I Took the Plunge - New Oven

[Joe Jones]

I decided to go ahead and start with an electric powder coat oven. It will be 4x4x6.5 feet tall inside, and 5'x5'x7' on the outside.

I looked at the Eastwood offerings, and others. They sure want a lot of money for an insulated steel box!

It CAN'T be that difficult to build one.

So I ordered the 12,000 Watt 240VAC (50A) oven controller from Amazon. The DE-LUX model with the fan controller and light controller. I also got the door seal, the blower fans and the heating elements.

I'm going to find (or make) 6" steel studs and set it up for a roll-in situation, where a rack can be rolled in on the concrete floor. I also have to build a powder coat spray booth, but how difficult could THAT be, really? A three-sided booth that sucks air
and powder through a wall of filters?

Eastwood wanted well over $10,000.00 for the setup, and close to $11,000.00 delivered. I am into this for a little over a grand so far, and I already have the sheet metal I need to line it. I still need to find the mineral wool insulation, build a spray and bake rack on wheels, and figure out how to set up the baffles for the air circulation, and to build the four 3,000 watt heating elements into the walls. Fortunately I have a good friend with his own HVAC business. so I can design the baffles and even cut them on the 510 table, and have his guys bend and spot weld them together for me.

I know it sounds a bit over the top, but I have this whole pallet of 14 ga. 4x10 stainless steel. I think that at least the outside will be stainless, although I may use standard 16 ga. galvanized for the interior walls, or for the entire thing. I just don't want one of those saggy, wrinkled ovens that looks like it is cheaply made.

I haven't bought steel in a while, and I know the price is through the roof. Maybe I can default to the bumpy aluminum stuff they use on walk-in coolers, or ??

I might build this so it is outside of my shop. That will require a little more thought put into rain protection and so forth, but I don't know why it would NEED to be inside. My FrankenBarn has 400 AMP service, so I guess I could put it in there near the power panel.
Maybe I should build a separate tin building with the oven at one end, and the booth at the other end? Sheesh. Then I would need another concrete pad.

Advice and suggestions are welcomed. I will ask a lot of questions before I start cutting up metal studs. I even thought about building this on a trailer, so it is a self-contained and PORTABLE unit. I'd just need a long, heavy extension cord and an assortment of power adapters for the various receptacles. So many options.

Still waiting for the glide rails to move forward on the pipe cutter, so I am jumping into this project too.

I will post photos etc. when the project begins. I sure wish I could find a local and CAPABLE friend to help me. My buddy Dave had a massive stroke on New Year's Eve, so now he is no longer capable of this work. His girlfriend told me he was smoking TWO CARTONS a week! How many cigarettes are in a carton? I guess it was only a matter of time.

Joe

https://www.amazon.com/Auber-Instrument ... C92&sr=8-2




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[WyoGreen]

It's bad when you start to outlive your buddies, all of a sudden you are all alone on your projects. I've noticed that around here, I'm down to 1 buddy, and he's slowing down fast.

Steve

[AREA]

Cool find on that controller, I am very curious to follow your build on this as I too would like a larger oven.

I would suggest keeping the oven in your main shop close to where you will be coating the parts. Traveling any distance with unbaked, freshly costed parts can cause issues with powder falling off, dirt or moisture getting in your powder etc.

Can't wait to see your build Joe.

[rdj357]

I bought a shipping container and build the oven in it. Cut an opening and stuck the end of it into the shop.

For insulation I just used unfaced (no paper) fiberglass bats and it works just fine. I suppose you could just use regular fiberglass batts from the big box store and put the paper toward the outside.

I heat both of my larger ovens with gas but that 12k setup should work very well.

[SegoMan DeSigns]

Lowes stock rock wool, check under commercial insulators for your area and see what show's up. Over time fiberglass will break down under the heat especially if you do ceramics.

[Joe Jones]

I bought a shipping container and build the oven in it. Cut an opening and stuck the end of it into the shop.

For insulation I just used unfaced (no paper) fiberglass bats and it works just fine. I suppose you could just use regular fiberglass batts from the big box store and put the paper toward the outside.

