Trying to make some tea light boxes from fence pickets but i get shredding, not just on the top and bottom, but throughout the cut. Using new bits, up and down cut yielda same result, as well as the chamfer with rhe 60 degree bit passing at .1.
Is this a characteristic of treated pine, or could there be a workaround with toolpathing?
First, you REALLY should not be using treated lumber for anything that is for handling or devices that cause heating. Very poisonous fumes can be released by the chemicals used to treat the wood.
Second, treated wood is VERY wet. That’s why you’re getting the stringy texture from cutting. Wood should have a moisture content of around 5% to mill properly. Wet wood will not cut…it tears. Bits are designed to shear the wood fibers which they can’t do because they stretch and break if the wood is too wet.
I’ve cut pressure treated wood. It’s typically southern yellow pine, which really likes to fuzz. You have to make sure it’s dry and the best results I get are from conventional milling vs climb milling. I’ve had to mill up some replica 165 year old moulding that would have otherwise been unobtainable. Use good dust collection.