Dominik Tomasek

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Everything posted by Dominik Tomasek

  1. Well, let's check that! If I understand that clearly, to ensure that the blisters are produced by gases they should be empty inside, filled with air, am I right?
  2. Isn't there any risk of combining oil varnish and spirit thinne shellac?
  3. From your describtion it seems that the problem could be the matter of not giving the varnish enough time to dry. The bumps really are sort of blisters or something. Thank you for your advice.
  4. I meant with the brush applying another coat of varnish. Sorry for not being exact.
  5. Right - I have got this little update: I just varnished my viola. The steps were following: prepared surface, strong tea staining, gelatine applied. Then one coat of clear varnish. Once the varnish was dry I applied colourant on the back plate and put another coat of varnish. The result was nice, smooth and clear finish which I was satisfied with. Then I coloured the rest of the instrument and also gave it another coat over the colourant. This is still in the process of drying. But! Once I touched the already dry back plate (coloured and varnished) the sweating appeared! Absolutely confusing.... Dominik
  6. Dear Evan, thank you for you advices! These are my first instruments to varnish so...Long way to go I guess. I have no idea what is the composition of paints I am using, it would be better idea to buy high quality ones I would say. Well, next time I will know. Thanks
  7. Hi Fred, to cook the varnish I melted 180 grams of colophony, into wich I added 10 grams of calcium hydroxide (lime) dissolved in about 30ml of water. Once the lime mixed with the colophony completely I poured in 180 mililitres of linseed oil and cooked the mixture for about one hour (the instructions told me to cook it for 30 minutes only but that was not sufficient). After one hour the varnish got darker thicker and had a decent string. I thought that one hour is not enough but since it was my first time cooking varnish I decided to stick to the instructions. After the varnish cooled a bit I added about 100ml of turpentine to thicken the varnish. Regarding the colourant - it is oil based artists' paint I have no clue what are its ingredients. It is not stated on the tube. That leads me to the point where I think that this might be the problem...
  8. Yes that was Don's topic mentioned above. He had problems with thinner but it does not seem to by also my problem.
  9. No I did not as this was my first time cooking varnish and the instructions did not say so. I followed steps mentioned in this video: https://www.youtube.com/watch?v=gmHf5FHkh-c&t=18s . Yes I rubbed down the first coat on one of these instruments yet it was no help.
  10. I surely should do some testing on plain wood or to combine my techniques on some scrap samples to figure out what is wrong. I will definitely keep updating this topic.
  11. Thanks Don! I also thought it could be something with the thinner but I do not understand why it wouldn't occur when the first one or two coats are applied. Maybe the third + coat somehow reacts with the first two?
  12. The varnish showed in the pictutres is in the process of drying. The coats applied before were all right. Once I applied another coat the problem occured as soon as the varnish touched the instrument.
  13. Dear FredN, to cook the varnish I melt the colophony first. After all the colophony is melted I dissolve a bit of the lime in the water and slowly add it into the colophony. Once all the lime is mixed with it I add linseed oil and boil this mixture until I have decent string. After that I let the varnish to cool a bit and then I add a bit of turpentine to thin the varnish a little bit.
  14. I do not think so. The violin with the crack has no gelatine sealer and the problem still appears.
  15. The lime I am refering to is calcium hydroxide to bring down the melting point of the colophonny.
  16. Thanks for the answer! Yes, I have tested that. It dries after some two weeks and then the varnish is perfectly clear.
  17. Thanks for the answer! There are actually two violins in the photographs. The one with the crack was stripped years ago. I simply scraped down the old varnish (for training purposes) with scraper, then applied the colourant and then the oil varnish. First coat was great, varnish turned out to be very clear. After two or three weeks I applied second coat and then the sweating happened. To dry the varnish I used just the sunlight. The second violin, the one without the crack and the one made by me, was sealed using gelatine, then I applied thin layer of oil varnish, and then another coat of varnish mixed with artists' paint. Sweating happened. I have got another instrument - viola - that was also sealed, also had one thin layer of varnish, also had colourant and also had another coat of oil varnish and nothing happened. I am confused!
  18. Dear with_joerg, as an amateur maker I was in the same position as you are and I have developed this rule - do it to liking. Unless you are copying an instrument, do what suits you, wheter it is 10mm or 15mm in the narrowest area, simply be somewhere close. This way you will learn to carve and the future scrolls are going to be better and better. Best wishes! Dominik
  19. Dear Maestronetters, I have absolutely no idea whether "sweating" is relevant verb thus I am including some photographs. I have got this problem with my oil varnish - after it is applied it creates sort of tears, drops, lakes. My varnishing process is following - I prepare the surface, apply gelatine, than thin ground coat of my oil varnish (colophony, turpentine, linseed oil, lime), after it is dry I apply thin coat of artists' oil paint (colourant) and after the paint is dry I apply another coats of my cooked varnish. And then the problem begins. What could be wrong? I understand that some ingredient is drying faster than the other but why would it happen when the artists' paint is completely dry (even for several years)? Thank you in advance! Dominik
  20. I am sorry to go OOT, but what is the piece played on that tremendously sounding viola called? Thank you in advance!
  21. Stunning work Andreas! Sorry to be asking this question, but what is the purpose of different f holes lenghts? I probably did not get it from the posts above. Thanks!
  22. Thanks Andreas! Great work and perfect idea with the maple piece.
  23. Dear Andreas, would it be please possible to post more photos of the spruce neck? I am ridiculously curious about it!
  24. The board is about 34 cm long thus way too short even for a 4/4 violin...