Alternative skin options

[kd5edj63]

I have seen a nice build (not on here, but most likely a member here) of a nice build, but I forsee the aluminum skin being nearly impossible for me to install since I have no help at all. Since I am an automotive collision and refiniching guy, I was wondering what you guys think of treating the sides and roof like a car. I have painted speakers made out of MDF with car paint and it worked just fine. Would this hold up. I know UV wise it would of course. Any thoughts would be great. I could even roll on some primer surfacer, because you cant paint bare wood with urethane paint. Has anyone tried this or something similiar like a high quality roll on paint.

[loaderman]

MDF is very heavy and swells if water does get to it. not a good choice IMHO.

[kayakdlk]

So why not cover your plywood in fiberglass cloth and epoxy resin over any type plywood and then you can finish like a car. You can build up layers of epoxy to hide the cloth, then prime, spot fill and paint and if you take your time and with lots of sanding it will look as smooth as a car, and be very durable and water proof.

[michaelrsydney]

I can recommend an Aluminium Composite panel. It is 3mm thick with a resin core sandwiched in two alloy skins. It is light and has better insulation that just metal. I found it extremely easy to cut and fasten single handed. It bends very easily and has less "spring back" than most materials. The edge fastening is hidden under the corner extrusions and plastic insert plus I used construction adhesive at all contact points.

Mine has a brushed aluminium finish but it is also available gloss metal or with a painted finish which could be then sprayed any colour.
I am sure a similar material is available near you
http://www.mulfordplastics.com/products/signbond

[RandyG]

I put fiberglass resin on a mdf speaker box and painted it. It is still holding up to the weather 5 years later. But I do agree, mdf is too heavy. Just get a piece of scrap plywood and do a test, do like you plan and leave it in the weather for a month or 2. And spray it with the hose if there isnt any rain. Have you also thought of using a high solid paint? I think it is even more durable than auto paint.

[kd5edj63]

I wasnt going to use MDF. Im still contemplating. Maybe just brushing on some fiberglass resin (or even shelack) and going from there

[michaelrsydney]

I should clarify that the aluminium composite I used is not used to cover a plywood roof, it is instead of a plywood roof. It is placed directly on to the roof spars. Once fitted no further finishing or weatherproofing is needed.
It is reassuring to know there is no plywood to rot under a failed resin or paint or metal top membrane.

[kd5edj63]

So it sounds like it was a hassle free installation. Was it expensive

[michaelrsydney]

So it sounds like it was a hassle free installation. Was it expensive

Hi Kd, I have read your posts but have no idea where you live. I don't know if Australian prices are relevant to you.

Anyway, 8x4 sheets of the material I used cost me Aus $ 80 each. All materials are expensive in Aus compared to the USA. I believe that was cheaper, quicker and easier than using plywood plus some form of weather proofing.

If you plan to finish your TD with automotive finishes it would form a perfect base for spray painting with very little preparation,

[kd5edj63]

Thanks. Do you have a build thread for your TD

[michaelrsydney]

So your whereabouts will remain a secret?

I do.not have a build thread as such but if you click on my name (on the left here) you can view a list of all my posts and also the photos I have uploaded.

Was there something in particular you want to know?

[kd5edj63]

Im in the USA (Texas)
Im most curious as to the side thickness (how you built them) and the door. Id like to make my own (simple) door, but not if it will be a big hassle.
I commented on one of your photos

[michaelrsydney]

Im most curious as to the side thickness (how you built them) and the door.

Ah, yes, I "cheated" a little. Maybe I will regret it later but I felt there was less need for side wall insulation in the climate I anticipate. I opted for solid plywood sides and will line the cabin with marine carpet to reduce condensation. The roof on the other hand is well insulated against heat ingress having the aluminium composite followed by a 20mm air gap, a reflective foil surface (foil will not work without an air gap), 25mm polystyrene then 2mm "bendy" plywood

The sides are simply cut from 8 x 4 sheets of 3/4" plywood and the doors are the cut-outs on piano hinge. I have fabricated an inner section which I will photograph asap. The windows are home made "Wiley" type with a polycarbonate translucent panel.

[kd5edj63]

Thank you. Thats very helpful

[tony.latham]

"nearly impossible for me to install since I have no help at all"

I had help with my aluminum for the following:

-move sheets from the trailer to my outside work bench (I've got a side profile I used for a cutting pattern -highly recommended!)
-move the top sheet to the top of the tear
-move the second wall skin to the tear. I moved the first one and it was a bit wobbley where the door hole was. On the second assisted move, I spring clamped a piece of 1 by 2 across the door and really didn't need the help.

For the install on the walls, I set two temporary screws at the bottom of the walls for the aluminum to rest on and spring clamped it in the door opening –and then was able to step away. The roof piece was held down with cargo straps until I could screw it to the bottom-front and hatch opening with countersunk stainless wood screws. Once that was done I removed the straps and final-fit with a router. It was really a one person job –except for moving the largest (5x12') sheet to the bench. If you have your heart set on aluminum, think twice.

As for paint; I bought a commercial built 4x10 about ten years ago –this new one is 5x10. The "old" one, although covered by aluminum has had some moisture problems with it. The interior and galley were finished with laquer. It looks nice but does a poor job of sealing. The walls on it are made from 1/2" Baltic birch. Any area where water got in started to delaminate. (Refinishing with polyurethane and sealing with epoxy fixed the problems.) On this new build, the entire exterior is sealed with expoxy resin and the roof/wall seams are sealed with fiberglass/epoxy. Any water that somehow finds a route around the aluminum is not going to get into the wood. But here's my point: If I were to paint –which I almost did– I'd seal with epoxy first, and then paint with a highly rated paint, probably a marine product. It'd certainly work.

Good luck with your build!

Tony