I avoided the aluminum phase too long and need some advice

[bronco]

Well i dusted the cobwebs off of the teardrop after an almost 2 years break. I picked up some remnant pieces of aluminum sheeting. They are 4'x11' sheets i bought from a metal supplier in clackamas and i was told they thought the pieces were .028 gauge. But when I checked with some dial calipers they looked closer to .030 gauge. I should have checked here first because it looked like alot of you guys used .035-.040 gauge.
Will the thickness i bought be o.k.? They also were a little oxidized due to being stored on a pallet out in the elements. But the shop manager said they should buff out o.k. with some work. You guys would know better than me since this is my first tear build so i thought i would ask.
The other question was if anyone knew where there was another place to look on here for some good info for installation. I looked at all the links for aluminum in the site index but didnt see much on how to attatch the sheets. I am going to float the sheets as read on here. But on my roof pieces i am going to have to run them sideways with 3 sheets from the front to the hatch hinge. The vent will be in the middle of one of the sheets so i lucked out there. But do i just tack the sheets at where they overlap and then use edge trim for the rest of the attatchment. I will overlap the sheets 2" as suggested here by madjack. What fastners do you guys recommend? If anyone knows of a step by step instruction and could point me to a link where that would help out alot. Sorry for all the questions but if it's made out of wood i'm good, if it's metal.....not so good! ha!
Anyways i'm glad to be back on here again. Thank you for any help you can give!

[tonyj]

The thickness should work just fine and give you long service life.

I'll defer to others on jointing the seams, but as long as you have overlap and a good adhesive like SikaFlex or other metal adhesive used in the rv and trailer industry, you should get a good, watertight joint. Fastening could be done with screws or rivets.

[bronco]

Thanks Tony, with the price of aluminum i was concerned it would be too thin. Any idea which # of sikaflex caulking to use? It looked like there was several kinds to chose from.

[chorizon]

From listening to the sheetmetal gurus I work with, your situation is nothing unusual, so yeah, go for it. The thickness of a piece of paper is .003", so don't sweat it: that's nothing. The biggest complaint I hear lately at work is how our 16g (I think) CRS should be .060" and has been coming in at .055". This is within mil-spec and is acceptable. But when you get charged by theoretical weight (to the tune of tens-of-thousands of pounds per month), and then receive literally 8.5% less for the same price, you start to sit up and take notice. Point being is the company I work for is a pretty big consumer of sheetmetal, and they still find the arrangement acceptable since the material is within tolerance so I wouldn't worry about it.

[kennyrayandersen]

that should be thick enough if you are putting it over plywood, but may tend to ding just a bit if whacked hard. Still, it will be a bit lighter.

[tonyj]

Thanks Tony, with the price of aluminum i was concerned it would be too thin. Any idea which # of sikaflex caulking to use? It looked like there was several kinds to chose from.

It has been a while, but I think I used SikaFlex 221. It is more expensive than lots of other adhesives, but worth every penny. Keeping water out is not a place you want to skimp on price.

[Elumia]

most box stores also have a metal flashing adhesive that comes in white and grey. It is typically also used for rain gutters so should work out. It is butyl rubber based if I recall.

Mark

[bronco]

the teardrop is built from the generic benroy plans so i have the two layers of 1/8th plywood on the roof. It sounds like it should hold up good then. I have read about the dreaded rock ding issue before. Has anyone on here had some heavier gauge metal formed to cover the front radius portion of the their roof to take some of the hits from road debris?
as far as the fastners i read that alot of you used screws to fasten the sheets. Any recommendations on what screw would work best? I also read about someone predrilling holes spaced 2-3 inches apart in the aluminum prior to screwing the sheets on. Is that for ease of installation or is that to prevent the screws from stripping out? thanks again for the help.

[Rigsby]

If you skin the roof in thin ply first, and then use sikaflex to hold on the ally skin you should be ok. This is what i have done on my build and have had no problems. The sikaflex ive used is the same stuff used by auto body shops, as it is silicone free, and is overpaintable. My ally is folded over the edges and only held on with half a dozen screws at the front and back

[bronco]

rigsby, did you put on some aluminum corner trim to cover where you folded the aluminum over the sides? or were you able to make it clean enough looking without any trim? with the troubles i've read with annealing aluminum trim to bend around the radiuses i was just curious. Not only that i'm trying save $$$ wherever i can.