I need Help : Cutting 152mm Hole in to Drywall

[Rockingit]

I take it that you've had a look from above??

 

[DefyG]

Why do my posts keep getting deleted?

 

[ferg]

I think I've come across the material you have described before and it's a a pain.
It's like low density MDF used in what we call Swedish houses, built I think in the 60's and 70's in this case it was covered with hardboard.
It will clog up a holesaw in no time.
I used a multitool to cut it as a jab saw is next to useless.

 

[nicebutdim]

I think I've come across the material you have described before and it's a a pain.
It's like low density MDF used in what we call Swedish houses, built I think in the 60's and 70's in this case it was covered with hardboard.
It will clog up a holesaw in no time.
I used a multitool to cut it as a jab saw is next to useless.

Homes constructed from ceiling tiles?

 

[AngelLaHash]

i am worried the teeth are getting Clogged up, (this sint typical Drywall it looks more like Cardboard mushed up)
its not hitting joists for sure...
so the Pilot Drill bit is making the hole in the middle Bigger as its a Drill , also the Hole saw is big any wobble it grips one side and nothing else where it ripps out of my hand.

I am wondering about Pilot Drill bit and a 70mm Hole saw and then 152mm Hole saw all on the same unit.
Pilot guides the 70mm hole say in and then the 152mm hole saw is guided in by the 70mm hole saw (would mean the 70mm hole saw would need to be a bit Bigger.)
I think this would stop it from Wobble. As i would have a Center hole that is 70mm .giving me 41mm ever side of it (82mm)

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nicebutdim
This is a Bathroom Module, so its Metal and Plasterboard. there is no Joists in the way as i have the Ceiling in the Floor before its put in to place
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ferg​

This stuff is blunting the blades and that makes it worse as they expect me to cut with them and that will ADD to the chucking me off and Damage... when i complained about it i place it on my Wrist , sharp but not that sharp it cuts in to my skin. They got this board because it cheap and comes in ANY SIZE (i say any size they had a theory of using it on Wall, one board one wall so you can picture the sizes.. and you can also picture how hard it is to move without breaking and the weight of it. Managerment Ideas)
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DefyG​

I dont know why the post getting deleted, but i do want all your INPUTS
tob e frank and my name isnt frank.. This maybe one of the best Forums ive been on.
Active and helpful (some forums do get very drag queen bitchy )
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SJD
Nothing in the way, i can get the Ceiling before it goes on.
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FatAlan​

As said it doesnt feel like Plasterboard (some of Mush Carboard feel to it) [I used to work for British Gypsum for a bit and know what Plasterboard taste like ]
Couldnt of hit a Joist as done this a few times already and its always a pain. I also can get the Ceiling before it goes up so i can see the other side.
If i dont force it, it seems to wobble off. I drill in 70mm holes for Downlight and NO problem (i am using a different make of Hole Saw) [ as the company brought 76mm and i didnt like the sides visible so i reduced it to 70mm like the dam box these lights came in said!! i found these 70mm hole saw laying about the place at work, nice sharp teeth too, so i took them )
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loz2754
I will try and use a Lower Speed, never really drilled holes this big before..
only with a SDS in to Brezze blocks while hanging off the scaffolding
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pc1966​

I may have to bring my own Dewalt drill in (If i can put it back together) or get a new one
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Pretty Mouth
I did think about doing that, i do have a few hundard to do .. at this rate i may have to find a guy to do them all for me.
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loz2754 & James​

i will try with less torque and see if there is any way to improve it

 

[DefyG]

Might be better off with a carbide or diamond tipped holesaw if not your usual dry wall board.

 

[Rockingit]

I think I know exactly the stuff you mean - called insulating board (I think) and it's like the stuff you get on pin boards for thumb tacks. I had a previous relative buy an early version timber frame house that used this stuff and when we came to decorate (it had been covered in woodchip liner) it was so bad he decided to bite the bullet and we ripped it all out and replaced with standard gypsum and skim!!!

It will cut with a recip jigsaw and a course blade - and for god's sake make sure you wear a mask!!