# Forum Home Renovation Plastering  Internal wall corners and square set ceiling - paper tape vs internal metal angle

## solcom

What is better to use when plastering internal wall corners and square setting ceilings, paper tape or internal metal angle? https://www.bunnings.com.au/knauf-2400mm-internal-90-degree-plaster-trim-angle_p0730709 
Also, I will be square setting a ceiling that has had 55mm cornice removed, the sheets dont butt up against each other and there is a gap of approx. 35mm between sheet and ceiling joist. What is the best way to do this, should I cut strips of plaster 30mm wide to fill the gap and then use paper tape or metal angle, is there a wider tape or angle available? 
I normally use paper tape on everything, but when I visited a plasterboard supplier, the guy was talking about using metal internal angle for square setting ceilings, easier to trowel a straight line?

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## phild01

I much prefer the internal profile you show as it gives a crisp flawless line, especially for a ceiling. 
Recently I had the same problem you have.  I don't think just putting in strips of plaster is sufficient so I back blocked as best I could with either paper tape or thin ply, as much as I can remember (took a bit of delicate finger work too). I then filled it flush with the strips, or just bogged it where the metal internal fully covered the gap.  It all worked out perfectly in the end.

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## OBBob

Wish you could different angles other than 90 and 135 degrees ... I need closer to 115 degrees for a wall ceiling junction.

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## phild01

> Wish you could different angles other than 90 and 135 degrees ... I need closer to 115 degrees for a wall ceiling junction.

  Not sure but maybe the plastic versions work better for this.

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## OBBob

> Not sure but maybe the plastic versions work better for this.

  Thanks, yeah I think either option may pull all over the place rather than staying straight. Probably be the manual option. Perhaps a sheet-metal shop would bend the 135mm angle back 20 degrees? Now I'm really over-thinking it!!

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## Sir Stinkalot

Our extension has just been plastered and they used the metal angle for all corners and the square set ceilings. 
I did notice when painting the ceiling that the flushing didn't go all the way into the corner junction with the very small radius of the angle still showing. After painting it gave a very clean junction.

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## Spottiswoode

I had some reasonable success opening up a few bits of metal angle. Placed it on a hard smooth floor with the spine up this way ^. Then just presseed it down hard putting a bit of framing timber on top, it sprang open a bit. Sections w ere only about 1.5m long though.

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## OBBob

Thanks. I may have to experiment! 135 degree may pull into the corner with enough fixings. I shall see when I get to that point.

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## phild01

My room has a 72 degree ceiling internal and I resorted to paper tape for that one.

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## OBBob

The other trick is to score and fold the plaster sheet along that join ... but everything has to be fairly straight and you need help to lift a sheet that cut.

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## phild01

> The other trick is to score and fold the plaster sheet along that join ... but everything has to be fairly straight and you need help to lift a sheet that cut.

  This is one I did the opposite way:

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## OBBob

Work of art. I agree it's worth the effort to save having to do another joint.

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## solcom

Thankyou to everyone for your comment, you have given me so much helpful advice.

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## phild01

> Work of art. I agree it's worth the effort to save having to do another joint.

  Thanks, certainly was worth the effort.

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## solcom

What is the correct way to install an internal angle, should I screw it in, then apply base coat over it, or can I apply base coat first and then embed it in base coat without screws? https://www.bunnings.com.au/knauf-2400mm-internal-90-degree-plaster-trim-angle_p0730709

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## solcom

> What is the correct way to install an internal angle, should I screw it in, then apply base coat over it, or can I apply base coat first and then embed it in base coat without screws? https://www.bunnings.com.au/knauf-2400mm-internal-90-degree-plaster-trim-angle_p0730709

  Just found this useful link which has a summary of different methods for external angles, can I use the same for internal angles?   Plastering Diy Tips installing plaster metal external, beads and angles

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## OBBob

That's Rod Dyson's site, he's on here.

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## phild01

The basecoat will hold without fixings but problems can happen when things are not quite straight and you may need to force the profile into position.  when this happens I use a small wallboard nail to correct it.  This can be tricky as the nail head can be struck by the finishing broad blade.  Best to test that out before applying more coats.

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## Spottiswoode

It's probably frowned upon in tradie world, but in DIY world I've used some temp screws until the base coat sets, then removed them for the top coat

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## Rod Dyson

I usually pre-fill any gaps, scrape back flat, then if the gap is more than 20mm wide I will run a paper tape flat along the gap.   
I will base coat the metal internals in.  A lot of guys use staples but I find I get a much better job with just base coat.  But there is a method I use to get it right.  I butter up the angle like cornice.  Set it in place and wipe back the excess very hard along the metal NOT filling it in.  My blade is not running along the lip but the metal itself.  If a spot needs it I will put a temp screw in to just to hold the metal flat.  
I use an accelerator to make the plaster set off very fast.  I do the entire process ready for top coat with one mix for a section up to 8 lm.  When I fill in the large gaps if there is no backing I feed the plaster over the back of the sheet let it over hang a bit and let it set.  This gives me enough backing to fill it with another coat. 
Sounds easy but, requires a bit of nous to know what you can and cant do to get it right.  Plus you need to be able to get the plaster to set in about 3 to 5 minutes per "side" mix.   I call the side mix what I pull out of the bucket onto my hawk, That is what I add the accelerator to. 
Cheers Rod

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## OBBob

Not sure where to buy it (except online) but you can get a magic plastic bead that is flexible to suit strange angles. Just noting in case anyone else has the issue with angles between 135 and 90 degrees. I managed to cut and fold my main long angles (yes I'm please with myself  :Smilie:  ), so I only have a few small runs that I'll be able to do with paper tape or adjusted metal angle.

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## Spottiswoode

In pulling apart my walk in robe I've discovered the corners have been set with what looks like a combination of thin metal and paper. The metal seems to be really flexible and the paper appears to be to make the joint wider. I could easily fold up sections of this stuff to fit in the bin, but couldn't cut it with a Stanley knife nor tear it apart.

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## OBBob

I think at one point in the past there was a metal laminated with paper sort of product. Perhaps that?

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## Spottiswoode

> I think at one point in the past there was a metal laminated with paper sort of product. Perhaps that?

  Could be, seems to be a good compromise between a rigid corner and minimum impact/ maximum conformity of the feathered edge.

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## joynz

CSR has the plastic angle and the paper angle with a metal spine ( and may have more options now - been a year since I was there)

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## OBBob

> Could be, seems to be a good compromise between a rigid corner and minimum impact/ maximum conformity of the feathered edge.

  Metal / paper...      
Flexible plastic...

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## joynz

My metal and paper version looks quite different - much narrower without the 'flaps'.

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## phild01

I can't see the pics :Confused:

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## OBBob

> My metal and paper version looks quite different - much narrower without the 'flaps'.

  Yeah, just a google example ... not sure it's that common any more?

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## OBBob

> I can't see the pics

  Sorry.  :Frown:

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## phild01

> Sorry.

  Second one is now there, strange.

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