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How to ... clean and label pipes (post-excavation)Following the recovery of pipes during a fieldwork project or excavation, the next phase is to separate the pipes from other classes of finds and prepare them into a well-ordered and labelled archive ready for assessment and analysis. Each bag of finds should always be accompanied by two waterproof labels marked with indelible ink so that site information is not lost and stored in clearly labelled sealable bags providing information such as the site code, area/trench and context and/or small find numbers. The fragments must always be fully dry before the bags are sealed. Cleaning Pipes Most pipe fragments are fairly robust upon excavation and only require the removal of surface dirt with a soft toothbrush in clean water. If the surface has become soft or powdery, cleaning must be done very gently and care must be taken not to scrub away the original surface, which may retain traces of burnishing or other finishing techniques. Similar care must be taken with marks or decoration. Soil should be carefully removed from any marks or decoration, so that they can be seen clearly, and the ends of stems should be cleaned so as to make it easy to see the stem bore and assess the fabric. Where large numbers of stems have been recovered, this can be done quickly by bundling them side by side between the thumb and first finder of one hand and then squaring up the ends on a flat surface. The bundle can then be held together tightly and all the ends cleaned at once with a toothbrush. The bundle can then be carefully held together and turned over, and the other ends squared up and cleaned. All the pipe fragments must be fully dry before being sealed in durable bags for storage.
Any unusual pieces of bowl or stem with traces of paint, ink, organic mouthpiece coating, etc., should be cleaned separately (see below) and, if necessary, in consultation with a conservator. Some mouthpieces have glazed tips and French pipes sometimes have enamel decoration, both of which can be gently washed in water. Where pipes have been in a salty environment (e.g., marine or estuary conditions) or ground that may be contaminated with other chemicals (municipal tips, etc.), they should be soaked in frequent changes of fresh water for a week or two before cleaning and drying. This will prevent the salts or other chemicals from crystallising over time within the fabric, causing the pipe to spall and crumble. Buried pipes will frequently absorb iron from the ground, causing discolouration of the fabric and, in particularly iron rich environments, surface encrustation, etc. Where this obscures the surface detail of the pipe or where cleaning is required for display purposes, this can be done using an EDTA solution (Mirdamadi 1999). Chemical cleaning is not advised on pipes with enamel decoration or in the very rare instances where other forms of surface decoration (paint, wax, etc.) or marking (writing, ink stamped bowl marks, etc.) occur.
Sometimes late nineteenth or early twentieth century pipes were given a varnished surface or customised with rubber stamped ink marks, neither of which survive well in the ground. Likewise, mouthpieces were sometimes coated with paint, wax or some other form coating. If unusual surface coatings or marks are noted appropriate care should be taken and, if necessary, specialist advice sought. Ink stamped marks tend to be very faint and to disappear as the pipe fragment dries out (but will reappear if the fragment is made damp again). Any such marks should be transcribed and photographed while the pipe is still damp. Labelling Pipes It is important that a proper archive is prepared of any pipe fragments recovered. This includes making sure that they are placed in good quality bags that are suitable for long-term storage and that these are properly marked with the site and context information. The individual fragments should ideally all be labelled using waterproof ink, taking care that the markings are not placed on any marked or decorated areas of the pipe.
For complete or fragmentary bowls, it is often possible to mark the fragments on the inside, where the numbering does not obscure the surface finish or any marks/decoration on the outside of the pipe. This also leaves the bowl fragment clean externally for photography or display, as well as protecting the mark from abrasion in the bag. If a stem is completely covered with decoration, it is often possible to carefully fit the mark onto one of the broken ends. Small find numbers can be added as necessary to identify individual fragments (such as marked or decorated pieces) and to relate the them to any more detailed catalogue or illustrations of the pipes that are prepared. If there is a compelling reason why it is not possible to label all the fragments, then priority should be given to the bowls fragments and any other pieces with marks or decoration on them. These pages
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How to......clean pipes
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