I have just installed a pergola on my old patio and now need to notch a small u shape in the edge of two pavers to fit around the post. Is this something that could be done with a masonry blade on a reciprocating saw? I’ve also read a few internet things on angle 9 inch angle grinders with diamond blades but every article seems to suggest you are moments away from instant death Any suggestions for cutting or reassurances about using an angle grinder appreciated.
A 9” grinder certainly has some power to it and a gyroscopic like force so common sense and respect always needs to be applied, along with safe working practices (could mention a few but don’t wanna wrap you in cotton wool) If you’ve got a wooden pallet handy, this acts as a handy raised platform to cut blocks on but overhang blocks so blade doesn’t cut through and catch in wood Or some bricks to raise blocks on Need to hold block firm whilst cutting - you really don’t want it to move or can snag blade and certainly don’t want feet anywhere near blade Larger slabs are easily held firm with one foot (safely out the way) or can use a couple of clamps Smaller blocks or pavers are more tricky to clamp whilst being out the way of the grinder. A plank of wood, just on edge of raised block and then stood on with one foot hold block firm, whilst your safely out way of the blade Make 2 cuts to edge of U shape then use smaller grinder to mark between them, both top and bottom of block Obviously on top of block, cut across the width carefully so you don’t overshoot the sides - but you can’t cut very deep Make another cut underneath block, can overshoot the sides a bit Then knock out section with a narrow stone chisel / scutch chisel / etc
Good point, I did speed read and never picked up it was a square hole required, however depending on location and look required a round hole just big enough to allow the square tube to fit through would still work.
I think we can all guess that although the OP mentioned a ‘U’ shaped notch to be cut out to allow slabs to fit around pergola post - it’s highly likely, almost certain, I’m willing to bet on the fact, 99.9% the case, that the notch to be cut is like a square ‘U’ and not actually having a round base - as shown by the actual letter itself If I’m wrong, I’m more than happy to be corrected and admit that I’ve jumped the gun and offered incorrect advice regarding cutting a square ‘U’ with angle grinder But….. I doubt that I am wrong Yes, the OP could have said ‘square U’ notch but most of us realise that posts are mainly square whilst poles are round and other things may actually be ‘U’ shaped……. But not in this case !
Regardless of the type of ole, a grinder can be a dangerous bit of kit, but as with every power tool, you have to be confident using it . Don’t twist and bully it through the material, be prepared for the possibility of a bit of kick back and wear appropriate ppe. Goggles, ear defenders, dust mask. Some people do, but I never wear gloves when using an angle grinder.
So why ask about a U notch which will have a curve when you want a square one. There was NOTHING in your original post that says square - just the requirement for a curve.
Thanks all for the advice. Bought a 4 1/2 inch grinder, diamond blade and it was literally a very easy 10 minute job cutting on top and then bottom as suggested. On one slab the unwanted piece simply dropped out. Only bit that wasn’t perfect was my measuring but still happy with the result. Cheers