Cutting 7n blocks with recip saw

[dave_104]

Hi

I've got a stub of a wall to remove tee'd off from another wall which I believe is made in 7N concrete blocks. Ideally a 9" grinder would do it but I'm not comfortable using one above my head or while on a ladder - plus the insane amount of dust a grinder would generate is an issue. I don't want to disturb the adjoining wall too much (i.e. by using a breaker) but it doesn't matter if this takes a long time to do.

Before I go out and buy expensive blades has anyone had success with a reciprocating saw and diamond/TCT blades? How quickly do they cut, how long would the blades last, and would there be a similar gigantic dust cloud issue?

Thanks, Dave

 

[ajstoneservices]

I tried with a tct blade and failed miserably.

 

[noseall]

Hi

I've got a stub of a wall to remove tee'd off from another wall which I believe is made in 7N concrete blocks. Ideally a 9" grinder would do it but I'm not comfortable using one above my head or while on a ladder - plus the insane amount of dust a grinder would generate is an issue. I don't want to disturb the adjoining wall too much (i.e. by using a breaker) but it doesn't matter if this takes a long time to do.

Before I go out and buy expensive blades has anyone had success with a reciprocating saw and diamond/TCT blades? How quickly do they cut, how long would the blades last, and would there be a similar gigantic dust cloud issue?

Thanks, Dave

The problem with a recip is the pull and thrust of the blade can wobble the b'Jeezus out of the wall and dislodge the masonry.

Would a fine masonry drill not help (stitch drilling) ?

 

[dave_104]

Thanks for your replies guys. Stitching sounds good to me, I'll fix a bit of batten up for a nice straight line then jab away with a long SDS 4-5mm drill. If I'm lucky I might find the stagger between the block courses all lines up then I only need to do half the work (I know that'll leave half a block sticking out in theory and that's ok with me).

 

[robinbanks]

plus the insane amount of dust a grinder would generate is an issue

If you have a helper hold a running vacuum cleaner at the exit to the cut it captures an impressive amount of the exiting dust, but be aware that the bag/filter will clog fairly quickly so stop and give the vac a bang/replacement when you notice a reduction in effectiveness

I've always been impressed with how effective water suppression is, but you do need a non-electrical (or electrical-but-designed-for-it) saw for this, and it don't half make a mess of the floor..