• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.6-6
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• 2018

본 연구에서는 고문헌에 기록된 도금 재료와 도금법 등을 확인하고 이를 기초자료로 활용하여 매실산을 사용한 금(Au)-수은(Hg) 아말감기법으로 고대 도금(鍍金)기술을 되살리고, 이를 토대로 경주 월지에서 출토된 금동삼존판불을 복원하였다. 먼저, 전통 도금법을 되살리기 위해서, "오주서종박물고변", "확지신편", 조선시대 각종 의궤 등에 공통적으로 기록되어 있는 매실에 주목하고, 매실을 3~4개월 발효 숙성 후 착즙한 뒤 그것을 농축하여 만든 매실산을 도금 실험에 적용하였다. 금아말감 도금을 위하여 월지 출토 금동삼존판불의 바탕소지금속인 청동삼존판불을 구리와 주석 89:11(Cu:6kg, Su:750g)로 합금하여 주물사 주조법으로 복원하였으며, 동일한 합금비로 제작된 $2.3cm{\times}3.5cm$(가로${\times}$세로)의 시편에 사전 실험을 실시하였다. 현대적 산처리 방식에 사용되는 질산과 전통방식으로 사용되는 매실산으로 시편에 산처리 한 후 각각 비교해 보고, 금분과 금박, 상온과 가온에 따른 아말감상태를 비교하는 실험을 진행하였는데, 실험에 사용된 매실산 70%는 pH가 1.94로, 오늘날 산처리에 사용하고 있는 질산 20%와는 차이가 있지만, 청동 시편 실험을 통해 매실산에 20분 정도 담근 뒤 금아말감을 도포 후 24시간 지나 가열($380{\sim}400^{\circ}C$) 했을 때 금도금이 잘 되어, 현대적 방법인 질산처리로 도금을 한 시편과 큰 차이가 없는 것으로 관찰되었다. 사전 실험을 통한 결과를 적용한 월지 출토 금동삼존판불 복원은 청동삼존판불 표면처리, 금-수은 합금 및 도금하기, 도금 후 표면처리의 순서로 진행되었는데, 금과 소지금속의 밀착력을 높이기 위해 표면을 숯을 이용해 탈지한 후 물로 씻어내고 매실산을 도포하여 20분 동안 두어 부식 및 세척을 시행하였다. 금도금을 위한 금-수은아말감은 가온할 때 수은이 증발하는 양을 고려하여 금1 : 수은10 비율로 합금하여 완성하였으며, 금아말감 도포 후 약 24시간 지난 다음, $380{\sim}400^{\circ}C$에 가열하여 수은을 기화시켜 도금작업을 완성하였다. 금아말감도금은 평균적으로 6~7차례 시행하여야 완벽히 도금되지만, 본 연구에서는 단 4차례의 도금만으로 금아말감도금을 완성시켰는데, 이것은 금아말감을 바탕소지인 청동에 도포한 후 24시간 동안 금아말감과 청동과의 반응 시간을 두게한 것이 큰 역할을 한 것으로 보이며, 이는 청동시편을 이용한 실험과 과학적 분석을 통하여 입증하였다. SEM으로 표면을 관찰한 결과 아말감 도포시간이 즉시인 경우 도금이 거의 되지 않은 것을 확인할 수 있었고 36시간이 넘어갈 경우 금 도금층이 불균일하게 관찰되었으므로 도금시간은 12시간~24시간 이내가 적절함을 확인할 수 있었다. EDS로 성분을 분석한 결과 산처리 시간이 20분인 시료의 경우 5 wt% 내외로 수은의 비율이 다른 시료에 비해 낮은 것을 확인할 수 있었다. 실험 및 분석결과 산처리 시간이 20분이고 아말감 도포시간이 24시간일 때 도금이 잘 이루어지므로 이 결과를 토대로 금동삼존판불을 복원하였다. 이번 연구를 통해 도금법에 표면을 세척하고 부식시키기 위해 사용한 물질이 매실산임을 찾아내어 확인할 수 있었는데, 이러한 점 에서 이 연구의 가장 큰 의미는 전통 소재와 기술을 복원한 것으로, 앞으로 매실산을 이용한 금 도금기술은 관련 학계에도 큰 기여를 할 것으로 기대된다.

• Journal of Conservation Science
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• v.22
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• pp.87-98
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• 2008

Microstructures and chemical compositions of 24 bronze mirrors recovered from the Korean peninsula were examined using the scanning electron microscope equipped with the energy dispersive spectrometer in an effort to characterize the treatments applied on their surface. Their provenance and chronology are mostly unspecified except for two objects from a Koryo burial site. In antiquity the surface of bronze mirrors was frequently finished by mere polishing when their tin content was high enough to guarantee the required reflectivity. In many cases, however, their surface was given a special treatment. The most typical treatment was to coat the surface with tin in two different processes referred to as wipe-tinning and amalgam-tinning. In wipe-tinning only tin was used, but in amalgam-tinning tin and mercury were used together. The surface was often coated with mercury in a process known as mercury-polishing. The present mirrors showed that all these techniques were in fact practiced, not only on the reflective surface but, in some cases, on the decorative surface. The detection of mercury played a crucial role in the assessment of a specific technique applied in each mirror. Mercury often remained in the substrate in the form of sulfide and thereby allowed the method of surface treatment to be estimated even when the coated layer was completely lost. The future study is expected to uncover the regional and temporal variation of the surface treatments to the better understanding of bronze mirrors with respect to provenance and chronology.

