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Need help with ripping MDF
MonitorGuru:
The most common cause of wavy rip cuts on a table saw are due to a cheap blade.
Particle board is the absolute worst, MDF is better to cut, but both can cause problems if you use cheap blades.
And cheap meaning wrong type not necessarily inexpensive.
As much as it is nice to have a nice edge, do NOT use a large count alternating angle kerf finishing blade such as a 60 to 186 count blade. These blades heat up VERY fast and bend VERY easily, and the alternate angle that each tooth bends out are QUICKLY flattened by the material (especially with particle board)
ONLY use low count (18, 24) carbide tipped blades with heat expansion channels to cut this type of material.
Also run the board through twice.. once at about 1/4" depth, again at full (1"+ depth). This serves two purposes. The first is that it will create a clean groove without breaking out the edges, even on a low tooth count blade. Second it will remove 1/3 of the material to help the second cut go easier.
Yes, it's a bit more work, but you will be happier with the results.
I've built many a storage cabinet out of melamine coated particle board, and couldn't figure out why I kept getting wavy cuts (from a handheld circular saw besides) and the table saw did the same thing. I had much better luck with cutting oak laminated MDF for bookcases the year before. Anyway, my cuts got much straighter when I switched to a carbide tipped low count blade and made 2 passes through the wood. Afterwards I looked at the 186 tooth count blade and the kerf got flattened from 1/8" to about 1/16" as it bent all the teeth inward to almost flat with the thickness of the blade itself!
Tailgunner:
I typically use a 8' level for a straightedge when ripping full sheets of material.
rdagger:
--- Quote from: Apollo on August 02, 2004, 12:50:23 am ---Much easier way is to tack a straight pioece of timber to your MDF and use it as a guide for your circular saw.
--- End quote ---
This is an easy wasy. MDF works well for the straight piece as it is hard to get anything straight at Home Depot. I used a small handheld jigsaw for the majority of my cuts and ripping.