I'm working on a project at the moment that is using a lot of MDF. I have limited space and find it difficult to cut full sheets on my own. I came up with a very basic solution of making a frame to cut the full sheet on top of. Its made form treated 2x4's so it can be stored outside behind my shed.
I have a video here showing the entire process:
- Treated 2x4's
- 6mm MDF
- 10cm Wood Screws
- Wood Glue
Step 1: Make the Frame
To make room for clamps and to also make the frame easier to store I made it roughly 6ft x 3ft. This way the full 8ft x 4ft sheet is supported well and there is an overhang space to add clamps.
I start by cutting 2 pieces to 180cm and 4 pieces to 90cm. The longer pieces will be the outside pieces and 2 of the shorter piece will attach at the end. The other 2 shorter pieces will be placed in the middle. I was going to space them evenly apart but I opted for one slightly closer to the edge and one slightly further away. My reason behind this was in case I want to cut narrower pieces on the frame I have the option to support it then. If they were evenly spaces I would be limited a lot more.
With the pieces cut I simply drilled pilot holes and screwed in 2 10cm wood screw at each joint. the joints dont have to be very strong, the frame just needs to hold together. The reason for using 2x4's (100mx50mm) was so I could leave a decent space at the top of the wood free from screws. This will allow the circular saw blade to pass through without worry of hitting the metal screws underneath.
Step 2: Make the Saw Guide Rail
To make the guide rail I used 6mm MDF. To work out the sizes I needed to cut the pieces I measured from the edge of my circular saw base to the my blade which was 10cm. I then added on 1cm (you could add more if you wanted) which gave me 11cm total. I decided to use the same size for my fence piece too. It would give me room to add clamps out of the way of the circular saw motor.
So for my circular saw (Ryobi 18v) I needed 1 piece cut to 11cm wide for the fence and 1 piece cut to 22cm wide for the base. This will give me room to glue the fence onto the base leaving 11cm exposed. Please see pics to get a better idea of what I mean.
I simply glue the fence onto the base trying to line it up flush along the one side. its not critical but you don't want it too far off.
With the glue dry you can cut it to fit your circular saw perfectly.
Keep the saw pressed tight up against the fence and make the cut. The extra 1cm is cut off leaving an edge that fits perfectly along the edge of your saw blade. You can now simple place the guide on you mark and know it will all line up perfectly.
Step 3: Cut the Sheet Material
Now to break down the MDF all I have to do is set the frame on the floor (or on a stand if you prefer) and place my full sheet on top.
I can then measure 3 points for my cut and line up the guide rail with those points. Remember to cut on the waste side of your line. Then add a couple of clamps to hold it in place.
Then simply make the cut. As long as the saw is tight up against the fence you will get a perfect cut every time.
Like I said its very basic but I hope you found it helpful.