Circular saw with concrete cutting blade

[vespagts]

Hi all, just wondering if this is possible. My saw is a Homebase Powerbase Excel blade size 185mm diameter 20mm bore. Thanks

 

[Deleted member 323070]

Yes you can if you can find a cutting disc that will fit your circular saw.
You might need an arbor adapter.
Also check the speed rating of the disc to ensure it matches the speed of your saw.

 

[nickjb]

Yep, plenty out there. Just search for a diamond blade. You should be able to get a 20mm bore but some are bigger and may come with a adapter. It'll probably be working the saw quite hard so go slowly and let the saw do the work, don't force it. You may need to make a few shallow passes. It'll also make a load of dust.

 

[freddiemercurystwin]

Just because you can does not necessarily mean you should, plenty of S/H angle grinders out there, likely more suitable and controllable for cutting concrete but as ever there's no context been included.

 

[GhostIntMachine]

OP your biggest problem is going to be be finding a disc which will actually fit your saw. I have tried this morning and found nada, nothing

As it happens the majority of abrasive cutting wheels available in the UK have 7/8in (22.2mm) arbor holes - circular saws on the other hand tend to have arbors which are 20 or 30mm (EU standard these days, or in a few cases 5/8in (15.9mm - still a US standard so so.e Makitas, etc still have these) or 1in (26.4mm - some Evolution tools) - the old Imperial standards. So I think you'll be out of luck.

It certainly used to be the case in the 50s and 60s that saw manufacturers made abrasive cutting discs to fit circular saws, but AFAIK those were for the big 9-1/4in/235mm saws, not small saws like your 185mm. I can't recall ever seeing them on sale anywhere, possibly because proper angle grinders became so much more affordable from the 1980s onwards (when Japanese stuff went on sale).

Whilst the guarding on a circular saw is far better than that on a grinder, I'd say a big draw back is that a circular saws run a lot slower than equivalent diameter grinders, so any cutting would be excruciatingly slow. But this is not the same as putting a circular saw blade onto a grinder which really is Darwin Award stuff (i.e. life threatening)

There are circular saw blades specifically made for cutting some cement-based materials and which can be had in sizes to fit your saw - PCD (polycrystalline diamond) blades are designed to cut materials such as cement fibre board, but are also good on ultra hard stuff like Trespa, solid laminate worktops, composite decking, etc. Not sure how long they would last on concrete, though

 

[ree]

OP,
Dont use an angle grinder - carry on with your circular saw: you will have much more control.
Mark the cut line - set the guard for a 5mm nicking first pass, & increase the guard depth by 5mm increments until you have reached the desired depth.
As above, dont force the saw, allow it to slowly go forward with a little pressure.

 

[stevie888]

I've seen it done and had a masonry blade (abrasive type) in an ancient table saw myself before I invested in a proper (wet) tile saw.

As others have said though, even if yu get the right bore the typical circular saw will rotate slower than the angle grider the masonry disc will be designed for so it won't cut very happily.

 

[GhostIntMachine]

I've seen it done and had a masonry blade (abrasive type) in an ancient table saw myself before I invested in a proper (wet) tile saw.

I've seen it done with a 9in portable circular saw a few times, and I use PCD blades on circular saws for cement board, but I'd hazard a guess that when you saw it being done it was using a 10 or 12in (250 or 300mm) disc with a 1in (25.4mm arbor). You can easily get abrasive and diamond discs in those sizes. However, the OP's saw is 185mm

 

[opps]

OP,
Dont use an angle grinder - carry on with your circular saw: you will have much more control.
Mark the cut line - set the guard for a 5mm nicking first pass, & increase the guard depth by 5mm increments until you have reached the desired depth.
As above, dont force the saw, allow it to slowly go forward with a little pressure.

I have a Festool plunge angle grinder, it runs on their guide rail (and connects to my dust extractor). How would a regular circular saw be more accurate?

Granted, my depth of cut is limited to >27mm, but if I have to go deeper I would use a regular angle grinder once the slot has been started.

We have no idea which saw the OP has. Assuming that it is not a plunge saw with a retracting riving knife, how will the op start the cut? And what about dust extraction? Angle grinders are designed to deal with (some) concrete dust, circular saws less so.

I have a Rubi wet tile cutter, but when needs must, I have used an angle grinder (freehand) to cut 800mm porcelain tiles. Over the whole length, the straight line deviates by less than 0.5mm. Sure, those were (uniform) porcelain tiles, and yes, the stones in concrete are more difficult to deal with.

As per @freddiemercurystwin 's post, we have no idea about the OP's tolerances, or their end game.

I am not suggesting that your advice is without merit... but... you do have no idea what the OP wants to do. It may or may not be the case that the OP would be better off with an angle grinder and won't end up with a saw that needs to be binned after.

 

[GhostIntMachine]

Assuming that it is not a plunge saw with a retracting riving knife, how will the op start the cut?

From the edge of the material. Making cut outs or doing cuts requiring plunging cuts into concrete is probably best done by a water jet cutter

And what about dust extraction? Angle grinders are designed to deal with (some) concrete dust, circular saws less so.

Ah, but most angle grinders currently have abysmal dust extraction unless you shell out for a special dust extraction kit (there are exceptions such as wall chasers), however those kits are the preserve of trade quality grinders, so maybe a bit of red herring.

 

[Tigercubrider]

Or hire a concrete saw?

Cut Off Saw 300mm Petrol - Hire - HSS

www.hss.com

 

[ree]

Poster #9,
You have never used a circular saw to cut concrete if you have to ask how do you start the cut - you start with the V-notch centred on the line, and then slowly drop the blade into the line.
I've done this many times - no drama no problems. Its very simple to do. I use my old corded circular saw.

The OP has a "circular saw with a concrete blade" - its in the title of the thread; where's the mystery?
Plunge saws can work for cutting concrete but you would be desperate to use one for such work.
I said circular saws provide "more control". Most angle grinders seem to be sold & used without guide rails
The OP has a £30 tool and you are comparing it with a Festool - FWIW: using your Festool to cut concrete would be foolish.

 

[JohnD]

When I've seen it done, there has been a constant water jet on the cut.

 

[GhostIntMachine]

When I've seen it done, there has been a constant water jet on the cut.

That'll work well with a 230 volt electric saw...

 

[JohnD]

I was thinking that a DIYer repurposing a wood saw would be incompatible with that practice.