Replies

1. 
   IanDG | Aug 01, 2004 06:50am | #1

   A masonry blade in a 4" grinder is what I used. There was minimal damage to the lathe and plaster but it was dust-city! I had a helper hold the vacuum tube as close as possible which helped but still a lot of masking off needed.

   IanDG

1. 
   LarryC | Aug 03, 2004 05:57am | #14

   Thanks to all who replied.  I appreciate your time and ideas.

   LarryC

2. 
   CPopejoy | Aug 01, 2004 08:13am | #2

   Fein multimaster.  It's the civilian version of a orthopedists plaster cast saw.  Use a diamond blade or carbide blade, when you get to wood lath, switch to the wood blade.  Slow, blades are expensive, and they don't last long.  But there will be no damage to the plaster.

    If the plaster is reasonably solid, try a standard Sawzall (3/4" stroke, non-orbital) and the new Lennox "plaster master" blade.  Just used this combo on a re-wire of a 1920s bungalow.  Worked really well, blade lasts and little damage (but the plaster was pretty well keyed to the lath).

   Good luck.

   Cliff   

1. 
   LarryC | Aug 03, 2004 06:00am | #15

   Thanks for your reply.  I appreciate your time and ideas.

   Larry C

3. 
   4Lorn1 | Aug 01, 2004 08:29am | #3

   I have had luck using a diamond blade in a four and a half inch grinder. You can cut through quite soft sand plaster/lath surfaces. The softest I have used a 3/16" masonry drill bit to drill around the perimeter to remove the plaster and a new utility knife blade to score and snap the lath.

   When trying to install electrical boxes on dead soft walls or ceilings I have sometimes resorted to injecting thinned white glue into any cracks between the lath and three coats of plaster. It takes time to inject and you have to wait overnight for the glue to take but it really firms up the plaster.

   To give the box structural strength I wet the interior of the wall and, after mounting the box, I fill the cavity with spray foam. Once completely filled and solidified, overnight, I remove any of the the overfill that fills the box and finish trimming out the box in normal fashion. Even in sponge soft drywall, scarcely sturdy enough to physically hold the weight of a steel cut-in box, this lends a remarkable amount of strength.

1. 
   JerBear | Aug 01, 2004 03:22pm | #4

   I'm impressed with your technique.  I was a restoration - conservation plasterer for a large company out of NYC for a few years, and the injection of a glue into the plaster between the lath and the keys of the plaster is exactly what one does to arrest and mend any more separation.  I still have the large hypodermic needles we used and a gallon of the Roplex glue which I use from time to time.

   By the way, if it's weak plaster, a diamond wheel on a grinder or a saw is the way to go...just cut the plaster and clear it out, then a fine tooth blade on a jig saw for the wood .  I"ve also had good luck with a 1/4" tile cutting bit on a Roto Zip.

1. 
   DANL | Aug 01, 2004 04:31pm | #6

   Yeah, I like Roto Zip too. Lot's of other uses for one and they aren't real expensive.

4. 
   Shoeman | Aug 01, 2004 03:48pm | #5

   I like a diamond blade on a 4" grinder for larger holes - a plaster/tile bit in a roto zip for small holes

   zip wall area off and have a fan blowing out a window or door if possible

   Don't forget the dust mask

1. 
   LarryC | Aug 03, 2004 06:01am | #16

   Thanks for your reply.  I appreciate your time and ideas.

   LarryC

5. 
   RichColumbus | Aug 01, 2004 06:02pm | #7

   4" or 4 1/2" grinder with diamond blade... better than duct tape!!

   Gotta agree.  I use that bugger for so many things... and to think I resisted buying my first one! 

   The diamond blade will work once you get to the lath... but I would not recommend.  Change out the blade once you are through the plaster.

1. 
   LarryC | Aug 03, 2004 06:02am | #17

   Thanks for your reply.  I appreciate your time and ideas.

   LarryC

6. 
   dinothecarpenter | Aug 01, 2004 06:33pm | #8

   Hi Larry. Remove some plaster and find out where is the studs. It all depends as to how big is the cabinet and how you will trim around the cabinet.

   If you can get the cabinet to fit between the studs then is EZier.

   Draw the opening, (taking in consideration the trim and the new studs if needed) and screw 1x6" pine on the outside of your opening. Then use a sawzall to cut your opening. If you screw the 1x6"  on the studs is better. If not have someone applying pressure on the 1x6" while you"re cutting.

