plaster not going off

[doug boardley]

I told a plasterer not to leave his stainless trowel soaking overnight in brick acid as it would "pickle" it and send it rusty, he did, and it did:smilewinkgrin:

 

[faithhealer]

wow thanks for all that, going to work now to check on my plaster if anybody remembers that lol

still waiting for a reply on the plastering forum, some of you could pitch in now and again to get the ball rolling

 

[jay]

don't think the cement will work he needs to add plain old table salt to the mix that will get it moving



Ajax ever tried brown sugar on fresh concrete (driveways mainly) to acieve the pebble effect works a treat:8:

 

[Ajax123]

don't think the cement will work he needs to add plain old table salt to the mix that will get it moving



Ajax ever tried brown sugar on fresh concrete (driveways mainly) to acieve the pebble effect works a treat:8:

never done it with brown sugar but I have done it using other retarders. MOst old fashioned cement retarders are sugar based - usually based on plant sugars and wood resins. They are a bit more advanced and synthetic these days cos chopping down all the trees to stop consrete going off too quickly was considered not a great idea.

I guess with the brown sughar you would sprinkle it on and trowel it in then wash it off the following day like we currently do with exposed aggregate concrete driveways. Refined (white) sugar would do the same thing but would probably have a much deeper effect.

Never come acroos the table salt idea though. Will probably have to mix some up and try it now.........

 

[doug boardley]

so, ( sorry for deviating Faith😳) if I lay my patio concrete slad, sprinkle sugar over it, it would leave some of the aggregate exposed? and then I could get a polisher and polish it off to leave a terrazzo effect?:daisy:

 

[faithhealer]

oh well, plaster had gone off this morning and finish coat was drying nicely when I left tonight phew
now back to the chemistry lesson...

 

[White Room]

I told a plasterer not to leave his stainless trowel soaking overnight in brick acid as it would "pickle" it and send it rusty, he did, and it did:smilewinkgrin:

Cleaned a carbon trowel in my early years with brick acid:yikes:

 

[DHTiling]

wasn't in a position to argue as he's been in the game for 30yrs

Nobody has mentioned the old Ettringnite failure..???.. portland cement and gypsum..

 

[faithhealer]

Nobody has mentioned the old Ettringnite failure..???.. portland cement and gypsum..

As I said dave, thats what I thought first off but as I said didn't like to argue the point 'til I had more info. Printed this thread off today and gave it to him. Still waiting for a reply on the plasterers forum by the way, much traffic on there these days?

 

[jay]

never done it with brown sugar but I have done it using other retarders. MOst old fashioned cement retarders are sugar based - usually based on plant sugars and wood resins. They are a bit more advanced and synthetic these days cos chopping down all the trees to stop consrete going off too quickly was considered not a great idea.

I guess with the brown sughar you would sprinkle it on and trowel it in then wash it off the following day like we currently do with exposed aggregate concrete driveways. Refined (white) sugar would do the same thing but would probably have a much deeper effect.

Never come acroos the table salt idea though. Will probably have to mix some up and try it now.........

you mix raw sugar and water fairley strong then with a eeeerrrr back pack spray unit (garden spray unit) apply it to the surface like you would normaly with exposed ag concrete:8:

 

[jay]

so, ( sorry for deviating Faith😳) if I lay my patio concrete slad, sprinkle sugar over it, it would leave some of the aggregate exposed? and then I could get a polisher and polish it off to leave a terrazzo effect?:daisy:

nah just get concrete supplier to use pebbles ( little roundish rocks ) instead of agregate then you can wash the top of or just get it polished looks neat:8:

 

[Tecnik2000]

I had a plasterer come in to plaster a wall today. the wall varied from 'down to brickwork (Looked damp if I'm honest) to new plasterboard. my plasterer said that a handful of cement speeds up the drying time of (bonding) plaster!! Anyway, first coat of about 10/12mm didn't look as if it was drying (about an hour) so he put another 10/12mm on and left it. Still not setting when I left later on. Checked the 'use by dates', bonding ok but cement well out' Will I be hacking it off tomorrow do you think lads?

I'm slightly confused ,you used the term plaster, in my experience,plaster is only applied in thin coats up to about4- 5mm, & as a finish. is this a render coat or a one coat finishing system.Like thistle universal,or carlite

 

[faithhealer]

I'm slightly confused ,you used the term plaster, in my experience,plaster is only applied in thin coats up to about4- 5mm, & as a finish. is this a render coat or a one coat finishing system.Like thistle universal,or carlite

Excuse my terminology, if it's wrong,but the first two coats were 'bonding' and final skim was a 'multi finish plaster

 

[doug boardley]

I'm slightly confused ,you used the term plaster, in my experience,plaster is only applied in thin coats up to about4- 5mm, & as a finish. is this a render coat or a one coat finishing system.Like thistle universal,or carlite

bonding is a gypsum basecoat, you skim onto it.

 

[Tecnik2000]

bonding is a gypsum basecoat, you skim onto it.

Hi Doug,I'm aware of that thanks,hence the term carlite, associated with browning & bonding both base coats & often referred to as render coats down south, I was only curious as to what the application was as you guys would normally have picked up on it by now..Though your man did say another coat implying the use of the same stuff

 

[doug boardley]

up here in the north Tecnik, render is sand and cement, plaster is an all enompassing term for gypsum base coats, top coats etc.

 

[Tecnik2000]

I'm to assume you are ok with the use of a gypsum base coat in a bathroom, as no one has advised against it?

 

[doug boardley]

if Faith is using ceramic as opposed to tiles with a combined (addy, grout and tiles)weight of over 20kg m2, and the bonding is skimmed, he'll be okay.

 

[Ajax123]

so, ( sorry for deviating Faith😳) if I lay my patio concrete slad, sprinkle sugar over it, it would leave some of the aggregate exposed? and then I could get a polisher and polish it off to leave a terrazzo effect?:daisy:

If you lay your concrete and don't bother with the sugar and then get a concrete polisher you will get a lovely effect. Only issue is that the aggregate distribution within the concrete is all important in an aesthetic sense. We have special mix designs for polishing. You could also put a bit of pigment into the concrete and have coloured polished concrete. Looks really nice when done properly

If you use the sugar idea it will retard the cement paste in the top few mm of the concrete. When you jet wash this off the following day you will get the effect of the gravel protrucing from the surface. Again the aggregate distribution is important but also the aggregate size. e.g. if you use 10mm aggregate and youe retard the first 6mm then you will have aggregate held into the surface by just 4mm of paste. It is likely this will pop out. All easy to do but difficult to do right.

google Artevia if you want some more info

 

[faithhealer]

if Faith is using ceramic as opposed to tiles with a combined (addy, grout and tiles)weight of over 20kg m2, and the bonding is skimmed, he'll be okay.

absolutely right Dougie

 

[White Room]

Hi Doug,I'm aware of that thanks,hence the term carlite, associated with browning & bonding both base coats & often referred to as render coats down south, I was only curious as to what the application was as you guys would normally have picked up on it by now..Though your man did say another coat implying the use of the same stuff

The name Carlite is not used anymore it's been branded as Thistle for many years.

Just me being picky:sombrero:

 

[Tecnik2000]

Am I showing my age ? 😳

 

[White Room]

YEP

 

[Ajax123]

don't BG still brand it Carlite then? Blimey - wish they'd stop changing stuff!

 

[White Room]

All classed as Thistle now Alan.

Some pricing scheduals still use Sirapite:yikes:

 

[Dan]

Just bumping some of the older popular (sometimes not so popular) threads. Probably wont be current discussion these days but I just need to do it. So just ignore the thread if it's not current for you.