I heat both of my larger ovens with gas but that 12k setup should work very well.

Yeah, I drew up a "dream" oven made of a 40 foot shipping container with an internal moving wall, like the piston of a bicycle pump. The thought was to create four or five stages, so bringing the wall forward would give you a small oven with ONE heating element set. Moving the wall back to 40, 60, 80 and finally 100% of the length would use 2, 3,4 and 5 heating groups.

Apparently, mathematically, they suggest a maximum cu. ft. volume for a 50A 12Kw electric oven. It is about 4x4x6. I asked them if I could set up TWO groups of heating elements, with two controllers, and would it work with an oven twice that volume. No straight answers. They said I cannot connect them TOGETHER to work in parallel, but that is not what I asked them.

I figure that if a 4x4x6 oven can work well with four 3Kw elements, then TWO controllers, each with four 3Kw elements should be able to efficiently heat a 4x8x6 oven, and THREE of them should be able to run a 4x12x6 oven. Is that logical? Three controllers, each working independently, would STILL turn on and off based on the temperature probe that controls THAT unit, so I would think that three controllers would just kick on and off as needed, as they each monitor 1/3 of the oven's volume. I think they would work well together, especially if the fans moved air across the three banks, suck from #1, into #2, suck from #2 into #3, and suck from #3 back into #1 ...

Anyway, I will start with this "small" oven (4x4 footprint inside, 6' 3" tall, two fans, four burners, 12,000 watts of heat at 240 VAC/50A.) If it generates any REAL money, I will throw it at a larger oven. The BIGGEST oven I ever saw was in San Antonio. I swear you could powder coat a locomotive inside of that thing!

Joe

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[Joe Jones]

It's bad when you start to outlive your buddies, all of a sudden you are all alone on your projects. I've noticed that around here, I'm down to 1 buddy, and he's slowing down fast.

Steve

My mom was a volunteer at the local hospital in CA. All of the "pink ladies" were in their 80's. My mom could not go a single week without attending two or three funerals. My step-dad used to tell her, "You need younger friends."

Joe

[Joe Jones]

Lowes stock rock wool, check under commercial insulators for your area and see what show's up. Over time fiberglass will break down under the heat especially if you do ceramics.

That is what it is called! Thanks! I could not remember it. Rock wool. My local Lowe's is a small store in a small town of only 9,000 people. He said it is all "special order" here. At our store, three 10mm sockets is a "special order."

Joe

[djreiswig]

If your location is correct, it looks like they have plenty in stock.

Screenshot_20220223-192339.png

[djreiswig]

And if you hurry, it looks like they have 4 of these in stock right now.

Screenshot_20220223-193323.png

[SegoMan DeSigns]

Lowes stock rock wool, check under commercial insulators for your area and see what show's up. Over time fiberglass will break down under the heat especially if you do ceramics.

That is what it is called! Thanks! I could not remember it. Rock wool. My local Lowe's is a small store in a small town of only 9,000 people. He said it is all "special order" here. At our store, three 10mm sockets is a "special order."

Joe

No Problemo.

I am having trouble visualizing the shearing process of stone cladded sheep

Rock Wool is also called Mineral wool, I see it is also available at Home Depot in different bat thickness/size A commercial insulating company can hook you up with panels of it which would make construction a little easier.

I am about to start on my oven build as well, I bought an old aluminum smoker that is 30x30x60 that will be my first oven, Then like you say build up from there.

Here is a great tutorial on building an oven:

https://www.powdercoatguide.com/2014/09 ... -oven.html

https://www.powdercoatguide.com/2014/09 ... Ln0GH-mLWB

[Joe Jones]

The thing about home built ovens is that most of the ones I have seen are very cheaply made. Thin steel studs with very thin skins on the outside. If the thing doesn't sit absolutely flat on the floor, or the weight of the door is too much, the walls buckle and sag. The interior isn't critical, but I always overbuild things, so I am sure I will do that in this case as well.

I am being told that I need to get the thing U.L. Approved. I am not selling them. I don't know why I would need to drag the gu'mint in on this project. I'll have to have a chat with my insurance agent.

