Computer Desk Top

[Mooton]

Hello, new to the forum so this is my first post.

I am currently building a 3 metre computer desk which will be finished with a birch plywood (BB Grade) top. Before I actually fit the top I want to get it cut and the finish done, then I will just place it on top of the 12.5mm MDF base I have currently in place.

Just wondering if anyone can recommend a good durable (spillage proof) finish? I was originally going to dye/stain it in a brown/black colour but I think this may look a bit patchy and cover up the grain. Current train of thought is to finish it in a more natural slightly darkened colour instead.

Could anyone recommend a good varnish/oil and if you would suggest a sanding sealer first? I have some Danish Oil already so I am going to see how that takes to an offcut this weekend.

Also, as the desk is 3.2m and the longest sheet of Birch ply I could get was 2.4, there will be a join at 1.6m. Any advice on hiding this? I appreciate it will be difficult due to the differences in the grain across the two sheets, just wondering if anyone has any tricks on hiding it?

Thanks

 

[oakmitre]

I will wait for someone else to recommend a specific product, but I will mention the following:

You were right to avoid the black imo, I find it a bit depressing and the colour of baltic birch is nice.

Please be aware that any type of wiping varnish/oil/poly can in some cases spontaneously combust if left on rags / paper roll etc. So make sure you dispose of waste outside.Rare but it does happen.

Finishes dry then cure to full hardness. The curing time of finishes varies. I really try to stick to water based poly-acrylic. It takes around a week to reach a decent hardness. It is strangely very vulnerable to coated paper during this time, those slightly glossy letters you get from the bank.If you put a cup of tea on top of the letter on top of the worktop, tiny fibres merge into the surface.

Regards the joint, flexing is the main thing to think about. If you use a filler, then positioning a desk support under the joint will probably stop it from cracking.If you use a sliver of wood vertically to join the two pieces then you could get away with it.Then again, if cut properly or flush trimmed with a router, glue may be sufficient. Ever seen those cheap unfinished thin wooden blinds ? That I believe is basswood, it is quite useful for this purpose but not very hard.

 

[thetyreman]

I would say go with danish oil, about 4 layers should be fine.

 

[ED65]

Could anyone recommend a good varnish/oil and if you would suggest a sanding sealer first? I have some Danish Oil already so I am going to see how that takes to an offcut this weekend.

Use sanding sealer if you need to, really no point otherwise

I think Danish should be fine for something like this where you don't need it to be able to handle more than the occasional spill or sweaty glass. For something that will be wet regularly it's worth using straight varnish and not an oil/varnish blend.

Also, as the desk is 3.2m and the longest sheet of Birch ply I could get was 2.4, there will be a join at 1.6m. Any advice on hiding this? I appreciate it will be difficult due to the differences in the grain across the two sheets, just wondering if anyone has any tricks on hiding it?

Maybe try not to hide it but instead make a feature of it?

 

[Roughcut]

The trouble with Danish Oil in my experience is that on light coloured woods (Birch, Spruce etc.) it can yellow.
If you want to keep the Birch ply as natural as possible I would try a clear polyurethane varnish which should definitely guard against accidental spills.
If you wanted to make the Birch ply darker I would stain it and then still finish off with polyurethane varnish.

 

[ED65]

Oil-based varnish and Danish oil will both yellow, usually more in the latter case because there's more oil in the mix. Which oil is used determines this and it won't always be possible to find out, but if they used linseed or tung they'll yellow very nearly equally despite the tung oil being initially a lighter colour.

 

[Mooton]

Thank you for the advice given so far.

I applied a coat of danish oil on a test piece this morning, looks a bit patchy and not yellowed yet but it is only one coat.

The kind of colour I am trying to achieve is pretty much the Natural Birch below:

I'll carry on with this piece and see how it ends up.

No doubt ill be back to ask more questions

 

[ED65]

Sorry the above might have been a little unclear. There are two ways this happens, the first is just from the finish going on and the second occurs after a certain time time.

Varnishes and products like Danish oil are naturally a sort of straw colour through to a deep yellow at the dark end and they add a bit of this colouring to any wood they're applied to. You see this colour change instantly the finish goes on so what you see is what you get.

The second yellowing I was referring to above is due to the oil ageing, after five years or more depending on how much light the piece gets.

 

[Sgian Dubh]

The kind of colour I am trying to achieve is pretty much the Natural Birch below:

If that's the look you're after, your best bet is a water based finish such as water borne varnish or lacquer. The clue for knowing you're dealing with this type of finish is the clean up instructions printed on the can, which will say something along the lines of scrape off excess product, rinse out equipment, e.g., brushes, rollers, pads, spray gun, etc with water, and finish cleaning up with detergent and water. Slainte.

 

[Mooton]

Again, thanks for the helpful information.

The test piece has now had 3 coats of DO and I am actually feeling pretty satisfied with the tone of the colour. That being said I wouldn't mind seeing what a shade darker looks like on another piece.

I have sanded (lightly with 240) between each coat and it does have a nice smooth finish.

However it is fairly patchy, there is a clear difference in tone between each half of the piece. If I use a stain or varnish would I likely see the same uneven finish without some form of sealer?

Also is there any brand people would recommend for sealer/stain/varnish that can be picked up locally at one of the big chains, or am I best using an online store such as wood finishes direct?

Sorry for the basic questions but other than painting MDF and Varnishing existing wood work this is all new to me.

 

[custard]

I am currently building a 3 metre computer desk which will be finished with a birch plywood (BB Grade) top.

Just an aside. Over the past few years I've made quite a few desks for commercial clients from waney edged slabs. One thing I discovered during this process is that a desk top for a computer, especially for a computer with a separate keyboard, places an enormous premium on the flatness of the top. A dining table doesn't need an absolutely flat top, but a keyboard desk does if it's not to rock infuriatingly whenever the keys are pressed.

Ply, even expensive Birch Ply, isn't always as flat as you'd hope. You might be lucky with yours, you might not. So check the top before committing.

Regarding finishing, as has already been pointed out, a water based pu varnish is probably your best bet. It's a good compromise between wipe clean, ease of application, and non-yellowing. Finishing birch ply can be tricky because the surface layer is often extremely thin, and the UF glue that's used to bond the separate leaves of the ply can bleed through until it's just underneath the surface in some areas, but more deeply buried in other areas. This can cause blotching and all sorts of finishing problems, a water based pu varnish isn't affected by this so it's a safe option. I like safe options!

Good luck.

 

[Mooton]

Thank you to all for the information given in this thread, I have now finished the top with just the bottom panels to do.

I used a beech interior varnish (satin) which has given great results.

Just wanted to come back and say thanks for the invaluable advice.

 

[vanitycat]

Thank you to all for the information given in this thread, I have now finished the top with just the bottom panels to do.

I used a beech interior varnish (satin) which has given great results.

Just wanted to come back and say thanks for the invaluable advice.

Look forward to seeing some pics to glean inspiration for my future projects


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