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Where and how to splice aluminum

PostPosted: Wed Feb 20, 2008 11:00 pm
by Aaron Coffee
Changed my mind and am now thinking about a grasshopper profile ten foot long. Rough claculation is that my roof skin would be 12 foot 8 inchs. Have priced 10 foot long aluminum, will check around for longer. Kind of thinking of starting at hatch with ten foot sheet and splicing at front. Two ideas come to mind. One is to bend a z hem (kind of like the way that rectangular ductwork is attached to each other) on the end of one piece(probably the shorter as it would be eaiser)and then flattening it. The other piece would then slip in this hem with some kind of silicone sealant. Hope this makes sense. The other would be a simple overlap with the raw edge covered by some sort of trim(insert molding without the one leg). They way I see it the first idea would have the advantage of still being able to float the skin as it wouldn't have screws as the second one would.
Thoughts, ideas, comments...

PostPosted: Wed Feb 20, 2008 11:28 pm
by doug hodder
Aaron...have you tried a truck/trailer repair shop.? You can get 103" wide as long as you want and not have any splices/joints in it. Usually rolled material is also considerably cheaper per sq ft. than flat sheets. Without a large enough brake, it might be tough to put a Z type seam on it. Just an idea. Doug

PostPosted: Wed Feb 20, 2008 11:39 pm
by Aaron Coffee
We have 2 brake presses at work. I just realized that wilson trailers is only about 30 miles from here. Will check that out. I think my supervisors brother works there. Sometimes my brain just needs a kickstart

PostPosted: Thu Feb 21, 2008 1:04 am
by madjack
...when we have to make a seam, we just overlap it a couple of inches, put a sealant between them and shoot a SS screw every 2"s(a little sealant in the screw hole as well)...this was done following advice I got years ago from Cary at CampInn...I don't think it show badly at all and if you were to paint the top, it wouldn't show at all..........
madjack 8)

PostPosted: Thu Feb 21, 2008 10:30 am
by Cary Winch
and you know Jack, with the right adhesive and a long clamp fixture going across the whole trailer it may be possible to not even use the screws.

PostPosted: Thu Feb 21, 2008 1:44 pm
by cuyeda
Great tips!

If an overlap was used (as MJ suggested), perhaps there is an unobtrusive channel cap that could be laid down with the screws. I haven't searched for it yet, but I am visualizing a channel strip with some type of cap that pops on to the top as a cover. Similar to what car trim is attached with clips or channels. 5x12 sheets are hard to find!

Not exactly what I was thinking about, but here are a couple of possibilities for a seam cap.
http://www.yellowdogextrusion.com
RV-5
Non-Insert
Seam Molding
WT/FT: .128
Perimeter: 2.329
RV-5-16 16' PC D 25 56
Image
RV-23
Roof Seam Molding
RF101
WT/FT: .067
Perimeter: 2.211
RV-23-16
Image

Check their web page for more options.

PostPosted: Thu Feb 21, 2008 4:37 pm
by madjack
Cary Winch wrote:and you know Jack, with the right adhesive and a long clamp fixture going across the whole trailer it may be possible to not even use the screws.


Cary, that is what SikaFlex tells me about their formula522 as well as my buddy, the autobodyman with 40yrs experience....

Cliff, they do make a insert trim, to do just that...I like the overlap and screw method becuse it really doesn't show as much as that long strip with the insert molding init...when I finally get around to painting the top of mine, the seam will pretty well disappear.........
madjack 8)

PostPosted: Thu Feb 21, 2008 5:30 pm
by Gerdo
I seamed my Filon to my FRP (FIberglass Reinforced Plywood) about 30" up on the front. My Filon is glued down and overlaps the FRP by about 1 inch. I then added a RV trim strip, with more sealer, over the seam. Sorry, not the best picture.
Image

PostPosted: Thu Feb 21, 2008 5:43 pm
by Aaron Coffee
Thanks,
I talked to my supervisor today, and he wasn't sure if we could do the z hem. Had thought about doing a single hem on each peice then flattening them together, but it would be a bear to bend a small lip like that on a full sheet. I guess I'm just thinking twenty steps ahead of myself.
Thanks

PostPosted: Thu Feb 21, 2008 6:10 pm
by len19070
Homemade Trailer siding

http://www.freewebs.com/kc8jwa/restorationresources.htm

Siding does not have to have the 6" creases shown.

Happy Trails

Len

PostPosted: Thu Feb 21, 2008 7:18 pm
by dhazard
Have you thought about using a 2’ 2” piece of diamond plate at the front it would look like you planed it that way as a rock guard?

PostPosted: Thu Feb 21, 2008 7:36 pm
by cuyeda
madjack wrote:Cliff, they do make a insert trim, to do just that...I like the overlap and screw method becuse it really doesn't show as much as that long strip with the insert molding init...when I finally get around to painting the top of mine, the seam will pretty well disappear.........
madjack 8)


MJ, Yes, saw the insert trim. I was hoping to find something that was less noticeable. The wider insert trims would definitely be easier to install. These tips, gives me hope that I don't absolutely have to find a 5x12 aluminum skin.

PostPosted: Thu Feb 21, 2008 8:57 pm
by G-force
Why not just a piece of extruded flat aluminum plate, say 1/2" and say 3/32 or 1/8" thick? Counter sink it for flat head screws and seal it down over the skin seam.

PostPosted: Thu Feb 21, 2008 11:48 pm
by madjack
Cliff. when I went hunting for 5wide al, I haddta go to a .065 thickness and didn't wanna, so I bought 4x10x.040 and cut it in half...worked out well for me...both look wise and price wise...I could have gotten the 4x10 in .024(tinfoil) and .032 as well but I was applying it directly to the spars and wanted something slightly heavier.....
madjack 8)

PostPosted: Fri Feb 22, 2008 1:08 am
by cuyeda
G-force wrote:Why not just a piece of extruded flat aluminum plate, say 1/2" and say 3/32 or 1/8" thick? Counter sink it for flat head screws and seal it down over the skin seam.


G-force, I haven't tried the suggestions I made above yet. However, I thought that the recess in the shaped trim may lend to using a bit of butyl tape underneath when screwed down. An overlap will probably be enough as MJ suggested, but if you didn't mind a trim cap over the top, it would provide more sealant over the top of the seam edges. I visualize that the flat trim would squeeze any excess butyl sealant out the sides. What do I know, I haven't started my build yet. ;) As said in some other post, I will probably do the opposite of every thing I suggest (just kiddin'). If it works for you, and is part of your design, go for it.