# Rough cutting 4x8 ply sheets



## Betsy (Sep 25, 2007)

Less than a year ago I would have "man" handled a sheet of ply onto a infeed and outfeed table and cut away - no problems. Now with my weight lifting limits that's not possible - well technically it is, but I'd hurt myself trying. Anyway, I've had this nice piece of ply laying straight up against the wall for about 2 years or more now and I've finally got a project for it.

I'm thinking about the best way I can cut the ply is to lay the ply on the floor and rough cut it down to more managable sizes. Seems to me the safest way would be to lay it onto some old 2×4's and use a saber saw.

I'd be interested to know how others rough cut their ply.

Also, I'd be interested in hearing opinions on safely cutting on the floor and tips on doing it properly.

Thanks in advance.


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## JohnGray (Oct 6, 2007)

Thanks Betsy I'd also be interested in a better "lighter" way to cut it up that doesn't cost an arm and a leg.


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## shack (Mar 30, 2007)

I use 2×4s on the floor and a aluminum straight edge and cut mine . If necessary I cut too size on table saw. make sure your saw blade is adjusted properly so you dont cut any thing like your floor.


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## ChicoWoodnut (Dec 15, 2007)

Ditto,

Wouldn't use a saber saw though. I'd use my skill saw if I had one (and I do)

Get a much nicer cut that way.


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## Radish (Apr 11, 2007)

I'm with John and Scott, 7.25" circular saw and a straight-edge offset by the edge to kerf offset of the saw's base plate (My Milwaukee is offset the exact width of the short leg of a framing square). The difference is I use a 3 inch thick sheet of styrofoam from some box or other under the sheet goods.


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## ajosephg (Aug 25, 2008)

I like Doug's way because you don't have to contend with the sheet sagging on the 2 by supports, wiggly saw horses, or having the off cut get out of control etc, etc.

Also there is virtually no lifting, only lowering it to the floor after which the weight of the individual cut ups are not a factor.


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## SteveKorz (Mar 25, 2008)

I like to lay a 2×6 or 2×8 on the floor underneath the ply where I'm going to make the cut (so my knees can fit on it as I crawl across the sheet when I cut). I put a 2×4 under each end to support the sheet. Then, I clamp an alluminum level to the sheet and make the cut with a circular saw. I would not use a saber or jigsaw. If you use a panel blade, you'll get a near perfect cut.

If you want to get a really, really nice cut…. after you cut it with the circular saw, clamp the straightedge on to the sheet to match the base on your router, then take the router along it with a nice 3/8 spiral downcut bit. This will create a very nice, straight, smooth cut with no saw marks- and no jointing necessary.

I have an 8' jig in my shop similar to Hawk's Jointability. I made mine, though… it looks almost identical. I stick the sheet or board in mine and zip a router along the straightedge with a 3/8 spiral bit in it, and you'll be surprised how well it works.

I made mine for about $50-60 about 4 years ago. $30 was just to have a big metal shop put the metal in a large break to bend it to the shape I desired, there's no way you could do it without the break.

Good luck.

Steve


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## Kindlingmaker (Sep 29, 2008)

If the interior wall of your shop is not sheathed another possibility is to clamp it to the wall and saw vertically between clamps using your skill saw with minimum blade. The foam is the best idea if you have foam and a place to store it for the next use.


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## dalec (Oct 3, 2007)

Those 4×8 sheets of plywood are heavy. Have someone help you position the plywood and the supporting pieces on the floor, (be sure to support both sides of the plywood), to avoid binding tearing off the waste side if the plywood is not properly supported. Better yet, have them cut it. 

Dalec


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## HokieMojo (Mar 11, 2008)

one that I've heard of is to use a sheet of 1 or 2 inch foam board under the plywood. You can cut right through the plywood into the foam without much flexing of the material (which may happen depending on the thickness of your plywood or straigtness of your 2×4's). just an idea.


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## Dadoo (Jun 23, 2007)

I posted a jig that works very well for me: http://lumberjocks.com/jocks/Dadoo/blog

I also use a 50" Clamp-N-Tool Guide to get near perfect edges with a circular saw. http://www.amazon.com/Tru-Grip-CT50C-50-Inch-Clamp-N-Tool-Guide/dp/B0000224DM The price is around $30.00!

I've also seen a homemade "cart" in one of the woodworking mags a few years ago that looked somewhat like half-moon with wheels on the bottom. You used it like a dolly cart to lift your sheet, roll it to your cutting area, and then by rotating the cart to the floor would raise the sheet flat and level to the bench! It was a pretty cool idea but I can't find it right now. And when you figure that a sheet of 3/4" MDF weighs around 100 lbs. it makes perfect sense to build one. Maybe one of our LJ's has seen this and can direct us both to the plan?


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## lew (Feb 13, 2008)

Betsy,

If you have a "Skill Saw", instead of the expensive "2 x" material, go the Borg and get some Styrofoam insulation panels- 1" thick- or greater- and lay them down on the floor. Lay the plywood flat on top of them. Now you can crawl around on top of the plywood, layout your lines and cut with the saw. No need to worry about where the 2 x's are located- the saw will easily pass thru the insulation. Just be careful about the saw blade depth of cut.