I am going to have two small inspection doors to shoot a laser temp probe through, so I don't have to open the big door and let all of the heat out JUST to check the temperature of the material being cooked. In fact, I am in search of laser temp probes that I can mount INSIDE of the oven and aim at the surfaces while they are cold. Then, a simple digital readout will tell me the temperature of the metal at all times. I don't even know if they exist, but I'm looking!

I like light. Lots of light. So there will be a lot of light in this oven. I don't like squinting to see things. My friends joke about needing sunglasses in my home. I have a lot of very bright lights in every room. All LEDs, so the bill is reasonable, but I just can't stand a dark room. Of course, there is the obvious exception ... while entertaining a lady! Then the lights can be low, or off.

Joe

[adbuch]

No Problemo.

I am having trouble visualizing the shearing process of stone cladded sheep

Rock Wool is also called Mineral wool, I see it is also available at Home in different bat thickness/size A commercial insulating company can hook you up with panels of it which would make construction a little easier.

I am about to start on my oven build as well, I bought an old aluminum smoker that is 30x30x60 that will be my first oven, Then like you say build up from there.

Here is a great tutorial on building an oven:

https://www.powdercoatguide.com/2014/09 ... -oven.html

https://www.powdercoatguide.com/2014/09 ... Ln0GH-mLWB

That's the one I am planning to build. Probably 4x4x6 or so inside dimensions for mine. I have a few Norton frames I want to coat.
David

powder coat oven.jpg

[Joe Jones]

That's the one I am planning to build. Probably 4x4x6 or so inside dimensions for mine. I have a few Norton frames I want to coat.
David

powder coat oven.jpg

See, now that is a GOOD looking oven! It doesn't look like it fell off of a truck!

I am curious why the inspection window is so large. All you need to do is point a laser temperature probe through a hole, right? I would think a 4"x4" door is all that you need. Maybe I am wrong...

Joe

[Joe Jones]

I have a few Norton frames I want to coat.
David

https://youtu.be/gX2qmboAXnY

[34by151]

My small oven 2x2x2 is electric
My bigger oven 8x4x4 is powered with Propane GAS heater (40kw)
You need a min of 150w per sq foot but figgure on double that of you fast recovery
This gets the oven up to temp in 18mins
Replaced with 2 stage diesel heater (Riello 40) 120Kw max
Heats up the oven in a few mins costs almost nothing to run when compared to gas and electricity
So fast heating it not worth preheating the oven

My coating booth is directly opposite the oven so part go from coating directly to oven
Coating booth has suction fans and lots of lights
The rack I hang parts for coating can can change in height and rotates to get all around the parts

[Joe Jones]

I wanted to use propane but I could not get a straight answer from anyone. NO ONE seems to offer a complete oven controller that uses propane, with real burners, made specifically for powder coat ovens.

All I could find are You Tube videos where some dude or another hacked a propane turbo fan heater or some chicken farm henhouse heater with ridiculously --- rigged components that amount to some old motorcycle parts, an old paint sprayer and a 8-track player!

So I just ordered the electric controller with four 3Kw elements. I will start with this one and see where things go. At least this SEEMS to be legitimate powder coat oven components.

I guess I am missing something. I THOUGHT there would be some company ... somewhere ... that makes specific components for larger propane heated powder coat ovens...

You tell them you want to build an 8 x 8 x 30 propane oven with four stages of heating, at 25%, 50%, 75% and 100% of capacity. They reply, "Here are your burners with piezo igniters ... Here is the controller that turns the gas on and off using these PID controllers ... here are the plans for a (?) x (?) x (?) oven with outside venting, two circulation fans and a bank of lights ..." NOPE! Just, "I figgered out a way to connect this old bar-b-que burner through a lawnmower choke valve that is controlled by my grandma's hair dryer. From there, it was easy to connect the fish aquarium pump and the tuba ..." I felt like I was living in Hooterville!

No matter what searches I tried, I could not find one single SERIOUS source for professionally built components and the guidance I needed to build a SAFE and powerful oven that is heated by propane.

