Cleaning.

Pressure washing of the 'Tijou' gate to remove loose layers (this operation was done before the protective enclosure was erected for obvious reasons.

Pressure washing of the ‘Tijou’ gate to remove loose layers (this operation was done before the protective enclosure was erected for obvious reasons). This operation has to be carried by a Conservation Blacksmith; he is inspecting and minimizing risk of damage to the ironwork as he cleans it. Being mindful to tie back on components in their original locations that might fall off during the washing.

Christmas and New year seem a while back now. Although very welcome, the holiday break disrupted our schedule again (if you’ve read the previous Blogs you’ll know we started a week late due to site preparation problems). With that said, we managed to get a couple of weeks of recording work in before Christmas just as we got going we had to stop.

Back to work again and it took a few days to get back into the swing of it. We had a good week 3, and made a start on phase 3 of the project which is to clean and consolidate the Ironwork structure. This work involves cleaning back whats left of the painted surface of the Ironwork, removing built up corrosion as we go. We are trying to achieve a suitable surface to prime ready for new coats of paint. It is obvious to a practical person what this all about, but I’ll elaborate a bit.

Our primary job in this phase is to conserve the existing structure. Conserving Wrought Ironwork generally means tackling corrosion and the damage it can do, there are other things to consider but I don’t need to bring them up here. There is little point in painting over layers of paint that potentially mask the wrong sort of corrosion. ‘Wrong corrosion’ I hear you say! All metals oxidize a little during and after manufacture and quite a bit during working, you can endeavor to remove these oxides, but metals ‘prefer’ this state  . If you observe stocks of Iron and Steel in dry store they are quite stable with this oxide layer in place. It is only when look carefully at the stock you see scratches and scrapes (due  handling process) corrode in the known manner (that’s the wrong corrosion). So it goes to say the right metal oxidization goes someway to protecting the metal, and if possible should remain if found or be encouraged, through correct hot working.

Picture shows ironwork that has been cleaned once and is waiting to be checked over by a second team and cleaned again if necessary. It will then be checked again as it painted in a holding primer by the quality control operative. Areas not up to scratch will be left unpainted and will have to be done again.

Picture shows ironwork that has been cleaned once and is waiting to be checked over by a second team and cleaned again if necessary. It will then be checked again as it painted in a holding primer by the quality control operative. Areas not up to scratch will be left unpainted and will have to be done again.

So the paint has to go, and we need to get down to the metal or as near to it as we dare. The paint has been already tested and recorded by an independent specialist, so that doesn’t need recording unless something else turns up. The tenacious grey primer you see in the photos has been applied over a thin black coat of paint. Its interesting to note that both these paints have been applied in void areas caused by layers of corrosion to build up then fall off. This suggests the paint layers you see are unlikely to be original and must be maintenance measures taken after significant corrosion had already set in.

The procedure (we know it as ‘method’) for cleaning of this large structure is to pressure wash the algae, dirt and loose paint off, being mindful that general debris needs to be collected as best possible and disposed of responsibly, anything of interest recorded and reserved. Then the remaining surfaces have to be flame cleaned, loosening the remaining paint and rust that then can be scraped, chiseled or brushed.

Conservation Blacksmiths using oxy-propane torches and wire brushes to clean back to original surfaces.

Conservation Blacksmiths using oxy-propane torches and wire brushes to clean back to original surfaces.

Where the metal is corrosion free, as much original surface should be preserved by careful brushing only . If the cleaning is conducted with the correct method, the resultant surface should be rich in character and most importantly as clean as possible (free of all but the most persistent primer and rust). There is of course a practicality issue here, namely there is only so much one can do with brushes and scrapers. It is so important that a Conservation Blacksmith is mindful that a more aggressive approach will start to undo good conservation philosophy and could damage the original structure more than the natural processes you are trying to halt or retard. This is why you don’t chemically strip the metalwork of all oxide, apply rust converters, shot blast or use a needle scaler.

Conservation Blacksmith cleaning difficult to reach parts using an adapted blade.

Conservation Blacksmith cleaning difficult to reach parts using an adapted blade scraper.

Priming the cleaned surface as soon as possible is important, there is little sense in doing all that tedious work only to waste it by allowing the corrosion process to get a fresh hold.
This painting can be applied as a light holding primer, this is the perfect start for the whole project. For the record, and with 20 + years of experience, cheap paint isn’t good value. Buy the best, it pays for itself in the long run.

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Gallery!

Welcome to the working day at Petworth gates.

Welcome to the working day at Petworth gates.

The time has come for photos!

I’m not going to exhibit photos that are mundane and official. I believe a website doesn’t warrant it. Instead I’m posting photos that are interesting and offer an inside and privileged view of this exciting project.

We are having fun and this is what we do; hopefully our enjoyment and passion comes through the pixels to you! Go to Gallery?

 

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Record, describe and collate.

Recording general gate information onto a prepared drawing.

Recording general gate information onto a prepared drawing.

More rotten weather and still playing catch up but things are looking up at the end of week 1 … 29 to go.

The task of accurately quantifying our work is midway, each section has been photographed, measured and the damage/work described. Where ‘interesting’ situations occur they’re singled out and specifically assessed. From this information a definitive component list can be made and a job list compiled. We follow the fundamental mantra’s of Conservation; minimum intervention, fit for purpose applications and most importantly the use of like for like materials, construction and techniques. Obviously there are times of conflict within the three guidelines, but that’s where rational, reasoned chat becomes the Conservators most valuable tool. These chats often need to noted and added to our handwritten day book along with that day’s goals, assessments and notes.

A chat about the correct approach to a problem!

A chat about the correct approach to a problem!

All this information will go towards a final survey and report, however it also provides vital quantitative information and office based tools needed to kick off the project. I have touched upon in the previous Blogs there is quite a bit of planning involved in this type of work and without planning, these projects can get out of control.

With the components identified, patterns measured and the work listed we can accurately order the materials, paint and estimate the consumables we are likely to use up. Fuel up to now has been estimated; diesel for the generator plant, propane and oxygen for the flame cleaning. We can now put accurate figures to those costs. We still have to allow for fuel to make the components and fit them, but now we know how many, we can make a best guess at that too.

Photo record of an Acanthus leaf fit to be reused. Showing scale, visual condition, orientation and tag with position on gates.

Photo record of an Acanthus leaf fit to be reused. Showing scale, visual condition, orientation and tag with position on gates.

So far I  have deliberately not commented about the gates in detail, but that is going to be addressed from now on; so blacksmiths and hands on types will be pleased and for everyone else it might get confusing. I will use some technical terms but I’ll try to temper them with day to day explanations. Please feel free to comment and ask questions with the ‘comment’ facility on the page, if you have a question I bet others do too!

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