The Start Of An Oven Build/ Just Basic Info

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duke46
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The Start Of An Oven Build/ Just Basic Info

Post by duke46 » Wed Apr 24, 2013 1:39 pm

The Start Of An Oven Build

I try to help you guys when you want to build your own oven. If I can catch it soon enough. Then I can give advice and with any luck save you time and money.

This is only the basics for planning and starting your build.

1. Check the voltage. Do you have 220 or 230 or 240? Higher is better and your heating elements will work better and your oven heat up faster.

2. Elements come in different wattages and sizes. If you buy to low of a wattage one and you have less voltage coming in then your oven will be slow to heat up. Top elements in an oven are the higher rated ones and are called the broiler element. They are also smaller in size and work well for an oven build. They are on the average of 3000 watts. You will need 2 to 4 for most builds unless you are building an oven bigger than a 4x4x8.

3. Consider where your oven is going to be used and where is the power feed coming from? Are you feeding off your house or a shop with its own powder? Guys have built their ovens and it was feeding off the house and when the oven was on then the house could not operate. No dryer/no cooking and no AC/Heat. Great way to tick off the wife or mom!!!! If that is best you can do then you will have to build your oven to operate slower. And keep in mind that your air compressor might not be usable at the same time.

4. When you start your build then find commercial suds for the main frame and the doorframe. The lightweight ones are ok to use between them. You don’t want your door to fall off do you? If you can’t find the correct studs then reinforce the front of the oven and the door with heavy gauge angle steel. Places that make up panels for the building trade should have the metal in stock. It is best that you weld your hinges on along with the locks for the door if at all possible. If you can’t then use the proper bolts and reinforce the back side with washers or flat steel. If you have to do this then place the outside panels on first and then finish the inside of your oven once the door is secure.

5. As for as mounting the panels then you can use rivets or self-tapers. If you use the tapers then use a drill with torque settings and set it so it want strip out your screw. Just remember to reset the torque when screwing into the lightweight studs. When using screws and if for some reason you need to remove a panel then it can be done with out having to drill the rivets out and that can be a pain to do. Self-tapers are also a pain right at the end of it. Be careful putting them back. You can strip the hole out real easy.

6. Some guys think they have to seal the seams of an oven??? You are not building a freezer or a watertight box. You are building an oven and there is insulation in the walls so just make sure your sheet metal is as tight as you can get it. If I was to use and sealer then I would put it on the corner and top and bottom studs and then lay the sheet metal on it and when finished remove any residue that squeezed out.

7. Ovens have to breath. When installing the door seal you want some gap at the bottom. Just a little is better than none. Just open the door on a regular home oven and you will see a seal that goes from the top and down the sides and nothing on
the bottom. If you are like the rest of us then you started with a normal kitchen one so just open the door and take a look. I am not saying leave that big of a gap but leave some. You can also look under the right rear burner and you should see a vent and it should just be setting there and going over to hole so the oven can vent out excess heat. That area is where your wife or mom would set a pan or a dish to keep it warm while finishing up diner. If you started out with one of the solid slick top ones then I would guess it vents out elsewhere? I would consider installing a vent out the top or side of your oven with a little light weight flapper maybe using like a 2” piece of pipe. There is a lot of heat at the top of an oven so just get creative with it.

8. Some oven builds use fans to help circulate heat and it will make your oven more like convection ones. Your heat will be more uniform. You can buy the small motors and install a regular type blade or you can get fancy and build one into your oven that will move the air from top to bottom using a duct system. Just remember you want to just move air a little and not blow it.

I think that is about all I need to cover to help get you started off right? Insulation and wiring and PID’s is all up to you and what you can find and then what you want and can afford.
All I have said is said just for meanness so I don't have to argue with anyone!

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duke46
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Use Of A Fan

Post by duke46 » Wed Apr 24, 2013 7:53 pm

The size of your parts is the pan and the food.

This is kind of interesting for you guys that don't know ovens.

http://en.wikipedia.org/wiki/Convection_oven" onclick="window.open(this.href);return false;
All I have said is said just for meanness so I don't have to argue with anyone!

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duke46
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Figuring Actual Wattage

Post by duke46 » Wed Apr 24, 2013 8:04 pm

Info on your elements verses your voltage.
Oven Checking wattage and amps
Yes, you could add to or replace both elements. Ohms law calculations will give you true output values, it is not an estimate. When I stated earlier that the wattage would be reduced by 25%, that wouldn't be an estimate, but an actual figure if the voltage dropped from 240 to 208.

If you have any 2 of the 4 electrical properties, the other 2 can be determined. The variables are Voltage, Amperage, Resistance(Ohms), and Power(Watts) and their relationship to each other is always consistent. You can measure Resistance, Ohms and Amperage with a multimeter. The easiest thing to do would be to measure the voltage across the 2 hot poles of your electrical feed. Then turn the oven on and do an amp check(clamp on meter if you have one) on one hot leg between the contactor and element. Then multiple volts times amps to get your actual wattage.

An alternative would be to remove the wires from the elements and do a resistance(ohms) check on the elements. Then multiple voltage times voltage and divide by resistance to get wattage. As an example 208 times 208 equals 43264. If the resistance is 10.5 ohms, then divide 43264 by 10.5 to get 4120 watts.

Also keep in mind that if you replace the elements with new, you need to compute their wattage based on your actual input voltage. Many elements are rated at a given wattage based on a specific voltage such as 250. If you are only inputting 208 volts to an element rated 250 volts, then the listed wattage is going to be reduced by about 30%

Ed
I am trying my best to post all I can in a row so all will be here in one place and one right after another.
All I have said is said just for meanness so I don't have to argue with anyone!

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All I Want To Do Is MC Frames

Post by duke46 » Wed Apr 24, 2013 8:34 pm

This is some great info on a build with all the info. Except for the fact you wonder how bad he burned the powder on the bottoms of any thing he put into his oven?

Make it a little higher and also put some shields over the elements and then have the DAG door open to the side and not the top. Might get you head burned :o

Other than that i think he might have done a great job? He could have left out the Eastwood name :(

http://www.powdercoatoven.4t.com/" onclick="window.open(this.href);return false;
All I have said is said just for meanness so I don't have to argue with anyone!

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