Viewing 15 posts - 76 through 90 (of 191 total)
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  • #5684
    Giulio TiberinI
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      Absolutely no! The pressure only serves to adapt the tool surface with pitch to curvature of the mirror.

      Once that has occurred adaptation , species in the final stages of parabolizzazione, necessary to drag the tool taking care not to have to think above with hands (moving it to the edge).
      This assumes that the hardness of the pitch is such as to be able to slightly soften the heat of friction of processing combined at room temperature.
      If this slight softening avvieneL'utensile not dig without giving in easily and has to create the form zonal errors .

      If the pitch Excessive yield, It can create micro surface roughness accompanied by’ Excessive consumption and deterioration of’ tool.(Tool that is good not having to redo during operation).

      #5687
      maurizio63
      Participant
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        Ok I didn't quite understand that sentence.
        Is’ that at this stage of processing I have many doubts, due to my inexperience.
        But about gulgoz pitch where can I find it?
        I tried to look for it but I couldn't

        #5688
        Giulio TiberinI
        Moderator
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          The pitch Gugolz #55 It is given to an operating temperature from 13 until 18 Celsius degrees; e
          the #64 It is given to an operating temperature from 18 a 24°C.
          Both are for sale on the website referred to in the following link, until 31 euro + shipment, for the cylinder 1kg.

          http://www.optiques-astro-moindrot.com/taille_de_verre.html

          I think the only European that commodity seller.
          I have not yet made purchases because you bought 1kg 55 with a French company that closed a few year ago, and still use and recycling that. (I work only in winter, when I can not do “gymnastics” open air for bad weather)

          There are also gradations 73 e 82, who work very temperature “exotic” (that are high), respectively of 24-32 ° C and 32-38 ° C, But except in special cases can be purchased only in America.

          If by chance you do to make us partakers of the acquisition times and reliability of the supplier.

          Thanks bye

          #5744
          maurizio63
          Participant
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            Hi guys,I ordered the pitch from the French site suggested by Giulio,they should send it to me today. I'll let you know the shipping times.
            As for my mirror, I'm still because I want to redo the pitch candies
            with the gulgoz64 .
            Hello everybody

            #5745
            Giulio TiberinI
            Moderator
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              hello Maurizio. Very well!
              I think the suitability of the pitch ristrettta guaranteed a certain range of working temperatures, can simplify work already difficult per se, at least when it “scratch” the first mirror.

              Meanwhile, we have the chance to test the availability and reliability of the new European supplier but only current at the time was, of that merchandise. :yes:

              #5813
              maurizio63
              Participant
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                Hi guys ,
                Five minutes ago I e’ gugolz64 arrived (it was time!) there was some problem with the shipment because living in the countryside they couldn't find me,however now all solved.
                I would like to ask Giulio how I should behave with this type of pitch,just melt it and put it in the mold to make candies? I ask you this question because I am seeing that in the jar of the package I tried to sink my nail but and’ very hard so I guess it will always be so hard even in the form of candy or not?

                maurizio

                #5814
                Giulio TiberinI
                Moderator
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                  hello Maurizio. And, I mine #55 hot transferred into pieces in the saucepan for melting, by hammering the cardboard cylinder in which it is melted externally, and then there’ I have reached about sixty degrees, sometimes in the kitchen oven, and others on an electric thermostatic plate. At that temperature it takes a long time to melt, but the advantage of low temperature is that it does not bubble and loses less volatile components.
                  Hardness is what makes it directly suitable for work within the rated ambient temperature range (that I can not remember, but it seems to me that the gradation #64 go by !8 until 24 Celsius degrees, as per the Gugolz table published in one of my articles whose title now eludes me).
                  I searched and found the following image where it reads that Gugolz # 64 has a melting temperature of 72 degrees. https://www.grattavetro.it/wp-content/uploads/2014/12/pece-nera.jpg

                  #5819
                  Bartolomei Mirco
                  Moderator
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                    hello Maurizio, you could give us some more information about the purchase?
                    Delivery time type, Shipping costs, etc…
                    So I get a more precise idea…
                    Thank you… :good:

                    #5820
                    maurizio63
                    Participant
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                      Hi guys,
                      shipping e’ that's how it went’ was first an exchange of mail in French e
                      thanks to the google translator I was able to communicate. Payment e’ through
                      bank transfer and the price e’ 31 + 16,68(Shipping costs) the courier e’ SDA of the Italian post office. On 8 April and’ was sent from France and i e’ arrived at the office on 20 April why’ my home address was unknown and I had to call SDA and change the address to that of the office.’ arrived.
                      maurizio

                      #5835
                      maurizio63
                      Participant
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                        Hi guys I wanted to inform you that in this period I am stopped with the processing of my mirror due to the many commitments I have here in the countryside (a little vegetable garden, api, and various chores to do at home) they will probably resume’ after the summer but in any case I will follow you on the site anyway.
                        Regards

                        maurizio

                        #5856
                        Giulio TiberinI
                        Moderator
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                          Well. Don't worry .. I'm a too “seasonal worker” the grattavetro! ;-)

                          #6905
                          maurizio63
                          Participant
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                            Hi guys how are you? I hope so.
                            I am reactivating to resume the processing of my mirror where I was left,
                            as a first operation I will have to redo the pitch candies with the gugolz64
                            and then we'll see if anything changes.
                            I hope that in the next few weeks to post some better images than the ones I have posted to date.

                            Hello everybody

                            maurizio

                            #6907
                            Bartolomei Mirco
                            Moderator
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                              hello Maurizio, nice to see you again, every thing fine here, I hope the same for you too… :good:
                              Well, I recommend dedicating the necessary time and care to the realization of the patina in pitch which is an essential aspect to achieve good results.
                              Then we will wait for the new Ronchi images to evaluate them together…
                              good job….ciao

                              #6911
                              Giulio TiberinI
                              Moderator
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                                hello Maurizio. Surely with the new pitch you eliminate the problem deriving from an important variable. And it's good, since there are still several variables to keep an eye on.

                                The suggestion is to break the melted pitch cylinder in the cardboard, beating the cardboard with a hammer starting from the mouthpieces and going up, having the cardboard tube in hand and turned upside down in an old saucepan (so you avoid spreading crumbs).

                                Better to melt it by putting the saucepan (if not in a kitchen oven) on the plate of an electric stove, however, thermostated.

                                Since the #64 is given to soften up 68 and melt a 72 degrees, you can calibrate the thermostat a 75 degrees in order not to lose the solvents by evaporation that make it soft at the temperatures of use indicated by its degree.

                                And as non-electronic thermostats usually only mark MIN and MAX, and even if they mark the degrees it is better to check their calibration, I would check first, by heating water, to which position the desired ones correspond 75 degrees.

                                I also remember in my case, that despite the thermostating, I verified the emergence of bubbles in the viscous mass that at the bottom of the saucepan and in contact with the plate, came to 100 degrees. And I remember even having to place a piece of thick iron sheet between the electric plate and the saucepan (an aqueduct flange) per “stabilize” the On and Off temperatures of the bad electromechanical thermostat (or plate too powerful?) which achieved the average temperature of 70 degrees by detaching at approx 100 to hang up at approx 50.
                                (With that thermostat it would have been better for me to use the Maria bath system).

                                #6942
                                maurizio63
                                Participant
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                                  Good evening,

                                  I started working with gugolz (for a 40 minutes in total) and it seems to me that the situation as regards the sharpness a little improved ,I also made some changes to the tester, but’ if I'm not mistaken I see a little hill in the center.
                                  It's okay if I keep working 1/3 COC ?

                                  the bonus 5 photos are with the copper lattice
                                  the others 4 with printed pattern

                                  http://s12.postimg.cc/cl5id65a5/IMG_20151031_083432.jpg
                                  http://s9.postimg.cc/f79el0uzj/IMG_20151031_152615.jpg
                                  http://s28.postimg.cc/8k4rykwu5/IMG_20151031_152618.jpg
                                  http://s17.postimg.cc/nve2y9mzz/IMG_20151031_153237.jpg
                                  http://s30.postimg.cc/xihle3kgx/IMG_20151031_153240.jpg
                                  http://s2.postimg.cc/q1wjvpjnt/IMG_20151031_160916.jpg
                                  http://s10.postimg.cc/tzkblq8e1/IMG_20151031_160922.jpg
                                  http://s11.postimg.cc/4ghq9x6dv/IMG_20151031_180120.jpg
                                  http://s1.postimg.cc/4kwf2b6i7/IMG_20151031_180128.jpg

                                  thank you

                                  maurizio

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