   The Idea is to eliminate the vibration. After you screw the 1x6" you can even score and remove the plaster with hand tools.

   It all depends to where is the studs, how big is the cabinet, what size of molding etc.etc. Some times moving the cabinet few inches or use another size cabinet goes a long way. Best thing is to open a section before you start and Take a .....look 

   YCF Dino

   
   

   ---

   Edited 8/1/2004 11:38 am ET by YCFriend

1. 
   LarryC | Aug 03, 2004 06:03am | #18

   Thanks for your reply.  I appreciate your time and ideas.

   LarryC

7. 
   PaineB | Aug 02, 2004 12:47am | #9

   I use an angle grinder w/ a diamond blade like the others are suggesting but wanted to pass along my method for controlling the dust catastrophe turning on an angle grinder inside generates.

   I got a large clear plastic bowl, available at discount stores, and cut a hole that permitted me to pass the cord and the back half of the grinder through.  The hole is big enough to move the grinder in and out and I used duct tape and a toilet tank gasket to seal the connection, this isn't perfect but good enough.  Close to the rim, I drilled a hole the right size to jam my vacuum hose into.  For the vacuum to work, air must be permitted into the bowl. So I bored another hole at the opposite end of the vacuum hole. I taped a section of a paper 3m dust mask over that hole to stop the dust from escaping.

   Since the switch is now on the wrong side of the bowl, I turn the tool on before placing the bowl against the wall and use a switched outlet that I control with my foot. If you are using a vac with the built in outlet, you can just turn that on and off. 

   I then place the bowl against the wall and start cutting. Even with a powerful vacuum, it gets pretty murky in there so I use the edge of blue tape to mark the cut line.  I wouldn't use the method to cut mortise and tenons but it does keep the EPA from shutting down your job site. 

1. 
   dinothecarpenter | Aug 02, 2004 03:27am | #10

   Why create the dust in the first place?

   After you stop the vibration (see previews post) remove 1"-2" of plaster with a hand tool. Wet the exposed lathe and CUT.

   YCF Dino

   Edited 8/1/2004 8:33 pm ET by YCFriend

1. 
   PaineB | Aug 02, 2004 02:34pm | #11

   Your point about vibration is well taken. I have faced a number of situations, however, where the plaster is unkeyed from the lath in lots of places and I needed to be much gentler than hand tools could be to make the cut.  In delicate places where I don't want the job to expand on me, I make 2 grinder cuts within inches of each other, remove the plaster and use plasterweld to glue the lath and plaster at that point and cut the lath after it dries.

1. 
   dinothecarpenter | Aug 02, 2004 03:49pm | #12

   Morning PaineB.

   If you need to be more gentler use a cushion behind the 1"x6" .Rigid foam insulation or Styrofoam can do the Job.

   After you secure the perimeter you can brake and remove the plaster  with an ax type hammer or (drywall hammer)

   The plaster weld is a good idea and you may want to use it before you remove the 1"x6".  It can only help.

   YCF Dino

1. 
   PaineB | Aug 03, 2004 01:28am | #13

   hey there YC,

   I will give your method a shot. I certainly agree with your earlier suggestion that one should first learn what is in the wall before you become dissapointed by existing conditions. 

   It occurs to me that we may be talking about different scenarios. The 1937 era plastering, mentioned in the original post is different from the hundred year old horsehair plaster on wood lath that I have learned to fear here in Brooklyn. Screwing the 1 by 6 clamp you suggest, into a stud would usually be okay, but when the stuff is really brittle, I would be inclined to take your idea of applying pressure by using lengths of wood cut to cram the 1 by 6 from the opposing wall. 

   I should mention to any who might have been interested in my salad bowl vacuum gizmo that one can buy tools set up to do this ready made. Bosch makes one, originally designed for tuck pointing, I believe. I think Metabo has one as well. The only real advantage to my system is that you actually see what you are cutting and I haven't bought a second grinder, only created an accessory for about ten dollars. Okay, I admit I spent a weekend making it job site ready. Is time really money?  

2. 
   LarryC | Aug 03, 2004 06:04am | #19

   Thanks for your reply.  I appreciate your time and ideas.

   LarryC

1. 
   JeffBuck | Aug 03, 2004 07:42am | #20

   Don't any of U people own a circular saw?

