Vacuum Conservation Method

"Carolus Monument" at the Semmering Pass

3. Vacuum Conservation Method

(Europa Patent Erich Pummer GmbH no. 1295859)

Stone conservation is necessary in order to stop the degradation of masonry that limestone and sandstone monuments are particularly at risk of due to frost and acid rain.

The patented "vacuum-circling strengthening process" (Europa Patent Erich Pummer GmbH no. 1295859) allows monuments, stone sculptures, facades and other free-standing and weathered objects to be preserved either in-situ or in the workshop.

Thanks to this technology, a basic principle that has been sought in stone conservation for decades can be realised: namely, that the right quantity of new bonding agent is applied to the damaged object and, above all, is injected deep into the stone. This is fundamentally important since simple surface treatment can cause the sort of follow-up damage that is all too widely seen. This damage includes cavities of just a few millimetres that become chipped after a few years, causing parts of the original surfaces of the artwork to be irreparably lost. The objects to be treated, which can be virtually of any size, are shrink-wrapped in airtight solvent-resistant film. The remaining air trapped inside the film and within the porous cavities of the stone is then drawn out with the vacuum-circling preserver so that a vacuum is created in the object itself. After a relative vacuum of 300–900 mb has been achieved, the appropriate strengthening agent (silicic-acid ester or acrylic solution) is injected via a precise dosing system, and distributed evenly and deeply into the stone thanks to the low pressure. The open pores and badly damaged areas are filled first, while the remaining pores and capillaries in the healthy and sound material take slightly longer to fill until, finally, the stone has been restored back to its even and original strength.

Effective and efficient demineralisation can be achieved using the same techniques by rinsing with demineralised water. More information in the article: "The cleaning power of water"

This conservation method is already widely accepted throughout Europe by scientists and monument conservationists. Our work has taken us beyond Austria into Germany, Croatia, Hungary and even Azerbaijan.

The cleaning power of water

07/24/2013 DBU Project Dresden – Sponsorship project of "German Environment Foundation 2013“ "Innovative method to strengthen complicated preservable environmentally damaged sandstone monuments and numeric geomechanic simulation of the risks” more

Consolidate with vacuum

10/01/2007 - 10/01/2013 Consolidation of natural stone always goes back to one question: How do you transport the consolidant agent into the depth of the stone? New perspectives are opened by a vacuum-circuit process by which first practice experiences have already been gained. by Erich Pummer more

Stone conservation / actual VAC-demonstration at Arsenal Innovative methods for consolidation of hard to conserve, environmentally damaged sandstone monuments and numerical, geomechanical simulation of risks Stone restoration on Seidenstraße The trinity column of Krems – Research · Preservation · Restoration Innovation Award in architectural conservation Bernhard-Remmers-Award 2010 The Bernhard Remmers Award 2010 Lower Austria WKO Innovation-Award creatively into the future