Patchy emulsion - Help needed please!

[Need Help21]

Dear All,

I don't know if I am being a perfectionist or not, but some help would be great on the following.

Around two weeks ago, I applied a mist coat of Gliddens Contract Matt to a kitchen wall which had been plastered one month previous. The mist coat contained around 20% water.

On Saturday passed, I applied a first coat of Dulux Endurance Matt emulsion which in line with advice I had previously obtained from this site was watered down by about 10%. This was applied using a Harris short pile emulsion roller sleeve. Perhaps due to the warm weather, it did dry pretty quickly. When returning to areas painted a couple of hours previously, I noticed that if I looked along the surface it appeared very patchy as it relected light in some areas more than others.

On Sunday, I lightly sanded the surface, wiped it down and then applied a second coat of the same paint which was once again watered down. I considered that perhaps the short pile roller sleeve was too short for the surface (and perhaps was not forgiving in any uneveness of plaster) and therefore used a slightly thicker pile roller sleeve. Upon drying, to me it still appeared to be slightly patchy.

Can anyone offer some advice on how to remove any patchiness. I was intending on applying a third coat and I feel perhaps I am going wrong by either:-

1. Applying the paint to thinly. For a wall area of 33 sq metres, I have used around 2.25 - 2.5 Litres per coat including water. I have been "rolling out" the roller quite a bit.

2. Applying the paint too slowly. For the area of 33 sq metres, I have taken around 4.5 hours per coat including cutting in.

A further point to consider, it that midway through and towards the end of each coat, the roller sleeve seems to clog up and go from what was either a short of medium pile to very dense/compact and smooth. I think this is because of the seamingly endless rolling of the sleeve in combination with the soaking in of the paint. Should I swop to a similar sleeve when this happens?

It would be greatly appreciated if someone could offer advice on the above.

Kind Regards





Need Help 21

 

[D.S.D]

Hi need help,

good post with lots of information there. The endurance paint is the retail version of Diamond Matt and all that range are difficult to apply even for some profesionals It suffers with what is known as flashing where the coats are dry/drying and you go over it again it will be seen as a patch in certain lights. Thats the easy explanation. The amount of time that you are taking to roll out the area is too long IMO. when using this type of paint cut in first. Leave to dry and then roll out. Start at one end of the ceiling and work across keeping a wet edge. You have to do it in one go on a ceiling otherwise you will get a patchy look when you start again with this paint. dont skimp on the paint and it dosen't sound like you are. I would not water this paint down at all but others may disagree The roller is fine but mine go like that when I soak it in mist coat so the water prob has something to do with it. Do not sand the surface anymore as that again with this paint will affect the look. You are sanding a surface in parts and then applying a watered down product over the top....it wont look right Don't forget that you will not have applied the emulsion evenly no matter how careful you have been. It will look very patchy as its drying and if you have applied it quite thick it may not dry until the following day. Give it 1 or 2 full coats making sure its completly dry in between and keep a wet edge. Do't sand down between these two and you will be fine. Good luck and I need a lay down now

 

[Need Help21]

Thanks for a Very comprehensive response. it is greatly appreciated. Are you saying that if I follow your suggestions, I could get away with one last coat, if I don't water it down? Also should I not sand it at all prior to the last coat?

 

[D.S.D]

thats right 1 or two coats, it will look patchy while its drying, do not sand. get back and let us know how you get on.

 

[Growler]

Agree with DSD.

I'm going to state the obvious but...

If you water paint down, it wont cover anywhere near as good as if you didn't.

There's far too much thinning goes on around here. I very rarely thin paint.

 

[D.S.D]

same here mate, only thin for the mist thats it and never thin special formulation paints like diamond matt each to his/her own though, works for some

 

[Big_Vern]

And never ever thin down retail quality paints

 

[joe-90]

It's all about flow. If it doesn't - it needs watering down. Otherwise you'll get roller/brush marks.

 

[54aardvark]

Flow is can be a real problem and I had a lot of problems when I started up a few years ago, particularly ceilings. However, I sorted it with adding a small amount of water to the finish coat - approx 50ml to 2.5L, just enough to give a continuous wet edge without reducing coverage. (yes I know, blasphemy to some, but it works for me!). Never used Owetrol but I gather its good stuff.

The main thing to avoid is the temptation to go back and touch up an area while it is still wet - guarantees roller marks.

 

[Zampa]

You can also stick a drop of acrylic scumble in emulsion..that gives it a bit more working time without thinning it.

Remember if you thin paint out its going to dry quicker too...and youll be back where you started if your not careful

Some paint needs it some dont..it depends on the conditions your painting in too...a warm room or a room with a warm breeze blowing through it on a bright summers day will cause you untold grief if your trying to keep a wet edge going

Always try and keep the room as cool as possible.

Also..once somethings painted...leave it, dont go back over it five minutes later or it will flash

 

[gcol]

.... flash

Ahaaa saviour of the universe.

 

[Zampa]