Pieces of Art

Following on from Stacks of Fun here is Pieces of Art. The elephant is my first attempt at lost wax casting – it was meant to be in bronze but my crucible broke so I made the best of a bad job and, with a make shift crucible cast it in lead. I made a lot of mistakes but I got something from it. Recently, a friend applied a bit of gilding. Its 80 mm high.

The paintings are oil on board.  The tunneler is 330 x 400 mm. A small flower is 460 x 560 mm and The gesture is  180 x 250 mm.

The painting was a bit of a phase, I thought I would have a go one day and produced these over a 4 month period.  I have a few more, some still unfinished, and I have a few ideas I would love to get going on but there just isn’t time at the moment.

Its not really work but maybe one day?

Limewash thoughts

I was asked if the roughcast render I was doing could be self coloured to avoid limewashing.

This is a misunderstanding of the role of limewash especially where roughcast renders are concerned.

Limewash is not actually a paint – it is a brush applied  render, applied very thinly in a minimum of three coats.  It renders the render. I.E renders the render more weather resistant.

The colour is a bonus.

I like to take the limewash over the stone elements, this is to seal the interface between render and stone, however, this upsets the builders on new build projects!

The colour of a limewash imparts to the building a tremendous visual impact – it glows in the midday sun and  picks up the sunset hues.

The predominant colour in the Cotswolds is Yellow ochre. In the forest of Dean, across the River Severn its more pink, this is because there was a lot of red oxide pigments found in the Iron mines. In the Cotswolds yellow ochre was found.

Generally, therefore, these colours are still preferred, yet there is always an opportunity to vary the tones and hues to some degree.

This slideshow requires JavaScript.

Themed yellow

Spring 2011 Struggling with lime in the frost

January 2011 was taken up with the monumental struggle against the conditions to render a rather nice extension.

A hundred and twenty metres of lime stucco onto concrete block.

Thin coats, lots of frost protection and some luck led to a very pleasing result.

A smooth render should be flat. I hate seeing those undulations that become prominent when the sun strikes the wall at an acute angle.

Corners should be crisp, and ruler straight. The finished surface should be floated as smooth as Bath stone.

Achieving the above is not easy, and the most difficult and time consuming thing is getting the smooth and flat finished surface. The choice of sand and lime is extremely important, and having tried hydraulic lime I am not at all sure that it is the right thing for the final coat. I think that even if the primary coats are hydraulic lime the final coat should be lime putty based as the material is so much more plastic and workable.

Corners are no real problem but there is a short cut: get the first side flat and level – use a straight edge to work to it has to be really flat. When this has set hard do the other side – use the straight edge held flat against the previously finished face, line the edge of the board up with the intended finished surface and plaster up to it, trowelling the plaster well into the corner formed by the board and the scratch coat. Once done the board can be slid away from the corner leaving a perfect edge.

Obviously, we are not using corner beads or dowels with this process. We, of course, do the window and door reveals this way as well.

On this occasion there was no ruling to do, which made life a little easier but the ashlar look is always pleasing when done well, the trick, I think, is to get the joints the correct thickness, the edge of a trowel is not the way.

The render was eventually limewashed to provide the final surface protection and colour.

Stacks of fun on Holiday

This slideshow requires JavaScript.

A number of stacks built whilst on holiday, mostly on the coast in Devon and Cornwall but also in Sicily and the Aeolian Islands, Spot Stromboli in the background. There is one built of cinders at 1500m on Etna. None are very big, the tallest, built at Southerndown in South Wales, reached almost 2 meters. All are precariously balanced and I knock them down after taking the photo.

Owlpen Manor – Render Repairs

The following is a description of work carried out by JBLimeplastering at Owlpen Manor in Gloucestershire

