What finish for spalted beech after 3 Danish oil coats

[Kryten602]

I have just made a box out of spalted beech from a tree down in our garden and I have given it 3 coats of Danish oil. I like the darkening in colour but not the matt finish. The oil went in like it was blotting paper but I prefer a bit of a sheen rather than no shine at all. Once it's fully dry what would be recommended to give it a bit of a lift? I used 2 coats of Danish on an oak box I made recently and that does have a nice sheen to it, but the beech is completely flat.

 

[thetyreman]

you could try shellac, that's usually what I do with 'dull' looking oil finishes, once the oil has fully cured.

 

[Kryten602]

Thanks for that TyreMan. Toolstation do a Flag brand shellac natural pale sanding sealer. √

 

[MattRoberts]

Just pop some high gloss polyurethane on top

 

[Kryten602]

Yes, thanks Matt. I was looking more for a satin than high gloss, but maybe I'll buy some anyway and experiment. Cheers!

 

[ED65]

Once it's fully dry what would be recommended to give it a bit of a lift?

Shellac or varnish will both work for this. Shellac would be much faster, but only if you already have some obviously

Incidentally you don't need to wait for it to be fully 'dry'. There's varnish in Danish oil already and that will simply meld with further varnish. Shellac doesn't care either way. So touch-dry is fine, basically as long as it has dried enough that the surface isn't very draggy.

I was looking more for a satin than high gloss...

You'll likely find because of the absorbency of the beech (hence the blotting-paper effect) that you won't easily get a shine, even with gloss varnish; same basic reason that it's often difficult to build an equivalent sheen on end grain as on the surface of a board.

Anyway knocking down the gloss on varnish is easily done if you ever need it, and actually it's much more reliable than using satin or matt varnish. It's the same process as used with shellac, a controlled scratching done with very fine abrasives. You can knock shine down just a tad by buffing with cloth or brown paper before something is fully cured (so the finish isn't at maximum hardness) and after curing using fine steel wool, any "equivalent" nylon abrasive pads, or very traditionally powdered abrasives like pumice.

 

[ED65]

...once the oil has fully cured.

With straight oil you can immediately start applying shellac after oiling. I've long suspected it's the same with Danish oil... if you think about it nobody actually waits for a full cure, they might erroneously say they do (and believe it) but because even a Danish oil with a really good drying time will still take many days to achieve a full cure, possibly as long as a month, they aren't.

 

[Kryten602]

Thank you Mr ED65, that's really helpful. I will be taking your advice. I wonder if I could pick your brains again please. The oak box I made has had 2 coats of Danish oil and after the 2nd coat it was a bit too shiny for me, so I sanded it down a smidge, which left some satin patches and some matt patches which did look terribly inconsistent. Yesterday I gave the top and bottom a 3rd coat which when applied look good, but this morning it has reverted to a mixture of gloss and matt. How can I achieve a consistent satin or gloss affect and why after its 3rd coat did it go so patchy. Please see below:

 

[MattRoberts]

What grit did you you send it to before finishing, and what grit did you sand it to after finishing?

 

[Kryten602]

Aah. I used 100 both before and after.

EDIT: Sorry these image are before sanding after 3rd coat as it's stick a little tacky.

 

[MattRoberts]

100 is probably a bit low before, and definitely too low after. I'm no expert, but you probably want to aim for about 120/180 before, and about 400 in between coats or after, allowing it to dry completely before sanding.

Sanding after coats is simply to remove any tiny high spots in the finish and create a smooth surface for the next coat. As such, it only needs to be a very light hand sand, to avoid stripping back the finish

 

[Kryten602]

Thanks Matt - appreciate that. Off to Screwfix I think.

EDIT: Screwfix only seem to do wet and dry at these finer grades. Will that be ok?

 

[MattRoberts]

Yep - if it does dry then you're golden

In terms of fixing your workpiece, you probably need to sand it all back to a consistent finish, and then re-do the oil

 

[Kryten602]

Brilliant thanks Matt - much appreciated. Off to Screwfix this arvo.

