Varnish over oil

[jfc]

If read about this but never really looked into it . Any members have experiance of it and the good and bad points ?

[mrgrimsdale]

There was a thread a bit back with Sgian Dubh going on about shellac; which sticks like sh*t to a blanket, on everything including on top of dried oil, resin etc (knotting) . Also stuff sticks to shellac so it makes a brilliant primer.
So yes definitely to french polish on oil, don't know about other polishes.
Am now going to wander off the point:
I got interested because I've often noticed: how old paint on top of knotting is often in really good nick even when the rest of the paint is shot: how old joiners used to shellac glazing rebates - which remain in excellent nick for 100 years plus.
So I've followed it up and discovered the virtues of old paint systems - linseed oil as primer, shellac knotting on glazing rebates, linseed oil paints. Have had this confirmed from various sources and am now using it on my chapel windows.
By coincidence an old mate dropped by on Monday with his mate an old retired painter/decorator. He looked at my windows and without any prompting said "yer want to put linseed on these, shellac the rebates, and paint with linseed oil paints, don't bother with all these total crap modern paints". ;D ;D
Was doing it today - snaps to follow.
The reason these things have fallen into disuse is because there is no money in it for the paint industry. They make more by inventing new high tech wonder paints and "systems". Result: the quality of paint work has gone down and down, along with the durability of joinery. Along comes the next high tech solution - plastic windows - which don't last even as long as the trad paint on a trad window.
It's a familiar story repeated in other areas; drugs for one - the huge investment in developing and selling new super drugs, which don't perform as well as earlier varieties of cheaper, but less profitable, alternatives.
Or food -
Or woodwork ;D a whole generation has been re-directed from simple sharpening methods in favour of crazy systems which involve the purchase of loads of expensive gear - which doesn't work very well!
Once you've gone down the crazy slope it's hard to get back to reality. There are 1000s of other examples

cheers
Jacob
feel better for a bit of a rant ;D

[jfc]

;D I feel better for reading the rant ;D I started laughing when you got to the drugs bit ;D But like i have always said , you do have a good point when it comes to joinery . Everything else and your on your own ! ;D

[pj]

Jason, not sure about the straight varnish over oil, but on the last table I made a used a mixture of matt poly varnish ,danish oil and white spirit in equal parts, and I have to say it went on well and gave less of a sheen. It also seems to not mark as much as using straight danish oil, or osmo polyox, which I have now stopped using because a strip of cheese left on a small table top, left a distinct mark
Jacob has mentioned shellac, which is a good to use in between non compatible finishes, so a quick whiff of dewaxed shellac and then your varnish may be the safest route.

Philip

[jake]

I kind of agree about paints - the modern mvp ones are coming around in a big circle. I'm not sure I agree about the motivation - having tried linseed oil paints, they take forever to dry, especially the really trad ones like Holkham (actually some Swedish firm I can't remember). I'm sure demand - by painters who want to get the second coat on and on to the next job please, and end consumers (who don't want the scaffold up for weeks and weeks) - has something to do with it as well those Evil Chemical Companies.

Osmo Country Colour is worth trying - it dries in days, not weeks, because it has all sorts of heavy metal driers in it probably, but its like a modern equivalent of LOP.

[engineerone]

basic rule is like over like.
by that i mean do not use water based varnish over oil,
or plastic varnish over water. this may not be specifically
true, but the principal is that various finishes dry in different ways.

some dry from the top down, some from the bottom up. so check with the experts otherwise, you will have crackling due to the
different surfaces reacting at different times.

since there are fewer proper painters and more customers, the likelihood is that most people will want to paint and dry in the quickest possible time, and if that means two coats in one day then so good.

however many finishes need to dry out properly before you put
a top coat on them.

i am not a particularly good at finish painting, but i do agree that if often was easier with the older products because you needed to be more careful i think.
paul

[robo]

I have used Sam Maloof's mixture which is 1/3 PU semi matt varnish, 1/3 Linseed oil and 1/3 tung oil - which worked fine and proved very durable. Can be finished off with his oil/bees wax mix. The varnish stops water spotting.

There was a programme on the box a while ago where the NT were restoring a listed grand house - they were using linseed for the window frames.

R

[Sgian Dubh]

Apr 4, 2008 18:29:52 GMT jfc said:

If read about this but never really looked into it . Any members have experiance of it and the good and bad points ?

If you're talking about oil based varnish, it has no problems adhering to a surface previously oiled with either linseed or tung oil. A constituent of these varnish types is one or the other, or both of these oils.

However, the usual cautions about a clean surface apply. For example, if you're planning to varnish over an old oiled finish then you need to make sure the surface is clean of dirt, debris, and wax; and secondly watch out for a thick gummy layer of oil-- one that was never wiped off properly after each of many applications.

A common way to use the technique is to put on a single coat of linseed oil and wipe it off thoroughly. Next day you start your varnishing. The idea of the oil is to darken the wood. In this case I see no point as the oil in the varnish does the same darkening job anyway. But I do use this first-coat-of-oil technique on pale woods that I want to darken prior to a top coat of a pale or bleached shellac or pre-catalysed lacquer. I also sometimes use it as a technique for warming up the most common walnuts, black and European, before applying a clear film finish.

Interesting to hear that Jacob remembers me 'going on about shellac sticking like sh*t to a blanket', or something like that. Slainte.

[mrspanton]

Just on the subject of linseed paint being durable, I painted a small stool which I made with firewood, an axe and brace and bit, it is rustic but any way I made a paint from boiled linseed oil, real turp, artist oil color tint, and acelerator (terebine) Just for a laugh I deliberately left it outside its been out over 2 years mow rain or shine the water hasnt even swoll up the leg tennon's, theres no flaking or blistering. I only put one single coat. I was just messing about I didnt know a proper mix or anything ;D

[mrspanton]

Apr 4, 2008 19:34:06 GMT mrgrimsdale said:

It's a familiar story repeated in other areas; drugs for one - the huge investment in developing and selling new super drugs, which don't perform as well as earlier varieties of cheaper, but less profitable, alternatives.
Or food -
Or woodwork ;D a whole generation has been re-directed from simple sharpening methods in favour of crazy systems which involve the purchase of loads of expensive gear - which doesn't work very well!
Once you've gone down the crazy slope it's hard to get back to reality. There are 1000s of other examples

Isnt that what they call consuerism?

[jfc]

I'm glad to see there is someone else that does things for a laugh ;D I thought it was just me !

The Varnish over oil was more to do with boats . I was thinking if you oil the timber and then varnish even if the varnish gets left for a season the oil will still protect the timber . Just bright work (grab rails and basic top side joinery)