Finishing Lativian Birch 12mm plywood

[fierycon]

Hi everyone,

First post on UK Workshop - hope you guys can help.

I've bought about 20m2 of Lativian Birch 12mm plywood to to clad the interior walls of my living room.

The plywood has a great uniform finish, few knots, consitent colour and very subtle "marbling" of the grain on its surface. However, I'd like to increase the contrast between the wood and the grain because at the moment everything is too subtle.

In a perfect world I'd like the following:

1 The grain marbling effect darkens slightly
2 The rest of the wood stays a very similar colour (a slight colour change is OK)
3 The wood is sealed and protect
4 The wood maintains a matt finish as far as possible

Im getting 1ltr of Manns Polyurethane Varnish delivered today to test on a few offcuts - my reseached suggests this might be the sort of thing I'm after.

Any advice will be much appreciated, I dont want to go and ruin 20m2 of birch ply or turn my living room into a look-a-like 1980s Swedish sauna! The wood is a very good quality so I dont want to realy change its appearance - just enhance it.

Regards,
Greg

 

[MIGNAL]

To be honest I think it's impossible to do what you want. The Birch is going to change colour anyway, over time and even under a finish. To stop that (or slow it down) you would have to permanently live in a darkened room!
The finish that gives the greatest contrast is an oil based one. They do Yellow slightly over time, perhaps Tung oil based a bit less than those that are based on Linseed.
You will have to buy a varnish that has a matting agent if you don't want gloss. Either that or just apply one coat.
I think Danish Oil will be a better option, 2 or 3 coats. The Colron from Screwfix is fine. With Danish you'll probably get a little soft sheen. There's a lot of solvent fumes to deal with though and careful with spent cloths and the fire hazard. You need to sand the Birch to a high grit, minimum 400 if you want to use a thin Oil based finish. It really highlights scratches/sanding marks like no other finish.

 

[Beau]

I have used quite a bit of birch ply in our place and used various finishes.

Polyurethane brings out the most contrast especially on the edge but does substantially darken and yellow the colour. Easy to apply but slow drying. Has proved very durable

Acrylic varnish kept the colour very natural but does not bring out much contrast. Relatively easy to apply but you need to work fast on large areas. Quick drying times. Looked pasty if used on the edge. Disappointed with it's resistance to damp

Finishing oil was closer to the colour of the acrylic than the polyurethane. Relatively easy application but I did not do any large expanses with it. It's not had a hard time but still looks good.

 

[fierycon]

Thanks for the advice. After receiving the Manns varnish this is the result on the birch (darker is the varnished region). Its the kind of thing I was after... although hard to visulise it on a larger are (sample 3" x 3")

 

[sitefive]

Just out of interest how much it was? since Im from Latvia myself ,here for 12mm it was around 5eur/m2 (~3.5gbp) or maybe a bit less depending on place.