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Goran74

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Posts posted by Goran74

  1. Quote

    2 hours ago, Davide Sora said:

    I think investing some time learning how to create a decent varnish is time well spent, the advantage is perhaps negligible for an amateur, but in my opinion mandatory for a professional.

    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 4That 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. 13 hours ago, nathan slobodkin said:

    Hide glue and overhanging edges are why violin family instruments last 400 years instead of 40.

    Titebond is a good glue for some purposes but not for instruments.

    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. 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) 

     

     

  6. 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? 

  7. 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! 

  8. On 11/12/2021 at 12:24 AM, chiaroscuro_violins said:

    wasteful to cook it and disassemble entirely

    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. 

  9. ->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. 

     

  10. On 10/30/2021 at 6:28 PM, Ranala said:

    I got it into my head to try and make a bow. I already disassembled some cheap bows to test the waters (still have to put the together though). Today I went to a local lumber yard to try to get some cherry wood for practice (which they didn’t have) and came back with a nice piece of walnut with fairly straight grain.

    The question is, is it possible to make a bow (stick) out of walnut it or is it a waste of time (other than practicing my woodworking).

    I am planning to make the stick and source the frog from an old (broken) bow (for now).

    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. 

  11. 17 minutes ago, David Burgess said:

     

    Why do you desire a smooth and flat surface on the top? Have you been taking advice from the wrong people?

    I have seen many instruments that have sanded top/ flat from modern makers with great reputation (and much greater prices) in Cremona and here in Europe generally. The instruments look very nice. 

  12. 1 minute ago, Paul McClean said:

    Thanks Goran.  I scraped the surface and added a little water to raise the grain followed by sanding but I think I could have sanded more to obtain a better starting surface.  I'm think the suggestion by Greg above will work better than the wet and dry sandpaper but also expect I may need another coat of varnish first.

    You have already a nice varnish. 

    For polishing:

    You have to choose on what you like

    - >Matt (abrasive component+oil) 

    Semi gloss (with wax as ingredient/ carnauba+beeswax) 

    Gloss (French polish) 

    Also you can try mixed types

    (abrasive, oil, water, wax , emulsifier together) 

     

  13. 1 hour ago, Paul McClean said:

    My varnishing schedule is as follows: Light sanding with 1200 grit wet and dry in between each oil varnish coat

    Sealed with gelatine.  Light sanding with 1200 grit

    Water based stain

    primer coat by Joha

    7 coats of oil based colour varnish

    2 coats of oil based clear varnish  followed by 2500 and 3000 grit with polishing oil

    Even though I sanded in between varnish coats the final surface is not flat on the front and you will see shiney spots and dull spots after using 3000 grit.  I have not tried sanding the back yet as the finish looks much better without sanding.

    Any advice on how I might improve the finish on the front?  The more I sand, the risk of creating lighter lines along the grain.IMG20210504175713.thumb.jpg.983f63e9c3a6de9020fbabd5f1d2b705.jpgIMG20210504175649.thumb.jpg.b89577a9f1f2d23fcb1423fb39738f0f.jpg

     

    You said you want a flat surface. Before anything else, how did you finished the surface? Scrapper or sandpaper? 

    For the flat front (which is not my favorite) you have to finish with sandpaper (that needs small sand. blocks etc). It is tricky and need care (because of the wood appiarence later). Then you need to pass all the violin with a little water. Dry it. Then sand it again. So, the surface have to be completely flat. 

    At this stage you will need more coats of varnish. Varnish/sanding til you find the flat. A process which is questionable. 

  14. 4 hours ago, jezzupe said:

    I'm pretty sure Strad used a Craftsman

    :lol: Come on.. For years I was using no power tools except drill. But, after time, wrists have some difficulties etc.

    I am sure that you do not like to have the "hands" of the old woodworkers, violin makers, Wood carvers etc. 

  15. Hello,

    I would like to purchase a scroll saw to cut various things for the violin-making process including the mold.

    Can you suggest to me what do I have to take care of?

    Here in Europe I see many good reviews for Dremel Moto saw or for Einhell . Their price is very good.

    Also, I would like to know something about their safety. Many woodworkers say that they are very safe as machines, even safer than a drill. (As violinist I have to take care of my fingers - as much as I can - but not on the obsessive/pathological way.)

     

    Thank you

  16. You can let aside commeical glues, of course they have their purpose in industry, and focus on natural glues. 

    Bone glue is very nice for construction. I would say some times I prefer it for the making process and let hide glue for repairs. Fish glue was also used tremendously in Mediterranean countries, from Spain to Egypt and to all kind of instruments. 

    The best glue is the good joining and right clamping. 

    I know guys that join plates with Titebond. Since they do perfect joints, glue comes in second place. 

     

  17. 2mm aluminium, or thin plastic or wood and you can cut your own.

    Avoid ready made templates for many reasons. 

    Pay less for a good plan, than a lot more for bad made (and useless as you will realize after time) templates. 

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