RE: Porcelain Sundials
Hi John, The old wall dials in France and Italy are often painted using the fresco technique. Here metal oxide pigments, ochre etc, are incorporated into the lime plaster which converts to limestone. They are permanent and last as long as the wall stands subject only to erosion of the limestone. This is why many Zarbula dials still look fresh over 150 years later but are generally they are washed by weathering or obscured by dirt. Chemically the fresco pigments are as stable as glass but lime plaster is softer and more subject to erosion. Regards, Roger Bailey -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of John Carmichael Sent: April 24, 2007 2:34 PM To: 'Sundial List' Subject: RE: Porcelain Sundials p.s. But I still love the hand painted wall sundials found in France and Italy, even if their paint doesn't last as long. --- https://lists.uni-koeln.de/mailman/listinfo/sundial
RE: Porcelain Sundials
Hi John C, Patrick et al, Chris Daniel once told me that the hour lines on the St Mary's Westminster dials are platinum leaf. Harriet James says that it's even worse to work with than gold leaf! Re gold in vitreous enamelling: the gold powder floats to the surface during kiln firing so you end up with a glass-protected solid gold line. Wonderful - but expensive! Regards, John D --- John Carmichael [EMAIL PROTECTED] wrote: Now this raises one more important question. Note that the hour lines and the numerals are shiny gold on a blue background. The blue color is certainly baked on powder coat enamel. But what is the gold color? Is the gold color gold leaf that was applied by hand on top of the powder coat blue background, or is the gold color also powder coat? If you talk to Chris again, could you ask him? John p.s. this question is important because if the gold color is powder coat, it would probably double the cost because each color requires a separate baking in the oven and a different stencil. You can not bake on two colors at the same time. Also, gold powder coat paint probably is not as shiny as gold leaf. As we discussed, it is hard to have very large kiln-Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Patrick Powers Sent: Tuesday, April 24, 2007 12:58 PM To: 'Sundial List' Subject: RE: Porcelain Sundials Message text written by Patrick Powers I shall ask Chris Daniel (who is not a member of this list as far as I know) about what he thinks the finish was on St Margaret's. Well, I did ask Chris Daniel about the St Margaret of Antioch dials and he confirms that they were stove-enamelled - like my Morris Cowley mudguards and not vitreously enamelled. This stove enamelling process gives a more flexible finish but the colour is a fired paint and is not made from fused glass particles and the paint is sprayed on using electrostatic attraction to give better adhesion so, (as far as I understand things), you cannot easily generate designs on the metal by this technique. However, as we see from St Margaret's, you can then apply size and then gold or platinum leaf to the stove enamelled surface to provide necessary dial furniture. Hmmm, I suppose that it might be possible to use masks and layers of different colours and multiple firings to achieve a desired design because my muguards had a grey undercoat as well as a later fired black top coat and they didn't merge!. Might be worth considering when big dials are involved - after all the St Margaret's dials are still going strong after 25 years - not bad for any dial finish. Patrick --- https://lists.uni-koeln.de/mailman/listinfo/sundial --- https://lists.uni-koeln.de/mailman/listinfo/sundial --- https://lists.uni-koeln.de/mailman/listinfo/sundial
RE: Porcelain Sundials
Dear Frank: Don't feel bad about sending so many letters to the list. I love hearing from you and I'm sure others do as well. It's always nice to hear the thoughts of an educated person. Please forgive me if I cc. my answer to your letter to the sundial List. If you have questions, others might have the same. I think that Americans have the same misconceptions about porcelain too, thinking that porcelain is just for dinnerware or insulators. People don't realize that it can also be fired onto metal (like a bathtub). As I told you at the conference, when it is applied to metal it becomes incredibly strong. I could not believe it when the manufacturer struck a sample with a hammer and it did not even crack! You wrote: I am starting to settle on the two terms: 1. high-temperature vitreous enameling (porcelain) 2. low-temperature oven-baked enameling (powder coat) I think that your terminology adequately describes the two types of durable enamel. (the third type of enamel is regular acrylic or oil artist paint applied at room temperature which is not nearly as durable). Just remember that powder coating always involves application by electrostatic attraction. The metal is charged with electricity using an electrical clamp in a special room. (I don't