The Traditional Paint Forum

The past few months have been busy for the TPF with two Conferences, a new initiative to establish a paint testing programme and the latest edition of the journal, Traditional Paint News almost ready for the printers.

Lead Paint: issues and alternatives
In October TPF in conjunction with SPAB held a conference to look at the issues raised by the possible disappearance of Lead paints. A distinguished panel of speakers talked on a variety of topics and some of the papers will be reproduced in the next edition of the Journal. One outcome of the Conference was the decision by the UK’s major building conservation bodies to look at jointly funding an objective trial of the different paint types available for protecting exterior timber. An initial planning meeting has been held and it is hoped that an exposure trial can start soon. If you would like more information on this trial, please contact the Chairman, Colin Mitchell-Rose on colinmr.paint@virgin.net

Traditional Paint News: Vol 3, issue 1
The contents for this edition are being finalised and edited and should be with the printers next month in time for distribution before Easter. Please pass any last minute correspondence or articles to the acting editor at colinmr.paint@virgin.net Copies of the Journal are free to all paid-up members of the Forum.

Subscriptions
Our financial year runs from the 1st of February and those members who are kind enough to pay by Standing Order should have their membership fees deducted within the next few days. Those not yet paying by Standing Order should send a cheque to the Membership Secretary, Christine Sitwell, at the address given on the membership form – please ensure you make clear who the payment is from! Anyone requiring an invoice or other supporting paperwork should also contact Christine in the first instance.

Remember that your membership is vital for the continuing work of the Forum and members received reduced rates for conferences and other events as well as a free copy of the Journal (and the chance to obtain back copies at very advantageous prices).

4th International Conference on Architectural Paint Research
University of Lincoln 3rd-7th August 2010
More information on this event can be found on the conference website

Conference Report
From ‘Gilding the Lily’ to ‘Any Old Iron’: The Traditional Paint Forum Conference 2009, at the Geffrye Museum, London

This focus of this year’s conference was metalwork, from painting onto different metals to creating metal effects through the use of paint. The Geffrye Museum itself had only recently had its external paintwork analysed and renewed so it was a particularly appropriate venue for this conference.

The conference was introduced by Traditional Paint Forum (TPF) President Dr Ian Bristow, who raised the issue of the EU Directive relating to lead paint. The TPF had recently collaborated on a successful study day with the SPAB on the use of lead paints and it was hoped that the TPF would continue to raise awareness on the subject. A second topic of current concern was the future of the English Heritage paint sample archive, and where it might be relocated so that it would remain available for use.

Beginning the first of the morning’s sessions was Geoff Wallis from Dorothea Restorations with a presentation entitled, ‘The Preparation and Painting of Ferrous Metals ’. Iron was the main focus of the presentation and in a scientific introduction to iron, Geoff explained how it interacts with oxygen and water, and how a painted coating helps protect the iron and prevent corrosion. Next, various options for the cleaning of ironwork were discussed, from the use of hand tools and power tools to dry abrasive cleaning and pressure washing; whilst there would often be a preference for the retention of historic paint, this did not always make for the best substrate for modern paints. Following on from this, Geoff summarised the range of different paint coatings available nowadays – of which, there is no ideal option, as each one has its positive and negative points. To conclude methods of application were assessed; whilst brushes provide the most traditional method of paint application, giving a good surface finish, another option is spraying. Sprays provide a very modern look and can maximise on the life of the paint. A question from the audience asked, ‘why is cast iron more resistant to corrosion?’ It was thought that the reason for this might be due to its ‘foundry skin’ and higher carbon content, however it was suggested that wrought iron would last better in the long term than steel.

The second presentation of the day by Rupert Harris considered ‘The Painting of Non-Ferrous Metals’ through a series of case studies, beginning with a clock tower project, the dome of which featured copper tiles on an iron frame, which had been painted and gilded. These required a very careful cleaning process. Yacht enamels and leaf gilding were used over an etching primer, to recreate the original bronze effect. Corrosion issues were highlighted through a case study of the figures at Osborne House. Here, copper and zinc in contact with each other had lead to a pitted surface. A water-jet with spinning nozzle was used to clean down the surfaces before they were filled and the ‘bronze’ surface was recreated with modern automotive paints used in an ‘artistic’ way. A series of other case studies were highlighted including, a project at Ham House to recreate sculptures for a 17th Century ‘garden wilderness’; and the restoration of the lead lion on top of the east façade of Syon House. Rupert admitted that he had almost ceased using lead paints in his area of work, except perhaps where a project involved retouching work to interior objects. One issue of particular concern to him was polychrome lead sculpture. Painted sculptures of this kind had originally been intended to be seen set against foliage and trees, represented in colour and not in lead grey. There are now very few examples of original painted lead decoration left. This in itself highlighted the importance of keeping paint samples in order to inform future decisions.

