Steam Vent Idea - comments please

[cnegrelli]

What was the vent that others used that automatically would open under pressure?

[UtahBeehiver]

I used a breather vent cap, which was Gulf's idea.

[Man Food]

that breather vent cap idea of Gulfs is great, I missed that! I will need to manually open mine or leave it slightly unscrewed to allow any steam out. Hey ho...

[Gulf]

Just uncap it when you do your initial drying and at any time you fire the oven after it has been out of use for some time, or you feel that the oven has taken on a lot of moisture. You should be able cap it securly most of the time. A simple gooseneck fitting will allow you to vent even while it is raining. There are lots of ways to do this.

[Man Food]

Fired the oven to 400c for the first time yesterday and the steam vent worked a treat! No cracks so far either....

[tommo21]

Great idea and i will utilize one too i think.
Was steam visible during curing?

[Man Food]

Hi Tommo

Yes I could see some whisks of vapour coming out which was a good sign it was working.

[cnegrelli]

Where were the Breather Vent Caps sourced from? I'm having trouble finding these and thought this would be as good a place as any to post this info.
The other great idea on this is david s breathable flue design, but seems to require some custom work with pottery materials. I'm thinking of casting something like that with the castable refractory - if David has any comment on that. It looks like two pieces with the top being essentially a collar to divert rain and the bottom piece used to mate the chimney to the flue. There must be some venting between these to allow the steam to escape, which may just be a function of not having an airtight fit?

[david s]

Where were the Breather Vent Caps sourced from? I'm having trouble finding these and thought this would be as good a place as any to post this info.
The other great idea on this is david s breathable flue design, but seems to require some custom work with pottery materials. I'm thinking of casting something like that with the castable refractory - if David has any comment on that. It looks like two pieces with the top being essentially a collar to divert rain and the bottom piece used to mate the chimney to the flue. There must be some venting between these to allow the steam to escape, which may just be a function of not having an airtight fit?

Yes that's correct. I have some skills with clay and a kiln to fire wares. When I fire them I don't fully vitrify them so they're still porous which is suitable for this application. The less than perfect fit leaves some space between the two like a saucepan with an ill fitting lid. You could fabricate something from another material, like cast concrete with plenty of random fibres or fabricate a conical form in stainless which is what I did for my mobile oven as it has a removable flue.

[UtahBeehiver]

Google "hydraulic breather cap", most auto stores will have them or Grainger, ebay, etc. can be less than $10.

[Gulf]

Also, when you find a source for the breather cap, go with the smallest they have. It will still do what you want, but be less conspicuous. The Donaldson TRAP site (as the one pictured above) has a Where to Buy tab at the top of the page. Just select "industrial hydraulics" and plug in your street address. It will list any local venders.

[Man Food]

I use simple 15mm brass plumbing connector and screw cap which is cheap and effective, though if you can get a purpose built breather cap it will save you having to unscrew it like I do

[SableSprings]

Yes Zoolander, your summary of the breather cap install and purpose is correct. You are hoping that any outside render makes your dome waterproof...but that's just not realistic. Lots of great products for waterproofing out there, but inevitably Mother Nature will win and moisture/water will find a way into the dome if it's standing in the great outdoors. The vent is just providing that easy exit for any moisture that does find its way into your oven's "guts" (insulation batting and/or firebricks ).

[snipe97]

Getting close for my stucco layer and reading up on the steam vents. As a newbie, wondering whether i could just use a small piece of 3/4" copper pipe that i have laying around, cap it, and then maybe cut/drill a few slits in the pipe to vent the steam? I don't know if I would remember to take off any cap when need be so trying to eliminate that forgetfulness...plus I might have some teens that could want to use the oven when I am not around. They certainly wouldn't follow every step to boot up an oven after some heavy rains, humidity, etc. .

[snipe97]

I guess one more while i am at it: anyone have a great approach to fastening down chicken wire over the insulation? I haven't really been able to find a great solution searching through the forums.