know if it is positively or negatively charged). The paint looks like dust and is oppositely charged so that it is attracted to the metal. After the paint dust is applied, the object is baked in an oven where the dust melts and briefly turns into a liquid and then hardens onto the surface of the metal. If two colors are needed, then separate applications and bakings are required. The first color must be covered with a stencil or masking tape so that it is not covered up by the second color. So you can see why it is difficult to have more than two colors using powder coat. I am sure that this explains why powder coated clock and sundial faces only have two colors. Porcelain glass dust (called frit) is not applied by electrostatic attraction. It is applied either by hand or by silk-screening techniques. Hope this clears things up. John -Original Message- From: Frank King [mailto:[EMAIL PROTECTED] Sent: Wednesday, April 25, 2007 2:34 AM To: John Carmichael Cc: [EMAIL PROTECTED] Subject: Re: Porcelain Sundials Dear John, I write off-list this time, mostly because the list has heard rather a lot from me recently!! Your correspondence has been fascinating. It has taken a while to sort out the different techniques. One reason is that U.S. terminology and English terminologies are a little different. As John Davis has mentioned to me: in England, we think of porcelain as referring to tea cups and high-voltage insulators, sometimes also to ornaments made in Germany and elsewhere. To English ears, the term porcelain dial sounds as though it is made of ceramic, perhaps made up from tiles. The term powder coating is also new to me and I have been trying to find terminology which would be well understood to English manufacturers. I think the word enamel would be used for both kinds of technology. I am starting to settle on the two terms: 1. high-temperature vitreous enameling 2. low-temperature oven-baked enameling The first is definitely the more exciting and more durable but limited in size. The second is obviously much cheaper and you can bake a whole car if you want to! I was most interested in your detailed explanations and, especially, that with oven-baked enameling one is limited to two colours. This might explain why most clock dials are just one or two colours in England. The main colour is usually blue but I attach a photograph showing a church clock with a red dial. This is S. Mary's Church, Penzance which is the most southerly and most westerly Town of England which is why you can see a Palm Tree in the foreground. I send this to you not just because of the red dial but because, just to the left of the dial, you can see the top of a pole carrying power lines. You can clearly see the white insulators (one of these is very close to the X for 10 o'clock). This white insulator is made of what we call porcelain! You can see why the idea of a porcelain dial is a little confusing to English diallists!!! By the way, the X and the other Roman numerals are almost certainly gold leaf. Best wishes Frank --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Porcelain Sundials
John Carmichael wrote Now here's a thought- All over England I saw the clock faces on all the churches have only TWO colors (either black and gold or blue and gold). This leads me to believe that these clock faces might be made of low temp baked paint enamels and not porcelain. Does anybody know exactly what the English clock faces are made of? Most (almost all) flat English church clock dials of the type John refers to are painted and gilded on a flat or convex ground. Others have a skeleton of cast iron which can be glazed though sometimes it is open or placed in front of the wall. The ground is sometimes wood in older clocks (when it hasn't been replaced by something else - though a surprising number survive from 17th and 18th centuries) or copper, and copper or cast iron (19th-20th centuries) in newer ones. Occasionally stone is used. The numerals when gold should be done with 23.5 or 24 carat gold leaf. Cast iron allows the minute spaces and hour numbers to be definitely as intended and little subject to the vagaries of the repainter and the contrast with white or opal glass makes a clear dial which can be illuminated (as in the Great Clock of Westminster, commonly called Big Ben). Modern dials (post 1960) are usually glass fibre and have sometimes (wrongly I think) been used to replace older church clock dials - and for new buildings (especially supermarket clock towers etc). I do recall seeing one enamel church clock dial in England but can't remember where - East Anglia perhaps? On the other hand clock dials on the Continent quite often have enamelled dials. Often these are made in sections, at least in France. I hope this is of interest. Are enamelled cast-iron baths relevant to this discussion (not that I know anything about them?) Andrew James 51 04' N 1 17' W PRI Limited, PRI House, Moorside Road Winchester, Hampshire SO23 7RX United Kingdom Tel: +44 (0) 1962 840048 Fax: +44 (0) 1962 841046 www.pri.co.uk PRI Limited is a company registered in England and Wales with company number 2199653 The Intelligent Metering Company This correspondence is confidential and is solely for the intended recipient(s).If you are not the intended recipient, you must not use, disclose, copy, distribute or retain this message or any part of it. If you are not the intended recipient please delete this correspondence from your system and notify the sender immediately. This message has been scanned for viruses by MailControl. --- https://lists.uni-koeln.de/mailman/listinfo/sundial
