After applying the second coat of regular mortar to the outside of the fire blanket, I understand I have two options for finishing/protecting the mortar: painting the mortar or not painting it and covering with brick veneer, etc. I want to cover with brick veneer, so here comes the question. I will be mortaring now, but do not have time to cover with brick veneer until August. I live in Oregon where the the shell will get rained on some (since summer not so much) and will be in the sun (around 80-90 degrees). Is this going to be okay for the unprotected mortar to be out in the weather that long, especially on rainy days, or should I cover the oven with plastic until I can put the brick veneer on?
You have to protect it in some way until you apply veneer. If you are not planning to fire the oven until August, I’d use either a large polyethylene painters drop cloth or a tarp. Your other choice would be a quart of outdoor walkway or deck paint (yes, that’s the same as what you’d use for an end stage paint job). It takes about an hour per coat to apply and will seal and protect the stucco as well as what’s underneath.
If you choose the paint option, you’ll need to give it a cleaning with a TSP substitute or similar to dull the finish and remove any soot. Then it’s okay to apply cements and your veneer right over it.