#1  
Old 04-15-2008, 07:15 AM
Serf
 
Join Date: Apr 2008
Location: Memphis
Posts: 3
Question Moldit-D and Transpiration

Hi,
I'm a newbie to the forum and midway through installation of a Valoriani 110 cm modular. I didn't get it from CA so don't have access to their forum...I have not been able to find ref-mix locally and shipping costs being what they are, I've been looking for an equivalent to add an inch to the dome for greater thermal mass. I plan to do some extended cooking...I found Moldit-D locally and the specs for elemental content are very close to ref-mix. Does anyone have experience with this material? OK to cover the dome with it?

A different question on vents for the loose fill chamber...I plan to use perlite and cover the upper chamber with flat stone/mortar covering. The instructions that came with the oven state (in large letters) that openings must be left for transpiration. Design layout and installation photos on the CA site show no provision for this so I e-mailed Italy and the response was that the openings are definitely required-presumably to vent water vapor. I plan to use a minimum of small 1/4" holes (maybe 5-8 of them) for this purpose. Is there a discussion on this anywhere? What do most FB builders do?
Thanks!
Reply With Quote
  #2  
Old 04-15-2008, 08:04 AM
gjbingham's Avatar
Il Pizzaiolo
 
Join Date: Sep 2007
Location: Longview, WA
Posts: 2,021
Default Re: Moldit-D and Transpiration

There has been discussions regarding the venting of enclosures. Try the search function at the top of the page. If that is fruitless, read through the entire forum on finishing/enlcosures. You can pretty quickly rule out the threads that don't apply to your situation. Sounds like what you have planned should be pretty functional though.
__________________
GJBingham
-----------------------------------
Everyone makes mistakes. The trick is to make mistakes when nobody is looking.

-
Reply With Quote
  #3  
Old 04-15-2008, 12:03 PM
dmun's Avatar
Moderator
 
Join Date: Jul 2005
Location: New Jersey USA
Posts: 4,216
Default Re: Moldit-D and Transpiration

If you are building your enclosure out of brick they make a nice aluminum brick vent, that just takes the place of one brick, and it's not bad looking either.





Sorry I don't have better pictures. If you are using wonderboard over metal framing, you can use an ordinary soffit vent, although cutting a round hole will be somewhat harder than in wood.

Venting the enclosure is not standard procedure. It seems to me that it's unlikely to cause a problem, as it would in a wooden attic.
Reply With Quote
  #4  
Old 04-16-2008, 05:52 AM
CanuckJim's Avatar
Il Pizzaiolo
 
Join Date: Jan 2006
Location: Prince Albert, Ontario, Canada
Posts: 1,480
Default Re: Moldit-D and Transpiration

Dmun,

I used brick vents as well on my oven. I think the major reason is to make sure the insulation remains dry and air humidity does not have a chance to get at it. I really don't think just drilling holes, especially that small, will be adequate. The actual oven enclosure on my oven has the brick vents, while the gable roof area uses standard soffit vents.

Jim
__________________
"Made are tools, and born are hands"--William Blake, 1757-1827
Reply With Quote
  #5  
Old 04-16-2008, 10:52 PM
gjbingham's Avatar
Il Pizzaiolo
 
Join Date: Sep 2007
Location: Longview, WA
Posts: 2,021
Default Re: Moldit-D and Transpiration

CJ,
What if you live in Florida and the humidity is 95 percent all summer long. Certainly, the humidiy gets in/out depending on the weather conditions. This whole idea stumps me a bit. It seems like any moderate amount of venting will allow the internal and external humidity levels to equalize.

I assume ( I know, ass of you and me) the venting is primarily to allow moisture to escape as the oven cures. After that, the oven is subject to whatever weather conditions exists around the oven. If the enclosure is watertight, it seems like just a few and smallish vent holes would be adequate. I'm not second guessing you and David, just curious.
Thanks
George
__________________
GJBingham
-----------------------------------
Everyone makes mistakes. The trick is to make mistakes when nobody is looking.

-
Reply With Quote
  #6  
Old 04-21-2008, 12:50 PM
Serf
 
Join Date: Apr 2008
Location: Memphis
Posts: 3
Default Re: Moldit-D and Transpiration

Thanks for the responses...it would seem, after putting everything together, that a minimal number of holes will suffice. I may also consider the small round slotted aluminum disks that are sometimes used to vent construction. It seems that few vent their structures (especially dome builders) and I haven't heard any disaster reports from failure to vent, so I'm not going to agonize over it.

As for the Moldit-D, it looks like no one has had experience with it so I'll let you know how it goes...
Kevin
Reply With Quote
  #7  
Old 07-02-2008, 06:14 PM
Journeyman
 
Join Date: Jun 2008
Location: Melbourne Australia
Posts: 399
Default Re: Moldit-D and Transpiration

Moldit d is a 1300c refractory castable, so yes, can cover your dome with it.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -7. The time now is 12:27 AM.

Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
2006/10 Forno Bravo, LLC