different primer colours?

Primer is sold to amateurs who think it is any different from undercoat, which it's not, you will never find a tradesman buying primer...moral of the story? - buy white undercoat, it's the same stuff.

Of course it is different. I used to use it on council patching jobs. It used to contain lead but now a lot has changed. What is used these days is water based primer -acrylics. The paint acts as a filler as as well as a sealant.

I usually have my primer tinted to the color of the top coat.

B**ocks!

Different stuff, that does a different job.

Primer: High penetration, low opacity, low filler content.

Undercoat: low penetration, high opacity, high filler content.

Moral of the story is to employ a tradesman who knows what a three coat system is and why it is used, not a cowboy who will slap on undercoat without priming.

Colin Bignell

They are different. Primer is high in binder and low in filler, so it soaks in to form a stable impermeable base. Undercoat is high in filler to provide a smooth opaque matt surface for the gloss. Gloss is high in binder and pigment.

Before water-based primers and undercoats were common, many painters used to slap on a coat of emulsion in the morning and gloss it in the afternoon - that doesn't mean it works well, it just means it's quick.

There may not be so much distinction these days with water-based polymer paints, but IME these aren't very good anyway.

I hope I'm not teaching my grandmother to suck paint tins, but have you tried stirring it? Even some white gloss can look horribly yellow after it's settled in the tin, but it's fine once it's properly stirred.

Even if it is slightly different, I'd still use it. Pink primer used to be common, even under white paint. Expect to need at least two coats of gloss, or, if you want a better job, one of undercoat and one or two gloss. This assumes you're using traditional paint, not the water-based muck.

Two coats of undercoat do the same job as primer and undercoat.

Your signature is borked, it needs tow dashes followed by a space, like this -- most decent newsreaders have facilities for inserting a signature, with the sig seperator, automatically.

No they don't. Where *do* you get this stuff?

not really...

My signature is fine - the problem must be your end.

indeed - as my one does.

Working for decorators for almost 16 years, talking to other tradesmen, asking in the paint suppliers, chatting to people who work at ICI, that sort of thing.

Dark primer is a good idea as long as it is good quality e.g. grey aluminium. Better would be black with purple spots! It means that you have to do a good job with the undercoat to conceal it and end up with a good paint job i.e. poor quality undercoat won't cover it and even good quality may need several coats.

cheers

Jacob

Primer is there to seal the wood (or whatever), and to give a smooth base that is firmly keyed to the substrate.

Undercoat is there to build up opacity and colour.

Top coat is to provide a sealed luster to the undercoat.

Some paints do more than one job adequately, but if you want top results, do it the traditional way.

SWMBO wanted some T & G painted for a Victorian look...'it doesn't cost much does it' she burbled.

No, but the knotting, sanding, priming, sanding, priming, sanding, first undercoat, sanding, second undercoat,sanding and very carefully applied top coat did not happen immediately.

BUT it now looks like powder coated MDF, so its not entirely wasted work ;-)