I need Help : Cutting 152mm Hole in to Drywall

[AngelLaHash]

im not sure where to post this.. and I need help
[ I posted here because i guess Heating systems may need a hole this big , and this is the only only site i've had that has been positive reaction to a problem ]

my Work (who dont dam help just get "JUST GET IT DONE" ) want me to drill a 152mm hole in the Ceiling for a Air Vent in a Bathroom.

They have given me a 152mm Hole saw and MAKITA DHP484Z 18V LXT BRUSHLESS 2-SPEED COMBI Drill
Its chucked me off the step up a few times.
Also tried to cut the holes while the Drywall is on the Floor and then put up but it just Agressive and i am black and blue over my hands
the Hole Saw clogs up quick and stops forcing the Drill to nearly pull my elbow out
if i dont have it pressed down it wobbles a lot and scatches outside the 152mm Area
some times it makes the Center hole bigger again wonders the Hole Saw then
Also have snapped one Center Drill bit so far.
[ NB i call it Drywall but it feels and Acts like Fiber Cardboard Mushed up together .. not a Gypsum dust feel to it ]


I have no idea what to do and its is Hurting me a lot, i've screamed at my manager .. maybe on the edge of being Fired (if not being given some of the worse jobs so i will just quick and their problem goes away) When i complained about how Dangous it is the first time, my Manager told me to get my apprentices to do it .. im not putting anyone else in danager if i cant do it...

I need a better system, worse case i buy things myself and SHAME them (brought my own Screws in before because they didnt have any long enough and it stopped the job) Million Pound company with ZERO budget

Did find this but i cant hold the Drill close to my body due to the Hole being in the middle of the board......
Just wonder if i stood it up to be level with me and Drill in to it AND get a Hand Grip out (non of the drills have one on) maybe then it will be a bit more stable

 

[westward10]

I assume it has the centering drill bit fitted this should stop it drifting.
Do not put too much pressure on it let the saw cut without forcing it.

 

[James]

If the torque is twisting you to the point of pain or chucking you off the steps, can’t you turn down the max torque on the drill? Often it is a coller near the chuck.

 

[loz2754]

If it's a 2 speed drill make sure it's on the lowest setting.

 

[Pretty Mouth]

Draw a 152mm circle on the board with a compass (or improvised alternative), then cut it out with a jab saw.

 

[davesparks]

If it's a 2 speed drill make sure it's on the lowest setting.

Not sure about that, putting it into the lower gear increases the torque output and the OP is already struggling to hold the drill against the torque.

Higher gear and low speed may be more suitable.

 

[pc1966]

I found my Milwaukee battery drill has an electronic torque limiter, not a mechanical clutch, and when using a hole saw on a plastic duct box it would jam at times and the inertial of the rotor pull it from my hands. Using the clamp-on side handle helped, as did gloves to protect my knuckles a bit, but I really wished for a slipping clutch like my old (but rather feeble) Makita drill has.

 

[loz2754]

Not sure about that, putting it into the lower gear increases the torque output and the OP is already struggling to hold the drill against the torque.

Higher gear and low speed may be more suitable.

That's true, but to maintain a low speed using a variable speed trigger is next to impossible. Using a higher speed will wear out the teeth on the holesaw.
Low gear, and "torque" rather than "drill" setting, should get the job done.
Or, as suggested, try a different method. Perhaps a jigsaw even.

If your employer refuses to provide appropriate tools for the job to be done safely, refuse to do the job.

 

[FatAlan]

Do you mean a standard skimmed plasterboard ceiling? How thick is the plasterboard. I take it you haven’t hit a joist? As others have said, don’t force it, just use a small amount of pressure.

 

[SJD]

Do you mean a standard skimmed plasterboard ceiling? How thick is the plasterboard. I take it you haven’t hit a joist? As others have said, don’t force it, just use a small amount of pressure.

A standard plasterboard ceiling should take a minute or two at most and not be that difficult, so long as there are still some teeth left on the holesaw!

So I'd also wonder if there is something in the way - joist, noggin, steel, water tank ... ? I'd have drilled a 6mm pilot hole and checked in the loft that you have clearance for the large hole.

 

[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!!