Lew


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## Brad_Nailor (Jul 26, 2007)

the best way to cut sheet goods down to manageable sizes is with a cutting guide. I made mine out of a piece of hardboard about 2 feet wide and 4 feet long. Rip a straight piece of 3/4 plywood about 3 inches wide and 4 feet long. Fasten the plywood parallel to one of the edges but inset the piece slightly farther than your kerf distance on your circular saw.glue and shoot it in place with some brads. When its dry just cut off the excess hardboard with your saw, butting the saw shoe against the plywood fence. Now the guide is sized exactly for the kerf of the saw. To cut sheet goods just mark where you want it cut on both sides of the board, line up one side of the guide and clamp it fairly tight. Then move to the other side and line that one up and clamp it tight. Then move back to the original side and adjust it so the edge is right on your mark and clamp tightly. Then (with the board properly supported on horses) make your cut with the shoe of the saw against your fence. I made mine two sided…one side is for my circular saw the other is set up for my router with a compression bit. I use the router/compression bit when I want to crosscut veneer ply without tearout.


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## sIKE (Feb 14, 2008)

I have a grid that rests on saw horses and breaks down when not in use, that is designed to support a sheet of plygoods. Utilizes a circular saw that is set 1/8" thicker than the sheet I am cutting. The problem is that no matter what you do a full sheet of ply is bulky and the thicker sheets get heavier. They have to be wrestled from the vehicle to the saw horses. If you know the largest piece you need you can have the Borg cut it down a bit over size for you there for free, I think the first couple of cuts are free.


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## Betsy (Sep 25, 2007)

thanks guys - these are all good ideas.

The reason I'm thinking of using a saber saw instead of a circular saw is that I think I can control it a little better. I'm concerned about the reach needed to cut the width of the ply - can't do it without sliding my knees onto the ply to reach all the way. I would think that I would have to stop a circular saw but a saber saw I could manage a little easier. Although the saber saw has quite a range of movement - that could pose an issue. I've also thought about using the circular saw to cut into the board short way - then going into the cut from the end - so that the pieces would be sized as I went-- not sure if I explained that right - but essentially cutting in pieces so I don't have to reach.

Brad - I actually have a jig like you describe for my circular saw - that I've not used in a very long time.

Dadoo - the folding jig is more than impressive.

I'm not sure guys - I may just need to have a friend come over to help me cut the ply - buy him a pizza dinner-- might be safer all the way around.

thanks for the suggestions.


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## dalec (Oct 3, 2007)

Betsy, It would be easier cutting a pizza than a full sheet of plywood and tastes better.

Dalec


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## Betsy (Sep 25, 2007)

quite right Dalec!


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## cabinetmaster (Aug 28, 2008)

Dang…......if I lived close by I'd take you up on that deal….........LOL


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## vjeko (Jan 19, 2009)

I will be doing the following (newbie, so can't talk from experience but am
excited to try it out - have bought a heap of the parts, now just
need to put it together/start using it - will put up a review with time):

build this: 
http://www.eurekazone.com/instructions/smarttableinstallation.pdf
(when your saw has eaten up the supporting lumber, screw down new 1×4s)

cut with this in case you already haven't got something practical
for straight cutting:
http://www.eurekazone.com/instructions/20060419/slidingsquare.pdf

and for repeat cuts :
http://eurekazone.com/products/detail/ezr18.html

for precise cutting there are other items in case you want to throw away
your saw  :
http://eurekazone.com/products/detail/smarttablesystem.html


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## rhett (May 11, 2008)

I use a grid I constructed for a base layer when making cuts on the floor. It is constructed of 2 1/2 inch wide strips of plywood. There are 3 - 8' long pieces and 5 - 4' long pieces. I cut half laps 3/4 wide by 1 1/4 deep and assemble it on the floor next to my stack. Like a loose torsion box. Drop pieces on and Festool my rough sizes. The plus to this is when unassembled it stores neatly against the wall and takes up virtually no space, there is also ample support to crawl on it with no sagging.


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## dustygirl (Mar 11, 2008)

Betsy.I use my skill saw to do this all the time.It works great with little effort.I just clamp the piece onto my table and let overhang the size I want.


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## Brian024 (Feb 2, 2009)

I use my Skillsaw and a straightedge that I made from some scrap ply and some sawhorses. If anybody has seen the one Tommy made on " Ask This Old House" then it's pretty much that except 8 ft long. I've been thinking of making a 4 ft or 5ft one to go along with it.


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## pommy (Apr 17, 2008)

skillsaw is the way to go betsy and if you want to stop the splinters run a pairing knive along your straightedge

andy


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## DrDirt (Feb 26, 2008)

I'm with Hokiemojo and Lew-
I use a piece of 1 inch blue foam insulation (4X8) and then I never have sags or binds and just set the depth of cut with a circular saw to cut the ply + ~1/8 inch.
I usually use my 60 inch Aluminum straight enge to guide the saw.


