USW  Local 18-4 Your Work Place

​​Float glass is made by melting raw materials consisting of sand, limestone, soda ash, dolomite, iron oxide and salt cake at a temperature of 2800 degrees. The raw materials are mixed together and fed into a large furnace that is natural gas or fuel oil fired. The raw materials, referred to as batch, blend together to form a large pool of molten glass. The molten glass at 2000 degrees is fed into the float bath (tin bath) through a delivery canal. The amount of glass allowed to pour onto the molten tin is controlled by a refractory gate called a tweel. The tin bath is provided with a protective atmosphere consisting of a mixture of nitrogen and hydrogen to prevent oxidation of the tin. The glass flows out onto the tin surface forming a floating ribbon with perfectly smooth glossy surface on both sides with an even thickness from .082" to .5". Thinner glass is made by stretching the glass ribbon to achieve the proper thickness. Thicker glass is made by not allowing the glass to pool. Machines called attenuators are used in the tin bath to control both the thickness and the width of the glass ribbon. As the glass flows down the tin bath, the temperature is gradually reduced to around 1100 degrees until the sheet can be lifted from the tin onto rollers. It then passes through the lehr where it is further cooled gradually so that it anneals without strain and does not crack from the change in temperature. The glass travels down the rollers in the lehr for about 100 yards and comes out at the "cold end" where it is cut by a cross cutter or rabbit and then loaded onto cart or racks with stackers and robots.

Currently there are 7 Union members of the United Steelworkers Local 18-4 on the seniority list that work at the Pilkington Float Glass manufacturing plant in Lathrop, CA. 
The plant was first unionized by the United Glass and Ceramic Workers of North America on June 19, 1962 until it merged with The Alumiunm Brick and Glass Workers Union on August 7, 1985. In 1998, the ABG merged with the United Steelworkers. In 1972 the plant employed 1255 hourly workers.
The plant has been in operation since June 4th of 1962 when it opened as a automotive fabrication plant. In 1964 the first Libbey Owens Ford Co. float furnace in North America went on line and has been producing flat and automotive block size since its opening.  The automotive fabrication ceased on 12-30-2001. The Automotive Value Added Department, which supplied finished automotive glass products for NUMMI in Fremont CA closed on March 31, 2010. Float production shut down January 29, 2014.  Pilkington currently operates a warehouse out of the building with 6 hourly employees.





50th Anniversary Pictures  - June 2012


How we use to make glass.

The Libbey–Owens–Ford Company (LOF) was a producer of flat glass for the automotive and building products industries both for original equipment manufacturers and for replacement use. The company's headquarters and main factories were located in Toledo, Ohio, with large float glass plants in Rossford, Ohio, Laurinburg, North Carolina, Ottawa, Illinois, and Lathrop,California. The company was formed by the merger of Libbey-Owens' flat-glass operation with the Edward Ford Plate Glass Company, both located in Toledo, in 1930.In the spring of 1916, Michael Owens and Edward Drummond Libbey, both manufacturers of sheet glass, merged their respective companies to form Libbey-Owens. In June 1916, the new Libbey-Owens bought Graham Glass along with the Graham brothers' patents for their glass bottle-making machine, allowing them to diversify into consumer products. In 1928, LOF (then Libbey Owens) was the first company to produce automotive laminated safety glass and won a contract to supply the Ford Motor Company with windshields for the Model A. Libbey-Owens mergered with the Edward Ford Plate Glass Company in 1930 to form Libbey–Owens–Ford.In April 1986, LOF sold its glass business and name to the Pilkington Group, a multinational glass manufacturer headquartered in the United Kingdom. The remaining three business units of the company, Aeroquip, Vickers, and Sterling, were retained and the holding company was renamed TRINOVA Corporation. The Sterling business was later sold and in the late 1990s, the company adopted its two leading business unit names, and continued as Aeroquip-Vickers, Inc., until being absorbed by Eaton Corporation in 1999.As part of the Pilkington Group, the company retained the LOF name. However, in June 2006, Pilkington was acquired by Nippon Sheet Glass, and the LOF name was abandoned in an effort to rebrand globally under the Pilkington name.

