I'm having trouble cutting my firebricks. I bought a new blade as I wore out my old blade (it was well used so not surprised). I bought one specifically for cutting hard materials just to make sure it was up to the job (http://www.toolstation.com/shop/p67488) but it only lasted four cuts and then it took 20 minutes to cut through the last one I needed to do today. Someone else on here claimed this was a good blade - did I just get a duff one?
I didn't press hard (used no more than the weight of the machine).
Have read that I should have soaked them first, so I was cutting them dry.
Is there a better cutting disc to buy? I need 230mm diameter with 22.2mm hole.
Should be fine. I didn't find the firebricks particticulay hard, but they're very abrehsive. Cutting wet cools the blade and will give you a bit more life but 4 cuts is daft with a diamond blade. Dry cutting also creates a ton of dust so make sure you have a dust mask on! Try the Erbaur balade from Screwfix would be my recommendation.
In any moment of decision, the best thing you can do is the right thing, the next best thing is the wrong thing, and the worst thing you can do is nothing. Theodore Roosevelt
Like Lamby I found my firebricks easy to cut as if they were a very soft material but they ate up a 115mm blade in my small angle grinder although I'm not sure of the quality as it came with the machine when I bought it, haven't had a problem with my 9" though and I've cut at least 60 bricks today ( twice each!!) and there's still plenty of life left in it!
G'day Diamond blades are industrial diamond bits imbedded in metal. They can glaze up and with no new diamonds on the surface don't cut. You have to wear the metal back to get new diamonds on surface to get it cutting again. Problem is there are 2 distinct types. One type responds to cutting harder material so try cutting a piece of old concrete. The hard stones will restore the surface. These are usually the dry type. The one I have, and still have. The other responds to something softer so a couple of cuts on a piece of sandstone or a soft house brick will do the job. They definitely shouldn't wear out after a few cuts Regards dave