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## toddc (Mar 6, 2007)

Lay it on 2×4's and cut it with a straightedge and circular saw. Be mindful that it is supported properly so that when the pieces are cut they do not pinch the blade or become unstable and pinch the blade which can cause kick-back.

I prefer to have my supports on the ground run perpendicular to the cutting length. Yes, I cut a bit into the 2×4 support material and that is the way that it goes but I find that laying the support underneath this way is the safest.

Set the depth to clearly cut through the material but not have too much extending through the underside. I set the depth about enough to see most of the gullet on the blade (the valley between the teeth.)

I use the my Festool or big tablesaw in shop, but I still cut plenty of sheetgoods in the field and I don't use saw horses most of the time.


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## Betsy (Sep 25, 2007)

Thanks for all the tips guys and gals. Certainly have some ideas now!

If I use the 2×4 idea - how many would you use to support a 4×8 sheet? I'm leaning toward this method as I have the timber, but I'd have to go out and buy the foam insulation.


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## vjeko (Jan 19, 2009)

As I was waiting for my Eurekazone parts (where I saw their "smart table" which is specifically made for what you're after), I made a makeshift "table" using 2" x 1.2" - you won't be cutting in deep, so you don't need anything thicker (leftover pine/rouigh/unplaned will do) - looks like a ladder.

You decide on the size - I made mine 35" x 72" - just large enough so the sheet material can lay on it
without too much bending/causing you trouble etc. (you can clamp the sheet to the rungs)

I cut 7 pieces 35" long for the "rungs" of the "ladder" - lay narrow side of wood down so you have maximum height - you will be cutting through the rungs. Now you have the rungs approx spaced.

Cut the 2 long pieces of the "ladder" and cover the rungs to form the ladder, screw together flip over and you can start cutting (on a table, on the ground, wherever is practical for you).

When you've destroyed the rungs after a lot of cutting(as every good woodworker will do , unscrew rungs and put on new ones.


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## klpete45 (Feb 8, 2009)

Betsy,

I have had a similar weight limitation since last year and I use a solution that I don't believe anyone has mentioned. I have the home center cut the sheet into 2X8 or 4X4 sheets for me. I plan my layouts via Cutlist software by entering the half sheet sizes as available cut-offs. This forces Culist to lay out the pieces on these sizes. I know this is not the ideal answer, but it is very easy and facilitates loading, unloading and all facets of movement.Hope this helps. By the way, I have never had to pay for cuts even when I have had several sheets and numerous pieces.

P.S. I realize this is not the answer to your immediate question, but I hope it will help in the long run.


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## mmax (Dec 9, 2008)

A while back I had some limitations on lifting and I found out most of the sources where I bought the plywood would rought cut it down to a size I could handle. Even the big box stores have panel saws and generally cut it for you for no charge. I realize this don't help for a piece that is already sitting in your shop, but for future projects I hope this helps.


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## TopamaxSurvivor (May 2, 2008)

I always flop it on 2 or 3 saw horses. I usually clamp a straight edge on to follow with my circular saw.


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## roman (Sep 28, 2007)

Festool's TS 55 EQ and the TS 75 EQ with guide plates will do everything you need and more….....just about replaces the table saw allowing you to cut perfect miters, cross cut and leave glue line edges…................I might have to get me one


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## spaids (Apr 15, 2008)

I use Brad_nailor's jig and 4 2×4's. This is for 3/4 ply. I put a 2×4 a couple inches on either side of the cut and the other 2×4's out at the edges. That plenty on 3/4. You can walk on it while cutting and when the cut is through the two pieces don't move or pinch at all. Thinner ply would need more support I'm sure. You may consider a large sheet of Styrofoam to support your work on the floor for breaking down thin ply.


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## jm540 (Jan 14, 2009)

I use 2×4s on saw horses all you have to do is slide the wood on the floor after you have it setup then lay it on the edge of the 2×4 you are naow close to the tip of balance and it is light then it is sliding and adjusting it takes 3 to 4 2×4s and you don't have to bend over with a bad back


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## billT (Apr 5, 2009)

Hi guys - please check out my $20 dual-sided circular saw guide

This guide lets you bring the saw to the work, instead of lugging onto a table saw. It is also much easier to use than a single-sided saw guide (I admit, I have been prone to wavy cuts, even before drinking beer…). It doesnt have to be clamped, no tearout, and it doesnt disable the blade guard.

I suggest supporting the plywood on a workbench in the center of the shop. Or even on a folding table or sawhorses with a piece of plywood. This is much more stable than placing on sawhorses only. On top of this I use a sacrificial 2'x4' piece of 1/2" mdf positioned under the cut. This supports the cut and eliminates tearout on the bottom face.

Hope this helps. I am sure your friends would still appreciate the pizza dinner…

Cheers - BillT


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## BethMartin (Feb 24, 2009)

Betsy, as a small woman who can't manhandle the big sheets, my personal favorite method is to let the nice guys at the local lumberyard (not the big box store) do the big roughcuts and then load it into my van for me.


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## rtb (Mar 26, 2008)

Betsy, getting back to the problem at hand… do it the smart way…get help..'nough said


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