Weathering of Oak

Where you are you'll need a bank of sun lamps, the wet you have! It's irrelevant, but I always wonder at how fast a thatched roof 'weathers down'.

As an attempt at an enterprise, I've been making wrought garden benches to an old pattern for a while, needless to say it wasn't long before someone asked for wooden slats. Wanting to be purist we used oak and they became not-new looking quite quickly. Reckon by next summeit'll have dulled quite a bit if not exactly grey. Actually from an aesthetic and comfort point of view the wooden slats are very good, warmer to sit on .

375 pounds (sterling not weight) for a 3-seater with steel slats if anyone needs one!

Cheers!

Mrs Cat is making yet another patio .... don't think she could heave an iron bench around tho'...

30-odd kg. Haven't tried to fit casters yet but who knows. Maybe I should consider self-propelled, that'd be an untapped niche.

A recent building extension uses oak as part of the structural timbers. Other family members didn't want it looking like an old church gate in a year or two so a proprietary treatment fluid was called in to retain a golden colour long-term.

Untreated oak will weather over time, reference some of the beautiful buildings in http://www.lavenham.co.uk/ among many other places. A year seems a bit ambitious. Some softwood structures have deteriorated over ten, for firewood...

The first thing that came to mind was an old episode of this Old HOUSE I viewed several years ago. In it they showed a product that was meant for just that application . Its purpose was to provide a variety of woods to acquire that grey Cape Cod appearance overnight and at the same time provide a durable weather resistant coating. Off hand I can't recall the name of the manufacturer but the first one to pop into my mind is coatings manf. Sherwin Williams. Hope this helps if that isn't it they may be able to direct you.

Del, I seem to remember spilling some chlorine bleach on my new deck a few years back and within a few days, the color had been bleached out leaving the wood grey. Why don't you borrow a cup of bleach from Mrs. Cat and try it on one of your wood scraps? You just may like what you get. Other than that, there are several paint and opaque stain products that claim to give instant results. But, it's not natural and will have to be redone from time to time. Hope this helps.

Post #7 struck a chord in this retarded brain of mine. It was lye I spilled on the deck not chlorine bleach.

Use Lye, in a moderately strong solution, it will do the weathering job in a few hours.

I have a glider bench on my patio (SW exposure) that has red oak slats. I power wash it in the spring, and it has already gone grey again, and by this fall it will mottled grey and black. I'm led to believe that the black has to do with tannin or some such thing oxidizing in the wood. This is simply from exposure to sun and rain (maybe some pollution). I'm thinking of using a penetrating wood stain/sealer on it, so my wife won't keep making me wash the damn thing every year (-->"ew, I can't sit on that, it looks dirty!"), which, by the way, I have to sand after it dries (the glider, not my wife), as the power washing keeps raising the grain and splinters (again, the glider, not the wife).

There, now that I've bitched about it, I feel SO much better.

AH YES

That mysterious mottling is called mildew.

do you live somewhere the is acid rain

Cheers for the ideas guys...

I shall play with some off cuts. If it turns out good I'll post a pic.

I generally try and go for natural finishes..the old beeswax and turps is my favourite.

I abhor the concept of 'stain' but ocaisionally for outside or on shaped ply it can look good. I once made a small decorative bow-pistol with avery sculptured stock for someone...stained it 'Mahogany'... came out like Tart's Lipstick !...rubbed it down and went over it with Dark Oak...the combination was glorious.

The beauty of oak, no that's wrong one of the beauties of oak is that it's likely to outlast whatever you put on it anyway! I appreciate the desire for a weathered appearance according to cirucmstances, but love the look and especially the smell of it fresh! Currently have a beehive (unused) in pieces in the living room; beat THAT for an air freshener!

I haven't tried this myself, but I heard about a fellow that buried his wood in soft, wet ground for several weeks. He claimed it gave an almost instant antique look to it.

Nice idea but I'd need a big hole...