 

[MattRoberts]

If you're happy to wait, you can get rolls of the stuff pretty cheap on amazon

 

[Kryten602]

Thanks Matt. No I don't mind waiting but it seems to work out (if you don't mind sheets rather than rolls) Screwfix prices are about the same per sq cm, approx anyway. They only do rolls in the coarser grades. Thanks for your advice though, much appreciated.

 

[thetyreman]

...once the oil has fully cured.

With straight oil you can immediately start applying shellac after oiling. I've long suspected it's the same with Danish oil... if you think about it nobody actually waits for a full cure, they might erroneously say they do (and believe it) but because even a Danish oil with a really good drying time will still take many days to achieve a full cure, possibly as long as a month, they aren't.

really, so if I have pure tung oil on oak, I can just whack on some shellac whilst it's wet? or should I wipe it away first, I've heard that french polishers use only the best pure tung oil, is that correct?

 

[ED65]

The oak box I made has had 2 coats of Danish oil and after the 2nd coat it was a bit too shiny for me, so I sanded it down a smidge, which left some satin patches and some matt patches which did look terribly inconsistent. Yesterday I gave the top and bottom a 3rd coat which when applied look good, but this morning it has reverted to a mixture of gloss and matt. How can I achieve a consistent satin or gloss affect and why after its 3rd coat did it go so patchy.

In line with what Matt was asking I'd sand to at least 180 on most hardwoods if I were using a finish like Danish oil. With a penetrating finish lots of people like to sand somewhat finer than they would otherwise, so to 320 maybe and sometimes higher.

Using straight varnish you can get away with coarser scratches because the film will tend to conceal them but Danish oil (which is usually made from a mix of varnish and oil, thinned with white spirit) is less forgiving so that's why you usually want to sand a bit more finely.

Now that you've already applied some finish I think there are two good options, one is to keep applying Danish oil as you normally do until you've built up a consistent sheen and then knock the shine back to the level you want. The other is to try wet-sanding the next coat of Danish oil into the wood using finer paper, approximately in the range of 280-320 although you could use finer. This tends to produce a good satin or semi-gloss finish, although individual pieces of wood can interfere with the plan!

 

[Kryten602]

Yes thank you ED. I probably have confused this thread by asking about spalted beech and Danish oil, then uploading pictures of an oak box with another question. I've fine sanded the Beech box and given it 2 coats of shellac which has sealed it nicely. I bought a cabinet scraper today to have a go at the oak box again. As Matt mentioned earlier need an even finish before applying any more Danish, which, through my ignorance didn't do, hence the scraper. Thanks very much for your detailed reply.

 

[ED65]

...once the oil has fully cured.

With straight oil you can immediately start applying shellac after oiling. I've long suspected it's the same with Danish oil... if you think about it nobody actually waits for a full cure, they might erroneously say they do (and believe it) but because even a Danish oil with a really good drying time will still take many days to achieve a full cure, possibly as long as a month, they aren't.

really, so if I have pure tung oil on oak, I can just whack on some shellac whilst it's wet? or should I wipe it away first...

You do want to wipe away the excess first as you would normally (particularly on an open-grained wood like oak, you don't have to be as scrupulous on something like beech or maple) but the oil doesn't have to be given any time to 'dry'.

I've never done it with tung oil but it works with other drying oils so there's no reason it shouldn't work the same with tung.

I've heard that french polishers use only the best pure tung oil, is that correct?

Traditionally over here it was boiled linseed oil. Tung oil is quite a recent introduction to finishing circles (it was in the US earlier, but it's still quite new relatively speaking).

For lubricating the rubber raw linseed oil appears to be the traditional preference in our part of the world, and some still prefer to use that, although it appears you can use any oil for this purpose since it's only acting as a lubricant and doesn't become a permanent part of the finish.