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How to choose one wood Circular SawSep 14, 2017 Writer:HENTO
1. INSPECT THE SAW
Before each use, run a quick safety check on the saw. Be sure the lower blade guard retracts smoothly and snaps back when released. Check the blade for chipped or broken teeth; replace the blade if you find any damage. On corded saws, inspect the power cord for cracks. If using a cordless saw, make sure the battery is fully charged. Remember to unplug the cord or remove the battery before loosening, tightening, or changing the blade.
2. CHECK THE BLADE
The speed and quality of the cut depends on the condition of the saw blade. Never cut with a dull, rusty, or damaged blade. I recommend using a thin-kerf carbide-tipped combination blade, which can be used for crosscuts and rip cuts in solid wood and plywood. With the saw unplugged or the battery removed, adjust the saw's depth of cut so the blade extends no more than 1/4 in. past the board's edge.
Circular saws aren't just woodcutting tools. When fitted with the proper blade, the saw can also saw through various types of metal, and through masonry such as brick, stone and concrete.
3. FIND THE PROPER SAW POSITION
There's no hard-and-fast rule regarding which direction to make the cut, but whenever possible position the saw with its motor facing toward the larger section of board that isn't falling away when cut. That way, the saw's base plate, or shoe, will be fully supported throughout the cut and you won't have to hold up the weight of the saw as the severed piece drops away.
4. MAKE EASY, ACCURATE CROSSCUTS
Making perfectly square crosscuts with a circular saw is easy, if you guide the saw with a layout square (a framing square or Speed Square will work). Hold the saw in place with its blade right on the cut line. Then slide the square against the saw's base plate, and press it tightly against the edge of the board. Check to be sure the blade isn't contacting the board, then squeeze the trigger and allow the saw to reach full speed. Now simply guide the saw along the square to produce a clean, square cut.
5. PREVENT BINDING
When cutting sheets of plywood or paneling, it's important to provide the proper support to eliminate dangerous kickback, which can occur if the blade gets pinched in the cut. Place four long 2 x 4s underneath the sheet you're cutting, spacing one 2 x 4 close to each side of the cut line. Then, when you make the cut, both halves of the plywood will be fully supported by two 2 x 4s throughout the cut. When cutting lumber on sawhorses, plan the cut outside the sawhorse pair (not between them). Allow the shorter piece to fall away, while the longer piece stays supported on the horses. Cutting between the horses causes lumber to pinch the blade as it falls through.
6. MAKE PRECISE RIPS
A rip cut is simply a cut that runs parallel with the grain of the wood, as opposed to a crosscut, which goes across the wood grain. Most circular saws come with a metal rip guide that attaches to the saw's base plate. This type of guide works, but it's limited to rips of only about 6 in. wide. A better option is to clamp an 8-ft-long board in place for use as a straightedge guide. You could make the guide from a perfectly straight 1 x 8 or 1 x 10, but I prefer a 10- to 12-in.-wide wide rip of 1/2-in. birch plywood. The factory edge of the plywood is always smooth and perfectly straight, making it an ideal saw guide. Mark the cut line on the piece you're ripping, then measure the distance from the saw blade to the edge of the saw's base plate, which, let's say, is 3-1/2 in. Now measure over from the cut line 3-1/2 in. and clamp or screw the straightedge guide in place. As you make the cut, keep the saw's base plate pressed against the straightedge guide. Here are our illustrated instructions on making a similar circular saw guide.
7. AVOID WOOD SPLINTERING
A spinning circular saw blade enters the bottom of the board and exits through the top, and as a result, splintering often occurs on the top surface. Now that's not a concern when cutting wall studs or floor joists, but it is when sawing expensive hardwoods or hardwood-veneer plywood. Here's the solution: Place the board or panel with its best surface facing down. That way, any splintering will occur on the top or back side. When trimming doors down to size, you want to eliminate splintering from both sides. Here's how: Again place the best side face down, meaning the side of the door that will be most visible once it's hung. Then score along the edge of the cut line with a sharp utility knife. Now when you make the cut, the wood fibers will break off cleanly at the scored line, leaving a smooth, splinter-free cut. I recently put this advice into practice when explaining how to build a classic wooden storage bench.
8. STACK, CLAMP AND CUT
When you need to cut more than one piece of plywood to the same size, try a technique know as gang cutting. Stack four or five sheets on top of each other, making sure the edges are perfectly aligned. Clamp the pieces, then adjust the saw blade to its maximum depth of cut, and saw through all the sheets at the same time.
9. SAFE BEVEL CUTTING
All circular saws can be adjusted to make angled bevel cuts up to at least 45 degrees. However, when the base plate is tilted all the way over, the lower blade guard has a tendency to catch on the edge of the board. If this happens, don't force the saw. Instead, release the trigger, raise the blade guard by hand, and then make the cut. Once the blade has cut an inch or so into the wood, you can release the guard.
10. GRAVITY-FED SAWING
At some point, you may need to make a long, straight, vertical cut into a wall, and the circular saw is right the tool to use. Just remember to start the saw at the top of the wall and cut down. That way, gravity will be working in your favor; simply allow the weight of the saw to advance the blade through the cut.