Cutting down paneling & plywood sheets can often times be a chore.  Not only that but trying to get accurate & reliable cuts is another obstacle all together.  Making a quick and easy guide to give you straight cuts each and every time from your circular saw is a breeze.  I saw a neighbor of  mine using one of these years ago & with my inquiring mind I just had to know more.  He called it a door board.  Just two pieces of 1/4″ MDF or hardboard is all the materials you will need.  Some of the items the make time in the workshop more fun couldn’t be more simply to make.  I have seen many variants of this simple jig over the years but if for whatever reason you haven’t tried one, I strongly suggest you give it a try.  The results are amazing!

 

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I started with a 2′ x 4′ piece of 1/4″ MDF.  I prefer MDF but hardboard or 1/4″ plywood will also work.

 

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Measurements for the pieces will depend on your particular circular saw.  Just measure the total width of your saw and add approximately 3-5″.

 

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Use whatever tools at your disposal to cut both a top and bottom piece.  Here I used a bandsaw.

 

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It is worth noting that the narrower top piece you should utilize a factory edge.  More on that below.

 

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Shown here is the wider bottom piece extending past the blade as well as past the motor housing by a few inches.

 

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This arrow indicates that factory edge of the MDF.  A factory edge makes a nice straight edge to guide the saw.

 

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The lighter brown pieces represent an exploded view of the 2 parts we will glue together shortly.  The darker brown one represents the project material to be cut.

 

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Having the pieces extend past the motor housing allows for any type of clamp to secure the door board without worrying about it interfering with the saw.

 

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I positioned the two boards & drew a line to indicate where to apply the glue.

 

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Apply the glue.  Try and stay away from the pencil line.  Any glue that squeezes out past the line will have to be cleaned up before it sets.

 

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Clamp the boards together & use some scrap wood to act as cauls to evenly distribute the clamping pressure.

 

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Run the circular saw you are going to use with this door board through the guide.  Each saw is slightly different in size.  Whatever saw you use for this step will be the one you will always use with it.

 

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If you want to pretty up the door board, you can even out the back edge & ends to make things nice and even.

 

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I also added a handle cutout to make it easier to carry.  You can find more details on that in my apple boxes project build.

 

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Secure the door board with a few clamps & make your cut into you project material.  You now have a circular saw straight edge guide that will give you awesome results!  I would love to hear from you guys if this is a method you use & let me know what kind of results you get from it.

Let me know your thoughts