   JeffBuck Construction, llc   Pittsburgh,PA

        Artistry in Carpentry                

1. 
   NickNukeEm | Aug 03, 2004 12:33pm | #21

   Ditto.  Coupled with a dust mask/respirator.  And goggles.  No, face shield.  And throw the $7 blade away when done. 

   I never met a tool I didn't like!

2. 
   dinothecarpenter | Aug 03, 2004 09:51pm | #22

   After you remove the plaster,

    you can use the circular saw to cut the lathe.

    But you still need a sawzall to finish the Job.

   It may take few more minutes to use only a sawzall

   But you save on clean-up and the blade.If you have many openings, then the circular saw can be the first tool to use.

   YCF Dino

1. 
   JeffBuck | Aug 04, 2004 06:52am | #24

   at the rip old age of 37 ...

   I've spent the better part of the last 30 years cutting holes ... big and small ...

   thru plaster new and old ....

   Circular saw all the way .... first time the sawzaw has a chance to grab tight ... the whole wall is needing new plaster!

   For cuts that involve a corner ... hammer and brick chisel ... or surgically pound in a wonderbar ... to make for a nice neat cut line that relieves the pressure and releases the opposite wall.

   btw ... you can reset the circular saw a little deeper after the plaster is cut thru ...

   I heard somewhere they work for wood too?

   JeffBuck Construction, llc   Pittsburgh,PA

        Artistry in Carpentry                

2. 
   dinothecarpenter | Aug 04, 2004 08:52am | #25

   Hi Jeff.

   You may want to see the previews post about securing the plaster before you start any removal of plaster etc. etc.

   Yes.the circular saw can do the job faster and with less damage to the plaster. If you can use it. (dust,debris,close to the corner or the floor)

   But You don't have to cut the plaster.Just the wood.

   BTW. The circular saw is the no 1 tool.

   And btw again it was first invented to cut sugar canes.

   Something to think about it.

   See you.

   YCF Dino

3. 
   JohnSprung | Aug 06, 2004 02:25am | #28

   I use a diamond blade in the little battery Makita circular saw for most of the cutting, but just thru the plaster.  You don't want to burn the diamond blade against the lath.  With the shop vac running, dust isn't bad at all.  The Makita's RPM's are much lower than an angle grinder.  For the ends of the lines where the Makita won't reach, I finish up with a diamond blade hand grout saw. 

   With the final lines cut, I make another cut parallel to one of them maybe 2" away in the area to be removed.  That makes a starting point for breaking out the plaster to get rid of.  When the plaster is out of the way, I change to a wood cutting blade in the Makita, wire brush as much crud off the lath as possible, and carefully cut the lath.  Again, a small hand saw finishes up where the Makita won't reach.  It's safer and gentler than a sawzall, and for the little bit of cutting there is to do, easier than schlepping the sawzall.  One of those handles for a sawzall blade would be ideal for that -- gotta remember to buy one some time.

   If the plaster is really weak, there are two possibilities.  Either take out a strip 2" wide to make access for getting glue in there, or just fuggedaboutit, demo the bad parts, and figure on re-plastering later.

   The important point is that demo isn't just smash and bash.  You can save yourself a whole lot of work just by not effing stuff up doing thoughtless demo.

   -- J.S.

8. 
   Scooter1 | Aug 04, 2004 12:30am | #23

   I use a Makita 9.6 volt cordless circular saw, and score the plaster first.

   Regards,

   Boris

   "Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934

9. 
   Clay | Aug 04, 2004 09:55am | #26

   After reading all these posts I have to say I could gave ripped out the plaster put the door in and replastered quicker than most of these techniques.  Why worry about a little plaster damage when it is so easily replaced?  I'd use the 1x4 framing and sawzall technique and then simply repair any damage that does occur.

1. 
   IMERC | Aug 04, 2004 10:01am | #27

   Why you guys haven't learned the super short sawzall blade and duct tape trick is beyound me...

   Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming....                                                                   WOW!!!   What a Ride!

2. 
   PaineB | Aug 08, 2004 01:49am | #29

   I have to disagree. Whether you use method A, B, or C, if you can make your opening without getting too involved with the adjacent areas, then you save yourself trips back to get the area ready for paint. As Elvis Costello says, it is the small humiliations that your soul counts up