Spar varnish finish

[Dan Fruth]

If you have ever used a spar formula finish you need to be sure the spar has not been "altered" by the EPA.
  I have used the "old formula" of 1-1-1, of spar varnish (satin) pure gum turpentine, and leaded, boiled linseed for some time. This was the finish of choice in the cabinet shop when I worked at the Ohio Historical Society back in the 70s and early 80s. I just mixed up a new batch with Mcclosky's spar, but it just wouldn't dry to that hard surface I was used to. I called Mccloskey and found out why.

  The original formula that dries nice and hard is product #7505....This is the original formula with high VOC content (500)
   #6505 is next in line, but with lower VOC (300), and should work OK
   #6535 is what I got, and because it is LOW VOC, it never dries hard enough, was made for southern California, and has made its way here to Ohio, and soon will be in the trash!

   DO NOT use anything but #7505, which is still available in quarts, and works GREAT!!!

[Dan Fruth]

Note: #7505 is not to be sold in many states, per EPA, but this rule applies to gallons. Quarts are still available.....The madness of EPA!!

[redheart]

Where do you get the "leaded BLO"? 

[Jerry]

Dan, Could it benefit to add Japan Dryer to the mix? Jerry

[Bsharp]

Where do you get the "leaded BLO"? 

So what are you using for your BLO?

[Dan Fruth]

I have been able to acquire about 1 1/2 gallons of leaded BLO, made in the 1960s. BUT, before that I used products from Natural Pigments and made my own.

  I bought white powdered lead, and cold pressed linseed oil.  I put a teaspoon of the lead into about a tablespoon of vinegar, and put that along with the oil in a pan. I used a hot plate outside the house and heated the mix to a rolling boil, stirring constantly. Let it cook about 1 hour, it will turn dark blood red in color. When cool, I poured it through cheese cloth to strain out any uncooked lead, and bottled it.

   When you mix the spar, turp, and oil, only pour out what you need for the job (I use small bowls) and add a couple drops of cobalt drier. Rub an area of the stock at a time, being careful to not flood the wood, but a thin film that is vigorously rubbed into the wood, the move to the next spot.

   It dries to the touch in 4-6 hr, and ready for recoat in 24.
https://www.naturalpigments.com/cold-pressed-raw-linseed-oil.html
https://www.naturalpigments.com/lead-white-pigment.html