The first Deer Sculpture I made was out of old weathered arris rails and gravel boards.The timber was superb, it was crazed and had 1/4" of rotted surface with really interesting textures...beneath that it was absolutely solid. Some was so rotten I had to wire brush it to get the lose off...the final effect was really soft and natural (I gave it a few coats of liquid preservative to keep further rot/insect at bay.)

#2 is coming on but is going to look just too homgeneous...it's difficult to avoid over working it and ending up like I'm trying to make a 'model deer'... it's s'posed to be almost abstract... 'essence of Deer' that I'm after.... that glimpse of a Deer through the trees...that just gives it away as a Deer...?

Sorry ...difty off into arty farty ramblings now...

I have accidentally done this with ammonia, dont know how uniform it would be, but I have red oak floors in my house, a bottle of ammonia on its side leaked for a day or 2 into one spot, turned a really cool weathered gray color.

You could always pee on it. I know that works for weathering copper as in roofing, etc. I know it sounds crazy, but I'm sure you could get one of the neighborhood boys to do that for you. Of course, they may start peeing on other stuff, so that might not be a good idea. Just a thought.

I was honestly going to put that in yesterday but opted not.

At my cousins, where I summered as a young man, they had an porch made of oak. We men were often griped for not walking far enough away from said porch before, letting go or nightly business.

The evidence? A discolored porch.

Suggestion: Ask the production manager in your local veneer mill about oak's reaction to air, sunlight and certain chemicals. Oak also reacts on contact with steel. No sure what other metals might do to it.

See if you can dig up information on "fake" antiquing in wood finishing. Bleach, acids, and lyes are all commonly used, but I can't remember which is less harmful to the wood. I might have a book in the basement at home with a recommendation.

Oak contains various acids. They rust steel and brass pretty quick, which is why glued-and-pegged construction is still popular in oak structures for the heavy bits. Wrought iron survives a bit longer.

Gang this is simple:

You need to use a solution of peroxide (2% hydrogen peroxide), 4% dicumyl peroxide, 3% benzoyl peroxide. Scrub it on, wait, say 2 hours, wash off with a 5% solution of sodium bicarbonate (baking soda). If it is not light enough then do it again.

A commercial wood bleaching agent will also work well, but the above is the least expensive way and the least environmental load if you use hydrogen peroxide.

You can also put about 2 drops of dish washing liquid in the peroxide solution, this will help the peroxide penetrate the wood surface.

Are you saying to use a solution composed of all three of the peroxides, or any one of the peroxides? Isn't the Oxygen the bleaching agent here and wouldn't a chlorine bleach be more agressive? Or a strong, hot lye solution which will turn the oils in the wood surface into soap that can be easily washed away? Or maybe a multi-step process involving a combination of these three? Or, maybe we should just relax and have a few beers, let nature do it's thing.

Or, maybe we should just relax and have a few beers, let nature do it's thing.

Ha..if we couple this to the pee-ing suggestion...?

I shall have to experiment...dunno where I get Lye...I shall have a google later..I've got some sort of peroxide commercial laundry destaing stuff ...

I can see hours of entertainment ahead.

Cheers all.

Lye is alkaline drain cleaner. Over here we call it Drano.

Acid drain cleaner (Liquid Fire is one US brand name) is actully sulfuric acid.

You want the alkaline stuff.

enjoy your beer(s).

milo

Drano brand contains aluminum chips that react with the lye to generate heat which helps to soften congealed grease. In the process the aluminum turns black. This may wind up staining the wood. I would suggest nothing but pure lye (sodium hydroxide also called caustic soda). Grandma used to save the lard from cooking and keep it in a pot on the stove. To this she would add lye to make soap then pour it into a small wooden box and let it harden into a bar. For laundry uses, she would grate the bar of soap on a grater. Now she had powdered soap. Almost nothing went to waste in our house.

WARNING! DON'T GET ALUMINIUM AND CAUSTIC SODA NEAR EACH OTHER! AN EXOTHERMIC REACTION ENSUES!!

