Knauf Proroll Max Plaster

[willowbob]

Afternoon all; I am new to the forum, I am doing a decorating job and have a small pillar area which needs a bit of a skim to get it nice and level (approx 6 x 2 feet). I do own a plasterers trowel and have seen (don't laugh!) some DIY plaster, in a tub, Knauf Proroll Max. Watching a video of a pretty knowledgeable builder using this (comparing this product and Gypsom plaster for comparison on the same plaster board), it seems like something I could possibly have a go at, if only to learn some (very) basic skill on a small area. Gypsum based plastering is out of my league.

My questions are;

1. Is this any good and has anyone used it (I believe its popular on the continent)
2. I can see nothing on the video/s I have watched or on any of the product information regarding timescales of when it 'picks up', or when it is ready to start trowelling/smoothing?
3. Once applied, indoors well ventilated room, how long do you leave it before working it, as per number 2 above? I know its a piece of string question to an extent, but, if anyone has used it before, indoors, applying say 1mm, how long did you wait until working it. A rough timescale is fine, is it 5 minutes or 5 hours? I can't seem to get any gauge or advice on it, so before I start, this would be a useful thing to know.
4. Anything else you think is relevant.

Cheers all and thanks.

 

[Wayners]

If wall is sealed it takes ages to dry off. Don't set like plaster or it would set in tub.
If wall has some suction its easier to use I found, but as it starts to set it can start to pick up and drag.
Best to get on and flatten then leave. Mechanical vacuum sand.

I think Sbr and multi finish plaster is easier then mechanical sand it over. Quicker. Cheaper. Harder surface.

Watch..on the trowel... On YouTube and decided for yourself

 

[willowbob]

Thanks, appreciate your reply; makes sense, it is a non porous surface, so, like you suggested, I have got it on, flattened as best I can. It was starting to drag like you mentioned, so , but I am going to leave to dry, then put a light skim again on tomorrow to take up the imperfections. I will then mechanical sand it back to get a good finish. Cheers

 

[Wayners]

Second skim can be problematic as you may find. Don't worry though as will sand fine.
Better to get it the best you can then sand.

 

[willowbob]

Cheers, I will report back when finished and let you know how it goes.

 

[cdbe]

I've used it on a badly skimmed (by me) 20m² ceiling. I didn't manage to get it on flat like those videos (probably because I didn't seal the plaster first) but it does sand down easily and perfectly, but this is because it's so soft so I'd be reluctant to use it on walls with much traffic.

I've been advised on here to use Toupret instead (not as a skim coat but to fill/sand existing rough plaster, if that's what you have - as it's stronger but still sandable).

 

[willowbob]

Taking all the advice on board above (thank you), I did a final skim yesterday and sanded down today. To be fair, its was a lot of work (but it was my first time using the stuff so learnt a lot). The second final skim 'picked up' within minutes, as the surface below was now porous with the first coat I had done the day before and was a lot easier to work. The guy in the video I watched was using it on new dry plasterboard, so, again, would be easier to work on that surface I would think. On the non porous surface I was using I did the base coat, flatted it off as best I could, but then left it 24 hours.

The finish is pretty good in my opinion, certainly acceptable. The pictures below show what I was confronted with when the wallpaper was removed. Did a first sand with a sanding block by hand with 180 grit, then finished it off with 800 grit again by hand.

As mentioned above, the final skim went on much easier, so less to sand off 24 hours after that. You need patience with this stuff as it does exhibit a small bit of shrinkage overnight;, do it in stages.

Good stuff for the DIY'r for smaller areas. The product does say you can plaster anything, so big areas could be done if you are skilful I guess. I think professionals wouldn't use the stuff just because of the time it takes but, speak as I find, I found it good once I got used to it.

Hope that helps someone.