sanding / sand blasting old oak

[Gibboncore]

I acquired a couple of nice sized chunks of quite hammered looking old oak which I might use inside or outside... however they are as rough as a badgers and require some TLC.
I don't really want to sand them as they will loose a lot of the character but I'm not really sure what the options are... I can only think of sand blasting but I don't know how well it would work.
Any advice gratefully received.
Cheers
Micky

 

[AThurlow]

Hope you don't mind me piggy-backing your post Micky but I have a very similar need for advice so thought someone might be able to kill 2 birds.....

I too have a lump of oak which I want to use above a fireplace in the cottage I'm renovating. Like Micky I don't want to loose any of the character of the oak so am interested in how best to finish it. I'm also wondering what, if any, preservers etc I should be thinking about treating it with before putting it in place, especially bearing in mind it will be relatively close to the wood burner it is above.

Any advice will be welcome.

Thanks

Adam

 

[Deleted member 174758]

Metabo make a machine for just this process. You do the initial clean-up (if required) with a brass wire brish or stiff nylon brush then finish off with a rough sanding brush. I know that both Elu and Makita also made machine like these in the past so it might be possible to hire one.

Other than that you could always try cleaning up the timbers with a brass wire brush (if needed) then finish off with an abrasive wheel disk on a grinder for the deep bits) and a belt sanding the flatter areas with a P60/P80 belt (but don't over sand). I've not long done a pub/restaurant ceiling this way, about 400 sq ft of really rough sawn softwoods, and I was pleasantly surprised at the end effect.

I'm also wondering what, if any, preservers etc I should be thinking about treating it with before putting it in place, especially bearing in mind it will be relatively close to the wood burner it is above.

It's oak and presumably old? If it has worm holes then they've already had their meal long ago, if not and in any case it's internal to the building so it will be dry. About the only thing you could really do is give it a couple of clear coats of clear Cuprinol. Black paint is no longer regarded as "de rigeue" and oils, like boiled linseed oil, tend to go shiny and trap dirt

 

[Gibboncore]

Hope you don't mind me piggy-backing your post Micky but I have a very similar need for advice so thought someone might be able to kill 2 birds.....

Not at all mate

 

[Gibboncore]

Metabo make a machine for just this process. I know that both Elu and Makita also made machine like these in the past so it might be possible to hire one.

Just looked at the prices and I think I'd look to hire given the amount of work I have to do on it.

You do the initial clean-up (if required) with a brass wire brish or stiff nylon brush then finish off with a rough sanding brush.

Is this because of the risk of staining using a steel brush or is there another reason?

Thanks for all the advice on the prep and treatment... all I need to do now is hope that satineermachine really is Dutch for burnishing machine!

Cheers

Micky

 

[foxhole]

You will need to treat it for woodworm, used a piece over fireplace and even though it had been stored for several years in cold conditions the woodworm were still active.

Untitled

• foxhole
• 3 Aug 2010
• 7

 

[Harbourwoodwork]

Any form of abrasion will take the patina off if it's only skin deep. If you've got a small bit to do, try a good old scrub with soap and water if your not happy with that, try something more aggressive. As far as the worm's go you can import new wood eating stock and may be new species too. If there are flight hole's some sort of woodworm killer is a good idea. For the finish, oil or wax is good. Coloured wax puts a lot colour into the wood. If you lose a bit on the clean up Iv'e had some good results with liquid wax. It really gets into all the cracks and blemishes and gives a good aged look.

 

[Deleted member 174758]

You do the initial clean-up (if required) with a brass wire brush or stiff nylon brush then finish off with a rough sanding brush.

Is this because of the risk of staining using a steel brush or is there another reason?

Brass or bronze brushes are a often thinner wire and less stiff than steel brushes - therefore less aggressive. Also if any of the bristles break off a steel brush and lodge in the oak any traces of moisture will result in a black stain apppearing. No problem if your timber is already dark coloured, but where the timber is lighter such stains are very noticeable. BTW the stains are ferric oxide (black rust) and are the result of moisture in the atmosphere leeching out tannin from the timber to form tannic oxide - tannic acid in conjunction with iron or steel makes black ferric oxide. As far as I know this is only a potential problem with three species: oak, walnut and swietenia (i.e. "real" South American, not African) mahogany

all I need to do now is hope that satineermachine really is Dutch for burnishing machine!

Good luck. All I can say is that I've seen German chippies wielding tools like those when renovating timber framed houses. Of course I missed probably a better known manufacturer of these tools, Flex

 

[mointainwalker]

I live in the Alps and sand-blasting ( or other abrasives ) is common for the structural wood-work in old barns which are being renovated.

The results I have seen have all been very good with no visual degradation of the wood, on the contrary it looks much better with dirt and oxydation removed.

Unpleasant to do as you need to wear head-protection with separate air-feed to be able to carry out work.

The general opinion here of these machines with toothed-rollers is complete waste of time.

Just for interest, professionals here charge £ 1,200 per day whereras you can hire the compressor +blasting equipment for £250.

 

[GreenOakFrames1]

if you are taking the oak to get it sandblasted make sure they use fresh sand , if its been used previously on any ferrous materials , wheels old baths etc . the iron particles in the mix will react with the tanin in the oak sending black. Of course if the oak is really dry this will be less . I also burnt oak on this job .......it gave a really pleasing effect http://www.thewoodworks.co.uk/grdnseatpic.html