Yup, another gun cabinet cerakote oven... *pic heavy*

[Wintermute]

Well, went pretty much the same route as many others. Take a gun cabinet, insulate it, install a thermostat controlled heating coil.

Here's the work in progress:
Stack-on 14 gun cabinet:

Install a junction box on the side for the thermostat and other wiring:

Lots of 2" thick ceramic wool refractory insulation (rated to about 2700 degrees):

--Wintermute
Cut panels to fit the inside of the gun cabinet with a razor knife:

Insert into cabinet:

Install the conduit to feed the temp sensor through:

Cont. in next post...

--Wintermute

 

[Wintermute]

Mostly insulated...I'm not finishing that side until all the wiring and the element is in. Also still trying to figure out exactly how I'm going to insulate the door:

If you look closely, you'll see I packed the conduit around the sensor with ceramic wool:

This is the element I'm using, it's from a jenn air grill insert:

The inside of the junction box (the thermostat is a two wire 230v universal):

--Wintermute

 

[Willybeen]

Thumbs up. Creative. Let's see some byproducts

Sent from my SPH-L710 using Tapatalk

 

[slavage]

theres that gap in the door.. take out the lock and bars put a el cheepo latch on the outside and use the gap in the door to put the ins. fibers

 

[long range newbie]

how hot does it have to get to bake the cerakote on?

 

[Wintermute]

how hot does it have to get to bake the cerakote on?

250 to 350 depending on your curing cycle. This will be capable of much hotter than that, but I'll also use it for pre-curing ceramic coatings for high heat parts (eg. not gun parts).

This oven should easily get up to around 500.

--Wintermute

 

[Wintermute]

As a random note, the wiring going to the element is high temp wire (1000 degree rated) since it'll be exposed to the inside of the oven. There will also be a bit of machining of Macor ceramic in this since I want to cover the element terminals. It'll be my first time machining machinable ceramic, so it will at least be a new experience.

--Wintermute

 

[Wintermute]

theres that gap in the door.. take out the lock and bars put a el cheepo latch on the outside and use the gap in the door to put the ins. fibers

Yeah, I've been thinking that an external latch would be the way to go so that I can remove the internal latching mechanism. I'll see if I can find some nice high temp fiber board insulation to use on the door.

--Wintermute

 

[19Scout77]

Nice...needs casters!!!!

 

[thrusty]

Nice work! Any photos of the inside finished product and where/how you placed the element? How'd you insulate the door?

 

[Wintermute]

Not yet, I just started this project yesterday afternoon . I'll have updates as parts show up and I get out to the shop.

--Wintermute

 

[pyrofx]

Your using the same cabinet as I did.
I used 2" rock wool , and hardy backer board to clamp it all together. I used 2" sections of conduit for standoffs. 2 at the top 2 in the middle and 2 at the bottom . Did the same on the door , and left the original latch in it .
For elements I used 3 500 watt smoker elements. All controlled with a PID controller . Take 15 minutes to get to 300 and cool to the touch on the outside.

Greg

 

[Wintermute]

The hardibacker board is an interesting solution...it holds up well to the heat? I think I'm going to pull the interior door latch to see if I can get a bit more insulation there. Did you use a seal for the door jamb (I was thinking of using an oven door gasket, but I'm not sure there's enough room for it)?

PID controller is something I didn't think of...I'll see how well it works with the universal 2 wire thermostat control...if it's not up to par then I'll switch to a PID. The element I'm using is about 2250 watts, so I'm guessing it'll heat the oven up right quick

--Wintermute

 

[pyrofx]

No seal . The door fit pretty well . The backer holds up great . The only place it didn't was where I made a fixture to hold the elements. After 10 cycles it got brittle like glass. Still works fine , but sounds like ceramic now .

Try not to cook above 300. The resins will fry in the C-Kote. I hit 400 with a mag color . Came out looking burnt bronze. To 30 minutes of sand blasting to get the stuff off too.

Greg

 

[Sean the Nailer]

I second the motion to go with a PID. But another suggestion I'd make, if it's not too late, is to set your thermostat box back at least an inch from the door. As it is, it looks like you only have to 'over-open' the door once, and it will take out your plastic thermostat knob, and the potentiometer that it consists of, and probably 'dint' the face of that box.

Just a suggestion. Looks good though, and I definitely wish I'd known about that insulation, when we did our build, long ago. Still wanting to 're-do' what we done, with that better insulation. But the PID's sure are nice. Most definitely.

