Need some info on building an oven.

[slammedxonair]

Hello everybody, I just reveived my PC startup equipment and I am interested in building an oven and adding powder coating to my business. I have been reading around on a bunch of forums trying to gather as much info as I can. I send Teds Fab an email on Tuesday and I was just wondering about how long it takes to receive a reply back? But I will post some of my questions here to see If anybody here can help me out.

I have been looking at Teds control boxes listed on ebay as well as some of the other parts he uses on his ovens listed on his web site. Here are a couple questions I have if anybody can help out.

Are the 4, 3200 watt heaters the largest you can run with the 2, 40 amp magnetic contact relays, or would I be able to run 4, 3800 watt heaters on those relays? I plan to start out with powder coating but would like to add ceramics also a little while down the road, I like to plan ahead. I was thinking about possibly building a 4x4x6 oven (maybe 3x4x6) and adding in a insulated shelf maybe 2' from the top of the unit when doing ceramics. I have thrown some other numbers around as well in the calculators online to try and figure this out.

Would it be possible to have 2 heater switches on the control box? 1 switch for the 2 main heaters for powder coating and 1 switch for the 2 secondary heaters for when I start doing ceramics? Or could all 4 just always run, cooler when powder coating and then they would crank up the heat with ceramics?

Would it also be possible to run the 3 elements on 1 power switch and then 1 extra element on a second switch or would that require a different magnetic contact relay other than what Teds boxes normally use? This is not a big deal 2 and 2 would probably work fine rather than 3 and 1.

I would like to keep the amps under 40-50 max when powder coating but when doing ceramics it could go over that (I will probably add the 2 extra heat elements later on for ceramics but want to have the controls there ready to go.)

I know I will also want to add a light inside and possibly a fan that Ted sells if it can withstand the ceramic temps. Does having a fan circulating the air effect the finish of the powder coating at all such as creating runs or anything like that?

Does Teds control box come with the connectors to connect the elements to high temp wire?

Thanks for any help.

[ed_denu]

Hello everybody, I just reveived my PC startup equipment and I am interested in building an oven and adding powder coating to my business. I have been reading around on a bunch of forums trying to gather as much info as I can. I send Teds Fab an email on Tuesday and I was just wondering about how long it takes to receive a reply back? But I will post some of my questions here to see If anybody here can help me out.

I have been looking at Teds control boxes listed on ebay as well as some of the other parts he uses on his ovens listed on his web site. Here are a couple questions I have if anybody can help out.

Are the 4, 3200 watt heaters the largest you can run with the 2, 40 amp magnetic contact relays, or would I be able to run 4, 3800 watt heaters on those relays? (2) 3800 watt elements would pull 32 amps at 240 volts. The 40 A contactors should handle this load without a problem. I plan to start out with powder coating but would like to add ceramics also a little while down the road, I like to plan ahead. I was thinking about possibly building a 4x4x6 oven (maybe 3x4x6) and adding in a insulated shelf maybe 2' from the top of the unit when doing ceramics. I have thrown some other numbers around as well in the calculators online to try and figure this out. Making the oven smaller for ceramics would obviously reduce the space required to heat and would allow the oven to heat faster. However, you may need to run the autotuning function when changing the oven dimensions.

Would it be possible to have 2 heater switches on the control box? 1 switch for the 2 main heaters for powder coating and 1 switch for the 2 secondary heaters for when I start doing ceramics? Or could all 4 just always run, cooler when powder coating and then they would crank up the heat with ceramics? When on, the elements will always output the rated wattage. The only way to vary the wattage would be to change the input voltage which pid's controlling contactors will not do. I personally don't understand the reasoning to have switches to turn on or off elements. The purpose of the pid is to control the oven temperature to the set point. IMO let the pid manage the elements. If you have concerns about the oven heating to quickly for PC, then you might look at one of the ramp/soak pid controllers.

Would it also be possible to run the 3 elements on 1 power switch and then 1 extra element on a second switch or would that require a different magnetic contact relay other than what Teds boxes normally use? This is not a big deal 2 and 2 would probably work fine rather than 3 and 1.

I would like to keep the amps under 40-50 max when powder coating but when doing ceramics it could go over that (I will probably add the 2 extra heat elements later on for ceramics but want to have the controls there ready to go.) Unless you plan on wiring the elements on separate circuits, you will need around an 80 amp circuit to support (4) 3800 watt elements.

I know I will also want to add a light inside and possibly a fan that Ted sells if it can withstand the ceramic temps. Does having a fan circulating the air effect the finish of the powder coating at all such as creating runs or anything like that?

Does Teds control box come with the connectors to connect the elements to high temp wire?

Thanks for any help.

Sorry but I can't answer specific questions concerning Ted's ovens or controls.

[slammedxonair]

Thanks for the help but does anybody know the best way to get ahold of Teds fab? The web site says they are only open April - October and I really want to get my control box ordered before they close. Thanks.

[baz]

Thanks for the help but does anybody know the best way to get ahold of Teds fab? The web site says they are only open April - October and I really want to get my control box ordered before they close. Thanks.

if you saw his business hours on the web site then you had his phone number right there !!!

[slammedxonair]

emailed twice and called and left a voicemail as well.

[slammedxonair]

Ok well I received an email back from Ted and he helped me out a lot. My questions now are, what gauge metal do most people do for their interior walls/ exterior walls? What gauge framing studs are sufficient for an oven? My local Home Depot has 25ga. Does anybody know where I can get Mineral wool insulation in northern Ohio so I don't have to pay for shipping? I think I am going to want to build this oven so I can do ceramics later and have the oven up to 750 degrees. Thanks.

[ed_denu]

Ok well I received an email back from Ted and he helped me out a lot. My questions now are, what gauge metal do most people do for their interior walls/ exterior walls? What gauge framing studs are sufficient for an oven? My local Home Depot has 25ga. Does anybody know where I can get Mineral wool insulation in northern Ohio so I don't have to pay for shipping? I think I am going to want to build this oven so I can do ceramics later and have the oven up to 750 degrees. Thanks.

I used 24 ga inside and out. Many people like 20 gauge, but either will work imo. I used the studs from HD on my oven, but if you want heavier, check with any drywall supply house and they will probably have several gauges to choose from. McMaster Carr has the mineral wool. They have a location in Cleveland.

[slammedxonair]

I also just found out The Menards by me has the framing studs in 25 and 20ga. So I will go compare their prices as well. I just found a couple places about 20-40min from me that sell the Roxul stuff I am going to call on prices tomorrow, as well as a contractor supplier that sells Thermafiber and IIG Minwool Curtainwall. But I will have to see if they will sell to me or not. I never knew there was a McMaster Carr anywhere around here. I've never really used that site much. It looks like they are about an hour and a half from me maybe.

I assume that I should use 2 layers of 2" or 1 layer of 4" insulation 8# or would any less be good? I am still waiting to hear back on a price for the galvanized sheet from my local steel supplier I usually buy from. This oven is adding up faster than I though lol I might have to make it a bit smaller to get started.

Are 2" wall studs and 2" insulation enough or do I really need to go with the 3 5/8 wall studs? Thanks for the help everybody.

[ed_denu]

I would stay with the 3 5/8 studs for insulation purposes. You could use 2" mineral wool and fill the remainder of the space with unfaced fiberglass. On the mineral wool be sure not to get the type used for sound deadening as it does not have good insulation properties.

[slammedxonair]

From what I have seen they all have sound deadening properties.