ny life project

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Investigation and Remediation of the Golden Roof and Lantern atop the NY Life Headquarters in New York City Presented by Michael Kramer, President, The Gilders’ Studio, Inc. APTI Meeting in Montreal, October 15, 2008

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The investigation and remediation of the failing gilding on the roof and lantern of the NY Life headquarters in New York City in 2007.

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Page 1: Ny Life Project

Fading Lustre: Investigation and

Remediation of the Golden Roof and Lantern

atop the NY Life Headquarters in New

York CityPresented by Michael Kramer, President, The Gilders’

Studio, Inc.

APTI Meeting in Montreal, October 15, 2008

Page 2: Ny Life Project

Designed by Cass Gilbert

Opened in 1928 the building featured 35 occupied floors with a crenellated masonry roof. On top of the roof was a 65’ tall gilded bronze lantern.

Another view of the roof.

Page 3: Ny Life Project

Leaks were always a problem.

Roof was re-designed in 1967

35th floor was removed.

22,000 enameled gold tiles were installed.

Lantern was made watertight and re-gilded

After 30 years the finish on the tiles began to fail and were replaced with all new tiles in 1996.

Roof in 2004

Page 4: Ny Life Project

After four years the gold glaze on the new tiles showed signs of

failure.

While the tiles are initially fired at over 2,000° F, the gold enamel glaze is only fired at @ 1,200 °F.

Changes in the glaze formula from 1967 to 1995 may have also played a factor.

An investigation and testing program was initiated in 2001.

Page 5: Ny Life Project

Observations in situ

Note the relationship between the areas of least gold and the wash patterns of the rain.

Page 6: Ny Life Project

Potential Avenues of Failure

Note crazing in gold glaze.

Uneven application of the glaze.

Page 7: Ny Life Project

Investigation and Testing

Various approaches were explored 1. New gold tiles – Manufacturer no longer offered them.

2. Replace tiles with copper shingles and then gild - $$$$!!!!

3. Apply gilding system to the existing tiles- Testing of various abrasive and priming/gilding systems was approved.

Tile blasted with two different abrasives

Page 8: Ny Life Project

Accelerated Weathering to ASTM standards and more

QUV Ultraviolet and Freeze Thaw.

Salt Fog

Acid Deposition

“Quenching” i.e. raising the samples to high temperatures and quenching with water to stress the system beyond conventional freeze thaw.

Testing was completed in 2003 - Six systems were tested and one in particular outperformed the others.

Page 9: Ny Life Project

Notice to Proceed – late 2006

Completion slated for October 2007.

Scaffold the roof , lantern and tourelles

Remove failing gold glaze layer

Strip lantern and make repairs

Prime and re-gild all elements

23 levels of scaffolding

January 1, 2007, New VOC regulations– priming system from 2003 became illegal.

Page 10: Ny Life Project

Rush Testing – 3 additional priming systems

Accelerated weathering of the systems while the scaffold was being designed and built.

Hydraulic adhesion tests after weathering provided quantifiable results.

New VOC Compliant system performed better than the one originally chosen.

Paint manufacturer supplied a 5 year warrantee based on the test results.

Page 11: Ny Life Project

Enclosed with mesh

Page 12: Ny Life Project

Tiles blasted with Sponge Jet system

Removed the gold glaze layer without damaging the fired tiles.

Recyclable - Collect and re-use up to 8 times

Virtually no dust

Page 13: Ny Life Project

Blasted tiles

Page 14: Ny Life Project

Application of epoxy primertwo coats - brushed and rolled

Page 15: Ny Life Project

The Lantern

65 feet tall – originally gilded

Top 40’ is cast bronze

Lower portions are copper from 1928 and lead coated copper from 1967

Different coatings on the lantern

Page 16: Ny Life Project

Lantern DetailsBandaids from 1996

and 1967

Inappropriate repairs

Page 17: Ny Life Project

Unexpected Conditions Bituminous tar layer from 1967, covered with powdered lead then lead paint, size and gold leaf.

In 1996 repainted over the gilding, then new gilding atop

140x

Page 18: Ny Life Project

Stripping options for the Lantern

Original Gilding from 1928

Page 19: Ny Life Project

AlternativesHeatguns Advantages

Controlled release of lead

Worked in one pass

Page 20: Ny Life Project

After Sponge Jet blasting

Page 21: Ny Life Project

Lead coated copper chemically stripped

Page 22: Ny Life Project

Deterioration due to previous interventions

Page 23: Ny Life Project

Repairs to the bronze

Page 24: Ny Life Project

Primed Bronze

Page 25: Ny Life Project

The Gilding Process

Page 26: Ny Life Project

Sizing

Slow oil size tinted with oil color

Page 27: Ny Life Project

Gilding

Page 28: Ny Life Project

Using 195mm ribbon leaf

Page 29: Ny Life Project

Sized Finial

Page 30: Ny Life Project

Gilding the Finials

Page 31: Ny Life Project

Completed Finial

Page 32: Ny Life Project

Scaffold Dismantle

Page 33: Ny Life Project

Tile touch up and replacement

Page 34: Ny Life Project

Summary of the Priming and Gilding Process

Tiles – 1.Blasted with Sponge Jet system2.Primed with 2 coats of epoxy3.Sized with slow oil size

Lantern –1.Heat stripped and blasted with Sponge Jet system.2.Bronze- primed with zinc chromate3.Lead coated copper- primed with epoxy.

All surfaces had a slow oil size applied followed by 23.75KT gold leaf in a extra heavy weight.

Expected service life – 35 years

Page 35: Ny Life Project

Challenges of the Project

Determining the avenues of failure and proper remediation

Working in Manhattan

Adapting to new VOC standards “on the fly”

Dealing with the lantern nightmare