ao_ceramics Posted May 31, 2017 Report Share Posted May 31, 2017 Hi allVery much a beginner in ceramics, learning along with my girlfriend as we get a little ceramics concern going.We're on the lookout for a small test kiln and have found a very keenly priced Potterycraft 40lt 4kw/20amp kiln in local listings. However, the kiln will be placed in a rented house and we don't think the landlord will be keen to hard wire it into the house's distribution board.We wondered if it's easy enough to convert to 13amp use to be run off a plug, and simply fire at lower temps?The kiln we've found is rated to 1300°, but we only need to fire at 1250°. Potterycrafts offer 20amp and 13amp models of the same kiln body, with the 13amp version rated to 1260°.http://www.potterycrafts.co.uk/Products/small-electric-front-loadersI think we could stretch to spending a little bit of money on the conversion as this kiln seems like a really rare, and very tempting find. I'd be very grateful for any advice on the feasibility and safety of trying this out. Is it simply a case of sticking a plug on and making sure we keep the temperature low? Thanks!Mat Link to comment Share on other sites More sharing options...
Dick White Posted May 31, 2017 Report Share Posted May 31, 2017 The only way you can safely decrease the amount of heat a kiln will generate is to change the heating elements to ones that are designed to produce less heat. The kiln is going to draw the amount of power that the elements are designed for. Setting the temperature lower does not decrease the amount of electrical power drawn by the kiln, just that it is on for a shorter time. Looking at the pictures on the Potterycraft website, it appears that the 3kW (13A) and 4kW (20A) versions of that kiln have the same body, so the difference is likely to be the heating elements. You could contact Potterycraft and inquire if it could be safely converted simply by replacing the elements with the lower wattage set. Also note that when a kiln has a nominal maximum temperature rating such as 1300C (cone 10) or 1260C (cone 8), that is the maximum you can expect when the elements are fresh and prime. Frequent firings to the maximum rated temperature will wear the elements and make it more difficult (longer and longer firings) to reach that temperature. For practical purposes, you should operate a kiln 2 cones (50-60C) lower than the maximum rating so you don't have to replace the elements as often. If your body of work is based on glazes and clay bodies that mature at cone 6 (~1200C), then the 3kW model rated to 1260C will be good for long term use. If your body of work is based on true cone 8 materials (1260C), then you will need the 4kW model for long term use. Link to comment Share on other sites More sharing options...
ao_ceramics Posted May 31, 2017 Author Report Share Posted May 31, 2017 Hi DickThat's great advice, thanks so much!We're using Botz glazes that have a workable range (offering different results) of between 1220 and 1280°c, but we're getting the finish we like best out of 1250-1260°c. We'll be sticking with this while we get our first couple of commissions made. So bearing your advice in mind we'd likely be better off with the 4kw. I think I'll email potterycrafts for the sake of interest, though. Thanks for pointing me in the right direction! Mat Link to comment Share on other sites More sharing options...
neilestrick Posted May 31, 2017 Report Share Posted May 31, 2017 You don't want to be firing to the max of the kiln. Like Dick said, any wear to the elements and you won't be able to hit temp. Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted May 31, 2017 Report Share Posted May 31, 2017 I have a pottery crafts 60L top loader, give them a ring and they will advise/make some elements up. You may struggle with 1260 but they will probably know more information. Keep a look out for old cromartie kilns. I have one that runs on 13amp and happily gets to cone10. It was sold as broken (£67) but I removed all the electric switches and the elements worked fine. 1ft3 size wise. That's probably the largest size you will get to cone10(1300) on 240v 13amp. Link to comment Share on other sites More sharing options...
ao_ceramics Posted June 2, 2017 Author Report Share Posted June 2, 2017 I have a pottery crafts 60L top loader, give them a ring and they will advise/make some elements up. You may struggle with 1260 but they will probably know more information. Keep a look out for old cromartie kilns. I have one that runs on 13amp and happily gets to cone10. It was sold as broken (£67) but I removed all the electric switches and the elements worked fine. 1ft3 size wise. That's probably the largest size you will get to cone10(1300) on 240v 13amp. Thanks Joel! Funny you say that - we had a quick bid on a Cromartie that went on Ebay last night, just missed out but that was 13amp/1300°c We're in the North East too - Sunderland & Morpeth to be precise - so it's nice to meet a local potter! Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted June 2, 2017 Report Share Posted June 2, 2017 No way I grew up in Morpeth, parents still live there but I live on the west side of Newcastle right now. Never thought I would meet anybody local on this forum Link to comment Share on other sites More sharing options...
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