Originally Posted by Ellpea in CA
KC, I'm fascinated by your aluminum "framing system." While you're sharing about your reno, would you include a few details about how you fabricate this system? What material do you begin with, what tools needed?
Would love to know more... (the "closet" in my Lil Bigfoot
was completely gone when I got it... I've installed a temporary shelving and plastic drawer system which is temporary and needs a better solution).
I use 6061-T6 aluminum angle, that is the type that is considered to be structural aluminum. I use aluminum pull rivets to put it together. Two at each intersection put on a diagonal. Because that type of angle has a rounded inside corner the piece that comes up to meet it on the inside of the angle needs to have the end rounded over to match that radius profile. By getting that end right up against the surface of the piece you are joining it to you increase the strength of the join since it can't rock sideways out of square as the movement is constrained. So rivets on the diagonal and a tight butt joint make for a strong structure that will remain square without a lot of extra diagonal bracing.
You can cut the angle to length with a power miter saw if you have a carbide blade in it. You will also need a metal file for smoothing off any burrs on the cut edges. But really it is only a few tools you need. The saw, a drill motor, a square, measuring tape, some clamps, a file and a rivet puller. Helps to have a disc sander too if you don't want to spend a lot of time hand filing to round over those edges
I pre-fabricate on a flat floor surface sections such as the front face of a cabinet run. Then using a square bracket as a brace I stand it up in place and measure and cut to length the pieces which go back towards the wall. I do it that way because the wall of the fiberglass RVs tend to be wavy with variations in the distance to the front face of the cabinet plus of course those walls are not square to the floor since they have to be fabricated at an angle to get the shell structure to release from the molds they are layed up in.
When I get started building cabinet frames I will create a photo tutorial with more photos of making the joins. But really it is very simple to do even for a beginner as long as you have the tools for it.
In the Sunrader i do have a closet for which I did some wood framing and added a drawer system. My drawers are food service tray pans which were designed to slide into tracks or be put into recesses for things such as salad bars. Here are some photos of that closet.
The runners are made from some PVC pieces that are for supporting PVC lattice fencing around the edges. They are mounted to upright 1 x 2 boards which are solidly glued to thin plywood sides. It is important that you have very good glue coverage between the 1 x 2 and the plywood. The uprights and plywood form a lightweight structure that is part of the class of structural types called "stress skin panel". A stress skin panel is actually quite strong for carrying a lot of weight
, it will hold up to some flexing movement without fracturing apart. The individual pieces in this type of building system do not have to be large as by means of that complete surface adhesive bonding they share the load as one large unit. Monocoupe constructions such as an Airstream trailer or airplane incorporate the stress skin panel theories.
My closet walls were then attached to the floor and to the ceiling. There are three wood shelves, top, bottom and middle which control the distance of the sides to each other. You will see a small block of wood under each of the rails on those upright 1 x 2 boards. Those blocks keep the plastic drawer runners from rotating down under the weight of the contents of the drawers which is why I could get away with using that light
weight plastic. They are essential to the project in terms of strength and longevity of use. So the drawers slide smoothly, they weigh very little and they don't rattle.
It looks a bit patchy on the inside because I had to splice one of the plywood sides not having a full piece long enough as I made that side out of 1/4" Baltic Birch which is only 5' long. Come to think of it the other side, the on the left in the photo below was only 1/8 thick plywood underlay since it was next to the shell of the fiberglass bathroom. The load is primarily carried by the 1 x 2 's not the plywood It is amazing how light
weight you can build when you put the principals of stress skin panel construction to use
Most people over build RV cabinets thinking that they have to be done like kitchen cabinets from a house. What you really need is a light
weight structure than can take movement without falling apart.