Thread: some advice for a noob on using a circular saw with no guide please?

Originally Posted by NCArcher

Jigsaws are not really made to cut in a straight line. They are excellent at cutting curves or complicated shapes but I struggle to cut a perfectly straight line with one.
A hand held circular saw (with a guide) or a saw table are a much better option for straight cuts.

oops... sorry, the title's supposed to be circular saw... for some reason i wrote jigsaw...

Originally Posted by J_SAMa

oops... sorry, the title's supposed to be circular saw... for some reason i wrote jigsaw...

Title edited.

There's usually a mark on the front of the saw base in line with the blade. If you keep that on the line, you should get a reasonably straight line, but you'll probably need to clean it up with a plane or something.

You can clamp a length of timber to the one you want to cut and use it as a guide to get a straight cut.

Make a dedicated guide, I doubt anyone can cut a sheet anywhere near square or straight enough for cabinets etc without a guide.

To make the guide you need a length of pineboard or flooring with the factory machined edge, your local Mr plywood could supply this from an offcut. In fact if they cut a board on their panel saw it will be good enough, it only needs to be 150mm wide if that, and the length to suit you. While you are there get a strip of three ply, again of the appropriate length and perhaps about 300mm wide. Place the pineboard on top of the plywood and glue them together and you should have enough overhang to run the circular saw along the machined edge of the pineboard cutting off the excess plywood. To use this guide mark and measure your board to be cut, place the plywood edge exactly on those marks and run the saw along the guide.

You can make the up market model by putting sandpaper underneath it to add grip but I don't like that too much myself or do what i did and put a few small protruding brads under it to grab the board being cut. I find that clamps aren't necessary with the brads.

Practice, practice and practice.

Wear good eye protection and watch the blade on your marked line. Dust extraction is a big help. Have patients, work slowly (but not so slow to burn the material) but remember the trailing edge of the blade as well.

A guide is your best friend. 18 months ago I bit the bullet and bought a German made track saw. My work is now quicker and straight cuts straight. There is little to no splintering with ply and little chipping with melamine materials.

Originally Posted by AlexS

There's usually a mark on the front of the saw base in line with the blade. If you keep that on the line, you should get a reasonably straight line, but you'll probably need to clean it up with a plane or something.

well, the thing is, i use it to cut timbers too. so the mark on the sole isnt always on the wood

Sam: Kind of depends upon what you're building. While a circular saw is great for
timber construction, I'd look for another way to cut panels, etc. for furniture and cabinetry.
The sole plate on my SkilSaw is black (metal.) Like you, I couldn't be certain that the blade really did hit the line.
So, I started a cut along a line, full depth (60mm), in some junk wood. Stopped the saw and lifted it out of the cut.
Put the saw back in the cut. I used a triangular file to make a nick in the leading edge which really did in fact strike the line.
About 1.5mm to the left of the factory mark stamped into the sole plate. It appears shiny metal, can't mistake it for anything else.

Me? I need to take the sapwood off western red cedar logs (sand in the cracks, soft rot spots, bug tracks, dents).
Next, lay out a grid in red grease pencil, most recently approx 40x120mm.
Good hearing protection and closed goggles (cedar sawdust in my eyes is N.S.)
Cut the entire grid to 16mm or so. Following the line and going around a log at the same time is a little tricky.
True, great accuracy for me isn't critical but I do try to follow my lines like I really care what I'm doing.
Pop everything off with a mallet & carpenter's 25mm chisel.
WRC splits so cleanly that I'm down to carving wood in next to no time.

Originally Posted by Handyjack

Practice, practice and practice.

Wear good eye protection and watch the blade on your marked line. Dust extraction is a big help. Have patients, work slowly (but not so slow to burn the material) but remember the trailing edge of the blade as well.

A guide is your best friend. 18 months ago I bit the bullet and bought a German made track saw. My work is now quicker and straight cuts straight. There is little to no splintering with ply and little chipping with melamine materials.

track saws? i would love to buy one of them but they are way out of my price range...

Chris Parks' post describes a cheap and cheerful track saw, here's one I built years ago for my Triton:

DSCF2057.jpg

For cutting narrow stock make a "Tee" square and clamp that to the timber. Here is one I made for my jigsaw, but the concept is the same.

DSCF2056.jpg

In both cases you make them slightly oversize and the first cut will trim them to length. You will need some way to clamp them to your workpiece too; the bottom part of my T square has sandpaper attached and a couple of brads points are embedded in the short "Tee"; this is fine for a jigsaw but I would be clamping the whole thing together before I put my circular saw to it.

You shouldn't watch the blade, you should use the mark on the plate. If the work is short enough you can't line up by the mark on the plate, use a speed square as a guide. Aside from that practice.
(Much easer to show than tell.)

Originally Posted by Chief Tiff

Chris Parks' post describes a cheap and cheerful track saw, here's one I built years ago for my Triton:

DSCF2057.jpg

For cutting narrow stock make a "Tee" square and clamp that to the timber. Here is one I made for my jigsaw, but the concept is the same.

DSCF2056.jpg

In both cases you make them slightly oversize and the first cut will trim them to length. You will need some way to clamp them to your workpiece too; the bottom part of my T square has sandpaper attached and a couple of brads points are embedded in the short "Tee"; this is fine for a jigsaw but I would be clamping the whole thing together before I put my circular saw to it.

Excellent advice from the Chief...

The T-square cross-cut guide could have a small "serif" added to the end of the T - it only has to extend 50-75 mm inside the T - to improve the clampability of it.

Secondly, some spacers, exactly the width between the T-guide and the saw-cut, will greatly speed up the use of the guide. I made mine by clamping the guide on some sacrificial sheet, pushing some thin plywood against the guide and then cutting that plywood. The resultant strip is exactly the width between the guide and the cut. In use, just carefully measure the cutting line, place the guide against that line, clamp the T-guide against the guide, remove the guide and cut accurately on the line - everytime.

Fair Winds

Graeme

Thanks for the endorsment Graeme!

With the spacer for the T square, the first time you use the square the shortest leg of the T gets trimmed by the saw so afterwards you just line up the edge of the T to your cutting line; if you zoom in on the last picture you should be able to make it the line drawn on the tmber aligned with the shortest end of the T.

I like the idea of the cut-out for clamping. My squares were designed for use with a jigsaw so clamping isn't necessary. I used to dock timber to length using a sliding table on the saw, but that was before I bought a chopsaw.

I actually have two squares; mirrow images of each other for left and right use. I made them for cutting out rebates in cabinet sides to clear skirting boards but they come in handy for any little notching or rebating jobs.

Originally Posted by Chief Tiff

Thanks for the endorsment Graeme!

With the spacer for the T square, the first time you use the square the shortest leg of the T gets trimmed by the saw so afterwards you just line up the edge of the T to your cutting line; if you zoom in on the last picture you should be able to make it the line drawn on the tmber aligned with the shortest end of the T.

Probably belts and braces, but for wider cuts I use the spacers to check that I have aligned the T-square properly ! Also use a pair of guides for aligning a strait edge to cut sheet material and for ripping.

I like the idea of the cut-out for clamping. My squares were designed for use with a jigsaw so clamping isn't necessary. I used to dock timber to length using a sliding table on the saw, but that was before I bought a chopsaw.

I actually have two squares; mirrow images of each other for left and right use. I made them for cutting out rebates in cabinet sides to clear skirting boards but they come in handy for any little notching or rebating jobs.

Why didn't I think of that? Will now.

Fair Winds

Graeme

PS: You can also cut a little oversize and then use the T-guide with a router to get a really smooth edge.