The results formed an interesting piece of entertainment in second year chemistry classes. Once seen, never forgotten.

I say old chap..no need to shout!

A good warning to those who are not in the know. DRANO exploits this exothermic reaction to re-liquefy congealed grease in drains where it can react with the excess sodium hydroxide solution to produce soap thereby helping to clear clogged drains.

By the way, I use sodium hydroxide every day to clean, de-grease, and etch aluminum parts. It's cheap, readily available, easy to neutralize and dispose of, and, it does a great job.

My grandaddy was fond of the saying: "Ah..., piss on it!" Here I thought he was frustrated and giving up on a project. Maybe he was on to something???

Well this discussion is very interesting and the question of which of the three peroxides in particularly interesting, and I hope that those with knowledge of the differences will expound on previous post or chime in! Guest is so much faster.

Well, I guess I should have said Liquid drano.

Thanks for the propmet correction.

milo

Good info' cheers!

'And had the side effect of killing some insect life?' (Not the Lawyers? )

He did say " insect life," not "contemptible vermin," not to be confused with our incorrigible Vermin correspondent.

milo

Yousef, You seem to be extremely knowledgeable and the ammonia fume coloring is very intriguing. What do you prefer to use as a final finish? Varnish, urethane, shellac, oil? I've taken a liking to a 50/50 mixture of linseed oil and turps. Your comments would be very welcome.

shellak . I read this recently in a text and was impressed by it. Just passing along.

Oak has tannin in it. This changes everything...and Cat should test ANY formulation on his off cuts to see what works and what ends up black as soot. Drano will make it look like a snow leopard..the little bits of aluminum will form cool looking black spots which are permanent on a snow white background.

Inside finishes....spar varnish and boiled linseed oil. Hand rubbed. Take your time. Nothing better. I like it because dust is not an issue. In fact, dust helps to fill the pores. Its what I use on gun stocks.

Outside finishes... High UV resistant urethane spar varnish. High gloss. First coat should be thinned half and half with paint thinner or turpentine. (read the instructions on the can!) Second coat should be just as it comes from the can. Sand it and brush on a thinned (1/4 turp) to touch it up every second year, BEFORE it starts to show signs of weathering.

hydrated lime and water, repeated twice a year make a nice whitewash finish. Good for fences, decks, outhouses, and chicken coops.

Linseed oil makes a great protective coating. It will mildew black fairly quickly though, so a preservative should be mixed in wtih it. Colour it with anyline dye to get a great "stain". Stain is not as thick as paint, and normally carries more colouring than paint. Stains are better than paint...I just paint it on, and don't bother to wipe it off...they last longer than paint, stick better, and don't blister like paint.

Generally speaking, I don't like paint. Natural materials have their own beauty. Decks and fences last longer when you don't paint them...the only enemy of wood is water. And ants....

I have used milk paint. Never made it from scratch, but I hear it is not difficult to make. Milk paint is the ultimate "antique" paint. Never comes off! An exterior door I painted with commercial milk paint has weathered for 8 years wtihout showing any signs of damage.

I am looking forward to reports about how you all find these techniques work.

Yup, I'll get back eventually with an update...

The sculpture is comoing on quite well...but I'm going to have a few tricky bits to get right. I'll be very conservative with anything I try... Here is a pic of work in progress, alongside mk1

Thanks again one and all.

I like 'em, I'm going quite doey-eyed! Actually as it's breakfast time make that doughy-eyed.

Hows about 'tung oil'?

