What is the best way to accurately rip 4-by-8 sheets of plywood using a circular saw? I am looking for a guide or something similar to make precision cuts.
My experiences with ripping oak, maple, and cherry ply (these are what I use) is poor. Not saying it can't be done with a circular saw, but I have found that a good table saw is the only way.
I've also found cross-cutting of parts for base cabinets (23-1\2 inches wide) to be more frustrating, until I purchased a 3 HP radial arm saw with a 24-inch cut.
I have had good results minimizing splintering by putting tape the length of the board where the blade will cut. I have talked to others who have scored the board with a utility knife to minimize splintering.
While it's no substitute for a panel saw or large table saw, (i.e. production work), it's true strength is for in-the-field and installation work, or environments that are too confined to accommodate the larger tools.
I forget just what I paid for it now - I'm guessing $400 to $500 for the complete system. That may seem pricy, but it really will provide cabinet-grade accuracy, and you can carry it all under one arm.
Anyway, mark back on the melamine the distance of your saw blade to the edge of the bed, plus 1/4 inch. The remaining width of your melamine is your next rip width for the next piece of melamine. Affix the smaller width on top of the larger with glue. I used contact cement.
Next, you need to run your circular saw along the edge of the top piece. This will rip the bottom piece to match the bed-edge-to-blade distance of your saw. Then all you have to do to rip ply goods of 8-foot lengths is mark both ends and clamp your melamine guide to the plywood.
I made mine 4 feet, for crosscuts and doors. For 8-foot rips I use a table saw. I also agree that the 40-tooth Matsushita will achieve a beautiful cut.
Comment from contributor R:
I've had good luck using a zero-clearance baseplate on my Skilsaw along with some custom guides. Just screw on a piece of half-inch mdf to your saw shoe and make a plunge cut with the blade. With the baseplate and a good thin blade, I get little or no chip-out at all. Also try putting a little self stick sandpaper on the bottom of your guides. Helps tremendously. Low tech is great and cheap.