Another DIY question if I may (having glued the thing together, I now need to paint it!)
Is primer necessary? I'm normally a varnish person where wood is concerned, as I don't like covering it up, but in this case it has to be painted, and I've never been too clear what a primer does that other paints don't. If undercoat is good at sticking to other paint, doesn't it stick equally well to bare wood? I realise it will need another coat, but is there anything special about primer, or is it just an excuse to sell another tin?
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>> Is primer necessary?
Never use it, two coats of topcoat
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Depends how critical your eye is going to be in the years to come. To get a proper finish raw wood has to be primed with something. It doesn't matter much what, primer or undercoat or even some old topcoat or even at a pinch distemper or whatever they call it these days. It has to dry thoroughly and (crucial this) be rubbed all over with fine sandpaper and all the dust wiped off. Then two coats of whatever (I like satin not gloss), with the first coat again allowed to dry very thoroughly and lightly sanded to remove any little bits. Then the topcoat.
You can't rush a paint job. Anyone will tell you that. Three thin coats is the minimum for a proper job. Not many people will notice the difference or give a damn. But there's a reason why good decorators are very expensive.
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>> But there's a reason why good decorators are very expensive.
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And a good reason why paint from a paint supply place is expensive.
My paint brushes were very expensive but very quick and easy to use.
Synthetic brushes are worth buying rather than cheap thin brushes that hold very little paint.
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If the wood is likely to have resin/ knots you should treat them first.
I usually cut out the worst bits and fill in with epoxy then smooth off.
Untreated knots eventually tend to bleed through paint.
Primer is supposed to seal the wood and make the next coat easier to apply and brush around.
Undercoats are easy to sand down ( they are soft and powdery) if you are after a really good finish.
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Paint according to the instructions on the finish paint. Some don't need undercoat, some do.
It's now been reformulated as a result of EU rules but the wood on the three wheeler was painted with International Yacht Paint which doesn't need primer. Not a high gloss, but I must have done something right as none of it is lifting or showing any other signs of distress.
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I think primer can work in one of two ways. In the old days red lead primer had unique powers of bonding to wood. I remember my father blowlamping doors ready for repainting, and the red stain never came out - it seemed to have become part of the wood.
The undercoat then stuck to the primer.
I don't think any substitute for lead works as well, so the modern principle seems to be to make the primer quite thin, so that it soaks into the wood and then dries. I've found the colourless kind works as well as any.
I've had better results with the woodstain stuff, like Sandolin. Sandolin Classic White, I think it is called, gives a nice satin finish and seems to last quite well. It just needs 2 coats, on bare wood or on top of whatever's there, if sound.
You can still buy leaded paint for listed buildings and for wooden boats (as indeed you can buy leaded petrol additive for old cars).
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I use Bullseye 123 primer, top quality stuff and used by a fair few decorators who buy product from where I work. On my own external window frames at home, I use Leyland Trade Truguard flexible undercoat and gloss for long lasting protection.
Where wood is unpainted, I am a Sikkens man. Lasts exceptionally well on my south facing sapele wooden window frames & doors.
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And don't forget Rustins knotting solution, available in different colours. Use on new woods before the primer...but then I can be quite pedantic.
Same with beer....
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I did have some knotting, about 40 years ago! I even did some French polishing, but it was a bit tedious!
Last edited by: J Bonington Jagworth on Sun 14 Sep 14 at 10:33
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Thanks, all. I do know how to paint, but I rarely have bare wood to deal with, as I'm normally repainting or refurbishing. I'm surmising that undercoat, thinned a bit to penetrate more, would be a reasonable solution - or maybe just some thinned varnish, although the undercoat may be easier to rub down.
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I fancy whatever advice you receive Sir 'may' be ignored and you'll plough your own furrow anyway. :-)
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MD - perhaps contrary to appearances, I am trying to take all views on board, but when the first and second responses are diametrically opposite, some advice I will have to ignore!
When I was younger, I tended to believe most conventional wisdom; now I'm more likely to query it, and forums like this are very useful.
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>> I'm surmising that undercoat, thinned a bit to penetrate more, would be a reasonable solution - or maybe just some thinned varnish, although the undercoat may be easier to rub down.
Yes. Primer coat should be thinned well.
You obviously know what you're doing JBJ.
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i think the idea of primer is to seal the wood and allow better bonding and finish of subsequent coats. If you think of plaster where you seal with PVA water mix first so that the water is not drawn out of the fresh plaster too quickly.
I'm a primer - undercoat - topcoat man myself but I can suffer from OCD :)
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Bare wood you can use a primer.Then undercoat and gloss.Slicht sanding inbetween coats.
Some people put two coats of gloss whatever takes your fancy.
If I did a proper job for outside wood from scratch I would use a primer.Maybe old fashion this day and age.
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Dutchie, not old fashioned, just the correct way to do it.
On new wood I sand using a fine paper between goats, then normally apply just one topcoat for outdoors . Internally I use an oil based eggshell for skirtings, frames etc , although a water based acrylic satin does not yellow with age. The downside is its longevity is reduced.
EU legislation is that oil based paints are becoming fewer and fewer. Or so our suppliers tell us.
The scarcity of Hammerite thinners is a case in point, the contents of which, I am led to believe, are a ' no no' under new regs!
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>> EU legislation is that oil based paints are becoming fewer and fewer. Or so our suppliers tell us.
>>The scarcity of Hammerite thinners is a case in point, the contents of which, I am led to believe, are a ' no no' under new regs!
Yes, the nanny state getting nannier and nannier.
You'd think the state would see the possibility of people drinking paint thinners as an economic advantage. No such luck though. It wants to keep us all going for as long as possible, whatever we may want. It'll be sorry in the end when we are all vegetables needing to be spoonfed.
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AC - I was pleasantly surprised to find that a Hammerite type solvent is available from Lidl as their 'universal thinner'. I haven't actually tried it with Hammerite, but it seems to contain all the important aromatic hydrocarbons and has dissolved every paint I've thrown at it. It's a very good general-purpose cleaner, although you have to careful near some plastics. You could probably even use it as an anaesthetic.
I agree about the nanny state, and I'm trying very hard not to mention goats...
Last edited by: J Bonington Jagworth on Sun 14 Sep 14 at 23:21
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I sand using a fine paper between goats,
Tea/keyboard interface here. Love the typo ,Leggy.
So you finish off one goat then do a bit of light sanding before starting on another one....you country boys must have some energy ! :-)
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Yes, we multi task here in Ribblesdale. Sanding between goats is the norm. Makes for a lovely blue creamy goats cheese. Expensive mind but reed grand with some o that fruit cake tha knows.
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>>Yes, we multi task here in Ribblesdale
Just booked another week at Gisburn in October...
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>> Just booked another week at Gisburn in October...
>
I would order your goats well in advance, Doc......Leggy seems to get through them fairly quickly !
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Fortunately for you I am away for a considerable time, so fears of a goat shortage are unfounded. Gotta head west soon to paint a friends house. And catch the final few Giants games at home. Then a short trip home to go on a boys trip to Madeira, although it seems a very strange destination for such a 'do' . Then back west for Thanksgiving and, hopefully, some early season skiing.
Anyone want a cheap (ish) 10yo 330 ragtop? Seems a shame to keep it in the garage unused for weeks at a time.
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Painting wood - Zero
