Oak finishing

[Bill]

We now have our new boiler and gas fire in and working, replacing the old back boiler. We have had the fire set in a chunk of slate which looks pretty good, so I now need to install some sort of mantelpiece so we have somewhere for the clock to sit.

After looking round a couple of warehouses, it became obvious that getting a plank and fettling it myself would look better, so, In between showers I dashed out to the shed and rooted round. To my amazement I found a piece of oak left over from the boatbuilding exercise 25 years ago. It will have originally have been purchased in about 1955 when the original owner of the plans bought the materials, and a late uncle of mine thought it was probably Spanish oak because of the colour.

On the boat we epoxied over it and then covered with paint or varnish depending on whether sunlight would press on it. It has yellowed quite nicely there.

So, is there any view on what is likely to work best in a house? Much info on the 'net seems to say that some sort of oil would be appropriate, but there isn't really enough spare to set a sensible area, and I haven't found any sort of info about what happens to the colour when the oil is applied. I'm tempted to just bung on some sort of varnish and hope.

The other complication is that the hearth has a mahogany or similar surround, so we have been holding up oak then mahogany. Eiter would look good, but the oak has more memories.

Finally, are the floating shelf prongs as sold on ebay and elsewhere any good for quite a heavy mantelpiece? We would probably have to set them either side of the fire opening to get thick enough and stable enough brickwork. Are they likely to droop or fail over the years.

Thanks for any insights

[Andy Dingley]

I finish a lot of oak as interior trim. Generally I'm aiming for a

1900s American Arts & Crafts finish (Stickley et al) so I begin by ammonia fuming it (dead easy) to a mid-brown. Then I usually finish it with oil and then shellac. The oil is Liberon, a commercial pre- thinned tung oil. Don't even think about linseed. The shellac is Screwfix's button shellac, as that's cheap and decent quality. It's best dewaxed first by letting it stand for a week first and then using the clearer top two-thirds. Keep the waxy stuff as sanding sealer. Apply with a 3/4" synthetic bristle artist's watercolour paintbrush first, then use a rubber if you prefer. I wouldn't french polish oak though.

I generally dislike varnish. I don't bother using nice timber just to make it look like plastic. However if finger wear is likely (a mantelpiece before a real fire) then I do use two coats (no more) of "Patina", a gel polyurethane that's applied on a cloth. Screwfix used to sell it, but now you have to be near Liverpool to find it. Funny really - gel polys are popular in the US but unheard of here.

[S Viemeister]

Why would you not use linseed oil?

[Andy Dingley]

Mostly because it yellows with age. Not too bad on fumed oak, but a disaster on pale wood.

Also because it's a quite strongly oxidising oil and really only suitable when you're deliberately trying for forming a heavy film. The main function of oils on fine wood finishing (especially under shellac) is optical - you soak the top surface in something that fills pores with a transparent high refractive index, highlighting the chattoyance of maples or "popping the grain". Although this is an important step, you want it to happen without "seeing the oil doing it", if you see what I mean.

I do use linseed, but pretty much only as a hot-boiled oil with lead driers, for doing repro work or making oilcloth. I boil my own.

[S Viemeister]

Thank you. Excellent explanation!

[Mary Fisher]

I wondered why you'd want to colour it at all ("I begin by ammonia fuming it (dead easy) to a mid-brown."

Mary

[The Natural Philosopher]

I guess you never have used lipstick, hair dye or nail varnish, Mary..

And your house is all bare natural colored plaster walls

And you dress in undyed beigey natural fabrics..

and drive an unpainted car or bicycle.

[Andy Dingley]

Well if it's 1900 A&C repro, you pretty much have to - it's implicit in the style.

Then having done a bit of it, you realise it's quite a nice technique anyway. It's also a decent way to "distress" the colour of repro oak accurately and without grossly invasive dyes. Now if you're starting from the position that "the present-day is sometime around 1500", then you might have a different attitude to the look of new pale oak. Personally I think it looks too much like post-war church fittings.

I've even ammonia-darkened whole buildings (timber frames) where the intention was to match new frames into an old building. As this was done wet, it goes to blackish rather than mod brown.

[Bill]

Hmmm. On the boat, where it has been exposed to sun and sea for over 20 years, it turned a nice yellowey colour. But because of the constant battle between u/v and epoxy, we have now painted over almost all the external wood.

