Historic HomeWorks Forum

TimB · Joined: 03 Sep 2009 Posts: 43

Sorry to post without references... I found the images unsourced on the internet. After a little more research, I find the crown glass image referenced as:
1832 Edinburgh Encyclopaedia

I believe the source for the cylinder glass image is:
The Builder, 14th April 1860 (though the reference is a little ambiguous)

Hope this helps.

Thanks for the direction to the glass repair discussion.

Vic · Joined: 05 Mar 2006 Posts: 59 Location: NYC

Bendheim sells 2 types of "restoration" glass. Both are mouth blown cylinder glass made by Lamberts in Germany. They are made the same way cylinder glass was made in the 19th century. One version "heavy" is thicker, has more distortion and more seeds. By are very clear.

By the way "seeds" are formed by trapped air in the glass, not impurities.

Bendheim also sells "restover" made by Schot. This glass has a slight green cast and light distortion. It resembles window glass made by the "drawn" cylinder method from 1900-1955.
Manganese was added to the raw glass recipe to counteract iron impurities, thus making the glass clearer. Unfortunately UV light will turn the manganese pink/purple over time. The addition of manganese was pretty much stopped around WWI.

Various glues can mend glass. BUT they all discolor with UV. Hxtal is the best as it lasts the longer without discoloration. That is why it is favored by stained glass restorers.

Tim Storey · Joined: 30 Mar 2007 Posts: 144 Location: NW Indiana

I've had some trouble cutting blown glass -it was cylinder glass, but I don't think it would matter. It does seem like the lack of uniformity would make it tougher to cut well. Do you do anything special when cutting wavy glass? Our problem was that the break would not follow the score well -and we don't have a problem with new glass.

Skuce · Joined: 08 Nov 2009 Posts: 188 Location: Ontario Canada

Old/Wavy glass has been the easiest glass I've ever cut.

jade · Joined: 11 Feb 2005 Posts: 786 Location: Hawley MA

some old glass is very thin and/or significantly curved which can make it difficult to cut...

i use a glass cutter with an oil reservoir and a comfortable plastic handle: http://sunshineglass.com/rcol/c-tools/toyo-cutters.htm i also use a straight edge with a lip that gives a good straight line (make sure the side you rest the straight edge on is square) from the same company (sunshine)...

the right amount of pressure is important and is a learned thing that takes time...i'm happy to say that we experience very little breakage during glass cutting...when it does happen it's often the last piece for a large project or a very large piece that is hard to come by!

...jade

johnleeke · Posted: Thu May 13, 2010 6:30 am Post subject:

I think glass cutting is an art, depending a lot on subconscious intuition. As with all art-level work, continuous practice is necessary for good results.

I don't cut a lot of glass routinely and my success rate is about seven or eight cuts out of ten. New glass or old glass I get two or three mis-cuts out of ten. (arthritis in both hands doesn't help)

The best tools can help, and it's certain that poor tools definitely hurt. I recently use an authentic century-old diamond glass cutter that had never been used before. (it was still in its original box and sealed wrapper) My friend and I both had a 100% success rate with it. Perhaps it was the diamond, or the bronze swivel head, or the rosewood handle, or perhaps it was simply the subconscious inspiration of using such a fine instrument.

sschoberg · Joined: 29 Oct 2008 Posts: 568 Location: Plymouth, Indiana

Smooth clean, consistant pressure and angle in one smooth motion. Experience is definitely the key, with proper techniqe. Some people are naturals and "got it , or get it" quickly.

Some here use the cheaper and some use the more elaborate, but cutting is cutting. We watched the cutters at our local glass shop and both the old man his son use the cheapies. And they don't miss a one. smooth.

Mike-in-Maine · Joined: 08 Nov 2008 Posts: 145 Location: Fort Kent, ME

practice practice practice.

Thats how to make consistent and perfect cuts every time. There is a "sound" that you hear when you know you "got it right" dont hear anything? youre doin it wrong! Ive saved many a glass piece by realizing the scribe was bad and running a second cut on the other side directly over the opposing "bad" cut. the result is a good cut! I will usually sand the edges i cut also, to help prevent cracking later.

cabinfeverarts · Joined: 05 Aug 2008 Posts: 114

The top of the line glass cutter is made by MacInnes. http://www.macto.com/macinnes_handheld_glass_cutters.asp You can purchase them at http://www.sunshineglass.com/rcol/c-tools/macinnes.htm . Essentially, they are like the old standby Fletcher cutter except they have amazing carbide wheels that are replaceable. Fletcher cutters are just fine, you just likely have to throw them away sooner after the wheel goes bad, especially if its steel. I don't like holding this style of cutter so I got the $2 cutter cozy found at the bottom of this page: http://www.sunshineglass.com/rcol/c-tools/toyo-cutters.htm

The toyo cutters are okay and I used them for a few years, but I prefer the made in the U.S.A. stuff and so converted to MacInnes and I'll never go back.

Still it takes practice to cut glass. And each glass is different. When I cut 100 year old wavy glass, a score can go cattywompus if the glass has a lot of flaws from abuse. The way glass breaks is through disturbing the molecules so each time you touch glass, you are messing up the molecules. Just imagine all the bumps, dings and scratches a piece of glass that is 100 years old has undergone. The glass will crack at the weakest point. If a spot where glass was bumped, dinged or scratched is weaker than your score line, the crack will jump over to that spot instead. Drives me crazy, but it is understandable. This even happens with new glass. Unless you cut it fresh, seconds after it was made, a piece of glass has to travel to your shop so if it gets bumped around, the molecules are already starting to shift.

sschoberg · Joined: 29 Oct 2008 Posts: 568 Location: Plymouth, Indiana

Vic, you mentioned earlier that Manganese was added early on to counter act impurities in the glass material, but they stopped using it because ultraviolet turned it pink or purple.

Thats interesting because we may have run into some of that where some of the glass had a pink tint. We thought it was made with a pink tint to match the rose color in the quartz rock they used on the exterior of this very large mansion.

I guess I have a question. Do you know or have you heard of adding something to glass with the intention of tinting it to a rose colored to match the exterior rocks on the wall?

Can't help myself, but I always though the family wanted to make sure they saw the worl through their "Rose colored glass".

What do you think? Or is it just magnesium that was added for impurities?
That would not be very romantic in the realm of the victorian architectural era, but?

Vic · Joined: 05 Mar 2006 Posts: 59 Location: NYC

sschoberg · Joined: 29 Oct 2008 Posts: 568 Location: Plymouth, Indiana

Geesh, of course. Thanks for that.

I've heard that they added gold to glass to get red. Is this correct? if so, can they proportion the glass to get pink tint?

thanks

Vic · Joined: 05 Mar 2006 Posts: 59 Location: NYC

johnleeke · Posted: Fri May 14, 2010 7:07 pm Post subject:

The mirrors in the Victoria Mansion in Portland, Maine (where I am maintenance adviser), are said to have diamond dust in the glass. These mirrors give a sort of spectral glow to reflected objects at certain angles.

johnleeke · Posted: Fri Dec 31, 2010 9:32 am Post subject: Authentic Glass Suppliers

Kennett Glass Company
110 West State Street
Kennett Square, PA 19348
610-444-4181
Kennettglass@verizon.net
www.kennettglass.com
Authentic Antique Glass, sorted into 25 year periods from the 1700 to 1925, will ship anywhere

Do you know of any outfits that salvage and supply old window glass? What are their prices like?