Wood primer - how essential is it?

[chocccie]

So, I'm all set to paint some skirting boards.. I've got my primer, I've got my paint, I've got new brushes ...... oh no!  ... the primer/undercoat is for metal only!  I could have sworn I had wood primer.  But if I do I can't find it.

If I don't use primer will my house fall down?! 

Can I just use wood undercoat and gloss?  Or would that be a mistake? 

 

[Tresco]

[quote user="chocccie"]

Can I just use wood undercoat and gloss?  Or would that be a mistake?

[/quote]

Yes, I think it would be.

I know it's frustrating but it's nearly dark now anyway. Get some wood primer tomorrow, and paint in daylight.[:)]

[Rik]

For longevity yes it is essential. I usually thin it a little and work well into the grain of the timber. Use Patent Knotting on any live knots first.  Live knots are usually light in colour.  Having said that, thinned undercoat is better than nothing. 

I'd also recommend oil-based paint over acrylic.

Rgds

Rik  

[Gluestick]

Painting anything, is all about surface.

Finishing wood is no different from finishing metal.

It's all about building up the correct surface upon which to apply the next layer!

Bare wood primer seals the raised bits of grain and provides a smooth and textured surface to which the next coat (undercoat) adheres, correctly.

This is of particular importance when painting softwoods such as pine: as is knotting, as already recommended, which prevents resin rising to the surface and going a nasty brown colour!

No: your house won't fall down: but the top coat will crack, flake and fall off quite quickly.

And then you'll have to do the whole thing again!

Hence the the old saw: "Lazy people take the most pains!"

 

[Charlotte3]

Interesting this......

 

In work (French painting contractors) on woodwork we use: one coat all purpose primer, two coats of finish.  We NEVER use knotting, only enduit on knots.

Most of our work is for the public sector where regulations are stringent and the 10 year guarantee applies.

Perhaps this is another case of do as the French in France not the English in England!

Aly

[chocccie]

 

Oh...  I suppose I should do the job properly!  especially as it is bare pine (cheapy cheapo stuff). 

Now, what's primer called in French please.  I'll pop and get some later. 

[BIG MAC]

We specify aluminised primer on hardwood framing as a matter of course for longevity. In other words some metal primers are fine for wood but can be expensive.

[BobDee]

For umpteen years I have used ordinary white matt emulsion paint as a primer for gloss top coats, on bare wood and rubbed down pre painted surfaces. Works really well, dries very quickly, can be sanded off in a matter of hours. I would perhaps think twice about exterior use but for skirting boards, interior doors, no problems at all.  The cheap white emulsion as sold in most French supermarkets at around 9 Euros per 2.5 litres is great. And before all the tradesfolk out there tear me to bits, the top coat dosnt fall off in months and results are just as good as using purpose designed wood (or metal) undercoat products.

BobD

[chirpy]

I WOULD SAY  you must have a very dry interior where you used the cheap water based product.

Properly formulated acrylic wood primers can give excellent results but as a former paint chemist I would recommend not using short cuts especially with the first coat as any failure here naturally brings off the topcoats and is then a bigger loss than the saving by using cheap emulsion.

I have recommended the best proceedures to clients world wide but have been guilty in my own house when I did not have the correct primer and used an emulsion as primer and a year later was face withh removing the areas which had not peeled off by themslves.!!!And my boss at home notices these things-help -and says would I like a haf cooked meal? if not d'ont do half a proper job!!!!!!!!![:$]