FINALLY!!! - Start Of Building My Oven

[Oven_Man]

Re: FINALLY!!! - Start Of Building My Oven

Hi Guys

I've decided to go with a fabricated steel trolley as my oven stand with no concrete base. I will have 50mm of Fiber Board sitting directly on the steel base and the oven floor will sit on the FB.

I have a few concerns though.

1) Steel conducts heat very quickly but I was thinking of wrapping the rest of the steel structure e.g. Trolley Legs, Steel bars and any other steel components that makes up the trolley, in ceramic blanket so even if it heats up, it won't be very hot to the touch, just thinking of safety concerns.

a) Would this work or do you guys know of other material I can use on the steel to make it less hot when oven is in use?

b) If I use Fiber Blanket, what can I place over the blanket to make it look neat rather than just having the blanket exposed which will be an eyesore for the oven?

c) I am going to attach wings to my oven trolley dat will basically be on each side of the oven and I will use it the wings more like a table but again my concern is heat, any tips on how to prevent this metal from heating up?

d) Lastly, I am going to attach a fold away metal vent landing at the front of my oven and again my concern is this will heat up and more quickly and hotter than other metal pieces as this will be right at the entrance of the oven where most of the heat is. What other material I can use that can withstand heat but is a poor conductor and it has to be able to fold away with hinges attached to do this?

Thanks guys for all the assistance
Regards
OM

[david s]

Re: FINALLY!!! - Start Of Building My Oven

Oven man,
My oven sits on a base of 3" aerated concrete which sits in a steel cradle made of 1/4" galv. steel. The bottom of the aerated concrete gets warm and the steel gets quite a bit hotter being denser, but never so hot that you couldn't hold your hand against it. I think you are wasting time money and energy trying to insulate it. You'd be better off making the insulating board a little thicker. I also have a 0.55mm thick stainless panel which sits in front of the entry. This is removable and proves to be very workable. the bottom of it sits on the side of my trailer and has not damaged the paintwork.

[Oven_Man]

Re: FINALLY!!! - Start Of Building My Oven

Hi David

You're right, i am wasting money but I'm quite a paranoid guy, just always look at what could go wrong.

I'm sure the insulation will prevent the steel from heating up too much. I will expect a small amount of heat to transfer and obviously any sane person who touches the steel structure will feel a small amount of heat and would move their hand quick enough before it gets too much but my concern comes about whereby if the structure gets too hot and someone places their hand on it for even a split second, they could cause themselves some serious harm since they wont have that pre-warning of minimal heat turning into maximum. I hope that makes sense.

Well, initially, I'll just have to work with the oven and take extra precaution when people are around until I'm use to it and satisfied that the heat transfer to metals is not enough to seriously harm someone.

Thanks
Regards
OM

[Oven_Man]

Re: FINALLY!!! - Start Of Building My Oven

Hi Guys

Now that I am busy planning my Table/Trolley, the question came about regarding the Trolley/Table height.

My personal height is 1.7M Tall so what do you suggest is the ideal height for my oven to easily access is without having a sore back every time i use it?

Thanks
Regards
OM

[david s]

Re: FINALLY!!! - Start Of Building My Oven

Some say the ideal floor height is 1 m mine is 880 mm which puts the fire at eye level for sitting guests. You definitely want to make the height on the low side for a mobile oven so the centre of gravity is not too high.

[Oven_Man]

Re: FINALLY!!! - Start Of Building My Oven

Hi David

Thanks, I'll keep that in mind for the height. May just settle for 1M eventually.

I know I've brought this issue up before but still trying to wrap my head around it. With regards to the vent, what would you recommend i keep the Length, Breadth and Height of the vent considering my oven size. I know its a personal preference but just a guideline to work with so i don't make it too large or too small.

Attached picture is my understand of Length, Breadth and Height, don't even know if that is correct, don't really like maths

Thanks
Regards
OM

[david s]

Re: FINALLY!!! - Start Of Building My Oven

Internal dimensions length 17" width 5" breadth 7" thickness of casting approximate. 1" Try to funnel it towards the flue. Flue 5" diam plenty for your small oven.Make the hole in the casting slightly bigger so the metal flue pipe can expand with the heat and not create pressure on the casting which will make it crack. I made this mistake on my second oven.

