Need Help Cutting MDF Boards

[Sidney56450139]

Basic question for experienced woodworkers out there. I have 4-pieces of 3/4"x11"x24" mdf with "bullnose". What's the best 7-1/4" blade and method for using portable circular saw to remove bullnose 1" from edge and keep the edge straight. Should I clamp 2-pieces for 1-1/2" thick and make one pass?

tia,
Sid

[CokewithLime]

With only a portable 7 1/4 saw just cut one board at a time. Use the straight edge of the second piece tightly clamped as a guide on the top of the piece you want to cut. You will need to offset this to have the edge of the base plate of your saw set so that the blade ends up cutting where you wish.

Measure carefully - then measure again, then measure again so that both ends of the guide piece are parallel before you make the cut.

Don't force the saw into the cut just let it smoothly work it's way through

btw make sure you have a new / sharp blade(carbide tip, 60 to 80 tooth blades work well for straight MDF rips) before you do the cut

Repeat for the other piece.

Oh and watch your fingers and the power cord of the saw

[MorfiusX]

I made a rip guide for my circular saw. You can find many instructions via google.

[moosespeaker]

Go here to make a "saw board".

http://www.benchnotes.com/Skillsaw%2..._guide_boa.htm

Best investment and cheapest straight edge cutting you can make with 1/8 inch Masonite (hardboard). The ADVANTAGE is that you never have to measure an offset or compensate for the blade thickness (kerf). Just place the edge against the measured line and cut.

I have made two. One is 24 inches and the other 48 inches.

George

[Sidney56450139]

Go here to make a "saw board".

http://www.benchnotes.com/Skillsaw%2..._guide_boa.htm

Best investment and cheapest straight edge cutting you can make with 1/8 inch Masonite (hardboard). The ADVANTAGE is that you never have to measure an offset or compensate for the blade thickness (kerf). Just place the edge against the measured line and cut.

I have made two. One is 24 inches and the other 48 inches.

George

Found your tip via Google,
Thanks Moose!

[Sidney56450139]

I made a rip guide for my circular saw. You can find many instructions via google.

Right you are! Got it on Google.

[Sidney56450139]

With only a portable 7 1/4 saw just cut one board at a time. Use the straight edge of the second piece tightly clamped as a guide on the top of the piece you want to cut. You will need to offset this to have the edge of the base plate of your saw set so that the blade ends up cutting where you wish.

Measure carefully - then measure again, then measure again so that both ends of the guide piece are parallel before you make the cut.

Don't force the saw into the cut just let it smoothly work it's way through

btw make sure you have a new / sharp blade(carbide tip, 60 to 80 tooth blades work well for straight MDF rips) before you do the cut

Repeat for the other piece.

Oh and watch your fingers and the power cord of the saw

Thanks for your words of wisdom. I like to keep all six of my fingers!<g>
I learned from my dad a long,long time ago, measure twice , cut once.

[jonpike]

Thanks for your words of wisdom. I like to keep all six of my fingers!<g>
I learned from my dad a long,long time ago, measure twice , cut once.

Yep... but that's after you've gotten good. Most folks have to go thru many years of "measure 5-6 times, cut once" till we get there...

[estreet]

no matter how many times you cut a board, it's never long enough

[David Gatti]

I use a router with a flush trim bit to get the best accuracy when cutting mdf.

[Sidney56450139]

Yep... but that's after you've gotten good. Most folks have to go thru many years of "measure 5-6 times, cut once" till we get there...

Can you measure too much??

[Sidney56450139]

no matter how many times you cut a board, it's never long enough

Well, I know it's easier to take off, but a lot harder to add to.

BTW,

Here's the links I googled for diy saw guides:
This one's from George (Thanks!)
http://www.benchnotes.com/Skillsaw%2..._guide_boa.htm

http://wayneofthewoods.com/circular-...ing-guide.html

[Sidney56450139]

I use a router with a flush trim bit to get the best accuracy when cutting mdf.

Hi mate!

If I catch the bug, I'll have to learn how to use one. There are some incredible results of fine woodworking skills displayed here.

[Sidney56450139]

Basic question for experienced woodworkers out there. I have 4-pieces of 3/4"x11"x24" mdf with "bullnose". What's the best 7-1/4" blade and method for using portable circular saw to remove bullnose 1" from edge and keep the edge straight. Should I clamp 2-pieces for 1-1/2" thick and make one pass?

tia,
Sid

Thanks for the tips, I got 'er done! Ripped 1 inch off edge of 3/4" mdf, using trusty Irwin Quick-Grip clamps, 3/16" thk. alum. straight edge and Ryobi portable circular saw with 5-1/4" 18T carbide-tipped blade. Nice clean edge with minimum sanding requred.Careful measuring with saw cut is required to setup edge of guide. Once that's checked (twice), all boards were cut and matched exact. $0.00 spent to do the job. HomeDepot made three crosscuts (n/c) in 8ft.long bull-nosed mdf board, but could not do rips on boards only 11" wide. That's just saw dust on the edge of final cut pic.