For some unknown reason, the manufacturer of my coach did not allow for any access to the under seat area in the dinette. This is a waste of valueable storage space, which is a premium in any RV.
Since I live about an hour from the Elkhart, In area, one winter day, we decided to take a trip to one of the several RV Surplus stores, where I found a couple of cabinet doors that were a 99% match to the doors in my coach. They cost around $11 ea, so it was a good deal, and certainly a lot less than trying to make my own.
Conceptually, I plan on installing the doors to the side of each dinette seat pedestal. For the rear pedestal, I am going to add a sliding drawer, and on the front pedestal, just an opening. The drawer is going in the rear seat as I didn't want to interfere with the seatbelts and wiring for the AC outlets and Propane detector.
In this "before" photo, I will have to route out an opening in both seat pedestal sides. I plan on doing this by adding 1x?" boards so that I line the opening, which will provide the necessary rigidity to mount the hinges, but also will serve as a template for the router bit that I will use to cut out the door openings.
The drawer is made of Poplar as it is fairly strong, lightweight, and inexpensive. One issue is that the dinette is on the slide out for the coach, so I didn't want to go overboard with adding a bunch of weight. I calculated the weights as:
Total added weight: 22lbs.
I would like to have kept the addition under 10lbs, but I really did not see how I could.
I used box joints for the cabinet to increase strength while not adding any weight for cleats or other cabinet joinery.
The drawer slides out a full 28", and that means the RV's slide out must be extended to access the full drawer. However, with the slide out in, the drawer will open all but about 6", so even when restricted, you can access the entire contents of the drawer.
I made the drawer a separate module for purely asthetic purposes, so that the front and rear doors would maintain symmetry.
But what if I don't have that fancy Incra jig for making box or dovetail joints? One alternative is to buy a less expensive box joint jig. I have seen table saw box joint jigs for under $75. In fact, you can often make your own jig to make a box joint - simply search the internet or YouTube for ideas.
As well, you can use a butt joint. A butt joint - also sometimes called a surface joint - butts one end panel up against the other. The chief disadvantage to a butt joint is that it can be weak, and you will at least want to fasten the joint together with both nails (or screws) and glue.
An improved butt joint can be had by cutting a slot (often called a Dado) in the ends of one of the panels as shown to the right. This provides a more rigit joint, however gluing and nailing is still recomended.
If you decide to go with this kind of joint, be sure to compensate the overall dimension of the box as the "step" will affect both length and width dimension of the drawer.
The slot can be cut with a router bit or saw blade, or dado blade.
Which method you go with is dependant on your skill level and tool set.