During the last decades, the discovery of nanolime and its introduction in the field of Cultural Heritage has entailed a significant advance for the consolidation of historic wall paintings. Nevertheless, its use is not completely generalized yet within the conservation practitioner’s community due to its undesired white veiling deposit on the surface after treatment which usually covers the pictorial layer. Given the scarcity of existing literature which specify how to mitigate this undesired side-effect, the aim of this work is to carry out the first assessment of possible cleaning and treatment methods to eliminate those deposits and, at the same time, to analyse their effects on the consolidation properties. To do that, we have developed laboratory fresco wall paintings specimens. After applying an artificial ageing cycle to all of them, we consolidated them with CaloSil IP25, one of the most currently used commercial product in the practice. The elimination of the whitish deposits has been investigated with different methods: (1) wiping off the superficial excess of product immediately after each application during the treatment; (2) mechanical cleaning (scalpel) after consolidation; chemical cleaning with rigid gels of water (3), ethylenediaminetetraacetic acid (EDTA) (4) and citric acid (5) after consolidation. The effectiveness of each cleaning method has been assessed by non-destructive methods before and after the consolidation, and repeated after cleaning, by measuring differences in colour, water absorption by capillarity (i.e., sponge test), superficial adhesion (i.e., Scotch Tape Test) and by quantifying the thickness of the deposits eliminated by means of photogrammetry. Results show that both the mechanical cleaning and the removal of the excess of product after each application during the treatment yielded the most promising results for conservation practice.

中文翻译：

---

防止墙面漆纳米石灰处理后出现不希望的表面遮盖：初步调查

在过去的几十年中，纳米石灰的发现及其在文化遗产领域的引入为巩固历史壁画带来了重大进展。然而，它的使用在保护从业者社区内还没有完全普及，因为它在处理后表面上的不希望有的白色面纱沉积物通常覆盖了图案层。鉴于现有文献很少详细说明如何减轻这种不良副作用，这项工作的目的是对可能的清洁和处理方法进行初步评估，以消除这些沉积物，同时分析它们的影响关于合并属性。为此，我们开发了实验室壁画标本。在对所有这些人进行人工老化循环后，我们将它们与 CaloSil IP25 进行了整合，CaloSil IP25 是目前实践中使用最多的商业产品之一。已经用不同的方法研究了白色沉积物的消除： (1) 在处理过程中每次施用后立即擦去表面过量的产品；(2) 固结后机械清洗（手术刀）；固结后用硬质水凝胶 (3)、乙二胺四乙酸 (EDTA) (4) 和柠檬酸 (5) 进行化学清洁。通过测量颜色差异、毛细管吸水率（即海绵测试）、表面附着力（即，透明胶带测试）并通过摄影测量法量化消除的沉积物的厚度。结果表明，在处理过程中每次应用后机械清洁和去除多余的产品都为保护实践产生了最有希望的结果。