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I have, what I'm sure is, a job site table saw and am having difficulty cutting a straight line in plywood. Since my saw table is smaller than to wood I cannot use a fence to guide me. Currently I measure with a tape and try to follow the line. Pushing that board makes it easy to make little mistakes that are easily seen when I look down the cut board but not while I'm cutting.

Another related issue is that when I get towards the end of the cut the weight of the board on the other side of the table prevents me from pushing and I end burning the end of the cut and stopping prematurely before I hurt myself. I would then turn the almost cut board around to finish.

While that does work my lines are not straight. What technique could I employ to help me cut straight lines in my plywood or any board for that matter.

  • I think that is my first downvote. Is doing something unsafe and trying to fix it worthy of the downvote? If my question is bad I would like to know what I can do to improve it. – Matt May 14 '15 at 19:21
  • To me it's a good question because what you're asking is (a) perfectly clear, (b) sufficiently limited in scope, and (c) it can be answered definitively and objectively. In woodworking there are many "common-sense" practices and techniques which are not obvious until you've been made explicitly aware of them. It is the duty of anyone posting an answer to point out if you're unwittingly doing something wrong. – rob May 14 '15 at 20:05
  • @rob Of course. Those types of answers were expected. Thanks for your input. – Matt May 14 '15 at 20:09
  • oops, I guess I wasn't very clear but what I was getting at is that I don't think it's appropriate to downvote your question for asking about an unsafe operation in this instance because you were asking from the point of view of someone who may not realize it's unsafe. On the other hand, if you said you were aware of the supposed danger but you were actively advocating unsafe tool use, I might be inclined to downvote. – rob May 14 '15 at 22:07
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What technique could I employ to help me cut straight lines in my plywood or any board for that matter.

I can't recommend any technique for cutting straight lines freehand on a table saw because you should not do that. You should always use the fence to guide rip cuts and the miter gauge or a sled for crosscuts. It's a safety issue: if the work happens to catch the back of the blade, the saw won't have any trouble lifting the workpiece up and throwing it at you in the blink of an eye, and that's one way that people get hurt.

If the workpiece is too large to fit between the blade and the fence at its widest setting, it's too large to cut on your table saw. Switch to a circular saw: you can buy one new for $40 or less, or pick up a decent used one for half that at a garage sale, Ebay, etc. You can easily make a saw guide out of scrap wood. The guide is essentially a long fence that you clamp to the workpiece, and you should be able to make very straight cuts with it.

Another possibility is to build a saw station that would effectively give you a larger table and greater cutting capacity. One example is the Table Saw Workcenter from Shopnotes No. 89. Building this would be a greater investment in terms of time and materials, of course.

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    Saw guide, circular saw, and cutting on a sheet of dense foam insulation or a simple half-lapped table mounted on sawhorses, is probably the tight answer for initially breaking down sheet goods., Cut the pieces a bit oversized and use the table saw to bring them to precise dimensions with a clean edge. – keshlam May 14 '15 at 13:27
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    Perish the thought, but a hand saw would work well too. If too expensive to buy new, they are plentiful in rummage sales and garage sales. Super safe! – Ast Pace May 14 '15 at 19:17
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You need to start with either a friend or an extension on the far side of the table to hold the far piece. There are different things you can use. The easiest is to buy 1 or two table saw roller stands. They are adjustable to meet the height of your saw so you don't have to try to hold the wood down to cut those last couple inches. building/finding a table of the same height and putting it behind the saw would work in a similar fashion.

Cutting it in a straight line, the simplest is lots of practice! :). Since I am guessing that paying lots to get a decent sized saw or getting a table extender are out of the question (I want an extender but ~$800!) so...

If you have a router with a straight bit, try and cut you pieces outside the line then use the the router, a guide board clamped down and a straight bit to give it a nice clean straight cut to the line.

Having a circular saw (also commonly called a Skil saw) and saw horses would actually be my recommended tool over a contractors saw for sheet material.

Last but certainly not least, a second person. They can help guide from the far side of the saw until you get it started, then they just help hold as you guide and push.

Then there is how straight are you looking for? even a regular table saw with a fence, still needs practice cutting straight on large pieces with one person, one corner or the other tends to want to move the wrong way, making a wavy line.

Actually the Last one is to have the big cuts made on your material at Home Depot or where ever you buy it. I think home depot gives 1 or 2 cuts for free. then a cheap fee for more. So cut the big ones down, and do the smaller cuts at home.

