Gonna be building a retaining wall out of pressure treated posts.

Have a dewalt that uses 12in blade.

Had heard user blade madE for that kind of wood, but pretty vague.

Dont really wanna ruin a 400$ saw!

SuggesTions associated

 

I don't believe a 12" saw is going to make that cut in one pass. In addition, you will need a secure table to hold lumber that heavy.

With your saw set up with a solid table, I believe you could cut 90% of the way through and then rotate the wood for the final cut.

As for a special blade for pressure treated, no, just a good carbide blade.

Others will comment (and correct if necessary) and will also know if a one pass cut is possible.

Bud

 

You won't ruin the saw, but PT can be hard on blades. A typical carbide framing blade 32 or 24(?)tooth would be fine. Best to clean the blade with a stiff brush after. I've heard that PT shavings can eat the carbide...I dunno.

Even a 12" won't make the cut on one pass. I'd use a speed square and a skilsaw and finish the cut by hand.

 

Any blade will cut PT wood. A carbide with less teeth may cut faster, but will also leave a rougher cut. I would probably suggest a 12" x 60 tooth combination blade. The arbor and guard on a 12" saw won't allow you to cut through the 6x6 in one pass. You will need to cut as far as possible, then rotate the 6x6, turning it upside down to finish the cut. This is because the arbor washer is about 2" wide, meaning you can only cut wide stock 5" deep. It can cut taller baseboard and crown moulding, but that is when it is nested against the fence behind the blade. A 6x6 comes out too far from the fence to cut all the way through in one pass.

 

I'll second Vic's method. Speed square, circle saw and reciprocating or hand saw to finish the core, since the circle saw can't cut through it either. Cut on all sides with the circle saw.

 

Part of what Vic and Chandler are addressing with the circular saw and square is the issue of stability, that is why I recommended a very sturdy table adapted for the chop saw. An 8' piece of PT 6x6 will weigh a ton and be difficult to handle to then cut with a chop saw. But, using a circular saw and speed square, a couple of saw horses with a plank across them would be safe and easy to make those cuts.

Bud

 

If I recall correctly, its been many years, if you put a piece of 2x4 flat between the back of the saw and the 6x6 so the 6x6 is out 1½" it will cut through.

 

The landscape guys all use chain saws for this. With a good sharp chain the splintering is minimal and easily cleaned up with a rasp, although in most cases the slightly ragged edge can be hidden to the inside of the wall. Has the added advantage of being able to cut near the ground, so you don't have to wrestle a ton of lumber up to the chop saw.

 

I still don't think so Ray. Maybe with a sliding saw, never used one of those.

As Bud elaborated on, it's all about ease of handling and stability. With the circ saw you can adjust your stance or angle easily, so just throw the wood up on sawhorses. Using a miter saw requires lots of support and precise positioning.

 

Yes, on further reflection I think it was 4x6s.

 

I will take a speed square and circular saw over hefting a treated 6x6 onto a miter saw, any day of the week as the saying goes. Whenever possible, I figure what I need in advance, so that I can simply slide them back on the truck or trailer and remove the waste before having to handle them.

 

Nope, I have the DW780XPS and as I mentioned, it cuts a 6x6 to a depth of 5". You just have to flip it upside down to finish the cut.

 

I vote for the chain saw. You are not building a rocket to go to the moon. Just cutting landscaping timbers. One cut and you are done. No turning over. No additional lifting.

 

I'd also probably use a chainsaw, if not I'd use a skil saw and then either a handsaw or saws all to finish. No way would I be wanting to hoists 6x6s up unto a saw bench.

 

Thanks. That's the same saw I have. I'll see what works out better. I was more worried about screwing up the saw than the blade.

 

The only way you might hurt the saw would be by forcing it into a bind. Let the saw do the work and it will be fine.

 

Back to the table I mentioned, trying to cut 6" off of an 8' length of 6x6 pt will put over 100 pounds of weight at one end and almost nothing at the other. It will be whatever you use for support on the long end that determines how the timber rests on the saw.

When you make the cut you will want to be sure the cut will fall open and not closed where it will bind, as mentioned. Depending upon the timber and the supports/table you may need to shim it up near the cut.

Just checked my saw and my motor will hit at 4 3/4".

One more vote for the speed square and circular saw. I could make the cute and finish with a hand saw in less time than two people could position one of those beasts for the first cut.

Bud