 

[Eastbay]

That's bad ass

 

[Wintermute]

Okey, you guys convinced me on the PID, so I ordered one in. I was surprised, they're not all that expensive (got one with the thermocouple and relay for about $40). I've also figured out how I'm insulating the door, I've ordered in some 1/2" and some 1" ceramic fiber insulating board (again, more high temp refractory insulation) and a vintage style ice box latch. I'm going to remove the internal latching mechanism, cement the fiber board to the door, and install the fridge latch on the outside. I'm still trying to figure out if I'll line the inside with the same isulating board, however, I'll probably smoke test the oven without that to see if the exterior heats up from where the metal edges are exposed inside. Other than that, just waiting for stuff to show up via ups and such and this'll be done.

--Wintermute

 

[Sean the Nailer]

Just make sure you acquire a mag as well (solenoid operated switch) as the PID is not strong enough to handle the current required. That is what the mag is for. You're off to a great start, and the possibilities are endless, eh?

 

[Wintermute]

Just make sure you acquire a mag as well (solenoid operated switch) as the PID is not strong enough to handle the current required. That is what the mag is for. You're off to a great start, and the possibilities are endless, eh?

Yup, that's the relay. The PID provides a low amp/volt supply to the relay which activates a small electromagnet to close the contactors to feed the heavier load to the element. In this case, the relay is a 25amp 230v unit, so more than enough to feed this element. Now my worry is that I'm going to build this oven out and decide that I need a bigger one for powdercoating .

--Wintermute

 

[Wintermute]

Moving on to insulating the door. I ordered in some 1/2" and 1" ceramic wool board to do the door with. The latch is getting replaced with a vintage refrigerator latch (not arrived yet).

Insulating board:

Remove the latching system:

Cut out the guides for the latching system and grind them smooth:

Cut some 1/4" aluminum spacers (the door inset depth is 3/4", so I want the 1/2" board to be flush with the inside edge of the door, then the 1" will be adhered to the 1/2" board):

Grind the powder coat off where the spacers are going so that there's a bare metal and roughed up surface for the adhesive to bond to:

Figured I'd use glue for wood stove gaskets...if it holds up in my wood stove it should hold up to this:

Now just waiting for glue to cure before cutting and adhering the first layer of board:

Updates later as a bit more gets done.

--Wintermute

 

[Wintermute]

First layer of the ceramic board in. It's been coated with a rigidizer (yeah, I don't know...basically something to make it solid on the surface so that it won't shed fibers). The rigidizer takes 24 hours to cure, so I'm waiting for that and then the 1" thick board goes over this stuff.

--Wintermute

 

[Wintermute]

Got the door latch and insulation done today:

--Wintermute

 

[redirt78]

We are using an old beverage cooler and just added some sheet metal and extra insulation. Might have to give something like this a shot next time around.

 

[pinsandpitons]

I wonder how much this treatment would help with the fire-rating of a safe used to store things rather than cook them?

 

[Wintermute]

Here's the next installment. Fabricate the plate to hold the element (made of 1/8" SS). I spent a bunch of time trying to figure out exactly how I was going to attach the element to the plate, then realized I was being silly and just tacked it to the stainless steel plate with the TIG.

I have to machine the ceramic piece to cover the terminals and wiring for the element. I'm not sure if any of you guys are interested in a video, but considering it'll be my first time machining Macor ceramic material, I was planning on taking one while I worked.

Last section here is the little bracket I made up to attach the thermocouple to. Since the thermocouple for the PID needs to screw into something, it needed something there for that. The bracket required a little thinking to come up with, but it's done now. Made of scraps of 1/8" stainless steel plate:

--Wintermute

 

[Wintermute]

Okey, got it all wired up and running. Took about 10min to get to 300F. I'm going to insulate the inside with more ceramic board since where there is exposed metal it transfers heat to the outside of the case pretty quickly. All in all though, it's a success so far. I'll get that additional insulation done and install a hanging rack at the top and I should be good to go.

--Wintermute

 

[DroidSniper]

I would think if You added a second smaller burner and fan it would heat up much quicker. Those PID's are sure nice.

 

[Wintermute]

I don't think I'll need either of those honestly. With the slight tweaks to the insulation and some additional insulation, it should cut the heat up time down to about 6 minutes (from 40 to 300 in 6 minutes is more than good enough). The real test will be after the additional insulation is in to see how often it has to cycle to maintain temperature...it could take 30 minutes to heat up and I'd still be happy as long as the temperature will remain stable and not cycle the burner excessively.

As a side note, the PID was from ebay and is one of the chinese models...very easy to wire, simple to setup. Great deal for the price. I did have to buy a different relay as I needed a dual solid state relay and the one that came with the PID was a single solid state relay.

