Tradition and modernity met at the conference in the Thierhaupten building archive
The conference topic “Old iron – new color” on February 19, 2016 also sums it up in the extended subtitle “Coating systems for historical wrought ironwork”: How do historical wrought iron and new paint coatings fit together when a colorful re-protection is necessary after the removal of rusted old coatings?
The answer was clearest in the summary by Dipl.-Rest. Jens Wagner from the restoration workshops of the Bavarian State Office for Monument Preservation (BLfD): the impulses and lectures should help to replace the “generally anthracite gray embarrassment solutions” with targeted color reconstruction according to findings with normative coating systems.
This was also the aim of the first presentation on the small 1 x 1 of corrosion protection according to DIN EN ISO 12944, “Corrosion protection of steel structures using coating systems”, in order to be able to carry out reliable corrosion protection planning. As Prof. Bernhard Mai from Erfurt clearly demonstrated, when selecting the type of coating, local influencing factors such as climate, moisture duration and air pollutants must be taken into account in order to achieve a desired protection period of over 15 years, for example.
He presented the restoration measures on the gate of the camp entrance to the Buchenwald Memorial with the red-painted inscription “JEDEM DAS SEINE” in the white-painted grid field (paint layer findings of the original equipment). Here, the presentation images in particular suddenly had a delayed emotional effect that touched everyone in the audience.
In the further course of the event, the factor of residual rust played a particularly important role, as completely metallic, newly blasted iron surfaces are not always desired or cannot be realized. After all, the general principle of metal conservation is that traces of manufacture, use and transmission should be preserved and remain recognizable.
The contribution by metal designer Ingo Fichtner provided helpful insights into the overall problem of residual rust treatment – particularly with regard to the application of rust stoppers and rust sealers in narrow gaps, such as under the frets of wrought iron fence and lattice bars. Air-drying, low-viscosity natural oils with a good penetrating effect such as Owatrol have proven their worth here. To be on the safe side, the actual penetration depth and the preservation effect should be checked by opening one or two bundles.
Dipl.-Rest. Mandy Reimann presented the results of a ZIM cooperation project on the topic of “Development of innovative corrosion protection systems taking into account the special requirements of monument preservation”. In this, as in other presentations, the focus was on the compatibility of residual rust on manually derusted surfaces and the performance comparison of modern thick-film systems with lead-primed coatings. According to the available results, the lead-containing primers can be replaced without major disadvantages, but such advanced industrial systems have so far hardly been used in restoration practice on finely structured to filigree forged iron designs. This would also mean that the surface features to be preserved would no longer be recognizable.
In contrast, other presentations emphasized the use of classic linseed oil paints as an anti-corrosion coating. In the case of the church painter Stefan Enzinger, who gave the presentation, this even went hand in hand with his own production of the tried and tested natural paints. The three- and four-layer coating systems presented were also convincing when applied to hand-rusted surfaces, as the first coat is applied with a lead soap primer produced in-house. The result shows an authentic harmony of the materials in the context of the historic paint substrate and the original decorative rust protection.
In summary, tradition and modernity have come together in the materials and conservation methods presented. There is an emerging trend for newly developed coating materials to be used in the preservation of historical monuments alongside historical ones. Their user-friendliness, long durability and safe service life are particularly welcome. The new materiality is also gaining increasing acceptance in terms of the further development of monument conservation work with contemporary materials.
In view of the great interest and the large number of registrations, the BLfD’s building archive is fully living up to its role as the Bavarian training and advisory center for monument preservation – especially if the event is repeated again in 2016 due to the strong demand.
On June 14, 2016, 4:30 to 6:00 pm, Dipl.-Chem. Wolfgang Conrad will hold a RESTAURO webinar on the topic of “Iron under monument protection”.