FredN

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About FredN

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  1. FredN

    Any Cremonese Basis for Colored Rosinates?

    curious to know what is a rosinate as being mentioned here. I think the simplest varnish one could make is based on metal resinates (rosinates?).
  2. FredN

    30 coats of varnish?!?

    Mine is usually 7 coats with some wet sanding around coat 5
  3. FredN

    Mike Molnar's Bench

    shows you just can't enough reflectance in the undercoat. Too bad the turn into the corner which normally has minimal wear isn't clear-
  4. FredN

    Removing shellac overvarnishing. Help!

    Hopefully if it is an oil varnish under all that stuff, try various concentrations of alcohol and water til you find a mix that will take off that stuff and just soften the base varnish. I'm guessing that stain is into the base varnish and only solution is remove all.
  5. FredN

    Cooking Colophony Down For Color, Low and Slow?

    Hi Mike, I cook light rosin in copper, thin with turp and let it cook for a while. Do this just above mp of rosin. The two colors we usually associate with copper is reddish for cuprous oxide, and black for cupric oxide, the stable form. Since it is multivalent, existing in two forms, it is a weak drier. Made up in a ratio of say 4:1 oil could be an undercoat, or also with no oil. The label on one cook says "green cast", so this might also be a state with rosin.
  6. FredN

    Cooking Colophony Down For Color, Low and Slow?

    If it behaves like rosin, heating will give you a lovely yellow
  7. FredN

    Oil Varnish

    Hi Finn- I bring the mix to a 1/4 inch rim foam which I think is around 500F. All contents are being cooked at the same time, rosin, oil, umber as a colorant and drier, so any color contributed by the rosin is mixed in. Literature states rosin and oil should be cooked together because there is an interchange between resin and oil. Doesn't describe the reaction. fred
  8. FredN

    Oil Varnish

    Hi David, appreciate your concern re dangers of making varnish. Like Rimino who has made varnish for 10 years, I've made it for a longer period and first started by making fossil copal varnish where at certain phases cooking temp's are around 625F and higher. Making a rosin varnish is almost ho hum compared to making that varnish.
  9. FredN

    Oil Varnish

    Rimino, in pulling a string, try dropping hot varnish on glass, tip it vertical and with one finger touch and pull horizontally. If in one of your pulls the strands seem to not sag and sort of snap when breaking, pretty much done.
  10. FredN

    Oil Varnish

    Nick, from experience pulling a long string often is deceptive and the varnish will take a longer time to dry than expected. I gave up on it and use heat to get a steady surface foam, even just a thin rim foam, and stop cooking when the foam starts to go away. A thin rim foam leaves you at the off-and-on vagaries of your heat plate, using a surface foam overcomes this.
  11. FredN

    Oil Varnish

    Have to add that I make small batches, ca 15gm lt rosin, 12gm oil, so I'm not pouring massive amounts of turp. I use an ordinary baby medicine dropper, drops at start with vigorous stirring, later squirts. There is a very complex event occurring, at start, oil is the solvent, adding turp eventually it is the solvent, oil is the solute. Hot oil into relatively cold turp can cause a rapid boil. Vigorous stirring prevents hot pockets during this transition. I wish I could explain this better, but I think that is what happens.
  12. FredN

    Oil Varnish

    Darn, I was hoping I could get away with that, I didn't. The problem is I add turp at a very hi temp, it spits when I add it to drive off the ever present water in turp. Not easy, but if you heat turp, siphon the vapors that come off and squirt them at a hot iron it spits indicating the presence of water. This water is the cause of problems later. I find it acceptable to start adding turp at 400F with vigorous stirring. There are so many variables involved I suggest thinning to something less than a watery drip, you can always add more later.
  13. FredN

    Oil Varnish

    Rimino- I notice you didn't mention anywhere that you did the standard test that bonds have altered sufficiently by pulling apart a drop between your fingers will give a fine bunch of strings. This indicates cook is complete and will take up oxygen. You can be mislead sometimes thinking cook is complete this way, only later you find out it isn't when your varnish won't go tack free. If you are making a rosin varnish you should cook both together cause there is an interexchange of bonds. Another way to signal end of cook instead of finger pinch is to raise temp to get around 1/4 foam, hold at that temp, usually around 30 minutes, until foam is reduced, indicating by products causing gas have completed. Cool and add turp to a rapid drop.
  14. FredN

    Lake, Rosinate, lightfast?

    Hi Johnmasters- yes, the iron replaces the alkaline end making an iron oleate. It undoubtedly is a mix of the fatty acids that make up Ivory soap. Years ago I wrote the company and they stated it was still pure soap. It would be interesting to make a rosin soap and see what happens. Age tells me my trying days are over. fred
  15. FredN

    Lake, Rosinate, lightfast?

    I guess the simplest to make and durable are metal resinates made by cooking rosin with some Umber artist pigment(manganese /iron) or Ochre (only iron). Some users state the color darkens with age, I never observed this. Johnmasters- not sure how you made your metal soaps, but make up some iron sulfate (green vitriol) in hot water and also Ivory soap in hot water. Mix the two with violent stirring, dry and heat to drive off the water and you'll have an oil soluble red dye that will give a really nice violin color