Replies

1. 
   DanH | Aug 22, 2013 11:00pm | #1

   A lot has to do with using the correct blade.  If you're cutting plaster you should probably use an abrasive blade, but drywall you can cut with a coarse-toothed blade.

   But there are many tools for cutting plaster/drywall.  A Rotozip style tool is often a good one to use.  Or a simple jab saw.

2. 
   calvin | Aug 23, 2013 05:31am | #2

   David

   Blades, no matter what kind, are usually marketed / labeled as to what they can or should be used for.

   If demolition-a sawzall with a plaster cutting blade-no set in the teeth and a shorter blade.

   For the multitool, I've used their diamond wheel and also the abrasive disc (grout blade) with pretty good success.

      Drywall will dull a sawzall blade or multitool blade, but plaster will do it quickly.

3. 
   rockinroger | Aug 23, 2013 07:09am | #3

   Cutting Plaster

   I do a lot of work in New Orleans on old houses that have plaster walls & ceilings.

   I use my 4" angle grinder with a diamond blade.Like butter, baby; but it is extremely important to secure the area around your cut by screwing the plaster to the lath with drywall screws. Same thing with using a Swazall. If the plaster is not secured to the lath, the vibrations from either tool will knock off more plaster than the area that you intend to cut.

   Draw the area on the wall, & just outside the lines put screws in EVERY lath. If you hit air, simply go up, or down a 1/4" or so, and you should hit lath.Do this gently, so that you don't start cracking the plaster right away. It helps if you go just deep enough to go through the plaster, about an inch or so wide, chip out the plaster & you will see the lath. Go slow to minimize vibrations.

    If the area is big enough, I use my circular saw to plunge cut the lath; less vibrations, (going slow, mind you) & a nice clean cut.

   I also use my circular saw on drywall (set to depth) if  speed is of the essence, & dust is not a concern. Definitely use a respirator, satety glasses, cap.& long sleeves, because you'll end up looking like Frosty the Snowman. Good luck!

1. 
   netrate | Aug 23, 2013 11:20am | #4

   I can see the back of the plaster and know where the seams are, so that is good, but yes - part of the problem is the shaking and vibrations make a mess of the rest and sometimes even long cracks.

   I wonder if I should come at the drywall from the back since I can see the seams?

   I was using a angle grinder, with a bi-metal blade - worked great, but the dust it kicked up lastly for hours.  I don't want to do that again.  I was also using a dremel oscillating blade with Drywall/wood blade, but like Calvin said, the drywall blade is great, but soon dulls.

   What I was doing was cutting the plaster first with a exacto knife.  Making a series of long cuts over and over again to get a straight line.  Then I was going in with the oscillating drywall blade to make the final cut.  Make s a great straight line, but the blades are like $8 bucks a piece and after doing one 4 foot wall, the blade was dulled to nubs.

   I have a sawzall, but haven't tried it for fear of the vibrations causing more problems.

   Which type of blade did you use with your circular saw?

1. 
   DanH | Aug 23, 2013 06:39pm | #7

   Note that if you can see seams on the back it doesn't mean it's drywall.  It could very well be plaster on rock lath or blueboard.

2. 
   netrate | Aug 23, 2013 11:24am | #5

   I just replied and it said I replied, but I can't see my post!

3. 
   netrate | Aug 23, 2013 11:24am | #6

   I just replied and it said I replied, but can't see my post!

4. 
   netrate | Aug 23, 2013 07:11pm | #8

   It is the plaster on rock lath, yes you are right.  I am going to buy a grouting blade and see if that works.

1. 
   calvin | Aug 23, 2013 11:44pm | #9

   David

   Plaster blade in a sawzall is what I would use.

   in my hands, accurate, quick, keep the shoe tight to the wall and zip through it.

   Plaster blade!