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I'm not really the brand new scratch glass. Unfortunately I can not find anyone to supply me abrasives and glass in Italy. Something I found in Germany, but also a diameter them 300 per 15 mm thick it seems to me nonsense, I always stick to the text of Paul ing Andrenelli !
Some of you may indicate some supplier?
Thank you
Hello and Welcome to the Enzo Grattavetro. for abrasives it is quite simple, I rifornisco from gemmarum.it are fast, reliable and have acceptable prices, but there are also other online shops which, however, I have no direct experience.
For the glass they are to be found in his own glassworks area that can cut the thickness 20 mm, the maximum production of calcium-sodium slabs. If you just can not find anything directly, I could cut them from my glassmaker and spedirteli, but it is cheaper to take a ride glassworks.hello Enzo. Welcome.
I agree with the signs of Massimo, and add that to the thickness 20mm Search, It should give preference to so-called industrial glassworks, namely those working the glass of that thickness to make tables and furniture, or walked on plans.hello Enzo, Milan is the calciosodico glass 25 mm, high-pressure cutting and chamfer chamfered edge, and also a historical company that has abrasives, if you go in person you can buy smaller quantities of classic bags 25 kg. grain from 24 to the 1500 , green silicon carbide. pure white to Corydon 99% from 24 to the 1200.
professional aluminizing, even for large diameters (1000mm diametro).excuse me, but it is not possible to give the name of the company referred to by Lelio? because I'm calling dozens of random glass works in the Milan area with no results
Here I do not think there is such a ban which is not intended for advertising purposes.
But not to wait for a visit from Lelio, who may not have activated its automatic alert to the inclusion of other answers to this question, you could send them a private message, clicking on the item “You have 0 unread messages” up right here on this page, and then choose “Directory”, e in fine “Send message” to the row of Lelio nominative, to write the message.
This way you would be sure Lelio definitely receive an alert for your inquiry.
excuse me, but it is not possible to give the name of the company referred to by Lelio? because I'm calling dozens of random glass works in the Milan area with no results
And, Julius is right, our policy does not prohibit you to insert links to commercial activities, or write the name of a company, God forbid, but only seeks to prevent attempts “spam”, that they have nothing to do with the purpose of the Forum and with the interests of the users who write in the Forum, limiting the request and to send commercial information that is relevant to the site arguments.
This choice unfortunately, forces us sometimes ask users ( motivated by the best intentions of sharing of useful information for the availability of products ), eliminate part of the messages, when these are similar to commercials, that in fact legitimize, each subsequent commercial message written by spammers shift and believe me, you have no idea how many users “false” every day they should be removed along with its messages / links to activities or products, including the user who recently joined and posted a first and only message: “I sell borisilicato glass telescope mirror, Great price”
I therefore invite those interested, to take vision of the Regulation : https://www.grattavetro.it/forums/topic/regolamento/ , We recently updated it trying to make it as clear as possible.
I apologize for this digression and clearly Lelio, if you would, It may indicate all the glassworks that provide the glass with useful thickness. In any case it remains the excellent suggestion of Julius to use the private messaging system that leaves more free to talk about names and prices contact.
Council to all those looking for materials to go directly to the manufacturer, they have their clients' lists, and will turn to you nearest-
Newport glass per il pyrex, Schott Italy for suprax, ITALY SAINT-GOBAIN for the excellent quality calciosodico.
Phone calls directly to the sales office because the big companies do not take into account email.if you go on the site reginato telescopes to voice tools are calciosodico discs
up to 610mm thickness 24mm
Interesting. Thank you!!
The problem, however,, at least the time of purchase of the blank of my 250, It was that calciosodici tool were provided only for the purchase of a blank.
the previous message was removed because our policy does not allow the inclusion of commercial ads or sales in general for products relating to the activities and topics of the blog / forum.
therefore, as well as to renew the invitation to all participants to Grattavetro to take vision of our Regulation, we are forced to remove any action that is inconsistent with our guidelines on publishing content.
This choice stems from the fact that we are not structured to ensure the accuracy of listings and proper negotiation seller / buyer and would not be able to protect neither the one nor the other.
There are very valid sites that deal with the astronomical material purchase plus have a public directly interested in such advertisements.I mistakenly violated the rules of the forum on trade ties, I apologize. Anyway there is a way to get from borosilicate glass 30 mm at competitive prices. If it were possible to open a topic for a group buy on the forum…The moderators do I know.
hello Luigi, I would say that if the announcement of sale of a blank is already in breach of Regulation, more so it would be a buying group ( presumably for a supply of several blank )which would open in fact a full-blown business “sponsored” on our pages.
This would set a precedent that would legitimize subsequent requests from anyone planning to sell any product, mirrors, glasses or abrasives which are, individually or in series.Coming instead to content, I would say that it is not prudent to evaluate the purchase of borosilicate glass for optical use only with the assumption of “price competitive”, for different reasons:
1- the production process of borosilicate glass must be made up of several phases before being able to dispose of the finished product suitable to our use. Even taking the Supremax directly from Schott ( the top of borosilicate glass for optical use professional quality), would still “annealed” to eliminate any internal tensions due to the rapid cooling of the typical process “rolled” in which the molten glass plates are subjected, hence the final price does not properly “cheap” for SUPREMAX.
2-Addressing other companies around the world ( lately it seems that the Chinese go crazy for the production of borosilicate ) the price of these products is directly proportional to the quality of the material is that of production, then in general a cheaper product is not said that it is a “deal”.
3-often the glass is subjected to a tempering process that increases the resistance but prevents subsequent processing. Beware that sometimes is not even explicitly stated in the data sheets, that it is glass “tempered”
4 – the stated thicknesses may not be related to the same castings, but could be laminated glasses, obtained with overlapping plates and bonded with thermoplastic polymers and materials to increase strength and make them compatible with the safety regulations for structural works, Constructions, etc…
Be careful because you are likely to have in my hands a blank unusable as a parabolic mirror, but very effective as a bullet-proof glass.
Ok, I see.
I kamikaze I bought one and it seems good. Considering the cost in Europe here we do not take much.
Between the’ Another is slightly lighter than a standard glass blank.
I still have in mind in the coming months to test the process on a marble plaque, I met an Indian who told me that amateur astronomers from them they did, but I could not know more, for the moment.Careful Louis that a marble plaque, or any other material having a crystalline structure, It would present a non-uniform surface hardness, and workmanship, the hardest veins that are found in all natural materials, cause of “ribs” relief, that make it difficult to achieve the precision of abrasion 68,75 millionths of a millimeter (nanometers high.), which characterizes the minimum quality of a so-called mirror lambda / 4.
The metals have a less varied texture of materials narurali. They are more pure marble, and in fact they have been used before 1858, when Foucault showed that the parabolic mirrors could be manufactured in glass, in the manner that still today we adopt amateur homebuilders.
The fact glass is the only amorphous material useful, ie devoid of crystal structure so as to be considered a liquid with infinite viscosity at room temperature. When not hardened, but it is annealed, It is uniform in its volume, and this is the premise that guarantees the possibility, with a good workmanship, to obtain the best optical quality.
In regard to the degree of gloss that is necessary to reach in the processing, You can also read just the short sentence “practical” by title “SHORT NOTES ON THE DEGREE OF TRANSPARENCY REQUIRED FOR OPTICAL MIRRORS”, in the article at the following link
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