Aluminum skin question

[planovet]

I have vacillated between paint and other materials for my outside skin for a while now. Currently, I'm leaning toward aluminum due to looks and durability (I’m not a good painter). Prices around here for sheet aluminum aren't too bad. The problem is that my tear is going to be a difficult length (and height) to skin with aluminum. The sides are 4'9" high and 11' long at its longest point. Initially I was wanting to do red sides with a white top. Turns out, the only painted aluminum I can get locally in red is 4x8 and 4x10. I can only get white in 5x10.
If I do the sides in 4x red, I will have two seams...one through the door area and one around the galley hinge area.

If I do the sides in 5x white (and the roof in red) then I will have only one seam on the side about 1 foot from the rear, not too noticeable.

But then I will have more seams on the roof because of the 4x red (my tear is 5’ wide). But I figure seams on the roof are less noticeable than on the sides. This is the dilemma that I have been tossing in my mind for the past several days and I don't know how I will proceed. Heck, I still may paint the darn thing.

To make a long story short (and to get to the point of this thread), if I do go the aluminum route, how do I do the seams for maximum sealage (is that a word?) but also to make it as less conspicuous as possible.

I've seen the thread on riveting and screwing (pic above) but can the edges be overlapped and glued without the screws? I'd like as smooth of a finish as possible but I don’t want the seams popping loose down the line.

Any suggestions, ideas or input (positive or negative) will be welcomed. I hope I have made myself clear.

[madjack]

Mark, my best suggestion in your case would be to get a two part panel bonding adhesive, widely used in the truck and automotive OEM and repair field...it is not cheap and you will havvta have a special caulk gun(it's a two part product)...check with an auto paint supply store or your local body shop and you may be able to "borrow" a caulk gun...I have never used this stuff but since about half of your car is held together with it, it should work....
madjack

p.s. this is one type of the stuff I am talking about...keep in mind it requires a special caulk gun to apply...there are many other brands...MJ
http://www.amazon.com/3M-Automix-Bondin ... B000PEW4MI

[mechmagcn]

Yep, what MJ says. Be forewarned, the adhesive is $30-35 a set and the special gun will run you in excess of $60.

[COMP]

Yep, what MJ says. Be forewarned, the adhesive is $30-35 a set and the special gun will run you in excess of $60.

would a windshield guy use that gun ?

[mechmagcn]

Yep, what MJ says. Be forewarned, the adhesive is $30-35 a set and the special gun will run you in excess of $60.

would a windshield guy use that gun ?

I doubt it, windshield urethane is only one part. The panel adhesive is a two part that mixes as you squeeze the trigger. The gun has two plungers side by side.

This one is from Eastwood and sells for $69.99

[madjack]

...yep and most of the guns are manufacturer specific(3M gun for 3M adhesive...etc.)...which is why I overlap a couple of inches, use an auto windshield adhesive and a row of SS screws...looks OK to me and can you can do a couple or 3 seams for around twenty bucks orso...(12-15 bucks for a standard sized tube adhesive plus screws).....
madjack

[planovet]

...yep and most of the guns are manufacturer specific(3M gun for 3M adhesive...etc.)...which is why I overlap a couple of inches, use an auto windshield adhesive and a row of SS screws...looks OK to me and can you can do a couple or 3 seams for around twenty bucks orso...(12-15 bucks for a standard sized tube adhesive plus screws).....
madjack

Sounds good but I think it looks better with plain aluminum. What if you (or I) have white or red aluminum? The stainless screws would stand out unless you painted each screw to match...

[shoeman]

How do the trailer (18 wheeler) guys fix those colored panels? I think they are screwed into a metal stud so maybe there are colored fasteners available from them too?
I've spent a fair amount of time in a friends body shop and have seen those two part adhesive guns in action. It is indeed a tough bond, and most cars use that fastening method on body panel/parts. I'd think the flaw with using that stuff is going to be your panel edges. Cars are designed so pieces meet with well thought out edges that look finished or have trim to cover seams. We're usually talking about a much thinner material here, and it's pretty easy to put a small crease in the cutting process when you DIY it at home. That would show up pretty badly on a bare edged glued seam. If you can manage to get a brake cut edge showing at all seams cut by a shop that would help, but you'll still need to be careful handling the panels during construction to avoid a bend or crease. The heavier the panel thickness the mope resistant it will be to dinging up like that, but weight and ease of handling suffer accordingly.
I've been working on my aluminum skin this past week and will be doing more next week, so I'm up to my eyeballs in the pros and cons. I'm using bare panels so screwing seams together looks fine to me. I saw the colored panels a a repair shop I visited and after thinking about it I decided bare finish was easier all the way around. Size availability is greater too.
You're most likely going to have trim pieces screwed on somewhere on your trailer around the doors or some edges. Most trim is bare, so will you have to paint that to match, or will you leave it bare? If it's bare then maybe having screws showing will not look so out of place on seams?
Aesthetics can make your brain hurt. I easily understand the structural stuff, but ask me what colors look good together and I faint from brain strain.

