This May Have Been Done Before...

[Victor]

But I'd sure like to see some recipes for homemade varnish.

[skuthorp]

http://www.woodenboat-ubb.com/ubb/ultimatebb.php?ubb=get_topic;f=6;t=004334
:cool:

[Frank Wentzel]

Victor

The UV absorbers are the major impediment to making your own varnish. The "Chemist", who I believe working in the coating industry, said that the UV absorbers were very expensive and not available in less than 55 gallon drums. If expense were the only impediment I'm sure that it would still be worth it to add the absorbers to any varnish you made or add extra absorbers to store bought varnish. But the problem is the lack of availability in reasonable quantities.

Without UV absorbers in your home-made varnish you can expect to varnish exterior brightwork at least twice a year. The other problem is that the damage to the wood-varnish interface will require wooding the brightwork on a regular basis. In addition to being a lot of work you will also be damaging and loosing wood each time you do it.

/// Frank ///

[Wild Wassa]

Victor, when you find a recipe for varnish, there is one cool advantage. Your selection of amber can be interesting for when the subtlety of colour is important.

If I was making a varnish, I'd use Copal medium as the dryer (not Japan) and an artist's oily drying medium (as well) ... and add a bit of Damar varnish as a hardener. It's no good making a varnish that will be a backward step.

The sap from the Bloodwoods and Coastal Mahogany are great as colourings (found locally). I haven't tried amber from the local grass trees yet in paint, although I have collected a bit from this neck of the wood ... and the boat will need to be called 'Shiraz'. There would be no other option with that red resin. The varnish can also be coloured with oil tints as another option if the resin's colour is ordinary.

Making varnish is good for interiors and things like little boxes and stuff where the UV isn't a problem. It will be a sad day when we accept only what comes out of a can, as the only way to go.

I like to tint and colour my clear poly (I do use varnish and poly/oil blend varnish). Colouring clear poly is the way I'm moving and have been for a while. The experimenting has been the real fun, with lots of mistakes. I colour poly with acrylic tints, I have a good range of pigments with high permanance levels. The metalics and rare mineral pigments, make for good transparency. Metalic and mineral pigments have high levels of stability, generally.

I only use varnish over existing varnish nowadays, to keep the paint binder similar and when wanting to save time. Home made varnish is not a fast setter. Using Japan, (Japan dryer) will shorten the life of paint if long term quality is needed.

A lot of people use Japan on this site, it doesn't matter using Japan for short term painting like boats but Japan yellows and makes paint brittle in the long term, if you are making varnish for anything different. I'd use an artist's oily drying medium instead of Copal medium or Japan for a long term coat. They can be found in fast, medium or in a slower drying oils. They are slower in yellowing but they will yellow. Copal goes brown as it ages.

Warren.

[ 06-19-2005, 09:16 PM: Message edited by: Wild Wassa ]