On Facebook, I posted this question: “Best angle grinder for cutting thick plaster?” Thank you to those who answered that question. And thank you for the other advice. But – with the exception of a RotoZip – I already tried it. Or I am not going to, following expert, on-site advice.
In short: I need to rerun a lot of electric to replace wires currently buried in plaster (in no conduit) on exterior walls – real, old, adamantine plaster over brick. I had two electrician friends over. I had an expert plaster guy over – a guy who does lots of work on old plaster, not drywall. We’re all on the same page.
Instead of hammer drilling multiple channels into the plaster and brick to run electric and conduit to meet current NEC code, we’re going to abandon the existing wire (and hall sconce, because it’s no longer necessary) and fish new wire from the panel up through the interstitial spaces in an interior wall, then come across the ceiling to pop up to the second floor for plugs on an exterior wall. There, I’ll have to remove the baseboard and drill out a small amount of brick to bury conduit; but the plug location is already cut into the baseboard (dammit), so I suppose I’ll put new outlets in the same spot. One less plaster repair, I guess.
I’ll also run new Romex to two interior walls on the second floor at the same time (at the moment, they’re on the same circuit; they won’t be). But that’s not quite as much trouble.
So, I have to take down enough plaster and lathe on the ceiling to get at the necessary joists (to which I’ll attach the new Romex) across the width of the hall – and to remove the old gas line that’s poking out. (I might relocate the chandelier to there – that must have been a fixture location 100 years ago.)
I have tried an oscillating multi-tool with a carbide grout blade. I have tried scoring, scoring deeper…then deeper still, then “chiseling” with a sharpened flathead screwdriver between those lines. I have tried cutting it with a drywall knife … well, no. I skittered the knife across the plaster for 10 minutes. I swear I heard the plaster laughing. Or maybe that was the birds/bats/squirrels scuttling in the chimney…hard to tell.
With the new electric run, I’ll be able to finish the stairs. And, I’ll have properly grounded outlets in what will be the study – so I’ll be ready to build bookshelves and a computer desk there, instead of having to hang out in my ersatz study, where my computer currently shares space with the litter boxes. (It’s the former second-floor kitchen – the only room upstairs with grounded plugs.)
The plaster guy, after taking a look at the exposed edge of plaster (at the top of the stairs where I took out the 1950s-added floor in the open well), and hearing what I’ve already tried, recommended an angle grinder. He specifically said to not use a recip saw, unless I was prepared for a far larger plaster repair bill. And yes, there will be dust. There are also dust bunnies, and cat-hair tumbleweeds in my house. I’ll be fine.
When I’m done, he’ll come back and put the ceiling to rights, and patch the walls where necessary. His expert help will allow me to more quickly move on to the next task: tearing out the existing bath. My destruction skills are quite advanced.
So anyway…I’m going to buy an angle grinder. I’m leaning toward a DeWalt. The Makita is alluring, but more spendy.
And yes, that’s the short version.
Hi Meagan, sounds like you have a great plan. I use my old circular saw with a masonry blade to cut plaster, cinder blocks and bricks. And my angle grinder is a Dewalt, had it forever, works like a champ.
For safety, be sure to buy an angle grinder with a trigger, not a switch. I have the DeWalt and its great. That said, I’ve heard good things of the Milwaukee too. I’m not sure if Makita & Bosch make trigger operated grinders, but if they do I’m sure they’re good too.
Good luck. I’m vicariously enjoying your home rehab.
Having lived in half of a home divided up like this, I know what a work of mercy this is to make it whole again. Good luck whatever you end up grinding away with.
What is that dark line running across the ceiling to the right of the chandler – just curious.
That remains from where I took out the 1950s wall that used to divide the house into a two family. I’ll be getting that fixed, too, of course 🙂
I have used a small circlar saw. You can use panelin blade.
As a commercial construction I have found there is no difference in performance in the brand, they both preform the same. The blades however are important. Don’t be skimpy on those.
Yeah…learned that lesson when I was taking out walls. Cheap recip blades…bad.
Check around. I bought Makita. Three years ago I found a two-for deal at Home Despot on Makita 9557NB2 7.5 Amp 4-1/2 in. Slide Switch AC/DC Angle Grinder (2-Pack). Checkout the Tyler Tool site today (http://www.tylertool.com/makita-9557nb2-7-5-amp-4-1-2-in–slide-switch-ac-dc-angle-grinder–2-pack-/mktn9557nb2,default,pd.html?start=3&q=Makita%20Angle%20Grinder) they have the same deal. Split with some one, or do as I did, use one for DIY and one in the shop for rough carving chair seats.
Why not use a wall chaser? Cleaner, faster and with the right model you don’t have to chisel out the waste.
I have a Milwaukee but it was a gift;I’d never spring for such a great tool. There are many blades and discs out there but they all produce plenty of dust.
I love it when you use words like, interstitial. The closeted English major in me gets all tingly. AND before you crank up that angle grinder be sure and change the pre-filters on your respirator and put on a shower cap. You already wear glasses so they go without saying. Bon chance, mon ami!
Thank you. Would that it were real…
Maybe you could get the vendors to send you some, do a tool review and send them back after putting them through their paces. Not sure if this is unethical, but it sure would be a good test of the tools. If you don’t want to test the grinders then maybe the blades could be reviewed. Good luck.
That would feel wholly unethical to me, I’m afraid. And actually, my neighbor has a couple of them, so he’s letting me borrow one.
Well I thought that might be the case so I am officially requesting an article on carving garden gnomes out of a log using a grinder and since I know nothing about grinders and blades, a review of a couple might make a good side bar. Seriously, I like gnomes. Honest. 😇
Right after we run plywood cutouts to hold garden hoses…
We do this professionally. The best way to avoid excessive dust (which likely contains lead and other nasties) that will coat your entire house no matter how hard you try to prevent it is to use a plunge cut saw with a dust collector. We use Festool because they seem to have the best dust collection which is imperative for remodeling- especially when the occupants are remaining in the house during the process. Don’t under estimate the hazard posed by lead. The EPA gives homeowners a pass when they are doing they own work, but as professionals we would get in a lot of trouble if we were to spray lead dust around like that with an angle grinder in an uncontrolled manor. Just because it is legally ok to do so as an home owner, does not make it safe. Lead dust is currently proven to be a major hazard to children, but in a few dozen more years they will likely decide it is causing major issues for adults as well.