... has anyone in this group considered or knows of a low carbon steel plate with walls at 45 degrees welded on as a form to build flat blanks or stainless...
Hi Roman, What exactly do you mean? Are you suggesting a steel or stainless steel mould for casting the glass into or are you suggesting an all metal mirror?...
... Thomas excellent information, yes I'm thinking exactly of casting a mirror in the fashion you "assumed" ;) . I had tought about a removable 3" sideband...
... /snip/ ... Thomas sorry to follow up on a second question, i just looked up Inconel 600 and it seems to have a lower melting point than low carbon steel if...
If your going to use MoSi2 heating elements I would look into all alumina refractory materials, colloidal alumina binders are running @$2.50/lb and you use...
... Well... You also have to consider that the steel will have a magnitude more expansion and shrinkage than the Borosilicate glass. As the mold and glass...
Nope, it’s true, but they press the blanks into the moulds, then do the final anneal step later. Cheers, Thomas. My taper shank drill sale: HYPERLINK ...
Check the hot strength of those materials, low carbon steel has an upper limit of @600’C (dark cherry red) at which point it becomes “plastic” stainless...
They used alumino-silcate fire bricks coated with a “kiln wash” of some kind to build the big moulds, at least that is what they did for the big blanks, I...
I'll have to disagree about the kiln wash,, or any other type os a release agent. Because if the super fine detail in the text that was on the back of the ...
Joe, There HAS to be something between the glass and a metal surface when they are both that hot, glass wets iron. Besides if you don’t have some sort of...
Hello All, I'm very interested in this thread, as I'm trying to fuse my own structured blanks from surplus borosilicate (from a local labware maker), that...
Hi Oscar, Your English is fine! I would just add that 1550’C isn’t needed to cast the glass, although it IS needed to make the glass. The optimum casting...
That's why I asked what they used,, I didn't say they used "Iron" The question was I wonder what they used. I've used Kiln wash many times before, and I can...
In addition,, a kiln wash surface would be a matte surface of some sort. This was a perfect 100% polished surface with absolutely no texture what-so-ever. A...
say thomas what about the material that is used to make firebrick? it can be cought in a powdered form that can be cast it will stand up to 3000 deg F or for...
hey Thomas I found a web sight that has a mold material that they claim can be used over for glass casting _http://www.artglass1.com/castrefractr.htm_ ...
That depends on the brick, most for that temp range are made from alumino-silcates, the higher the bricks rating the higher the alumina content. You can get...
The first thing that I note from the old blanks is that they are tapered on the sides. Second that I note is that the top appears to be a poured high...
I have any number of pressed blanks, they all have a matte surface on the mold contact surfaces, hell one even has a small “feather” of kiln wash/mold...
Yep, I have an attachment for my machine that has three (powered) diamond cups for generating a “flat” face on a blank, I can also set it to generating...
... Funny. I have several grades of smaller than that. The finest I have is 0.05 micron. Would using that as the base make that mold release method better?...
I guess, you can get finer :-) grades. That’s great to know. I don’t think the glycerine would be a problem as it would (being a hydrocarbon) burn out with...
Hi, Thomas, Only 1260ºC? Measured at the material or in the kiln? This simplifies and cheapest the whole thing a lot… A good electrical kiln to go up to...
Hi Oscar, That is 1260’C at the material, i.e. the glass has to be 1260’C to have a viscosity of 10^4dPas. Yep a good home built kiln is usually cheaper...
Yes, I had good luck with castable refracgtory, but the surface was not good enough for slumping. I had to grind the surface (as we grind a mirror and tool...