Doesn't the diesel heater require outside ventilation? So would propane, for the carbon monoxide concerns. There is no natural gas here. I was shocked to learn how much electrical power would be required for a LARGE oven.

I called my HVAC guy, but he said he didn't know of ANY option for using propane to heat a PC oven. There is a serious VOID in this industry!

Joe


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Joe

[Joe Jones]

What are your thoughts on a 2'x6'x6'6" high interior space? (11,700 Watts by my calculations)

Rather than a typical 4x4, this would have a narrow door on the end, and six feet of depth for railings and motorcycle frames, etc. 24" wide at the door opening ... Would that create a problem? I guess I couldn't put anything "fat" into it, but after all, I use a plasma table, so everything I make is FLAT-ISH.

It occurs to me that I could build TWO ovens, using ONE controller and a relay switch. Either fire up the long narrow oven, or the short squatty one with the big footprint ... The shared wall could contain the heating elements that would heat either oven, depending on which panels were opened or closed.

Joe

[rdj357]

.....
I called my HVAC guy, but he said he didn't know of ANY option for using propane to heat a PC oven. There is a serious VOID in this industry!

Joe

I've been an HVAC/R contractor since 1996. My solution was the Carlin EZ Gas burner. It is a retrofit for fuel oil heaters (used primarily in the northeast). These burners use either natural gas or propane and can be drilled out to burn at a set BTU/h range from 50k to 275k. As far as control wiring, I can do that in my sleep. My large oven is currently 10' deep, 7' wide, 7' tall. I have one Carlin drilled out for 275k and it is at temp in 5 minutes. I am in the process of extending it to 20' deep. I have another burner that I'll install and set to 150k. I will use a 3-stage PID controller and some relays to allow for 3 stages of heat (150k, 275k, 425k) by firing the small burner as stage one, large as stage two, and both for high stage.

I agree, there is a serious void in the HVAC industry. There are a lot of contractors and technicians that have very little knowledge of theory, thermodynamics, electrical controls. I have made a life-long business of fixing things others could not or would not.

[SegoMan DeSigns]

To those with a completed oven what did you skin the interior with? Some sites say that galvanized metal should not be used above 392* F as the zinc starts off gassing. One site recommended an aluminized vs galvanized sheet metal on the interior.

The nice thing about building your own is you can make it as big/strong/well lit as you want, everything in my shop has wheels under it so it can be moved with ease as the job dictates.

[34by151]

interior is skinned with 2mm zync steel
You want the termal mass inside
The thicker the material the longer it takes to heat up but the more stable the temp becomes
I used a 25mm RHS steel frame made and isie and outside box with 75mm beteen inside and outside
Rockwool between
Outside sheeting does not matter, used the pannels from and old garden shed
The steel frame is exposed on the inside and I weled mesh to the sides and roof
Yhis also adds thermal mass and provides hangers for parts
The side mesh allows me to add rails as needed for hanging multiple layers

[adbuch]

interior is skinned with 2mm zync steel
You want the termal mass inside
The thicker the material the longer it takes to heat up but the more stable the temp becomes
I used a 25mm RHS steel frame made and isie and outside box with 75mm beteen inside and outside
Rockwool between
Outside sheeting does not matter, used the pannels from and old garden shed
The steel frame is exposed on the inside and I weled mesh to the sides and roof
Yhis also adds thermal mass and provides hangers for parts
The side mesh allows me to add rails as needed for hanging multiple layers

Photos please.
Thanks,
David

[34by151]

What are your thoughts on a 2'x6'x6'6" high interior space? (11,700 Watts by my calculations)

That is a absolute min in reality you need 2-3 times that (500w per cubic foot)
You will need about 40kw which will be 180amps on 220v power

Do yourself a favour and get a Riello burner

You can get Propane and Diesel
I went diesel
Exhaust and oven vents are routed outside using 3in exhaust pipe covered with insulation

With 12Kw as you plan it will take over an hour to preheat
It will take about 30 mins to recover after putting your parts in
Say another 30 mins to heat the parts

So about 2-3 hours to cook a batch

With 500w per foot your batch times will be 45mins
A Riello burner will give you waht you want, output is adjustable
The G10 is perfect for your oven (54 - 100 KW)

All you need is a Riello burner and a PID controller

The PID has a temp probe (thermocouple) in the oven
It triggers a sold satate relay (SSR)
The SSR provides power to the Riello Burner

When the burner gets power it starts

[Joe Jones]

I've been an HVAC/R contractor since 1996.