[aggie79]

Mark - very nice job on your build so far. I'll be curious as to your solution since I'm thinking about going taller than 4 feet for the sides on our teardrop.

One of the things I've considered is to use two pieces horizotally on the sides butted together at about the midpoint of the trailer. I would then use a trim strip to cover and seal over the but joint with double fasteners
into both pieces. This detail is like the New Cub design in Andrew's design library. If you did something like this you could paint the trim strip white and use a horizontal trim strip to continue the Swiss flag theme. The downside would be that there would be quite a lot of cut-off waste from the aluminum sheets.

Tom[/url]

[RICHARD FURROW]

Has anyone tried this? I have not, but it reads like it could work. Some of these tapes are very good. You may damage the material before you ever pulll it off. Maybe a call or email to 3M could tell you.

http://multimedia.mmm.com/mws/mediawebs ... P4COrrrrQ-

[madjack]

:thinking:
Has anyone tried this? I have not, but it reads like it could work. Some of these tapes are very good. You may damage the material before you ever pulll it off. Maybe a call or email to 3M could tell you.

http://multimedia.mmm.com/mws/mediawebs ... P4COrrrrQ-

Richard, I think the VHB tapes can work, the one question/worry I have about them is proper sealing, especially around the ends of the taped area...with a caulked adhesive, I KNOW the "squish out" is filling voids and sealing everything and that is a comforting feeling to KNOW that my investment is protected from the elements.....
madjack

[planovet]

Thanks Tom. I thought about the horizontal application but I would still have a verticle seam at the rear because my tear is over 10' long. The tape seams like a nice idea also but it's pricey also. And like MJ said, I'd worry about complete sealage. Maybe a tape and caulk combo would work. I still don't know what I am going to do. Painting is still an option I guess although I'm still leaning toward the aluminum.

[Sparksalot]

...Prices around here for sheet aluminum aren't too bad...

Where did you find to buy Al in the area?

[Esteban]

Have you considered fiberglassing the outside? It's an alternative to an aluminum skin with it's seams, that you want to minimize, for a trailer the size you want to build. With fiberglass you can eliminate seams that show altogether.

It's probably cheaper and lighter than using aluminum, too. It frees you up to build just about any size TD you want with few if any any seams or joints that might leak.

Your proposed TD's size and profile is very similar to the TD I'm building. I ran the front sheet of plywood with it's length (height in this case) from the front to a joint above and below the door - similarly to what you show in your first, red, profile. Then used a second plywood sheet with it's length going from the joint (above and below the door) to the rear. Above that is an 8" horizontal strip of plywood to get the 54" wall height I wanted. It took cut outs from 3 sheets of plywood to skin the walls that way. I attached the side peices to the inner wood frame then fiberglassed the walls with them flat on a work bench. So far so good.

[planovet]

Where did you find to buy Al in the area?

Try Regal Plastics or Robert & Sons.

Regal Plastics quoted me $71 for 4x8 red aluminum, $95 for 4x10 red aluminum and $117 for 5x10 white aluminum. (I35 and Royal) http://regal-plastics.com/

Robert & Sons quoted me $83 for 4x10 red and $95.51 for 5x10 white. Cheaper but they are a little further away (I20 and Cockrell Hill)

I did not ask what their prices were for plain aluminum.

I thought about fiberglass Steve but I would still have to paint the sides. I had to use 3 sheets for the outside skin and they don't match up well enough for a woody and the quality was not as nice as I would want for a woody. I'm thinking I will just use a white 5x10 aluminum sheet for the sides and have a small seam at the back and then use the red for the roof. I really do not want to paint if I can help it. I like the way Philip's Napsack looks and so I will do my color scheme that way.

Wow, it's my 300th post!