RE: Porcelain Sundials
Message text written by Patrick Powers I shall ask Chris Daniel (who is not a member of this list as far as I know) about what he thinks the finish was on St Margaret's. Well, I did ask Chris Daniel about the St Margaret of Antioch dials and he confirms that they were stove-enamelled - like my Morris Cowley mudguards and not vitreously enamelled. This stove enamelling process gives a more flexible finish but the colour is a fired paint and is not made from fused glass particles and the paint is sprayed on using electrostatic attraction to give better adhesion so, (as far as I understand things), you cannot easily generate designs on the metal by this technique. However, as we see from St Margaret's, you can then apply size and then gold or platinum leaf to the stove enamelled surface to provide necessary dial furniture. Hmmm, I suppose that it might be possible to use masks and layers of different colours and multiple firings to achieve a desired design because my muguards had a grey undercoat as well as a later fired black top coat and they didn't merge!. Might be worth considering when big dials are involved - after all the St Margaret's dials are still going strong after 25 years - not bad for any dial finish. Patrick --- https://lists.uni-koeln.de/mailman/listinfo/sundial
RE: Porcelain Sundials
Well that settles it Patrick! Thanks for clarifying that point. Now hopefully, some of the dialists who have followed this discussion will make some colored metal sundials in the future, either using powder coat or porcelain. John p.s. But I still love the hand painted wall sundials found in France and Italy, even if their paint doesn't last as long. -Original Message- From: Patrick Powers [mailto:[EMAIL PROTECTED] Sent: Tuesday, April 24, 2007 2:14 PM To: John Carmichael Subject: RE: Porcelain Sundials Message text written by John Carmichael Now this raises one more important question. Note that the hour lines and the numerals are shiny gold on a blue background. The blue color is certainly baked on powder coat enamel. But what is the gold color? Is the gold color gold leaf that was applied by hand on top of the powder coat blue background, or is the gold color also powder coat? If you talk to Chris again, could you ask him? It isn't gold on St Margaret's - it's platinum leaf. (some info at: http://www.stonehouses.co.uk/categories.php?mcid=24;) That's applied like gold leaf - the artwork is painted on using 'size' and then the leaf ie rolled onto and sticks to the size.. Then the whole is burnished to a brilliant finish. Patrick --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Porcelain Sundials
Message text written by Frank King John Carmichael explained that the biggest oven that his suppliers use will accommodate a maximum size dial of 46 square. The Margaret of Antioch dials are over twice that size. I wonder whether Brookbrae could still do a job that big. If so, they may have a customer! I don't know. There have been changes at Brookbrae over the years. Earlier in this thread John Davis referred to an enameller that he used and I seem to remember that it used them at least partially because they were one of only a few who could accommodate the size of dial that he then had in mind. I am sure that he will read this and will explain the issues. I am actually unsure of the needs of the technology here because the problem is supposed to be the paucity of ovens of a size that can take the metal bases. However in a very extended restoration of a vintage car (it's 42 years since I last drove it!! ), some years ago I needed to get some replacement mudguards repainted. I then discovered that the originals had been stove enamelled and in trying to be authentic I have found no difficulty in getting that done first with a matt-grey priming enamelled layer and later with a gloss one. Are the ovens used for stove enamelling car parts (the ovensI used for my mudguards were of a walk-in size) the same sort as those used for artistic and enamelled signs etc? I have heard that stove enamelling needs a higher temperature than powder coating It would be nice to know if a combination of the two technologies can be used to solve the problem you have. Patrick --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Porcelain Sundials
