learning to plaster - success so far

[sm_jamieson]

I bought a piece of contiboard about 200 x 60, screwed it to wall, gave plastering a go. Plaster was too runny. Splashed everywhere and would not really stay on the trowel. I kept holding the hawk at an angle and it ran off onto the floor! Waited half hour, came back gave smoothing a go. Not too bad, until I held a light at a very low angle and a horror of dents and stratches were visible. When set, I scraped the plaster off. The plaster flaked of wonderfully and I could examine the thickness of the plaster "flakes". Generally less than 2mm, i.e. a bit too thin. Next time, and next, *still* too runny. Next time I will try it thicker. Smoothing is not really that hard I have found, but spray loads of water on. Undulations are more of an issue. When smoothing, the trowel misses bits. I have since realised that these areas are the dips, so of course they must be filled in during the smoothing. I have managed to get some areas looking "perfect", now I just need to extend this to the whole area! Due to the way I have improved in just 3 goes, I'm sure I will get there eventually. But of course a whole large wall, corners, curves, ceilings etc. is another matter. I have found you need to be able to "imagine" the surface that you are about to create, and be familier with what a flat wall is like. Go on, get up and stroke a wall. Seriously. Your nearest will think you have taken up buddism or something. I am sure all these tips are what a plastering will gain over time whether he realises it or not, but it may help to analyse them. Simon.

[Vass]

Well Done!

I remember trying after watching a pro do it

he threw splashes of water from a paint brush on areas he needed to go over as the plaster was going off, I tried the same and found it really helped me

Keep going !

[The3rd Earl Of Derby]

Keep the trowel clean at all times and if the mix is too runny this will give you scratches as the contents of the plaster has not the right consistancy, the plaster should not slide of the hawk easily, try and use large sweeps up the wall and not overlap the preceding sweep.

Sir Benjamin Middlethwaite

[The3rd Earl Of Derby]

That's the technique, but at some stage or other you'll have to keep on wetting the brush so a spray bottle holds an adequate amount to do all four walls without the need to refilling it at intervals.

-- Sir Benjamin Middlethwaite

[sm_jamieson]

A flexible bucket I will be buying, and also darby, or a few of different lengths. Also, a very long trowel will I try, just to reduce the undulations. By the way, I have to ask - are you really an Earl ? You may plead the 5th ammendment if that is appropriate. Sorry if I offend (!) All the best, Simon.

[Chris Bacon]

The 5th. amendment to what?

[sm_jamieson]

The US constitution, or the up-and-coming 5th amendment of part P, which prohibs the DIY switching off of the telly without a building regs application. Take your pick. Simon.

[Chris Bacon]

Argh! Part Pee - run away!

[sm_jamieson]

Can you do wiring before the room becomes a kitchen/bathroom, and so not be subject to part P ? Did ya see the post on possible part Q plumbing ? I am getting worried. I know a chap who worked on gas turbines for years, but could not get corgi certification because he did not have the relevant experience. I would much prefer him to do my gas than anyone else. Simon.

[Lobster]

But why contiboard? (you do mean the plastic-laminated chipboard, right?) It must be much harder to plaster a smooth, shiny surface like that, but more significantly, it's surely going to behave very differently than in the Real-Life Situation because the absorption properties of the surface (ie zero) will be very different to plasterboard or brick. As a chunk of 4'x3' plasterboard only costs 1.99 GBP, why not practice using that instead?

Or (hmmm..) am I missing something and is this a recognised method of learning plastering?!

David

[Rob Morley]

What he said.

[sm_jamieson]

Yep, got lots or plasterboard anyway. The only point about contiboard is that the plaster scrapes of easily afterward, so no loads of badly-plastered PB to dispose of. Absorption will of course be nil, so you get longer to work it ! Also, I guess if the PB is PVA'd anyway it will absorb less. I will move onto PB, er, soon. Simon.

[sm_jamieson]

Tried another one this morning. I am finding it very hard to get an even initial coat on. The plaster seems to congregate at the bottom of the sweep and tapers off to nothing as I go up. I guess I need a much sharper angle at the bottom. A very poor initial application makes the next stage much harder. Simon.

[The3rd Earl Of Derby]

You need to press firmly in and make sure the plaster is evenly distributed on the sweep and at the same time closing the blade as the plaster gets less. I don't know how much plaster your loading up on the trowel but if its a large amount try reducing it.

-- Sir Benjamin Middlethwaite

[sm_jamieson]

I almost thought I had not enough on the trowel. The plasterers I've seen on the TV seem to sweep up about 3-4 feet in one go, and very fast. I think the speed would help to reduce undulations, which tend to be a result of arm wobble. Also, as I sweep I have in my head the thought that I have no idea how thick the layer is I am putting on ! You have to read that last line in the context of plastering. Simon.

[The3rd Earl Of Derby]

These undulations your on about what exactly do you mean? i.e are they ripples? if so this is because the blade has scraped the wall rather than sliced across, whenever you hear a scrape or experiance a judder in the blade immediatly smooth out that area again. Do not take particular attention to discrepencies at the early stages of applying the plaster as these can be rectified when it comes to polishing the plaster, your main objective is to cover the whole area in as little time as possible without the need to rush like a demented demon.

I do hope your using a drill paddle for the mixing as this gives a better consistancy to the mix and also negates the need for an helper.

-- Sir Benjamin Middlethwaite

[The3rd Earl Of Derby]

One other thing... There are no rules as to where you start the plastering i.e ceiling,floor or side sweep. Its whatever you feel comfortable with.

-- Sir Benjamin Middlethwaite

[sm_jamieson]

Yep, I've had the judders. I don't mean that. I mean the depth is not consistent across the area. It you try to apply the plaster too slowly, the natural wobbles of your arm will effect the depth, unless you have a surgeons steady hand.

Yep, I use a drill paddle. My drill tends to run too fast thought. A drill with a gearbox would be useful.

[The3rd Earl Of Derby]

sm [e-mail] wrote: [snip]

Ha! no need to plaster the wall then. lol :-)

-- Sir Benjamin Middlethwaite

[Lobster]

Hmm, tell that to the last plasterer I employed. He absolutely insisted on doing ceilings first despite it causing me a lot of grief doing it that way round (ie, I hadn't got ceilings ready in time); basically pulled the old "me-tradesman-you-DIY-knownothing-muppet" routine on me. Love 'em.

David