The masonry revealed by the removal of the cement render was very friable with missing elements. The building mortar used in the construction was predominantly mud/loam mortar and so had suffered badly under the heavy, non breathing render. Despite the alarming appearance, quick progress was made to fill the voids and build up the surface (dubbing out) with stone inserts replacing missing masonry elements and broken terracotta tiles used in conjunction with well haired lime mortar to build up hollows to create a more even surface suitable for applying a trowelled lime render. Once the surface was repaired an initial coat of lime mortar was applied by trowel to an average thickness of 15mm. This coat was diagonally scored to provide a good key for the second coat. Care was taken to build up the surface in order to remove some of the undulations. Extra compaction was applied by beating with a bundle of withies (thin flexible twigs) in order to provide extra key but primarily to compact and counteract shrinkage thereby achieving greater strength. This first coat was left to cure. The second coat was again trowelled on and was similar in nature to the first coat. However the surface was scored with a stiff brush rather than scored to provide a key for the roughcast coat – some further beating with the withies took place. The final render coat was thrown on (roughcasting or harling) to provide a weather resistant rough crust. This coat was applied in a semi fluid state and so is no more than 8mm thick. Care was taken to achieve a uniform pebble textured surface. Once this final textured surface was dry a coat of unpigmented limewash was applied by brush. Two more coats of coloured limewash were applied with brushes before the winter break with the intention of returning after the winter to apply a further coat. During a severe winter immediately following the project a few small patches of surface damage required repairing before the final limewash coat was applied. Mixtures Repair mortars and trowelled coats: One part Natural Hydraulic lime NHL2 Two and a half parts limestone dust from Wickwar quarry (5mm to dust) Horse hair: A generous handful to two cubic feet of mortar Roughcast mix: One part NHL2 Two and a half parts South Cerney grit sand. Limewash was made from lime putty: Pigments: The main colour used was Yellow ochre (coded Y42) Modern pigments are too vibrant and rich to achieve a correct vernacular result and so the tones have to be tempered by the addition of Umber: Raw Umber, as used here, imparts a cool tone trending towards green whilst Burnt Umber imparts a warmer tone trending towards red. Notes on the Mortar mixtures. A decision had to be made regarding the type of lime to be employed. A large consideration was the time of year and exposure of the gable. These factors ruled out the use of lime putty as the binder due to its slow setting rate and its vulnerability in the first few months after application and so I chose Hydraulic lime as the binder. I was very conscious of the condition of the masonry and felt that I needed to try and achieve a render that was tough and weather resistant without being too hard and unbreathing. With this in mind I selected a local limestone dust as the aggregate – the nature of which created an easy flowing mortar. Hair was added in generous quantities to add tensile strength to the render which would be kept as thin as possible, I felt it was important to keep the weight of the render to a minimum – a thin render will carbonate quicker, shrink less and stay attached to the wall longer. JB

Conservation and repair of an historic lime render – Gloucestershire.

This slideshow requires JavaScript.

The render probably dated from the 19th century. It had replaced an earlier render, traces of which were present here and there. Traces of coloured limewash on the quoins suggested that at one time the quoins were left unrendered as a feature element. The render now covers all the masonry except, of course, for the mullions, although during the project a small window was found beneath the render. The render was generally sound, although there were some loose sections totalling about 20 square metres, in addition there were a few long cracks associated with historic settlement. There was another 20 metres or so of cement based roughcast patches. The whole render was very grimy with a lot of lichen. The first task was power washing to remove the lichen and grime, the washer is not over powerful but enough to dislodge any defective render along the way. All the cement patches were removed and work began on repairing the exposed rubblework. The next task was to apply the first coat of lime render. Mild hydraulic lime was used mixed with a generous amounts of animal hair. The cracks were gently widened and filled with lime mortar. Numerous amounts of nail holes were filled as well as the narrow cracks on the extremities of the render. There were some areas of severe lichen encrustation that couldn’t be removed. These were keyed up to coated with a very well haired roughcast mix. The repairs were roughcast, allowed to set and then given five coats of limewash. The first two coats were unpigmented – the white contrasted well with the black nail and bee holes allowing us to do further filling. Once again a coat of white was applied. A coat of yellow ochre based limewash was applied all over for approval. The client felt that the bold colour was too much and so A fresh batch was prepared with the required modifications, this new colour was felt to be much better and so the fourth colour was applied. The difference in colours, the first colour on white and the second yellow on the first allows one to see what’s been limewashed and what hasn’t, applying the same colour again often to leads to areas being missed or inadequately coated. The render was now thoroughly coated with four layers of limewash, with the colour now approved the final coat was applied. This final coat was easy to apply because every hole had been filled and the rough texture of the roughcast had been reduced to a much more homogenous and gentle texture. The final touch was the repair of the window masonry and the subsequent limewashing of the stone in a contrasting colour. Mixes: Repair mortar for the render – 1 part lime to 2.5 parts sharp sand Reinforced with animal hair. Crack filling – 1 part lime to 1.5 parts fine sand. Limewash – undercoats Lime putty, water, Reinforced with chopped hair, fine polypropylene fibre and silver sand for the first two coats Limewash – Final coats Lime putty, water, yellow ochre and raw umber, tallow.

A simple lime plaster cornice

running a cornice in situe

This is in a National Trust property in Gloucestershire, UK. The building is a summer house and tends to be damp in the winter, for this reason I decided to fashion this cornice from lime plaster in situe rather than have a moulding made up in the workshop. It was felt that anything based on plaster of Par is would deteriorate in the damp conditions.  The final mix, seen here, was composed of lime putty, brick dust and sandstone dust. These three ingredients would act upon each other and create a strong plaster, with resistance to shrinkage during the drying and curing period.

The backing coat consisted of Lime putty, sharp course sand and lots of animal hair. This sticky mix was applied to wooden laths fixed between the ceiling and wall at 45 degrees. The lath cradle had the appearance of a railway track running around the room.