On 12 Jun, 19:44, "John" replyingroup@notemail wrote:
wrote:
On 12 Jun, 16:14, "John" replyingroup@notemail wrote:
Just bought a set of garage doors from
ebayhttp://preview.tinyurl.com/5wn987(notexactly those - ours have
no windows) and I've got to say, they're very good. I couldn't even
buy the wood round
here to make them myself for £49 and to be honest, I'd probably cock
it up
anyway. I like to work (read mess about) with wood but I'm just not
very
good at it (

Anyway, we fancy just staining and varnishing them rather than
painting, but
would that provide adequate protection? I know that if we were going
to
paint them, we'd start off with knotting, primer, undercoat and
finally
exterior gloss, but what's the procedure when you just want to keep
the look
of the wood?

TIA

John

Dear John
Protection against what?
Answering my own question presumably
a) insect attack
b) fungal decay
c) UV degratation

If I were to want to protect the wood without painting I would
1) take it to a double vacuum treatment plant (Protimising) that still
was operating on OS (organic solvent) and slip the operator a fiver to
leave them in the bottom of the cylinder for a couple of days work so
several charge cycles (absent this one will suffice)
2) allow it to dry for several days / week until dry
3) paint it first with a low build non-viscous Water Repellant
Preservative Stain (Saddolins) paying particular attention to the
bottom joints and endgrain where the rain will hit it and, if
necessary, dipping in the paint for some minutes
4) paint it then with a medium build WRPS in the "colour" I liked
which still allowed the wood to be "seen". There is a trade off with
the opacity and UV degradation which only you can decide

If I was painting it (I would not) I would do steps 1 and 2 as above
and then
3) green primer of Dulux Weathersheald followed by exterior under (x2)
and gloss (x1)

Trouble with this is that you have to get rid of the gloss in about 7
years and start again which is not true of WRPSs which simply chalk
off in a couple or 4 years

Chris G

Dear Chris,

Whilst I did ask the question and although I am very grateful for, and very
impressed by, your extensive answer, I'm afraid that most of it went
straight o'er me ed mate *)

All I really wanted to know is, instead of painting the garage doors white
again like I've done every four or so years with the last lot, would stain
and varnish be as good at keeping the weather at bay - it is only a set of
garage doors costing £49 *)- Hide quoted text -

- Show quoted text -

John
Short answer "No". Stain and varnish would degrade pretty quickly.
First the varnish would micro crack (you don't see it) due to UV
degradation, then water would get in and not get out, then you would
get precursor blue stain fungi (which don't damage the wood but do
discolour) and finally both UV and fungal decay damage. All this would
go on under the "apparently" good varnish before it became really
obvious. That is why it is necessary in boats to varnish more often
than appearances dictate.
If you want the varnish look go for a WRP stain but it is not really
equivalent to a stain as good ones are opaque.
Chris