Jump to content
Maestronet Forums

Goran74

Members
  • Posts

    154
  • Joined

  • Last visited

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

Goran74's Achievements

Member

Member (3/5)

  1. Excellent comment from Mr. Sora. Mike has a point too. To make the iron rosinate varnish you need water (0 costs), rosin (all we have), a strong alkali (costs almost nothing in a local store), hydr. acid sold for home use (1gal. for ~12$) , red/brown iron oxide costs nothing 100gr and can be found everywhere) etc. The only serious cost would be the mask / a good 3M one for inorg/org. gases protection if someone wants to do it indoors. The cost is minimal and the time to make it is nothing. I would consider other varnishes or wood treatments to be much more time-consuming that this operation. Someone needs to have a little knowledge of basic chemistry (not even 20% of the high school chemistry - I think all we went to high school).
  2. Hello! Before some days I bought a small container 250gr of powdered Manganese dioxide (MnO₂) to use it as a drier in my varnish. It is sold here as "gray manganese" pigment dye or in chemical supply stores in small quantities. I read the Safety Square which indicates No 1 for health Exposure would cause irritation with only minor residual injury (e.g. acetone, sodium bromate, potassium chloride, turpentine). Also, the indication was "harmful if ingested or inhaled" (that means not to eat and pull your nose out of it / no fumes, not making dusts as logic says). Kremer at his safety data details writes Acute toxicity (oral), hazard category 4 Acute toxicity (inhalation), hazard category 4. That means Acute toxicity Categories 1-4 (with 1 being the most dangerous) and bottom line: Toxicity category IV -> is Practically non-toxic and not an irritant. So, I opened carefully the container (without shaking it before), took to grams to put in the oil, closed the container, and washed very well the spoon, the funnel I used for the flask, my hands because it lefts a lot of "black", like many other pigments. There was a metallic smell essence when it came in contact with linseed oil, and I avoided smelling it and I closed the vessel immediately. Then, I heated the linseed oil outside in the open air with a tube that bubbled the fumes in water for half an hour (below 200C) and stayed away during that. I did not eat it, did not make dust around, neither put my nose in the container. I opened it for 2 3 minutes, transfered of 2 gr in the 100gr linseed oil and washed all very good after. ->Is manganese dioxide so harmful that even the above operation can cause to me health problems? Or it is another expression of my hypochondriac nature...? From the one side I see kids on youtube using it like a "toy" (I think most of us have opened an alkaline battery as kids), others that pulverize it without any protection https://www.youtube.com/watch?v=QrJmei4yi7U and from the other side I read about the chronic exposure effects /manganism disease. {Next time I would wear a mask even of the container opening - if I ever use it again.} Thank you!
  3. 5 star answer. Excellent.
  4. You need someone to teach you joinery. You can learn it very fast, without loosing time and money. Joint has to be perfect. It is very basic woodworking skill and a good carpenter (not even instrument maker) can teach you that. You ask here for very basic skills... When you want to learn maths chemistry etc. you go to the University (as you said that you are studying). Imagine someone trying to learn basic reactions from forums... Maestronet is a wonderful place full of information, but not a substitute for real life teaching.
  5. https://www.wood-database.com/ipe/ https://www.wood-database.com/?s=Beech
  6. There are so many other species (and cheap), from IPE, massaranduba to accacia, with much much more good properties than beech for the purpose of bowmaking. Also the carbon fibers are here too! I cannot find a single reason somebody to use this wood for bowmaking except one : someone that has factory and beech stock. So he wants to make trash quality bows to sell the with cheap violins, as this bow is the picture. (for bow wedges is good choice)
  7. Thank you for your answers. I will stay with my magnifying lamp and I will try to test the loupe glasses.
  8. Hello. I am using successfully a magnifying lamp, with led lights at the lens. So, I have light, broad view and a good magnification at the same time. Since my brother is a scientist working at the lab, I have tested some stereo microscopes to inspect violin defects. The problem with stereo microscopes is the view, and it is very narrow. I could never imagine repair or retouch anything under this view, since I loose the periphral view. Does anyone have advantages by using microscopes or a lamp with a good magn. lens is all we need?
  9. Thank you very much for your suggestions. I will try some of those and I hope to achieve better results.
  10. Hello! I have used some fillers for retouching in the past but I would like to hear your "recipes" and ideas on that. I have used various glues mixed with color, sawdusts mixed with glues, resins etc... Strobel recommends a shellac sandarac mix (at Violin maker's notebook). I used it, but without a lot of success. My main problem is that the most of the fillers that I used, have different light reflection in contrast to the wood next to them. They are more opaque, matt, blurry or they lack transparency. So, my main concerns are: 1. To be reversible 2. To be esthetically "right" 3. To be something that does not affect the sound quality I would appreciate your help. Thank you!
  11. Yes. The guy has to do the process again. It is not time consuming job to put blocks on form and then ribs.. Just take care of the corners. Use divider and not template.
  12. ->Cook it. To disassembly, whatever glue you used, put it in hot water in a big vessel or whatever you have. Then put it at the oven at ~100 Celsius or bit more. In 25 or a bit more minutes you it will be completely dissasemlied and you will have all the pieces without any flaws. Ribs will be deformed but you will fix them again. Let the pieces dry and fix any issue. Humidity and high temperature dissolve both titebond original and hide.
  13. It is waste of time. You can find easy IPE, massaradumba and ironwood to try - > go where selling wood for floors and there you can find these hardwoods. Acacia is great for making too.
  14. So, you like to see names and judge the term "great reputation". This is not on my intentions, it is off topic and I have nothing to prove to you. (except my respect that you already have it).
×
×
  • Create New...