Following on from Rupert, Patrick Baty gave a presentation on ‘The Colours and Treatment of Historic Ironwork’. It appears that early ironwork tended to have been painted a ‘lead’ or ‘iron grey’ colour often using lamp black as a pigment. Later on, indigo was sometimes used to create an alternative lead colour, although it is not clear how frequently this was used, particularly as the use of it began to decline after the introduction of Prussian Blue. A ‘smalt’ pigment, coloured by the use of cobalt glass, created another fashionable but expensive blue paint. Later on, ‘Invisible Green’ was seen to have been a popular choice for painted railings. This was for a time considered to be a ‘picturesque’ treatment for fences. However, with the introduction of chrome yellow came the possibility of making brighter greens. A ‘bronze green’ was seen to have been in extensive use throughout the 19th Century. Towards the middle of this century red lead and red oxide were discovered to be effective in protecting against corrosion. It appears that the popular theory that ironwork was painted black following the death of Prince Albert is not based on fact. It seems more likely that black only became a popular choice when faster drying alkyd paints became available in the post-war period.

In ‘Painting the Forth Bridge – A Never Ending Job?’ Colin Mitchell-Rose outlined the history behind both the Tay Bridge and the Forth Bridge. The Tay Bridge had been built in 1878 of cast iron, but following its collapse in 1879, the design for the Forth Bridge was reconsidered. It was eventually built from 52,000 tonnes of steel and opened in 1890. Every piece of this steel needed a protective coating of paint. A paint consisting of 85% red oxide and 15% linseed oil was selected. For many years a team of painters was employed as part of the bridge maintenance team. Midway through the 20th Century, the paint for the bridge was changed to an alkyd paint, and it was suggested that this may have lead to the eventual delamination of the layers of paint. In the late 90s the owners of the bridge were forced to review the paint system. The new approach involved using three coats of a two pack epoxy blast primer, a two pack epoxy gloss flake barrier coat and a two pack acrylic urethane top coat – all of which was to be applied by spray. Unfortunately, this system required the stripping of all previous layers of paint, resulting in the loss of 120 years of coating history. This presentation highlighted the need for understanding what type of paint is being painted over.

In her presentation on the Clock and Tijou Screen at Hampton Court, Suzanne Groom provided an overview of the complex history of Hampton Court’s ironwork and then described its current state highlighting some of the issues they are currently facing. It has proved very difficult to find any historic paint remaining on the railings, although one cross section had been found to reveal many layers of paint. Historic Royal Palaces are now currently facing the dilemma of which modern paint to use. They need one that will protect against corrosion whilst also providing a finish similar to an old lead paint - and being low maintenance at the same time. No decisions had been made as yet. The clock on the Gate Tower had originally been made for Henry VIII in 1540. It had undergone many decorative schemes and repairs over the years; the 1960s redecoration had used an alkyd-based paint. The dilemma with this was whether to preserve or completely strip this scheme. A lead-based oil paint was chosen, as it was hoped that it would degrade in a more sympathetic manner than a modern paint system. To finish with, Suzanne Groom referred back to the topic of painting lead sculpture. Hampton Court has a lot of early 18th Century lead statuary, and are currently facing the decision of whether to return it to polychrome or not.