Hi Frank et al, The Houghton Hall sundials were made by Vitramet Europe Ltd. (http://www.vitrameteuropeltd.com/). I notice that one of the dials actually features in the photomontage that heads their homepage. Although Vitramet have some facilities in the UK, the Houghton Hall dials were actually enamelled in Mexico(!) because of their size (1320mm diameter or around 53.5). I only had to deal with the UK office, I'm pleased to say. I don't know how much bigger they could go. One nice feature is that the gold lines feature real gold particles which are ground up in the paste enamel and then fired in - they do have a cheaper option though! One of the dials (the N face) had to be in two pieces to allow it to be assembled around the original 1727 gnomon which is fixed into the stonework behind the dial. Thus if you wanted to make a dial which was bigger than Vitramet's oven, it would be possible to assemble it from separate panels mounted edge-to-edge. Regards, John D -- Frank King [EMAIL PROTECTED] wrote: Dear Patrick, Your short message is a mine of information... I am fairly sure they (the dials on St Margaret of Antioch's Ch) ARE enamel! You are quite right to refer to this place as the Church of S. Margaret of Antioch and, likewise, I should have referred to the Collegiate Church of S. Peter in Westminster rather than the vernacular Westminster Abbey! I must try harder! As far as I know, the latter has no dials (though I put one in the street close to its Chapter House) whereas the former has four. Even more interestingly you say: Yes, they are enamel They are huge too - 8ft 6ins in diameter. This measurement raises further questions. John Carmichael explained that the biggest oven that his suppliers use will accommodate a maximum size dial of 46 square. The Margaret of Antioch dials are over twice that size. I wonder whether Brookbrae could still do a job that big. If so, they may have a customer! Frank --- https://lists.uni-koeln.de/mailman/listinfo/sundial --- https://lists.uni-koeln.de/mailman/listinfo/sundial
RE: Porcelain Sundials
Message text written by John Carmichael Porcelain is a vitreous enamel which means that it is composed of glass frit (fine dust sized particles of glass). It requires HIGH firing temperatures of about 1500 degrees F. and kiln-type ovens. But the enamel and powder coatings used on car parts or lawn furniture is more like traditional paint and is baked at much lower temperatures- about 350 degreesF. Thanks for that John, pretty clear one doesn't want the vitreous/porcelain stuff on a car because it must shatter if bent! However, the interesting thing is whether or not the fired enamel paint and powder finishes would be just as good as dial finishes. I shall ask Chris Daniel (who is not a member of this list as far as I know) about what he thinks the finish was on St Margaret's. Patrick. --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Porcelain Sundials
Dear John, Thank you for your message. I was delighted to have the opportunity to meet you face to face at the BSS conference and to hear about the techniques you use... especially our discussions about the possibility of using durable fired porcelain instead of paint I shall certainly investigate this technology though my current client is keen to stick to paint! I have something else in mind for a year or two hence and may look very carefully at this technique then. I noted a number of intriguing linguistic differences in our discussions... I think we use the term `enamel' for `fired porcelain' which means something slightly different here. I also noted that when I talked about `fixing a dial' this was not a usage that you recognised!! Your CD, by the way, is full of absolutely splendid delights. Best wishes Frank --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Porcelain Sundials
Dear Frank (cc Sundial List): I just wanted to tell you how much I enjoyed seeing you and getting a chance to talk with you at the conference, especially our discussions about the possibility of using durable fired porcelain instead of paint for the replacement of old deteriorated painted sundials. As you noticed, I am a big fan and advocate of using baked porcelain on metal or ceramics as the best media for making durable sundials in full color. Porcelain is the most durable of all media for making a sundial in full color. I really want to see more porcelain sundials being made in the future. I have had five of them made: four black and white ones on my sundial cupola (http://www.advanceassociates.com/Sundials/Stained_Glass/sundials_files/Stai ned_Glass_Sundial_316.jpg ), and one colored one for an attached vertical wall dial (The Wall Sconce Dial- cover of the last Compendium. http://www.advanceassociates.com/Sundials/Stained_Glass/sundials_files/Stain ed_Glass_Sundial_317.jpg ). We need to spread the word to dial designers and makers about the advantages of porcelain. I am sure that there are companies in the UK who make porcelain signage and wall art. In fact, while touring Suffolk after the conference, I came across these two companies. I have not talked with them, but I'm sure that they could make custom porcelain sundial faces from a pattern provided by a dialist : 1. Norton Castings of Norfolk Telephone: +44 (0)1953 860 998 http://www.nortoncastings.co.uk/ This company mostly makes fancy hand painted porcelain address plaques to attach to your home or business. They fire porcelain designs on to aluminum plates. They can be in full color and they will do custom designs and different shapes. These are high quality. 