That is interesting!

Again, you probably have it "figured out" but even you have to RIG something that works.

Quick question ... I was thinking of making my oven walls SIX inches thick, rather than using the default 2x4 steel studs for the body of it. Is there ANY reason that a six inch thick wall, door and ceiling is unnecessary or overkill for a powder coat oven? I don't mind spending the money to make it Bigger ... Better ... Stronger ... (Cue the Six Million Dollar Man theme song here) if there is a real advantage to thicker walls.

As a guy who knows little more about heat than what I learned while playing with matches as a child, this is all Greek to me. I want to walk into The Everything You Could Ever Need In The World Store, walk down the large propane powder coat oven supplies aisle and load up a big cart with the stuff I need to build a large oven using a simple four page color illustrated pictograph 30-step assembly guide!

I will be the first to admit that I know nothing about three-stage PID controllers, or BTUs, or propane burners, or much else on this topic.

In my mind, a GOOD oven accomplishes a few seemingly simple tasks:

1. Get to temp QUICKLY. An oven that burns energy for an hour or two JUST to get to temperature is worthless and inefficient in my eyes. I met a guy recently who has an 8x10x9'H oven he wants to sell. I was interested until he said, "It gets to temperature in about 90 minutes, and it keeps the SHOP warm in the winter..." Heat the entire shop JUST to powder coat a golf cart frame? That sounds like a highly inefficient and costly oven to operate, regardless of the heat source.

2. Maintain a temp within +/- a couple of degrees. That means RELIABLE burners that fire every time, and won't fill a big metal box with propane before finally igniting the fuel.

3. Offer the usual times, and alarms, and auto-shut off and such, to automate the baking process so I don't have to babysit the oven.

My neighbor heats his shop with a fairly compact wall mounted propane heater that was used on a chicken farm. It is about 16" x 24" and four inches thick. Yes, it cranks out heat, but is it EFFICIENT for an on-again-off again duty cycle that the powder coat process requires? I have no idea.

Honestly Robert, if YOU put a package together that works well, and doesn't end up looking like it was built by the Three Stooges with Lucy and Ethel supervising the project, I'd certainly be interested, depending on the total price, of course. You could either sell the PLANS with a detailed and sourced shopping list of parts, and some comprehensive HOW-TO assembly instructions (or a video?) OR you could sell the parts and ship them out at a modest profit, but that seems less logical, considering how easy it is to get most anything delivered to your door these days.

My pipe cutter is coming along slowly. I WAS going to sell the plans, and some of the parts I had sourced, etc. I decided to get it together with some demo videos, and just give it to whoever wants to build one. I'll give out the .dxf files for the components I designed that one could make with their plasma table, and a list of part numbers and sources for all of the rest of it. People CAN build this themselves and even modify the dimensions etc., with the files I have created for the pieces that you cannot buy on Amazon. I am certainly not going to ship 12-foot long Schedule 40 pipe rollers!

The electric oven controller arrives tomorrow. Apparently it is a box of pieces and parts, and I have to build it with simple easy instructions that are HOPEFULLY NOT in Chin-English. The glide rails for the pipe cutter are on their way. Lots going on here.

I have a mountain of church pews I acquired over a year ago. All Red Oak and beautiful wood. Wondering what to do with them. Bird houses? Wall clocks? Urns? A friend called. He wants to build a DECK outside of his home, using the church pews. That is an interesting idea, but I have to research how Red Oak handles long term OUTDOOR exposure. I have only ever seen Red Oak used INDOORS.

So much going on. so little time...

Joe

[Joe Jones]

everything in my shop has wheels under it so it can be moved with ease as the job dictates.

Yep! That is why I LOVE my little used Toyota forklift!

Joe