be cut in half so that's not a big deal (about .046"). The length will be the main thing it will be working on. I guess the only other way to slow it down would be to paint it white to cut down on the heating and lower the top temperature.

For now I'm just going to do the mill finish at 90f & see what happens.

Re: .040 aluminum panel edge trimming

PostPosted: Tue Sep 22, 2015 10:39 pm
by jonw
My .040 aluminum is attached only at the edges and sits directly on the roof spars (ie. no roof sheet material underneath the aluminum). I don't have any oil canning that I've noticed.

One thing I recommend is to start by attaching one side first, the top edge at the hatch (where your hurricane hinge is). Then drill only a few holes at a time on each side of the and aluminum and edge molding, screwing it down before drilling the next set of holes, working your way from the hatch forward to the front bottom edge. Doing it this way to dry fit the roof and molding will give you a nice flat roof that goes tightly around your profile curve, and you may find you have some excess to trim off the front bottom edge. Then go back and unscrew it all and re-attach it using caulk underneath the molding and in the screw holes.

Re: .040 aluminum panel edge trimming

PostPosted: Wed Sep 23, 2015 7:56 am
by noseoil
Thanks Jon, duly noted & makes perfect sense to me. I figure (in the heat) if I start at the back & work forward, as you suggested, it should stay flat when I get to the front. Once night gets to cooling things down a little, it should "shrink" a bit & tighten up. Appreciate the input! Again, thanks for helping keep me out of trouble on my build.