Removing the styrofoam mold

After reading multiple reviews and questions about problems with removing the Styrofoam mold, I decided to remove it before building the back wall of our Mattone Barile oven. I didn’t get to that phase of construction until several days after building the dome itself. I figured I didn’t need the mold for the back wall anyway. Also, while I was building the dome I had tapped the mold from behind to move it a fraction of an inch which dislodged any mortar that had stuck to it. That made it easier when, several days later, I pushed the mold from the back out towards the front of the oven. No problem! Using this approach I didn’t have to chip any Styrofoam apart or deal with pieces stuck inside parts of the dome.

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I agree, leaving the oven to dry for a least a week and removing the mold before building the back wall is the way to go. But also I used another ingredient, PAM spray oil !! Pam|225x225 before I mortar firebricks.
After a week I finished the arch I tapped the styrofoam legs with a wooden block from the back of the oven and the arch mold dropped and not a single piece got stuck inside. The mold came out pristine like the day I pulled from the box just a little oily.

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I think there must be some kind of a prize for ingenuity. I know it would be a disaster on several levels to use a petroleum-based spray (like 3-in-1) for that purpose. But vegetable oil will burn off, and as far as I know won’t add any calories to your bakes!

The point that you both raise is that, following this method, the arch must be allowed to set before the mold is removed. That time is built in to the instructions, so working outside of that sequence means setting your project aside for a week. If you’re doing weekend-to-weekend work, that’s easy; but someone who wants to plow through needs a strong warning to stop and let things settle before pushing out the mold.

This would make a good @FAQ for people concerned about the reports on the challenges some folks have had extracting the mold.

Thank you Matt!

I have added this conversation / topic to our Directions 2.0 folder and we will address it on the upcoming Installation Instructions update. Good catch!

Thx again!


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Do we really need to wait a week between building the arch and building the back? We were hoping to do them both in a day. Did anyone else have success just using the spray oil?

If it was me I would leave the foam arch in there a least a week. Very bery important for the arch to have that support while setting up and drying.

If your really good at brick work and can get the whole barrel done in a day that’s awesome. Personally I don’t see a problem doing the back while the foam mold is still in there but you will have a challenge to get the mold out.

Can not contest for the Pam oil spray for I didn’t do that. But according to the reviews above it seams to work. I would coat it up. It may be easier to get the mold out.

Happy building!


Thanks, @423tommy! We are pushing to do as much as we can quickly, because I go in for surgery on Thursday, and I think there are limits to what my 17 year old will do on his own! So whatever we get done now will have a long time to dry while I recover! But we’ll start with the Pam spray and hope that makes it easier to get out the mold later.

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Go slow. Let it cure. And do the spray. I used spray olive oil in keeping with the Italian theme!! Worked great. I still have my mold.


Good luck with your surgery! Get well doon so you can enjoy your pizzas.

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It’s hard to wait when you know you have such an important date coming up. As others have said the arch gets its strength from allowing the mortar to dry and cure. It’s all that will be keeping bricks from dropping down into the oven cavity and perhaps dive-bombing a nice lasagna.

There are a few “hard stops” in the process, and this is really one of them. This would be true whether you were doing this “by the (1.0) book” or the open-back method, but the time is hidden in the 1.0 instructions due to all the other steps stacked behind completing the arch. By the time you pull it out in that version, it’s at a minimum four days after the arch is completed.

Very best wishes for your surgery and recovery!

Thanks, all! We built the arch AND back yesterday and are hoping to get on the ceramic blanket and stucco in the next couple of days. Then it will have a good 10 days to cure. That should be enough, I hope, for the bricks to hold. We put a ton of Pam on the foam, but who knows if that will be enough to pull out the form, since we closed up the back. Otherwise, I guess we cut it out eventually.

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As Kumumby did, I sprayed my form with olive oil and I too have saved my dome. I let mine cure for a week and I laid the back with the dome in place. Hope this helps

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That’s very reassuring, @msertich. Thanks!

You are really cruising! You are wise to keep the foam mold in place—and just to be sure it’s said, that’s the recommended method in the v1.0 instructions. Discussion about removing it before starting the rear wall is an emerging alternative.

Again, best wishes for you in the days ahead.

So appreciate the good wishes! We got the first layer of stucco on yesterday, but I may have to trust my kid (and husband!) to get the second one on in a day or two after I’m laid up.

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Last night, I removed my mold. I didn’t grease it or anything. I used a reciprocating saw then I switched to a very long hand saw to prevent damage to the masonry. It took some time. I smacked my elbows on the base breaking the top of the mold away from the arch.

If you haven’t started building yet, I would suggest lightly greasing it. If you didn’t grease it, just take your time and maybe put something down to cushion your elbows.

First fire went great.

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Congratulations, and thanks for the great advice! The whole “thing” about extracting the mold is evolving, and it’s good to have the advice of a veteran.

Here’s to your next four fires!

I’m with you. I didn’t put anything on it to make removal easier, now I’m laying in the oven, prying foam from the wall during a heat wave. It’s hot. It’s like an oven in there. Otherwise love this kit.

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I really, really empathize! Though clearly your goal and your results are in alignment. :slight_smile:

Good luck with your next steps!

I did not use any sort of grease or release agent on mine and was able to remove it very easy. It took my 12 year old grandson to figure it out. He asked me why I did not use that saw, as he pointed to a long dry wall cutout saw and cut 2 lines front front to rear about 4 inches apart. Once I did this and removed the foam within these 4 inches with a small pry bar, the remaining sides almost just collapsed inward and I was able to take the long pieces out without hassle.