Ask The Trades - Print Page

Ask The Trades
https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Painting, Decorating & Tiling Questions >> painting & knotting https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1181749008 Message started by raf on Jun 13^th, 2007, 4:36pm

Title: painting & knotting
Post by raf on Jun 13^th, 2007, 4:36pm

Hello all... my 1st post in this section and im sure to cover many sections on this forum as ive just bought my 1st house and im decorating parts of it as and when i can.

now reading a few threads in this section its appears there is a hell of alot more to painting than i thought :o so i guess i'll make my self comfortable....

skirtings & doors etc: in the house they've been painted white gloss but are a bit gritty in places, drips (i hate drips and im a novice) a few brush hairs.... not a good finish.

so what do you peeps recommend; shall i sand down till smooth... do i put a primer on (if so which one?), undercoat then a top coat? do i sand between these coats?

also i read something about knotting and bleeding; can someone explain what this is please so i can avoid the errors of many.

thanks all

Title: Re: painting & knotting
Post by WOLF on Jun 14^th, 2007, 12:47am

Right firstly RAF, welcome to this here forum, and i hope you enjoy the help and advise, .. you have started off in the right way, by asking questions... after all we are here to help! , and remember...
"THE ONLY SILLY QUESTION IS THE ONE YOU DO NOT ASK!!"

Congrates on your 1st home!!!!

right business time....

Knotting/bleeding... when a piece of timber is new, and non painted, you will find the odd knot or two along its length... it is these knots that can sometimes, when left alone, and just painted straight over, "BLEED" resin, from them selves, which results in yellow marks and not fully dried paint where the knots are!! which is why when timber is new, the knots are normally painted over with something called KNOTTING SOLUTION!

as for the gloss work, "keying up" is an essential part of painting, as it offers a KEY to the surface, allowing the new paint to STICK to the old ... as is wiping over with sugar soap solution, to remove any greasy prints etc, as well as the dust left by the keying up!

if gritty /and or runs... then a fine sandpaper, to just take the mark/s out will be best......

for a full run down of the way to do it, i will try and get Cora, or Hammy, our resident Painters to pop in here and advise you better!!!

regards WOLF!

Title: Re: painting & knotting
Post by hamilton on Jun 14^th, 2007, 9:56am

Hi raf,

As regards the bleeding and knotting Wolfie is dead on, I would suggest though use white knotting not brown, as the paint covers better if you are using a light colour.

If the paintwork is really bad and no amount of rubbing down will make it look acceptable, then you will probably have to remove it and get back to bare wood. Of course you will have to take into account time, money, care of carpets etc.

If you can get away with rubbing down, spot prime any bare surfaces using wood primer, followed by an undercoat and gloss coat (if that is the system you are using.) Always rub down between coats to 'key' the surface and get rid of any nibs.

Keep the room clean and dust free when you are painting, hoover round the skirtings and keep room clear of anything that is not needed.

Make sure wife keeps the tea coming. (Tell her you need it because of the lead in the paint, not true, but hey!)

Afterthought: Wipe surfaces with a tack cloth between coats of paint to remove dust, and avoid water based paints as the finish is not as good as oil based (brushstrokes do not flow out as well.)

Title: Re: painting & knotting
Post by CWatters on Jun 14^th, 2007, 2:38pm

Sorry if this is obvious but..

Water based paints are generally intended for walls. Oil and solvent based paints are generally for woodwork or metal.

There are some exceptions. I once found a water based primer for galvanized metal. Didn't think it would work well but it did.

Tips: If using oil based paints...

The instructions will probably tell you to use white spirit to clean the brushes. If you are going to need them again next day you can just store the brush in a jar of water. Don't try to wash it in water just pop the brush in. Next day dry the brush on paper towel and carry on painting. The water stops the oil paint drying on the brush.

If you run out of white spirit or you get paint on your hands...Try NEAT washing up liquid. Make sure _all_ the paint has been loosened before using water to rinse it off. The instant you use water it seems to stop the washing up liquid working.

Title: Re: painting & knotting
Post by hamilton on Jun 14^th, 2007, 6:07pm

CWatters wrote on Jun 14^th, 2007, 2:38pm:

Water based paints are generally intended for walls. Oil and solvent based paints are generally for woodwork or metal.

Not so.

They have been interchangeable for years. I was putting oil paint (flat oil, eggshell etc) on walls 40 years ago. Hadfields came out with water based gloss probably 30 years ago. It was crap so never took off.

Quite a few foreign countries only use water based paint nowdays (H&S). Watch the tele and see how many times you see gloss paint, very rarely.

There are whole systems which are water based (acrylic), fine if time is a constraint and the job has to be done in one day, or if the client doesn't like the smell of oil paint. The trouble is it dries much quicker than oil paint so the brushstrokes don't have a chance to flow out.

The acrylic gloss never has had much of a shine to it, but as most people like a satin finish nowdays it's not so much of a problem.

The acrylic eggshells are fine for walls and ceilings. The so called kitchen and bathroom paints are really only acrylics.

Title: Re: painting & knotting
Post by raf on Jun 15^th, 2007, 12:17pm

Many thanks folks.... now i know what you mean by knotting, ive seen the yellow marks!!!

one of my pet hates is sanding down as its laborious and as the skirting is profiled it prolongs the nightmare! but the finish is worth the effort.

i may try one of the satin finish paints for the wood skirtings etc (i wont mention Varn!$h :-X)

thanks for the warm welcomes... theres so much to read & take in on this site; its great to learn how to do it the right way ;)