Heavy Gauge Steel Lined Vault Oven

[halfbakedpixel]

Hello everyone. I've been scooting around this forum for a while now and researching through other peoples threads but haven't added anything till now.
This is my first oven project although in one of my pix you can see my Ugly Drum Smoker i've built in the background.



Over the last few months i've been collecting materials to build a steel lined vault oven, and once i get some time i'm going to make a start.



This is the steel half tube i picked up from the scrap bin at work. It needs to be cut to length and some steel added but i'll have the extras laser cut and weld them on at work before taking it home.



This is the table i'm building it all on, an 8mm thick steel topped table which should be able to take the weight of the bricks, masonry and steel tube.

As the project progresses i'll add more and more pix and info to keep you all updated.

The main thing i'd love to have as the project progresses is all the valuable advice that you lot have, this is my first project building an oven of this type and i'd love your input.

[v12spirit]

Re: Heavy Gauge Steel Lined Vault Oven

Looks like you are doing it right and have all the materials in hand and a plan already to start with. Watching with interest.

[halfbakedpixel]

Re: Heavy Gauge Steel Lined Vault Oven

Thanks.
I'll hopefully be cutting the tube to length this week.

[halfbakedpixel]

Re: Heavy Gauge Steel Lined Vault Oven

Update time.
Managed to get the half pipe cut this week and lifted onto my table ready to be welded up.







Next to go on is the side extensions, blank back plate, front plate with door opening and the 8" chimney.

[halfbakedpixel]

Re: Heavy Gauge Steel Lined Vault Oven

As the weather was pretty good this weekend I decided to get the stove welded up ready for the brick base and outer layer.
I drew all of the parts in Solidworks and got them laser cut, then my dad kindly welded them up for me. I haven't welded in 15 years, he's a bit better at it than me.

[halfbakedpixel]

Re: Heavy Gauge Steel Lined Vault Oven

Quick update.
Got hold of some fireboard for laying underneath the bricks on the base level. This should hopefully help with the insulation and keep the heat in.

[david s]

Re: Heavy Gauge Steel Lined Vault Oven

Having made the decision to have the flue exiting from the inside of the oven (updraft rather than cross draft ) will lead to the flames wanting to rush straight to the flue. With some fairly vicious flame going up the flue pipe you will find that your galvanized pipe (it doesn't look like stainless in your pic) will need replacement within a year.
If you intend on doing retained heat cooking (roasting and baking) then you will also need a damper in the flue so you can close it, otherwise heat will rush straight out the pipe, particularly every time you open your oven door.

[halfbakedpixel]

Re: Heavy Gauge Steel Lined Vault Oven

The pipe flue is 316 st/stl
Would it help if i extended the flue down inside the oven, so its level with the top of the door?

[david s]

Re: Heavy Gauge Steel Lined Vault Oven

The pipe flue is 316 st/stl
Would it help if i extended the flue down inside the oven, so its level with the top of the door?

Yes, possibly, try it and see.

[Gulf]

Re: Heavy Gauge Steel Lined Vault Oven

Having made the decision to have the flue exiting from the inside of the oven (updraft rather than cross draft ) will lead to the flames wanting to rush straight to the flue. With some fairly vicious flame going up the flue pipe you will find that your galvanized pipe (it doesn't look like stainless in your pic) will need replacement within a year.
If you intend on doing retained heat cooking (roasting and baking) then you will also need a damper in the flue so you can close it, otherwise heat will rush straight out the pipe, particularly every time you open your oven door.

The pipe flue is 316 st/stl
Would it help if i extended the flue down inside the oven, so its level with the top of the door?

Yes, possibly, try it and see.

Now, that is a great example of "thinking inside the box" .

[david s]

Re: Heavy Gauge Steel Lined Vault Oven

Now, that is a great example of "thinking inside the box" .

And you'll need to make sure you don't drop the flue too low or you'll be "scraping the bottom of the barrel"

[Wiley]

Re: Heavy Gauge Steel Lined Vault Oven

Here's a thought you might want to consider:

David S. is correct that there will be significant heat loss thru the chimney as the WFO is presently designed. Since you still have access to the interior I would suggest you consider cutting an interior bulkhead (for want of a better term). This bulkhead would be shaped a great deal like your present entry and be welded near the flue but on the inside toward the interior of the WFO.

This entry would be cut so that it has the 63% ratio to the height of the interior of the WFO. I would then suggest the SS chimney be attached flush or near to flush with the shell. You may want to consider cutting this interior bulkhead from heavier plate so that erosion from hot gasses etc. as well as distortion is kept to a minimum. This is working from the idea you would like this WFO to still be working 10 or more years into the future.

I would then suggest you enlarge the present entry so that you can easily place a door against the new interior bulkhead/entry. This is to contain heat for baking, roasting etc.

Although cutting the exterior entry larger than it is at present, consider leaving a significant arch so that the new area acts to gather smoke before it exists out the chimney, much like the entry on a more traditional WFO with chimney with its dual arch entry. Enlarging this outside entry will also make working and access to the WFO easier.

Making this modification will diminish the interior cooking area, which is unfortunate, but I expect will result in a WFO that will work better.

Hope this helps,
Wiley

[halfbakedpixel]

Re: Heavy Gauge Steel Lined Vault Oven

Ha ha thankyou. I'm off to North Yorkshire this weekend mountain biking, but hopefully the weekend after i'll cut the welds on the chimney and drop it down inside the oven.
Also got to lay the fireboard and brick base and weld the flat bar edging as well, so still lots to do.

What is the ideal mortar mix for the bricks that will line the outside of the steel?

[halfbakedpixel]

Re: Heavy Gauge Steel Lined Vault Oven

Here's a thought you might want to consider:

David S. is correct that there will be significant heat loss thru the chimney as the WFO is presently designed. Since you still have access to the interior I would suggest you consider cutting an interior bulkhead (for want of a better term). This bulkhead would be shaped a great deal like your present entry and be welded near the flue but on the inside toward the interior of the WFO.

This entry would be cut so that it has the 63% ratio to the height of the interior of the WFO. I would then suggest the SS chimney be attached flush or near to flush with the shell. You may want to consider cutting this interior bulkhead from heavier plate so that erosion from hot gasses etc. as well as distortion is kept to a minimum. This is working from the idea you would like this WFO to still be working 10 or more years into the future.

I would then suggest you enlarge the present entry so that you can easily place a door against the new interior bulkhead/entry. This is to contain heat for baking, roasting etc.

Although cutting the exterior entry larger than it is at present, consider leaving a significant arch so that the new area acts to gather smoke before it exists out the chimney, much like the entry on a more traditional WFO with chimney with its dual arch entry. Enlarging this outside entry will also make working and access to the WFO easier.

Making this modification will diminish the interior cooking area, which is unfortunate, but I expect will result in a WFO that will work better.

Hope this helps,
Wiley

What a brilliant idea, and that is so much easier how it is right now. I can get it cut from heavy gauge mild steel and stick weld it on the inside.

[halfbakedpixel]

Re: Heavy Gauge Steel Lined Vault Oven

Update.
The baffle is being laser cut for delivery on friday so i should be able to weld it in this weekend.

What mortar mix should i use for the bricks around the outside of the steel vault?