Beginner to Lime Plastering - Knocking Up

[DogEars]

I've got some premixed Rough Stuff in a plastic tub - I need to do some 'dubbing out' so I need a small amount 'Knocked Up' what do I have to do?

My guess is to scoop some out onto a board and use a shovel to, "mix it up a bit," is this correct?

Cheers,
Graeme.

 

[MatthewC]

I'm sure that more experienced practitioners will respond, but I reckon that you have to knock it up until it adopts a nice smooth (almost creamy) texture, and has a consistency where a big lump of it does not fall off your hawk when held upside down (over your mixing board!).

 

[MdB]

One of these,

one of these,

+ £30 SDS drill. A normal drill is geared too high and will burn out (which I've done )

Lime does like to be bashed around a lot before use. I've tried doing it by hand but it doesn't seem to have the same effect - at least not by the amount of effort I'm willing to put into it.

 

[DogEars]

OK, next question: what are the implications of insufficiant 'Knock' i was a bit impatient and had a go just knocking up a small amount on the hawk with a small trowl!! It just seemed like [quite wet] cement.

Am I in trouble :roll:

Cheers,
Ears (Graeme)

 

[robgil]

should be ok , its pre mixed so it should be ok with just a good mix to revive it. ive often let plaster stand for a day or two as i find its more workable when left for a bit. its rough? what are you using it for? also beware of frost , because lime sets slowly i8ts more prone to be damaged by frost if the water in it freezes.
to knock it back up , unless using a lot of it i put it on a board and just mix it with a trowel. kind of kneed it until you are happy that it will spread nicely , you can add water if its too dry or sand/lime if its too wet.
is there hair in it?

 

[FamilyWiggs]

should be ok , its pre mixed so it should be ok with just a good mix to revive it. ive often let plaster stand for a day or two as i find its more workable when left for a bit. its rough? what are you using it for? also beware of frost , because lime sets slowly i8ts more prone to be damaged by frost if the water in it freezes.
to knock it back up , unless using a lot of it i put it on a board and just mix it with a trowel. kind of kneed it until you are happy that it will spread nicely , you can add water if its too dry or sand/lime if its too wet.
is there hair in it?

Sorry to see your loss Rob, let me know if you find it again. :wink:

 

[FamilyWiggs]

Welcome DogEars (Graeme) to the forum.

Alternatively you need a big flat board on a workmate or other convenient level, and a trowel. And big muscles.

Whack it about on the board until it goes like what MdB said above. It's quite therapeutic - especially if you can watch someone else do it for you!

 

[robgil]

What ive lost cannot be found FW. Once its gone it gone. Still , the empty space keeps me light on my feet so its not all mushy brussels.
fOUND IT AGAIN.
bugger.
Edit - Bugger is not a bad word, especially if you know how to get around the forum censorship bad word editor thingy.

 

[DogEars]

In answer to a few questions above:

It's rough stuff.. I'm just dubbing out before the first coat for internal plastering. I'm decorating the bedroom in a mid 19th century cottage near Huddersfield, West Yorkshire. We have a little damp that's got a bit out of hand so we've stripped off some ridiculous plastic paint that the previous owner has applied [I'm guessing] to try to remedy the mildew problem. We've just fixed some issues in the Roof and improved ventilation and are hoping the [sympathetic, is that the right word?] decoration and repairs should improve the situation.

And yes it's got hair in it..!

Cheers,
Graeme.

 

[robgil]

Sounds like you have got it all under hand, if the plaster has got hair in it its best to fold it while mixing it , you dont want the hair to clump. I am not sure if as paddle drill type mixer will mix it without clumping it either. I have always been told the best way to mix large quantity's of haired plaster is in an old bath and trample it in.