[Oven_Man]

Re: FINALLY!!! - Start Of Building My Oven

Hi David

Thanks for the dimensions.
Forgive my lack of understanding, but just so we're on the same page, I've taken your dimensions and details of how the vent should be, and once again placed it in the form of a picture.

Can you tell me if my understanding of your description is correct or did i misunderstand something somewhere along the way?

Just with regards to the internal Length and Internal Height. The length in my assumption should be a little bigger than the length of the oven opening?
The height on the other hand should be from the oven opening height to the very top of the oven. My Oven height is +-13" high. My Opening height is approx 9", so my assumption is my vent height should be 4 Inches or so.
Is this Theory correct?


Thanks
Regards
OM

[david s]

Re: FINALLY!!! - Start Of Building My Oven

You've got it just about right. But my internal breadth is 5" Regarding the height you'll have to go back and look at the picture I posted in this thread. I cast legs for the vent to sit on, you could cast yours like your picture and sit it on some bricks on the sides.

[Oven_Man]

Re: FINALLY!!! - Start Of Building My Oven

Hi Guys

So my Vent Mould is complete, just for me to fill in the Cement and I'm good to go but then I got thinking. My vent design already has a 6" hole at the very bottom closing in upwards to a 5" hole for the 5" flue but then I completely forgot about my Flue and where I'm getting it from.

So I did some searching to try and find a local supplier and this is not a very easy task. I'm not able to find one easily or some of them are asking ridiculous prices. So I thought let me get the Flue Fabricated by the same person that has fabricated my Steel Trolley. This guy is no pro at manufacturing Flue's but he's a Pro when it comes to general steelwork. All I need to do is give him my Specs and he'll handle the rest.

1) What I need to know from you guys is what material the flue should be manufactured of.

2) I was thinking of having a Thread similar to that of a screw on the end of the flue and place the other part on the vent itself so I can easily screw and unscrew the flue but do you guys think this is a good idea.

3) What other tips would you guys suggest when manufacturing my own flue?

Thanks Guys
Regards
OM

[david s]

Re: FINALLY!!! - Start Of Building My Oven

If you go to any sheet metal fabricator they should be able to do the job. Use stainless steel, that way you won't be replacing it in 3 years time. Ask them to taper the flue slightly so an extra length can easily be placed over the top of the previous one if necessary. 0.55 is the usual thickness used. You can simply cut three tabs in the bottom bend them out 90 degrees and your flue will sit inside your casting snugly and stand up. You can then place some more cartable around the area where the tabs sit. Alternatively you can set in a stainless collar on your flue gallery and slide your flue into it. There are probably a number of other ways to do it too.

[Oven_Man]

Re: FINALLY!!! - Start Of Building My Oven

Hi David

I will discuss with my fabricator and see what he says.
I'd prefer if the Flue could detach away from the Vent.

Would you advise i insert a Steel Collar with Threads and have threads on the Flue as well so they can screw into each other, only concern is what would happen with heat?

Is there any other precautions i should take apart from using Stainless Steel? I read that some places have strict regulation when it comes to the construction of the Flue, I'd hate for it to catch alight while in use.

Thanks
Regards

[Oven_Man]

Re: FINALLY!!! - Start Of Building My Oven

I also forgot to ask, you mentioned the usual thickness is 0.55, is that 0.55"/mm?

[david s]

Re: FINALLY!!! - Start Of Building My Oven

I've done a couple of ovens with removable flues and found the sliding collar idea simple and effective. I doubt that making threads on thin sheet metal would be easy. I meant 0.55 mm it's a standard thickness for this kind of application.

[Oven_Man]

Re: FINALLY!!! - Start Of Building My Oven

Thanks, I'm definately going with the Sliding Flue.

If my Flue Diam is 5" , then I guess my collar should be a little bigger but the question is how big?
How do I make sure the flue fits into the collar snuggly enough for it not to tilt or move with wind?
I'v been told to insulate the flue, how do I go about doing so?

Any idea if a post exists on the forum or anywhere for that matter on how to go about with this type of flue design?

Thanks
Regards