--Wintermute

 

[Wintermute]

Next installment:

Started wrapping over the inside with DEI floor and tunnel shield (heat shield material made for cars...shielding exhaust, etc...). This material is rated to 1750F so it's just fine for the inside of the oven. Cuts easily enough with a set of tin-snips or a very sharp razor knife and repeated passes. I measured, cut, and bent the material to fit the inside of the oven. After that it was just a matter of putting it in and using a modified set of vise grips to ensure a clean hole drilled through both the metal of the oven and the material. I then pop-riveted the material to the oven so that it will hold in place tightly. All good from there. Anyways, here're the pics:

Drilling holes with the modified vise grips (basically two flat pieces of 1/8" steel welded to the jaws and a 1/8th hole drilled through to guide the bit through both the cabinet and the heat shield material):

The inside of the oven mostly lined:

Pop rivets:

Pop rivets from inside the oven (small washers were added to ensure the material wouldn't just pull off of them):

Just the thermocouple sticking through:

The box of material. This stuff is produced by Design Engineering Inc. under their Boom Mat product line. Works great actually, used it in race cars before and it's wonderful at keeping things from getting cooked that shouldn't get cooked (like your feet ):

--Wintermute

 

[Wintermute]

Okay, learning experience time . Don't use the metal insulation on the inside...it has an adhesive back to it (which happens to be covered in plastic). If you don't realize this, you will fill your entire shop with acrid burnt plastic smoke.

So I removed the tunnel shield insulation. Doesn't need it anyways (at least not at anything up to 350F).

Oven works great, coatings come out nice and evenly heated and the temperature control stays within a couple of degrees.

--Wintermute

 

[downrange67]

Don't forget to install some kind of hooks to hang parts off them.

 

[Wintermute]

I always attach the hooks to the piece that I'm spraying/baking instead of attaching them to the oven. That way when I'm hanging the part to spray it the hook is already attached to the wire holding the part. The attached hook just gets dropped over one of the bars in the rack in the top of the oven.

--Wintermute

 

[bower4311]

That is awesome. Turned out great.

Couple questions, how much are you up to total?

Another, I have a propane smoker that I'm looking to use all winter long up in northern NY. Where the hell can I get board insulation for high temperatures at a reasonable price? How much did you pay for it and where did you get it? Will they send you just a couple boards? My smoker is smaller than your oven.

 

[Wintermute]

Hmm...I'd guess I was up to somewhere around $400 or so (I think...I didn't really tally everything up, but between the cabinet at $100, $40 for the element, $60 or so for the PID, $200 for insulation, most everything else I had laying around the shop).

I bought my ceramic board insulation at this place: Skyline Components, LLC.

And yup, they'll absolutely sell you just one board. Their prices were the best I could find online.

--Wintermute

 

[bower4311]

Thanks for the info!

 

[Dave Berryhill]

Thanks for the great thread! Will that blanket insulation that you used on the walls of the oven shed loose fibers that could stick to your cerakote while it's still wet?

 

[Wintermute]

Nope, no worry about the fibers coming off...that stuff is actually a lot more dense than it looks. Looks like fiberglass...weighs about 10 times as much per cubic inch. I haven't had any problems at all with fibers coming off and floating around.

--Wintermute

 

[DroidSniper]

I wonder which option use less electric the slow cure or fast cure.

 

[scpaul]

When I 1st. got my gun safesome of the insulation had been broken.Ordered more fitted pieces from factory. Guy I spoke to indicated (indirectly of course) that insulation was gypsum board. I'm sure that the paper covering had been treated to make it fireproof but it's cheap enough to try it. You can even buy arasol fire proofing spray, possibly at the hardware store. Just a thought. scpaul

 

[MarcS]

Good idea.

 

[PlinkIt]

I wonder which option use less electric the slow cure or fast cure.

way too many variables to calculate that one out... efficiency .. thermal transfer.. cycle times.. preheat times.. blah .. blah..

if you can borrow a good data logging meter from a local industrial electrician friend you could learn the actual usage on each said cycle though..

 

[DroidSniper]

way too many variables to calculate that one out... efficiency .. thermal transfer.. cycle times.. preheat times.. blah .. blah..

if you can borrow a good data logging meter from a local industrial electrician friend you could learn the actual usage on each said cycle though..

True. Any idea on a weight capacity? I am going to buy a used lathe and was planning on using up the last of my black cerakoat as the paint for the tailstock and headstock.

 

[cal50]

I went the cheap route and used a donor high school locker for a cabinet. I added insulation and a layer of stainless steel sheet metal over the top. A support rod thu the top for hanging parts. A light mounted to aid in spraying.
I used a process controller , mechanical relay and a $7 hot plate for the heat source.