External Hard Angle Chimney Stack

[Hodgo]

Hello fellow plasterers.
Im re-rendering a single chimney stack on an old property which is roughly a meter wide. I want to keep the old look of the existing work so i've opted against using angle beads as im sure the finish wouldnt look right. The finish on the external angles isnt bullnose and its not a straight hard angle just kind of free hand looking.
Ive hacked off existing render, meshed and put a bellcast above the lead flashing. I have applied the scratch coat free hand on the angles.

The question is, im unsure of how to rule and float the faces of the stack while achieving this "old looking" hard angle?
Should I fix timber batons to plumb and rule one four faces of the stack, then work around each face while still wet and float it up as I go?
OR render two opposite faces with batons then fill in the other two while still wet and use a float to work the angles?

Sorry about the confused essay its harder to explain than I thought!

Many thanks Nick

 

[Micilin]

Coat it all up then hold a batten in one hand and float with the other at the angles, returning the batten as you go.

 

[Hodgo]

Thanks for quick reply Micilin,

Would you let the render pick up a bit first so the timber doesn't pull the gear off?

I'm guessing it would if it was too wet?

 

[roughcaster]

This is where real skill comes in. As Micilin says, you're render coating all the four faces at once, but "not" fixing any battens. Once you've coated the chimney stack, the batten is "held" against the each wet corner, and "returned" as you rub up. Slide the batten "away" from you, when you want to remove it. You would repeat this a few times as the render tightens up. When you get to the final stages of rubbing up, ""gently"" run the float down the square edge of each corner, just enough to give each edge, a slight "pencil round". Finish the whole thing off by rubbing over the render with a sponge. Dip the sponge into clean water, wring it out and rub the render gently in a circular motion. Clean the sponge regularly as you go.

 

[roughcaster]

When you use battens in this way to form wet returned corners,, you would let the render pick up a little, but done correctly, you could still use a batten on wet render without pulling any off. You would always make sure the batten was clean and "wet". Run a wet brush over it each time, just before you use it, and keep it wet/damp. Never use a dry, dirty batten. The batten will more or less hold itself in place on the render, but when you're ready to remove it, carefuly slide it up and away from you, at an angle. Don't "pull" it away from the render, or you will pull the wet render off. Takes a fair bit of practice overall, but give it a go.

 

[Hodgo]

Ahhh I see, I've got it, thanks for the advice guys very much appreciated. Easy when you know how eh !!!!
Sounds like fun especially as the the scaffolders have made it so easy to get around!!!

 

[Hodgo]

I was just going to ask about the timber but you got there before me roughcaster.
Thanks again

 

[roughcaster]

No problem Hodgo,, It's also a very theraputic job to do,, you'll enjoy it. Watch out for the weather though at this time of year though, (especially frost),, rain etc.

 

[Micilin]

This is where real skill comes in. As Micilin says, you're render coating all the four faces at once, but "not" fixing any battens. Once you've coated the chimney stack, the batten is "held" against the each wet corner, and "returned" as you rub up. Slide the batten "away" from you, when you want to remove it. You would repeat this a few times as the render tightens up. When you get to the final stages of rubbing up, ""gently"" run the float down the square edge of each corner, just enough to give each edge, a slight "pencil round". Finish the whole thing off by rubbing over the render with a sponge. Dip the sponge into clean water, wring it out and rub the render gently in a circular motion. Clean the sponge regularly as you go.

I should have waited for a proper answer!!!

 

[Hodgo]

Tell me about it the scaff has been up a month and I've managed to hack off, mesh and scratch coat it, its been that bad and now the snow!
This is definitely my last external job for the winter