By Roger Marshall
article from Interlux website
Adding Door Vents
To ventilate lockers you can leave the doors open when you leave your boat and the chances are that they will bang around as the boat moves to wave action. Or you can fit vents in the doors, and increase your boat's value as well as ventilate the lockers. The first step is to make the vents. I suggest that you measure the doors first; layout the sizes and make each vent before cutting a locker door to install them. To make a door vent, you will need to cut trim to suit the opening size and assemble the vent before installing it.
Figure 1: Fit two door vents in each door where possible. This allows hot air to escape at the top and draws cool air in at the bottom. When determining the size of the vents divide the door into equal parts. Door A is divided into 6 equal parts horizontally and 12 vertically. Door B is divided into 4 parts along the top and 8 vertically. In my opinion door B is more attractive but the layout in A allows more air to circulate.
Figure 2: The layout of the vent trim. Piece A is used to cover the rough plywood edge. Piece B is a half round used to cover the rough cut, and Piece C is used to cover the back of the rough cut. You can omit part C if you don't need a finished door back. Parts A and B can also be cut on a router table as one combined piece. If you are going to fit louvers you will have to make an additional piece, part D, to hold the louvers.
Figure 4: If you prefer top fit a mesh or cane screen, part A is cut as shown and the edges of the screen are held in place with a square bead E or with a quarter round F. Glue the screen in place using Epiglass Epoxy Resin and HT120 Glue Powder and use small tacks to hold the beading in place. In this case, piece C the back molding, is used to cover the joint between parts E and A and between part A and the door.
Figure 3: How to layout the louver detail. You can vary the angle, but I find that setting the louvers at 45 degrees works best. Make sure the
louvers overlap each other slightly so that nobody can see through the door vent.
Here's how to do it. First measure the locker door. If the door is more than 20" high, you might want to install two vents, one at the top, the other at the bottom, as shown in Figure 1. Make the vent not more than 1/3 of the width of the door and a maximum of 6" high. Getting the proportions right can enhance or detract from the interior look. Figure 2 shows some proportions. On the left, door A is divided vertically into 12 parts and horizontally into 6 parts. The vent is 4 sections across and 2 sections high. The door on the right B, is divided into 8 sections vertically and 4 sections horizontally, making a slightly smaller vent opening. If you section your doors in this manner the vent spacing will remain consistent throughout.
The next step is to cut the vent trim. Figure 2 shows each part assembled. Along the top are three pieces: a piece to trim out the rough edge of the plywood door (A), a half round trim piece for the front (B), and a rectangular trim piece (C) for the back of the door. If you like, you can make the front trim rectangular and omit the trim on the back. If you have a table router you can make parts A and B in one piece. The important step is to make sure the trim can hold the louvers or mesh and cover the rough edge of the cut in the door. If your locker doors are teak or mahogany it is best to use teak or mahogany trim unless you want to make the vent a highlight or accent. In that case you might want to use a lighter wood, such as ash or maple.
If you want to install louvered openings you will need to make additional side pieces (D). These will need to be cut to accommodate the louvers. Figure 2 shows the layout of the louvers. The side piece can be routed out as an integral part of parts A and B, or it can be a separate piece fitted later.
Installing mesh or woven cane is easier, in that the material is installed and a piece of square beading (E) or quarter round (F) is used to hold it in place, as shown in Figure 4. Note how the back trim piece (C) is used to cover both the door cut line and the inside edge of the beading (E).
Use a miter box to cut the corners of the trim to fit. Since the trim will be contained within the door, mitered corners are fine. Glue the mitered corners together, glue the louvers in place (or install the mesh or cane), and offer the work up to the job. Make sure it fits snugly and glue in place. Add the back trim (C) and the job is done apart from a final sanding. If you intend using Cetol Marine or varnishing with Schooner or Goldspar, do it before installation so that you only need to add a final coat when the vent is installed. This will help to avoid getting oil or varnish on the door.
Original article from Interlux website