Finishing Wood......now with images

[bushtuckerman]

I would have posted this in the 'woodcraft' section, but I couldn't find it.


"Oils such as olive are non-drying and can leave a sticky surface and increase the growth of mould."

I read this on a certain website and it got me wondering what people use themselves to finish their carved wooden objects.

I myself have always used olive oil, simply because it's easily available, but also because it's delicious and most of the things I make are used with food. I haven't ever found it to be sticky, but non-drying and too easily washed off, yes. I have therefore refrained from using soap when washing these implements and simply used hot water.

I once used sunflower oil but it very soon began to smell undesirable.

I wouldn't personally consider varnish, but I am interested if you do and why.

If your replies are many then I may post a summary here in this post for others to view more easily.

 

[Scots_Charles_River]

We use Vegetable oils in school for finishing any food use product eg wood turned bowl,egg cup or a wooden spatual.

Nick

 

[wanderingblade]

You are limited if the items are to be used with food. Maybe change the way you finish with Olive oil? Do you give it a few coats or a good soak for a few days? It may be worth soaking, drying fully then soaking again after a light sand, just to ensure a good, deep penetration of oil.

Personally I use Danish oil / Linseed oil mix to soak the handles of the knives I make or use stabalized wood.

 

[bushtuckerman]

What is Danish oil? Do you make sure to buy non-toxic linseed oil?

 

[DoctorSpoon]

Oils that cure
Some oils cure, that is they will set in the wood, and some do not. If you use one that does not cure there is a chance it might go rancid in the wood. With an object as small as a spoon there is only a small chance - I have only seen it with larger things such as salad bowls which have been regularly oiled with olive oil and rarely washed. More of a problem is that the oil will wash out of the wood when you wash the spoon, so it will need re-oiling periodically if you want your spoon to remain protected. That is why we use and recommend oils that cure.

DIY oils
Oil is naturally quite viscous, so many oils sold for DIY use contain chemical thinners which help them penetrate the wood. The thinners are not food safe, but because the oils are not sold for food use there is no obligation for manufacturers to even state their presence on the label, let alone say they are poisonous. Whilst the amount of thinners that would go into your body through eating with a spoon coated in such an oil is minimal, it is not what I would choose to put in my mouth!

Recommended oils
For small quantities for personal use we would recommend some type of cooking oil. Walnut oil is the best; it cures quite quickly and smells lovely, but obviously is not good for nut allergy sufferers. Linseed oil sold for food use is also excellent and safe for those with allergies, health food shops sell it, often calling it flaxseed oil. Sunflower oil also cures, but it will take much longer. Olive oil does not cure, so is not recommended. We use large quantities as Robin oils bowls too, so bulk buy cold pressed linseed oil from an agricultural merchant; it is sold for feeding to horses as it makes their coats shiny!

... can you tell I've been asked this so many times I keep it on my computer and cut and paste it where required
Nicola

 

[tom miller]

I like Tung oil, it doesn't go rancid like Linseed can.

 

[DoctorSpoon]

I like Tung oil, it doesn't go rancid like Linseed can.

linseed oil cures and will not go rancid.

Tung oil also cures so will also not go rancid however, firstly it is often sold for DIY use and has chemical thinners added, secondly it is made from a nut and is not good for folk with nut allergies. If it's for your own use and you are fine with those things then that is absolutely fine. If it's for sale or to give away I would be cautious.
Nicola

 

[loz.]

Boiled Linseed Oil or danish oil,

Regards Tung oil. This should be foodsafe after 30 days, even for someone with alergies, although dont quote me on this, or test it with someone with alergies, just something i have seen quoted on many a finish suppliers site.

Loz

 

[tom miller]

Just going on past experience, I had to chuck a tin of Linseed because quite frankly, it stank to high heaven. Never had that problem with Tung oil.

 

[pwb]

I use linseed oil taken from a drum once used by my grandfather. It must be 60 or so years old and it's still crystal clear. I love the smell it brings loads of memories to mind.
I find it gives a lovely finish to wood especially after use and handling.

There's an old saying I heard as far as oiling wooden tool handles etc:
Once a day for a week,
Once a week for a month,
Once a month for a year,
and
Once a year for life.

Not sure that applies to objects used for food though.

Pete.

 

[stevesteve]

I have used the oil sold by Ikea for their breadboards. It seems OK.

Cheers,
Steve

 

[bushtuckerman]

Thanks guys.

I still am unsure as to what 'Danish' implies and whether or not it is food safe. Tung oil I have never heard of either, but if it is toxic then I would not use it for anything, perhaps there is a non-toxic version?

loz, why do you boil the linseed oil? does it take away some of the smell? I am not sure yet whether it would be a suitable smell on objects I give away as presents (the main outlet for my work, helps the hobby pay for itself) as some people are particular. I know no nut allergy sufferers so I will investigate walnut oil, but again the smell is a main factor, as with sunflower oil which I found to be pretty horrid after a while.

wanderingblade, I usually coat it once in olive oil, wait until dry and then coat again. soaking is not an option because the quality of the oil is such that it would be expensive to do regularly.

puub, that's a nice guide, thanks for that.

 

[DoctorSpoon]

'Danish' oil is just linseed with chemical thinners in it so it soaks in the wood more easily. Tung oil is not toxic on its own but also usually has thinners added. Linseed oil can be bought ready-boiled. Boiling it means that it'll cure more quickly, but makes it thicker so they also add thinners to it.These thinners evaporate off over time technically making them food safe but it's not what I'd choose to put in my mouth!

 

[loz.]

loz, why do you boil the linseed oil?

