Restoration of 200+ year old leather & casting
Another interesting project from a lovely couple who are doing an amazing job on sympathetically restoring an amazing period property (I’m genuinly not just saying that in case they read this!). They have an eye for decent quality and slightly quirky, less mainstream antiques. This project was to restore the bench top of a heavily carved walnut bench seat. The seat folds up and you can store items underneath. The problems it has had over its long life (built circa 1800) is that the leather top has had the support webbing changed so many times that the wood had a crazy amount of holes. The most recent attempt was done with screws, unconventional. You could tell by the shape of the leather that it had a gentle dome shape to it. This was now seriously sagging and the webbing gave no support. Also any wadding/horse hair that was underneath had long gone.
After removing the leather, some areas were so badly decayed they literally fell apart. The quality of the leather was extremely high, it had amazing carved creatures. In places where there was little damage you could see it was seriously thick, almost 5mm. Some parts however were paper thin and falling apart.
What I had originally in mind was to back the leather with pig skin. This is supple and very strong. Because of the tension it would need to be under when re-upholstered, on the thin areas it would pull a bit too much and change the shape. Also it would not behave the same way when reacting to the pressure of the wadding from below. I decided a better solution was to back the leather seat bases with automotive grade leather. Any areas of repair needed were touched up using special leather repair putty. This can be sanded when dry and is very flexible, it also takes on any dyes that are needed to colour match.
To revive the leather I first used a specialist leather cleaner, after getting off the years of dirt, grease and wax underneath I discovered there were still some areas where the original leather top had been painted. The red had survived the most, there was only a couple of segments of blue left but it would have looked amazing when first made.
The repair putty used to restore the missing areas is white and therefore needed to be painted to match the existing leather. Firstly a cleaner needs applying over the area to be sprayed. Then a leather bond needs applying and a heat gun used to dry it off to a tacky state. After mixing a good match of paint I also added leather bonder and a matting agent to get to the right level of sheen. This was then sprayed on using an airbrush. Several coats were applied to give the right level of depth. As this leather was not just one uniform colour, for some coats I changed the tone to add more red, a bit more brown or a bit more black to try and give as natural a look as possible to match the different areas. Each coat is dried using a heatgun. After curing for a further 24hours the whole leather top can then be treated with a nourisher.
With regard the seat base, because it looked like swiss cheese from all the holes it had been subjected to over the many re-upholstery attempts over its life, it had lost its structural integrity and could not cope with another set of webbing nailed under tension. The solution I used was to insert a wooden base, this would then be jointed across the weak holey wood using ‘biscuit joints’ onto more solid timber. When the hessian backing was applied no-one would be any the wiser but another advantage is that it gave the seat base more structure, all the joints were wobbly, in some areas broken, repaired and weak. Even though I repaired all the joints it still felt far more solid with the wooden inserted bases.
You can see from the photos that even though the leather tops are laying flat they have shrunk over time and no longer fill the space. The solution to this was to edge where they sit with 5mm walnut. This could then be made into a feature and would mean the leather tops could get the dome shape back and reduce the need for lots of filling.
Brass decorated nails.
There have been a range of different brass decorated nails used over time. It was tricky to work out what ones were likely to be the original. The customer and I agreed that the nicest were the ones circled below.
Now the challenge was to get some the same. After extensive searching, even with specialist brass caster Marshall Brass, I could find nothing even close. The only solution was for me to cast the 22 missing domed nails.
I used delft clay which is a specialist casting sand used in the jewellery trade. It keeps the detail better than anything else. Casting using the lost wax process would have been a lot more time consuming and expensive. Using delft clay I could try and cast using the 12 remaining ones. You can see the succes rate increase from the photo below. There were a combination of issues. Initially I did not have enough vents to allow the gas to escape, the studs were pressed brass so I had to increase the depth to allow the brass to flow more and also more importantly the chanels to allow that linked the studs and allowed the brass to flow were too narrow meaning the brass cooled too quickly and didn’t flow to the following ones.
After casting enough studs. I used a dremel with a carbide tool bit to grind off the extra rear depth. After cleaning and polishing I then had to replicate the aged look on the original studs. The original ones had aged to a deep brown, slightly coppery colour. It often looks better if you can take some of this away on the high points while retaining it in the recesses so you get a contrast and it replicates what would have happened if it was being burnished from peoples clothes as they sat on them, especially the ones at the front.
A special brass patination fluid was used from Liberon to change the colour from shiny brass to a deep brown. After leaving for 1/2hour you have to wash it off to neutralise the acid. Then it was waxed and then buffed over the high points. The end result was as close as I could get to the original 200+years of natural ageing.
This was a really interesting challenging project that required a range of different skills to restore. All told this took 32hours and was therefore not a cheap option. A lot of people would have just get rid of the leather, insert a base with some fabric on top. But this would have meant the amazing leather tops and nicely made brass studs would have been lost forever.
I feel when you are dealing with a quality piece of furniture that you are not the owner, you are the custodian to later hand it onto some future generation.
Thank heavens there are some people out there who feel the same and are willing to get restorers like me to get things back to original as possible condition and preserve these things for future generations to love and appreciate.