Attached aluminium to wood? How?

[Scubieman]

Are we referring to putting aluminum on the sides? or put the flooring down?

[halfdome, Danny]

Iv’e heard of people using craft paper but wonder how it would work in a vertical situation.
If dowels don’t appeal to you just cut strips of equal sized wood but break the edges so pieces of wood don’t transfer to the glue. Danny

[KTM_Guy]

Are we referring to putting aluminum on the sides? or put the flooring down?

I put three little blocks of plywood on the bottom of the camper and cut notches in the aluminum sheet to match. Then I rough cut the aluminum leaving 3/8” - 1/2” to trim.




Once the cement was ready just line up the notches and make the contact. It was really pretty easy. Then trim with flush trim bit.



I used the Kraft paper on the roof.

Todd

[Scubieman]

Are we referring to putting aluminum on the sides? or put the flooring down?

I put three little blocks of plywood on the bottom of the camper and cut notches in the aluminum sheet to match. Then I rough cut the aluminum leaving 3/8” - 1/2” to trim.


I used the Kraft paper on the roof.

Todd

So many questions

Kraft paper roof? I'm missing what that means sorry.

What kind of alumnium is that? I was going to do white but i may like that more.

You can use a flush mount trim bit on alumnium??? similiar to this one? https://www.menards.com/main/tools/power-tool-accessories/router-bits-accessories/cmt-1-2-flush-trim-router-bit/806-629-11-cmt/p-1444426661730-c-10080.htm?tid=2123029465992988423&ipos=3

[halfdome, Danny]

Here's a video that might be of help.
Laying laminate or aluminum is the same process.
There's no need to test the dryness of the contact cement as she shows, just use a knuckle or two to do the test.
Danny

[Scubieman]

So Danny. Apply aluminium same way. Thanks!

Sent from my Pixel 2 XL using Tapatalk

[halfdome, Danny]

Yes it's the same process.
She was using 1/2" dowels which is an overkill, 3/8" dowels or 3/8" x 3/8" wood strips is fine.
If you apply enough glue they will temporally stick to the contact cement so you can apply aluminum to your walls or roof (vertical or horizontal).
I apply 3 coats because once it's down it's very difficult to remove.

In emergency's I've been known to squirt some lacquer thinner from a clean glue bottle, or the like, to a spot that stuck without my intentions.
Also a sharpened steel spatula can be used to cut away the glue if something accidently tacks down.
Always do a small mock up test on some scrap to learn the process.
Danny

[Scubieman]

How you cut alumnium? can you use a cut off bit?

[tony.latham]

How you cut alumnium? can you use a cut off bit?

I use a fine-toothed jigsaw blade and cut it about 3/16" proud and then use a bottom-bearing router bit to finish it off after it's on the cabin.

You'll want to use safety glasses and full-face protection with the router. The chips are brutal.

Tony

[Staryder61]

Awesome thread Scubieman..
Thanks Danny, Tony, KTM, for all the great answers..

This thread should be made a post it or what ever it's called. At the top... and added to the (( Skinning Secrets ))
Would be a lot of help to others and should be make easier to find..
I'm sure others have had the same questions... and didn't know where to look for the answers...

[halfdome, Danny]

I’m happy we were of some help.
Maybe ask administrators to make it a stickey.
Danny

[noseoil]

Agree with all of the above, but a slight change in how ours was done is worth mentioning. Since wood & aluminum will expand at different rates, I didn't use contact cement on the entire panel for attachment.

We used small temporary blocks (with a 1/8" deep saw kerf notch) along the bottom edge, to hold then bottom edge of the panel. A solvent based contact cement was run around the perimeter at the top & sides about 2" wide, which would act as a clamp for holding the panel after it was trimmed to size. The outline of the camper was traced along the top & sides of the panel on the back side with a magic marker. The panel was trimmed (face down) on a pair of saw horses & 2 - 2x4's were used to support the aluminum (we used .040" for the sides & top). Be careful not to scratch the face, ours was green pre-finished sign panel. An oversize panel was the result, with about 1/8" of meat standing proud, to trim for the entire panel, top, sides & bottom. The contact cement did its job holding the panel in place long enough to trim the outline at the top & sides (actually, it's the front & back). The last trim was done along the bottom edge, once the small blocks were removed. Make sure to drill out for the lights if you have them so wires can run through the panel prior to attaching the panel.

I used a 1/2" carbide cutter with the bearing on the bottom (flush cut bit), which acts as a guide on the body of the camper. If it's only about 1/8" to trim & slow passes are made, the bit won't clog with soft aluminum. If there's too much aluminum edge to trim, it will start to heat the cutter & aluminum will clog the cutter's flutes. It's miserable to have to stop & clean the bit, so keep the trim as small as possible. The reason I didn't glue the entire surface was due to the difference in expansion (wood & metal) between the substrate & finished aluminum. The aluminum "floats" on the side of the camper, but it's held in place by the metal trim along the top, front, back, bottom & doors & windows in our version. I was concerned about expansion, since the trailer lived at the time in Tucson, where it's not unusual to have the sides too hot to touch in the summer & nights in winter are down into the 20's at times. When it's very hot outside, there's a small amount of "oil can" showing on the sides, but at night it shrinks back & lays flat.



This has held up very well over a few years & many miles of towing. There's not one correct way to attach the metal, but it's easier or harder, depending on how many hands are available & the approach!

[halfdome, Danny]

From your own admission your having oil canning issues because your aluminum is basically floating.
Contact cement is basically a rubber glue and may move slightly under certain conditions, which in my experience is the perfect solution to oil canning, which I have not had.
This theory of different expansion rates dosen't concern me since we are using engineered sheets of laminated layers of glued up wood, in opposite directions, commonly referred to as plywood.
The through coverage of contact cement, as mentioned before, is a expanding/contracting vehicle between the two surfaces.
I use a quality plywood throughout my builds.

If we were using solid wood then it will move under different conditions of humidity.
On my solid wood tops I use what's referred to as a breadboard end with a floating mortise & tendon because wood usually expands and contracts in width.
One solid Red Oak coffee table shrank about 1/64" at each end after 20+ years because of it's proximity to the wood stove.
This is the reason we run a humidifier in our home when the wood stove is being used.
Our goal is 50% humidity because of the custom solid wood furniture and musical instruments.
Danny

[noseoil]

Danny, the linear expansion of the aluminum sides in a temperature range from 20f (winter) to 150f (summer sun in Tucson) is .175" or about 3/16" from cold to hot. This is why I chose to build as I did for the Tucson heat & allow for floating. As I said, there's no right or wrong answer IMO, just what works for each builder.

"Sometimes it makes me humble when I think how great I am." Quote is from from my dad, Bob Curry, somehow it just seems to fit here...

[Scubieman]

Ok Danny, trying to calm my nerves here ha ha, Thinking of doing the top today. That sad.
I havent done sides yet, so hope top is okay to do first.

Use contact cement to attach, no staples(edges)?

will a pint do 4x8 sheet of alumnium(already own)?

50 degrees warm enough to apply?