                                                                                     History of Lathrop


History of the Lathrop Plant The LOF automotive Glass facility in Lathrop Ca. was designated as Plant 10 and construction started on June, 19, 1961. Read on for more information concerning the Plant.
June 4, 1962 - The Automotive plant opened with 68 employees.
July 3, 1962 Ray Glow was elected the first Union President.

July 5, 1963 LOF announces float will be built at Lathrop with construction starting immediately
Also in late summer 1964 - the first LOF float plant began operating. This was only the second float plant in North America. The furnace and bath were designed for edge roll automotive windshield production.
In mid June of 1964 there was a strike at LOF that lasted 6 weeks.
Sep. 14, 1964 Dennis Long begin his employment at Lathrop and is the longest tenured hourly employee. Retired in 2014.
On December 5, 1965 the Grinding & Polishing department was shut down. There was a layoff in '65
There was a layoff in '66, '67, '69
Also in 1970 The float was rebuilt. The furnace and bath were enlarged.
In October of 1970 the first female was employed on the factory floor.
There were layoffs in '70, '71, '72, '74, '75, '76, '78, '79 & '80

 On February 7, 1972 the Union buys the property for the future Union Hall.
 On October 9, 1973 The Union membership votes for a special assessment for the Union Hall construction.
 On April 13,1976 Construction begins on the hall, finished in October of 1976.
Also on Feb 7, 1982 Automotive Glass operations begin to shut down until 1984. Some employees were on layoff till 1985. A small cold repair was performed on the furnace.
Also in 1983 another small cold repair was performed in preparation for Flat Glass production. Automotive operations begin again as the NUMMI Plant opens in Freemont.
In early 1985 Pilkington buys LOF. 
In Oct. 1993 a major rebuild of the float furnace begins. The Wareroom is totally refurbished.
In April 1994 The float Rebuild is complete and production resumes.
Apr. 1, 1997 The last original employee (Darce Emerson) retires.
Dec. 1, 2001 Automotive Glass fabrication operations end.
January 2005 A hot repair is scheduled and production will be down for around 42 days.
March 2005 Hot repair complete furnace back in operation.
June 2006 Nippon Sheet Glass buys Pilkington.
May 9, 2008 Pilkington/NSG announces a $100 million dollar repair and upgrade starting in October 2008. It is canceled.
Jan. Feb. & March 2009 Layoffs hit due to economic slowdown. 
August 2009. NUMMI announces plant shut down in March of 2010. Lathrop Value Added operations to cease. This will end 47 years of automotive production at Lathrop. Some employees on layoff
April 1, 2010. Value Added Operations cease as NUMMI closes. Some employees on layoff.
January 1 , 2011 We'll still be running to a repair or 2014. Some employees on layoff.

 January 2012 - Still in operation. Some employees on layoff
 June 4, 2012 - Lathrop Plant 10 hits a 50 year Anniversary.
 Feb 15, 2013 - Still hope for the future of Lathrop.
 Sep 9, 2013 - Still running good,
 October 18, 2013 - I think it's going to happen. I was wrong.
November 11, 2013  - NSG announces Lathrop plant closing. Feb 1 2014 is scheduled sheet cut.
January 29, 2014  - Glass production cease at the Lathrop plant.
​March 3, 2014 - First layoff of 43 employees.
May 2, 2014 - Second layoff, only 25 employees left.
June 26, 2014 - Third layoff, only 20 employees left.
April 3, 2015 - Down to 7 employees in the warehouse operation.
December 20, 2015 - 6 employees working in the warehouse.
Each day when the furnace operated, it produced 600,000 square feet of glass or enough to cover 14 football fields. The Plant used 4 million cubic feet of natural gas per day or enough to supply all the households of Manteca for a year. The plant also consumed 120,000 kilowatts of electricity per day. The plant sat on 165 acres (out of the original 800). Square footage of the plant was 900,000 square feet.