Just ahead of the lunch-break, Christine Lalumia, Deputy Director of the Geffrye Museum gave a short introduction to the museum and some of the recent project-work. The Geffrye Museum depicts English interiors of the urban middle classes from 1600 to the present day. It was founded in 1914 at the heart of the East End furniture trade, to inspire better and more sophisticated work. Originally, the almshouse contained displays of furniture and woodworking, but after the trades dispersed the idea of presenting period rooms was put forward. Most recently the museum has undergone a project to represent the exterior paintwork. Bright white paint has been taken back to a cream colour on the windows, reflecting a scheme typical of the 18th Century. The black metalwork has been painted a grey, whilst the doors have gone from a Racing Green to a duller green colour. All of which combines to make a subtle, but significant difference in appearance. Another recent project was the redecoration of one of the alms houses in an early 18th Century scheme as well as a 19th Century scheme. One floor of the house was painted with a putty coloured oil lead paint and distempers, whilst the other floor used a buff oil paint typical of the 19th Century. The rooms are lit and furnished with items from each period. A tour of these rooms was conducted for the groups in the afternoon session of the conference.

In the first presentation after lunch, Laura Stevens discussed ‘Sign Writing on Metal’. She reflected on her career in this subject, showing examples of sign writing that she had enjoyed over the years. The images illustrated how sign writers used personality, proportion, balance and elegance compared with the present technology using vinyl letter cutting. This also served to highlight the problem of a loss of traditional sign writing skills. Examples of generic pub signs and temporary banners illustrated the loss of a human element - personality, design and patience. Laura concluded her presentation with some examples of war shields from Papua New Guinea, which can be seen on display at the British Museum.

Paint Consultant, Peter Rumley led the final presentation on ‘The Conservation of Decorated Lead’. Peter also identified a skills shortage, but in terms of decorative leadwork. He showed examples such as the decorative rainheads at Knole and pieces from Ightham Mote where he is Consultant Archaeologist. Peter explained the process of ‘tinning’, which was used to provide the first colour decoration in leadwork. ‘Plumbers black’ was an agent that stopped the tin from sticking to other parts of the object. Lead can also be gilded or painted – St Johns College in Oxford was shown to have the finest examples of decorative leadwork in Britain.

The next session of the conference had a more practical focus. The delegates divided up into four smaller groups and were treated to demonstrations of oil gilding with Paul Humphreys of Hare & Humphreys; Bronzing with Joy Huning and Saskia Patterson; a tour of the alms house projects and free time to look at the museum collection.

During the gilding session, Paul Humphreys explained that oil gilding is mostly used for architectural work, whilst water gilding tends to be used on furniture and smaller objects. He passed round examples of different grades and colours of gold leaf – the main colours used in this country tend to be medium deep, red and lemon gold, whilst in France a citron colour is more popular. ‘Dutch metal’ is an imitation gold leaf, which needs to be lacquered to stop it from tarnishing. Aluminium leaf was shown to be a popular choice for theatres, where a coloured varnish is often applied over the top. Gold leaf does not need a varnish as it is unaffected by weather. A demonstration followed where Paul used a brush to pick up a sheet of gold leaf from a cushion and lay it onto a thin layer of gold size. The gold was then tamped down with a soft brush called a ‘gilders mop’ which also lightly burnished it.

In the bronzing session, Joy and Saskia described a project at Kenwood where they had worked on the balusters of the deal staircase. Here a linseed oil paint was made up and a scumble glaze of linseed oil and aluminium hydroxide applied over the top. 176 balusters were painted at roughly 7 minutes per baluster. Three coats of the base colour was required and then the scumble glaze followed by a modern varnish for maintenance purposes. The green colour chosen for this had to match the doors and the stair runner. As Saskia described the project, Joy demonstrated the painting techniques involved on a sample board. A second bronzing project was the lions on the gateposts at Victoria Park in Bath. These had required a red lead primer, a black linseed oil paint and a pigmented varnish to create the bronze effect.

Finally, there was a visit to the almshouse project in House 14, which had previously been occupied by museum staff until the mid-1990s when there was an opportunity to restore them. The modern additions were stripped out and following paint analysis, one floor of the house was redecorated in 18th Century paints and the other in 19th Century paints. The aim was to show what life might have been like for an elderly couple living in the house at these two points in time. The rooms were furnished in the style of 1780 and 1880 with objects from the museum collection. These three practical sessions, plus the chance to explore the period rooms of the museum, were a fantastic way to round off the 2009 TPF conference.

Ingrid Wellard
December 2009

Please note: Each issue of SMUDGE is written, in turn, by a member of the Traditional Paint Forum, subject to the control of the Committee. The information is provided in good faith. It is not necessarily the view of other members of the Forum; it is offered only as a contribution to the ongoing debate.