Hi,

Its boiled to reduce the drying time. I use it to raise the fibres on pieces i am turning as part of the sanding/finishing of an item, helps get a nice smooth finish, and acts as a good base for other finishes, such as wax or polish.

 

[loz.]

These thinners evaporate off over time technically making them food safe but it's not what I'd choose to put in my mouth!

I appreciate that, each to his won. However if we analyse everthing we put in our mouths we would proabalby starve!!!

Was just reading this am a peice regarding shellac finishes, and the coating on some medicinal tablets, M&M's and smarties. - mmmm beetle parts on our kids munchies

 

[bushtuckerman]

Does that mean that if I were to buy pure flax seed oil and I boiled it myself, then applied it hot to the wood maybe to get it to soak it more readily that it would be as effective as thinned linseed oil?

I'm worried about linseed oil raising the grain, as I would want to use it as the finish. I do sand the objects quite often and have found sandpaper to be very short lived if it's used on oiled wood. Is it the thinners which raise the grain or just the oil itself?

I've heard about the coatings on these sweets, but then most of us eat animals, so insects don't seem to be any different to me. Toxins are probably more likely to build up in meat from animals reared on farmland than in beatles say in a pristine environment such as rainforest, so it's all relative and dependent on what has gone into the animal, and the animal's food source too.

 

[burning]

If the wood isn't hard the grain WILL raise usually but that's not a bad thing just more work to sand off and oil again.
For eating utensils beech is the one to go for but I wouldn't recommend it for first timers, practice with the easy stuff then move up.

and don't forget or you'll cut yourself ........ "there is no spoon"

 

[robin wood]

Does that mean that if I were to buy pure flax seed oil and I boiled it myself, then applied it hot to the wood maybe to get it to soak it more readily that it would be as effective as thinned linseed oil?

Yes that's exactly what I do, It does not have to be hot just warm is enough, if there is no one with nut allergy around I recommend walnut which comes in a 250ml glass bottle, stand the bottle in hot water for 5 mins, wipe on then wipe excess off, job done. The "boiling" that is done to factory boiled linseed is not just boiling it is a complicated process which can not be repeated at home, raw oil will cure anyway in time and you can use the spoon straight away whilst it is curing. Boiled linseed has heavy metal driers added, it used to be lead but that was removed as it was so toxic, it has now been replaced by other heavy metal driers but they don't disclose.

I'm worried about linseed oil raising the grain, as I would want to use it as the finish. I do sand the objects quite often and have found sandpaper to be very short lived if it's used on oiled wood. Is it the thinners which raise the grain or just the oil itself?

Well that's a problem due to the action of sandpaper which does not cut the fibres cleanly but abrades them leaving a microscopicaly mashed surface, that surcace feels smooth when full of fine dust and freshly sanded but as soon as it gets wet by whatever means it feels rough again. The trick is to work down through the grits then when you have done your last sanding with your finest grit (say 600 grit?) wet it with water then when dry give it a very light sand again, you only want to skim the tops off the grain that was raised not cut through to a new surface. Finally I would apply the oil and sand with the finest grit gemtly whilst very wet with oil. This will not clog the paper in the same way as you have found with oiled wood as the oil will carry the particles away. You can sand wet or dry but damp wil clog the paper quickly. Its all a bit of a pain to get a good durable sanded surface, better in the long run to work on your knife skills until you can get a good finish straight off the knife.

 

[bushtuckerman]

I have always used sandpaper begrudgingly. I don't really enjoy the feeling that I'm doing something I can't replicate away from the [theoretical] workshop (unfortunately I've never had one of my own). But I do enjoy the smooth finish on the wood if I can achieve it, and even more so the clear sight of the grain when oiled too.

My ability with the knife has improved dramatically in the past year from making things constantly, and I now feel I can make any shape I wish to, the only limitation being the availability of the right wood and the right tools. I have been using knives since I got my first opinel at about 6. I pride myself to a small degree in having made do with what I have, but now I want to fine tune a few things, and for that I lack knowledge.

I would like a new spoon knife too. I might make one and try to improve on the one I made before, which I can't sharpen properly and which is too flimsy...but I use it anyway and have made many things I'm happy with, albeit in twice the time really necessary with proper tools.

I am still learning to sharpen my knives properly and having only got my own Japanese bench stones a couple of weeks ago I feel I still have a way to go. My point is that I should have the ability to carve smoothly enough, but my tools are not kept sharp enough. I can get a razor edge on my sloyd knife but it quickly goes smooth and loses bite.

As for sandpaper I have generally used 320 grit until it's worn down a bit, and then rub it against another piece of 320 to make it finer and used that for a bit and then oiled. More recently I've experimented with ridiculous grits from 800 to 1500, just because I can, but it's not really doing it for me. 600 sounds about right, but in due course I'll leave sandpaper behind with the exception of the effects I like with sandpaper on a roughly hewn piece of wood, as it leaves the sharp faces left by the knife but rounds the edges which are uncomfortable in the hand. This is what I always did until not so long ago, not really being bothered to go through every grade to get a perfectly smooth surface, just 'hand smooth' is good enough for me.

I have just finished a cup in the style of a Danish one on a postcard my sister sent me from Denmark when on one of her archaealogical digs. I'll post it here to give an example of the finish I get with 320 - 800 - olive oil, on birch burl, alongside the beautiful cup in the postcard. I think the original might be a horses head handle, but I made this one for my sister who likes chickens, so it has a chicken head (perhaps). A perfect example by the way of my jumping on the chance at making something I haven't made before, as I struggle with my own designs. I think I'll investigate more viking designs for ideas.

Thanks for the advice.

 

[bushtuckerman]