Official Luthiers Forum!

Make Your Own 'Tru-Oil' Varnish


Traditionally oil varnishes were used on the bowls of lutes, violins and other musical instruments (such as ouds?).

Oil varnish is basically made by heating linseed oil and softwood resins so that they combine together and then allowing the raw varnish to oxidise in sunlight for several months before use. Making an oil varnish suitable for instrument work is tricky and hazardous - the materials being highly combustible when heated. Oil varnish also requires some skill in its application by brush.

A popular alternative today is to use a so called 'hand rubbed' oil/varnish finish - an attractive semi-gloss finish that is easy to apply. Such finishes are generally known as 'Danish Oil' varnishes of which 'Tru-Oil' is a popular example.
Unlike making an oil varnish 'from scratch', a 'Danish Oil' is quickly and easily prepared by simply mixing together, in the correct proportions, materials readily available from local hardware stores or paint suppliers.

The components of a 'Danish Oil' varnish are Boiled (not raw) Linseed Oil and an oil based varnish all diluted to a desired 'watery' consistency with a paint thinner. Polymerised (not raw) Tung oil may be used in place of Linseed Oil and the thinners may either mineral spirit or pure Turpentine.

'Tru-Oil' is made from a mixture of 56% mineral paint thinners, 33% oil varnish and 11% linseed or Tung oil. The exact specification of the components are, of course, a trade secret.

The proportions of a 'Danish Oil' may be varied - the more varnish the quicker the drying time and the greater the dilution with thinners the more coats that are required to build a finish.

For these trials the same proportions as 'Tru-Oil' were used with a mixture of Boiled Linseed Oil, an indoor Polyurethane varnish and pure Turpentine. The test piece was quarter sawn Black Walnut - fairly opened grained - planed smooth but with no grain filler applied.
Each varnish coat was brushed on so that the surface was saturated. After drying for about 10 to 20 minutes any surplus varnish remaining on the surface was wiped off with a paper towel - wiping across the grain (important!).
After drying for 24 hours the surface was lightly sanded - in the direction of the grain (important!) - with a 'Norton' 3X 320 grit open grained paper. The varnish dust created fills the wood grain. The next coat is then applied - brushing across the grain (important!) - and is allowed to dry for 10 to 20 minutes before all surplus varnish is wiped off - again across the grain.
After drying for 24 hours this process is repeated and eventually results in the wood grain being completely filled - in this case after about six coats.

The final finish is smooth and hard, very easy to apply with good penetration, and with a semi gloss lustre bringing out the pattern of the wood grain to good effect.

There are boats that go to islands. They carry things like heavy equipment, cars and any other thing that are impractical to ship by air. it may take a while, but it will get there the same way that acetone and other chemicals get there. I spent many months in Taiwan as an engineer working in semiconductor fabs. Believe me that there are chemicals far nastier than Truoil that make their way there

Man, I miss the hamburgers at the Cosby Saloon....the tomato soup too. Some other things I won't mention...LOL.

If I remember correctly stewmac offered shipping by boat, awhile back. It took about 1 month for the package to arrive in Europe but it was very cheap (If the package was big and heavy).