Tung oil is a fully drying cabinet grade oil. Not normally used in outside applications, but I hear it is good for thinnning spar varnish. I have used it on inside furniture. Brings the grain up really nice, and does not raise the grain at all! It smells nice, (well, sorta) is inexpensive, and quite poisonous, so you would never use it on anything kids can eat off of or chew on. It dries a lot quicker than boiled linseed oil, and is therefore much in demand by impatient cabinet makers. I have never tried it mixed with spar varnish, so I don't know how it would perform mixed like that.. It often has chemicals mixed with it to help it dry even faster...these chemicals are kind of nasty. It is made from nuts, and I hear that people with peanut allergies may react to the finish....so its use is discouraged when the final purchaser is not known...like wood shows and such. I use it only on rush jobs. Danish oil (with chemical dryers) is a better substitute, but more than twice as expensive. When you use linseed oil, use only "boiled" linseed oil, raw linseed oil will NEVER dry! The boiled stuff takes a week to dry. And spar varnish takes 24 hours. Mix the two, and the result will be ready to re-coat in an hour, and will be dry to the touch in two! It sets up under your hand, which is why I like it! The result is okay to use outside, on signs or wood scul;ptures. You might skip the varnish part, and just rub oil on it once a week for month, then once a month for a year, then once a year forever. That will look good, provide a semi hard matt finish.

Man, I asked and you delivered.

Thanks. I have an old 'golden oak' breakfast table (ca1920) barley twist legs that I finished in tung. New nothing of any residual hazards.

Thanks

cr3

Don't think you have much to worry about unless you were using tung oil to beautify salad bowls, wooden spoons, and such things that might end up in people's food or their mouths. If you like the open grain of yellow oak, oils work well. A coloured oil (minwax transparent stains for instance) will bring out the grain, and they are good to touch up blotchy finishes, and of course such finishes are very forgiving. Boiled linseed oil is much safer to use on items which have to be food safe, but it takes a week or more to dry! If you add an oil finish to weathered grey wood (like in del's sculpture) it will turn a really pretty dark grey almost black. IMHO that looks good on a half timbered building. And when you are oiling a deck or a building or a big outside wood sculpture, you want to go with the inexpensive option....which is of course, linseed oil.

All brands are different. Read the ingredients list on the can, and follow application instructions. Be safe. Some common paints, and oils are really toxic. Nitrile gloves are available everywhere. Maybe Del has the right idea...let it simply turn grey in the sun!

Del,

See if you can find a copy of George Grotz's The Furniture Doctor. He covers ammonia, lye, burying, etc.

Cheers, I'll have a look, sounds like a v useful volume.

It is a useful book and an entertaining read. George Grotz has a short chapter on bleaching wood and covers several formulas for bleaching, but generally recommends using sodium Hypochlorite (clorox or other commercial laundry bleaches) or Oxalic acid.

I do believe I have that book. I knew it would come in handy one day!

Get a couple of bottles of vinegar and pour them in a plastic bucket and then add some steel wool. After about a week, you can apply this liquid to your oak and it will make it look like it's been around for a long time. The longer you let the steel wool 'steep' in the vinegar, the faster the greying will occur in the oak.

If you wish to get the liquid ready sooner you could dilute some muriatic acid and do the same thing. There is a chemical reaction between a weak acid and the steel that results in a chemical that will weather the oak.

Good luck!

Peroxides: Yes they work slow, but you are not using a hard base like (lye, AKA sodium hydroxide) or gas phase ammonia. You can modify the peroxide with sodium bicarbonate, that will prevent the raising of the wood grain. Using bleach (hypo or hyper) is also used, however, I don't like the problem of neutralization of the salts. Ammonia is rather nice in that you use acetic acid as the neutralizer, then all the acetate salts are water soluble.

However, for the big kick, use a 1:1:10 sulfuric acid (38%), hydrogen peroxide (30%), and 10 to 50 parts water. This highly aggressive etch will work very fast. Leave on no more than 20 minutes, then wash off with a solution of sodium bicarbonate.

You can mix peroxides if you wish, solubility issues will start getting to you. Yes Oxyclean stuff is a good peroxide (can't remember which one, dicuyml I believe (lowest form of knowledge, even a guess has more validity).

We've read about some gruesome sounding and clearly noctious smelling chemical agents but clearly none come close to cat pee in terms of noxicity, so you hve the answer Del.

Get some mates round.

And feel free to inspect our carpets, curtains and furniture any one of you who doubt.