• Journal of Conservation Science
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• v.16 s.16
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• pp.52-63
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• 2004

This study tries to investigate the differences in combination of gold and other metals used in the surface guilt of the gold-guilt relics found in the Seonwonsa Temple of the Korea Dynasty. Our findings are as follows. The gilded roller knobs found in the Seonwonsa Temple of the Korea Dynasty can be classified into three groups by the color of the surface guilt: gold, white-gold, red-gold. By the color it is found that gold type contains $Au\;81.0\%,\;Ag\;3.5\%,\;Cu\;5.6\%$, white-gold type contains $Au\;82.1\%,\;Ag\;10.6\%,\;Cu\;2.4\%$, and the red-gold type contains $Au\;59.9\%,\;Ag\;3.7\%,\;Cu\;33.2\%$. The gold metal used for guilt is found to be amalgam of Hg and the depth of the guilt was uneven with the average of $2.5\~25{\mu}m$. These gilded roller knobs were produced in two methods. One of them was made out of pure bronze, and the other out of bronze veneer and led. Since we found led on the outer surface, we conclude that the led juncture was later guilt with gold.

• Journal of Conservation Science
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• v.31 no.3
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• pp.309-318
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• 2015

The staff given with chair to Yi Gyeong-seok, senior official over 70 years old by King Hyeonjong of Joseon Dynasty is representative handcraft of Joseon Dynasty. Results of analysis on the metallic decoration show that the metallic ornament of the end part which is connected to the spade was made by rolling of iron plate and brass plating. The plated part is limited to the ornament of the end part connected to the spade and the plating was not applied to the spade. Brass including 20% zinc was used for the connecting part of guard while brass gilded iron was used for the spade. This suggests that the tone of the connecting part of the guard and the spade was not different for reason of visual harmonization. Potential applied plating method can be amalgam, dippping in molten brass, and brushing but the analysis result suggests that dipping in molten brass method is the most likely accepted method. The brass guard of knife was joined by tin-lead solder. Rivet used to fix the blade was made by pure iron as an optimum material which satisfies flexibility and strength.

• Conservation Science in Museum
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• v.8
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• pp.49-69
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• 2007

This is about the scientific analysis of the 10 items of the gilt-bronze Panbul excavated from Anapji, Gyeongju. First, the composition of the Panbul was confirmed, using X-ray fluorescence spectrometer (XRF), and the patinas covering the surface of the Panbul were analyzed, using X-ray diffractometer (XRD). And the micro structures and gilt layer of the Panbul were investigated, using microscope and scanning electron microscope with energy dispersive spectrometer (SEM/EDS), and in order to investigate the internal conditions of the Panbul, X-radiography was conducted. As the result, it is found out that the material of the Panbul excavated from Anapji was the bronze of copper (86~95%) and tin (4~12%), and coated with gold. And cuprite (Cu₂O) was detected from red patina of the gilt-bronze Panbul, and chalcocite(Cu₂S) also was detected from the black patina. As the result of the observation of the micro structure through microscope, it is estimated that it was manufactured, using the wax molding method, and, judging from the fact that the thickness of gilt layer was not even, and that the groove had been filled, it was presumed that the amalgam coating method had been used, but some questions still remain, because mercury was not detected. Lastly, through the X-radiography, it was observed that the tiny round spots existed, which was presumed to have been generated during the casting.

• Journal of Conservation Science
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• v.26 no.2
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• pp.157-169
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• 2010

This study focused on the material characteristics and archaeometric relationship between the molten glass and bronze materials within the crucibles and gilt-bronze Bodhisattva statue excavated from the Ssangbukri site in Buyeo, Korea. Yellowish green to red brown vitreous material in the crucibles was identified as lead glass which contained scarce amount of BaO, and low $Al_2O_3$ and CaO. Metallic molten material was identified as bronze of copper-tin-lead alloy with low amount of impurities that indicated well-refined materials. Also, cassiterite was used for raw metal ore of tin. The Bodhisattva statue consisted of major copper with trace impurities in the core metal, and gold amalgam in the gilded layer. Though lead isotopic analysis showed contradictory results in each lead glass, bronze and Bodhisattva statue that required further examination, it could be stated that the statue was made in the Ssangbukri site based on the high-level technical skills of bronze production.