All this talk of fuming ammonia sounds scary, but I'll look it up. I've also been scouring the internet without finding where to buy "Patina" near Liverpool. I seem to spend my life ringing suppliers and asking for things they have never heard of and I don't know the name of. (Last year it was or turned out to be "sex bolts" - for them I had to put a pic of the old ones on Picasa and ask what they were called).

I think I'd be happy with light oak colour. She doesn't know!!. My gut feeling is that oak should look natural, and if I wanted a darker wood, I'd start from mahogany, but it's all guesswork.

[Mary Fisher]

LOL! Very, very rarely.

It might well have been uncoloUred had it not had wallpaper when we moved in - which we painted white.

Whatever I get from the charity shops.

The bike was green when I acquired it, the car was blue when we bought it second hand. It hasn't been touched up where the paint has gone.

What are you trying to prove?

The difference is that if the old garden gate is blistered and faded a lick of paint wouldn't do any harm. But one wouldn't paint a lily or rose. I've never stained timber for any purpose - even for 'period authenticity' - Andy probably knows that.

But as a natural philistine you wouldn't.

Sorry, Bill, I only see np's posts when they're included in someone else's - someone I'm prepared to read.

It was a fashion. Andy's quite right.

Sex bolts? Tell us more.

Same here. I think the same about any timber. In my youth there was 'light oak', 'medium oak' and 'dark (or Jacobean) oak'. Very little light oak was seen and the result was dark, dim rooms which needed atificial lighting even during the day. I inherited a hanging light fitting in 'dark oak' from a beloved godmother and the hand-made-by-my-uncle fire surround had also been stained or varnished in 'dark oak'. I insisted that they wee both scraped and sanded until they were light - they look wonderful. And Dr Charles Kightley, an historian, period house and furniture restorer came one day and danced in the room in glee admiring the fire surround - perfect for its time (1937).

We don't use mahogany - it's exotic rather than native - but horses for courses.

See above about the garden gate and flowers - cf young and old aged skin :-)

Mary

[Mary Fisher]

...

Timber frames inside old buildings were originally the light colour of oak but they were darkened by smoke. When such buildings are restored nowadays the new timbers are left the natural colour to show that they're new - in my experience.

Of course, if they're in private houses and the owners think that darkened timbers look more authentic ...

External timbers were usually painted in pastel or even bright colours - pink was especially popular. 'Black and white Tudor' timbers is a myth.

Mary

[Andy Dingley]

You make a big box / tent and put a tray in the bottom of it with some strong domestic cleaning ammonia in it (doesn't have to be .880, doesn't need to come from the mythical draughtsman's suppliers). Then wait 24 hours. I usually want to fiddle after about 12 hours, so I have a look inside and often re-arrange bits so that nothing is getting shaded.

For small pieces, big Tupperware is enough. For most work, I use a Perspex "coffin" that used to be a piece of terrifying lab electrophoresis kit (keeping the chemists away from the killervolt supplies). Wardrobes use a custom-made tent out of polythene sheet, beansticks and parcel tape.

Don't spill the ammonia. Direct liquid contact goes black.

Watch out for sapwood. The ammonia reacts with tannins in the heartwood alone and sapwood stays pale (like the crap I saw for sale in Habitat last weekend).

I wear a full-face mask, but it's not essential.

Langlow make it (in Speke, I believe). I'd given up hope of seeing it again until I walked into Newlands in Ormskirk recently and they had plenty.

[Bill]

In message , Andy Dingley writes =

I'm not sure I'll be trying this, although I did steam some 25' replacement rubbing strakes for the boat using layflat polythene tubing standing up vertically beside the shed with an electric kettle taped to the bottom, re-watered through the spout. When we built, this was the only way, and the tube was threaded onto the stringers horizontally so they could be eased into shape in situ. In those days I used old pyjamas to keep the heat in. But I digress......

Don't you just love it when a plan comes together. The turmoil caused by having the house re-plumbed for the heating meant that I needed to find an additional desk for my 'office'. Been scouring ebay, placed a bid of a fiver and collected it today from near Ormskirk. Desk absolutely ideal and a bargain, and I found Newlands and bought one of their cans of "Patina". Newlands seems to be a great shop. Whilst in there I was accosted by a fellow customer asking if I could read the price on the sledgehammer he was inspecting. I didn't have my glasses either, but managed to achieve crucial distance and read the price. I think we were lucky he didn't drop it on either of our feet, and he returned it to the rack. But I wish there were a shop like that near me.

The family jury is still out, and I will have to dig out some smaller scraps to see how the oak goes. The family seems to be leaning towards a mahogany mantelpiece, though.

Thanks Andy for all this really valuable info.