using Router on Plywood !

Tearout is an issue when running a router on plywood, but I tried something new. Instead of a conventional cut, I did a climb cut, and tearout was pretty minimal.

gmoon1 year ago

Sure, direction of the bit (and cut) can make a big difference -- just like when using a hand plane. I totally get that.

Leaving a bit more material on the thinner weak parts of the piece, and cutting them to final dimensions later can help too (for some cuts).

I hate routing playwood but I noticed with the right settings / setup it works quite well.
One major problem is the glue as some boards just don't use enough to fully soak the wood chips - that is what causes them to fry.
The router bit must be really sharp, dull ones that still work good on solid wood are of little use.
As we can't go along a grain or such the material take out should be kept relatively small as otherwise the bit will chew out big wood chunks.
Speed should be really high but not so high that the wood starts to smoke ;)
I had a spiral router bit especially for such complicated materials but some idiot though it would be good tool to work on metal - never found a replacement :(
Unlike the standard, straight bits this bit had a spiral going against the rotation of the router.
So all cuts made are done as a slight downward cut, keeping the wood chips intact.
Big downside was that you needed air assist to keep the saw dust out of the cut.

Another old trick my grandfather often used was to take the old steam iron to work the surface of the playwood with a lot of pressure and hot steam.
Mind you he was not wetting the wood but instead using the steam to moisten the wood / glue mix.
If there was visible moisture on the wood he would continue with less steam until there was only a slight discoloration of the wood.
I tired it with mixed results and mybe the bad ones were due to the lack of expertise but the ones that worked came out really great, even for normal cutting jobs.

One thing to consider would be a router bit with more cutters on it, so instead of the usual 2 aim for one with 3 or 4 flutes on it.
I used a 20mm one with 4 flutes and it proced much nicer cuts than any of my normal router bits, especially when working on plastics.