hello all i am going to try & make a tung oil urethane mix for finishing a project i am doing.i think i need to use linseed oil in the mix,do i use boiled linseed or just ordinary.any advice wil be greatly appreciated.
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hello all i am going to try & make a tung oil urethane mix for finishing a project i am doing.i think i need to use linseed oil in the mix,do i use boiled linseed or just ordinary.any advice wil be greatly appreciated.
I am no expert on mixing poly finishes, but I think you would have to boil the linseed oil as I understand this prevents (or at least reduces ) it goin tacky.
You can mix Polyurethane with either Tung Oil Or Linseed. You don't need B.L.O. as the driers in the poly will cure all of these oils.
What you are effectively doing is making a homeblend Danish Oil.
I mix equal parts Poly, Raw Linseed Oil and Turps. It works very well.
I use raw linseed which I can get easily from a local farm supplies.
Paul, use Boiled Linseed Oil (aka BLO). Please note that Boiled should not be taken literally, you should never "boil it". Oil is warmed for application with beeswax and turpentine, but not anywhere near hot enough to boil it (air blown through it at 60-100 degrees C), this is done to increase the viscosity of the oil.
Boiled linseed oil has driers added. I'll try to find a link for you that explains it better.
Edit #2:
John Paquay's Oil finishing essay
Sydney Woodturners Article
Edit #1: I just read Bob's reply about the driers in poly drying the linseed oil, very interesting, I've never tried that.
I thought BLO had a gas bubbled through it not actualy boiled?
It's a marketing misnomer, much like the mixes they sell as "Tung Oil." :rolleyes:
BLO from a century or two back was boiled, but the closest you can get now is polymerised linseed oil (if ya can even find it) which probably isn't boiled anymore due to modern methods.
The modern version (the stuff with driers) has simply assumed the traditional name...
There is a linseed oil product that is actually boiled still. It is called "Tried and True" brand varnish, and there was an article on its use in FWW a few years back. Thinking that I had the inside track on a great finish, I went out of my way to get some for a cherry cabinet that I had made. What a disaster. I ended up removing as much of it as I could and using a danish oil finish. It was still sticky like fly paper a week after application.
I have an old formula book that gives the general procedure for boiling linseed oil, but mentions that this activity caused many factory fires back then.
Boiled linseed oil is oil that as been modified from its raw state by either blowing air through it to increase the oxygen content and thus speed polymerisation.Or washing it in a mild acid or warming it using the double boiler method.
thanks for all the advice al i will try some different ways & post a reply to let you know how it went & what i used
Great Links Groggy. Thanks!!
Answered a lot of questions about what I need to use on the next project. Coffee Table.
Echidna, when you say Poly, do mean those off the hshelf polyurethanes that you do floors etc with?
Wish I had read this awhile ago. I took it literally and boiled some linseed oil I had at home in one of my wife.s good saucepans. It left a baked on brown ring and The saucepan and myself were banished.
Any single pack poly will do, I usually use a full gloss as it gives a satin sheen when mixed with the oil but matt or satin is ok.Quote:
Originally Posted by Rookie
Once you add the oil do you have to use your poly straight away ie does it lower its shelf life?Quote:
Originally Posted by echnidna
I've still got some I mixed about a year ago and its quite usable with a good stir.
Just keep it in the dark with as little air as you can manage.
it will eventually go off, but has a pretty good shelf life.
Jacko