  • I should have expected this: or where ever you buy it. Yeah... i don't pay for most of my wood. My plywood is from pallets mostly. – Matt May 13 '15 at 20:08
  • @Matt and it's big enough that you can't use a fence? those are big pallets! – bowlturner May 13 '15 at 20:09
  • My saw table is maybe 2ft square (I loathe its existence but its all i got) and the pallets are bigger than 4ft square. It's when im cutting in half this becomes a problem. – Matt May 13 '15 at 20:11
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    Using plywood for the top could create a circular logic problem :) – Matt May 13 '15 at 20:13
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    @Matt Only if you want the top to be nice and square! – bowlturner May 13 '15 at 20:14
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How can I cut plywood in a straight line on a smaller table saw freehand?

Don't cut freehand on your table saw. Although you may have gotten by until now without incident, any freehand operation on the table saw (and with many other power tools) is generally considered unsafe.

The best solution to cut sheet goods larger than your table saw's capacity will depend on the type of cut you're trying to make, and the size of your workpiece.

There is one logic-based solution that you should always keep in mind when a cut seemingly exceeds the capacity of your tool: for every cut, there is an offcut, and often it's helpful to invert your thinking and make your final piece the "offcut." Although it may be wasteful if you don't have a use for the narrower parts, you can divide what would be your offcut into one or more cuts, then whittle the large piece down to its final dimension.

Here are some solutions for cutting sheet goods larger than your table saw's capacity...some have already been touched on by others, but I'm including them for completeness and in some cases I may go into more detail:

  • Circular saw (or router with a straight bit, or high-quality jigsaw, etc.) with a zero-clearance straightedge guide (aka homemade track saw)
    1. Lay a sheet of 1/2" thick or thicker housing insulation foam on the ground (or set up sawhorses with 2x4s spanning them, if you prefer)
    2. Lay your sheet of material on top, measure and mark as necessary, and position your guide on the marks.
    3. Set the circular saw blade to cut just slightly deeper than the thickness of the wood and make the cut, holding the tool against the fence of your straightedge guide.
  • Clamp a straightedge "fence" to the underside of your workpiece so it registers against the side of your table saw's table at the appropriate location to make the desired cut.
  • Have the material cut to rough dimensions at the store. Note that the store saw doesn't always produce a clean cut and the workers don't always account for the kerf, so you should get your parts cut oversized and plan on cutting to final dimensions yourself.
  • Install a longer fence and add an extension table to your table saw wing
  • Build a table saw station (you may need to use one or more of the other methods in the process of building the table saw station, but once it's complete you can use it to solve the same problem in the future)
  • Use a handsaw, jigsaw, circular saw, router, or some other tool to cut slightly oversized, then register the factory-cut edge against your fence to cut to final dimension.
  • Build or buy a sliding table extension, sled, or sliding top

There are also a few options to solve for your second problem, in order of preference:

  • Outfeed table (for full-size sheets it's also helpful to have an infeed table)
  • Roller stand
  • Have a helper stand on the outfeed side of your table saw and hold the outfeed end of the sheet level with the table saw top as you finish the cut
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    Clamp a straightedge "fence" to the underside of your workpiece is marvelous. That is a realistic solution for me right now. Thanks Rob. FYI I knew it was unsafe which is why I asked the question. That's why I never finished the cuts cause I saw bad things happening. – Matt May 14 '15 at 18:38
  • "The store saw doesn't always produce a clean cut" - I've never had anything other than the cleanest cuts when I've had sheets cut in store (and they've understood kerfs too). YMMV of course. – Martin Bonner Jul 3 '18 at 8:34
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Get yourself an 8ft. level from Home Depot, Lowes,ect and clamp it to the plywood and use it as a straitedge (guide) for your circular saw. These levels are precision milled at the factory, you can see the milling cutter marks on the aluminum edges so you know these things are pretty straight. Be careful when you clamp the level to the plywood, you don't want to damage the level as they are not cheap, I have been using this technique for 15 years, works great.

  • He didn't say he had a circular saw. – bowlturner May 14 '15 at 16:49
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    @bowlturner I think it's ok to suggest solutions that involve other tools commonly found in a garage or shop, especially if the basis of the question is flawed or unsafe. – rob May 14 '15 at 17:51

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