2. The Personalized Plaque Company Tel: 01692 58528 www.broadlandceramics.com http://www.broadlandceramics.com/ This company also makes fancy porcelain address plaques to attach to your home or business.But these are porcelain that is fired on to ceramic plates instead of metal plates. They are also in full color and can be custom designs and different shapes. Also- high quality product. In the United States, I have found three excellent companies. I'm sure they ship anywhere: 3. KVO Industries Tel: 707-573-6868 (talk to Steve) www.kvoindustries.com http://www.signsearch.com/cgi-bin/redir.pl?url=http://www.kvoindustries.com title=dtl_42868 This is the company who made my porcelain sundial faces for me. They use advanced photographic techniques to transfer designs to steel sheets. So they are not hand painted. Their quality and customer service is excellent. They can do full color and different shapes. I highly recommend this company 4. Winsor Fireform www.winsorfireform.com http://www.winsorfireform.com/ Also, a very good company. Also uses advanced techniques. If you go to www.ceramics.org http://www.ceramics.org/ you will find more companies. Hope this helps and that you try out porcelain for one of your dials in the future. --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Porcelain Sundials
Hi John and sundiallists everywhere,
You might be interested to know that Harriet James and I are currently making
a vitreous enamel on steel dial to replace an art-deco painted steel dial on a
private house. The original iron scrollwork gnomon will be reused. The firm
doing the enamelling are called Vitramet - they also did the set of four large
vertical towers dials I designed for Houghton Hall in Norfolk.
During the BSS Cambridge Conference we all admired the set of 6 dials on the
Gate of Honour at Gonville Caiuis College. These were enamelled in the
1960s, I think, by a firm in Birmingham who seem to have disappeared now.
Regards,
John Davis
John Carmichael [EMAIL PROTECTED] wrote:
st1\:*{behavior:url(#default#ieooui) }Dear Frank (cc
Sundial List):
I just wanted to tell you how much I enjoyed seeing you and getting a chance
to talk with you at the conference, especially our discussions about the
possibility of using durable fired porcelain instead of paint for the
replacement of old deteriorated painted sundials.
---
https://lists.uni-koeln.de/mailman/listinfo/sundial
RE: Porcelain Sundials
Hi Frank: I think the terms: fired porcelain, baked porcelain, or porcelain enamel mean the same thing. I have heard the term baked or fired enamel used in reference to porcelain. But you are right, baked enamel usually refers to oil based paints or powder coats that are baked on at low temperatures (like the paint on your car. John -Original Message- From: Frank King [mailto:[EMAIL PROTECTED] Sent: Sunday, April 22, 2007 8:57 AM To: John Carmichael Cc: 'Frank King'; 'Sundial List'; [EMAIL PROTECTED] Subject: Re: Porcelain Sundials Dear John, Thank you for your message. I was delighted to have the opportunity to meet you face to face at the BSS conference and to hear about the techniques you use... especially our discussions about the possibility of using durable fired porcelain instead of paint I shall certainly investigate this technology though my current client is keen to stick to paint! I have something else in mind for a year or two hence and may look very carefully at this technique then. I noted a number of intriguing linguistic differences in our discussions... I think we use the term `enamel' for `fired porcelain' which means something slightly different here. I also noted that when I talked about `fixing a dial' this was not a usage that you recognized!! Your CD, by the way, is full of absolutely splendid delights. Best wishes Frank --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Porcelain Sundials
Dear John, Does anybody know if the four round blue dials on the tower at Westminster Abbey in London are made of porcelain (vitreous enamel)? They are on the Tower of the Church of S. Margaret's Westminster (quite different from Westminster Abbey) and are by Christopher Daniel. You can see a little about these dials in: http://www.sundials.co.uk/~thames.htm but it doesn't say what they are made of. I am fairly sure they ARE enamel! Best wishes Frank --- https://lists.uni-koeln.de/mailman/listinfo/sundial
