SuperIsol Installation for 42" Pompeii

[Ken524]

Hello,

After scouring the forum, I'm still a bit unsure about how to cut/arrange SuperIsol on the hearth. For a 42" oven, the instructions recommend using 4 - 24"x36" panels.

Using my CAD software, I positioned the 4 panels on my hearth and (as you can guess) they aren't sized for a no-brainer installation. Some cutting will be required.

Exactly what parts of the oven should the SuperIsol be under? Obviously the cooking floor. Probably the dome as well. Should it extend outside the dome?

Are folks cutting this stuff to arrange it into a circular shape or rectangles?

Anyone have pictures of their cut and positioned panels?

Thanks a million!

Cordially,
Ken

[Hendo]

Ken,

I've attached a couple of shots of my insulation sheets before the cooking floor went in to show how I did it. I didn't think there was much point in cutting a circular shape and discarding the off-cuts, so stayed with the rectangular shape. At the end of the day, there is a lot of wastage, but what else can one do? There was no way (by my calculations) that I could have saved a sheet by judicious trimming!

One thing I'd recommend if it's not too late is to ensure you achieve a very flat hearth slab. Cal Sil sheets are very rigid and just don't want to bend. I ended up with some minor (1-2mm) valleys, and despite glueing the sheets down with high temperature cement (Kaogrip), I still ended up with several hollow sounding areas, indicating the sheets are proud of the slab. Tough!

BTW, my oven is 1100mm (43.3") internal diameter (floor inside dome) and the Cal Sil sheets are 2" thick by 24" by 39". The faint circle on the first photo represents the diameter of the cooking floor (approx 1090mm). My vent chamber extends beyond the hearth slab over a bench-top / prep area, and the insulation sheets extend out to the ash slot, so I ended up with a T-shape hearth.

Hope this helps.

Paul.

[Ken524]

Paul,

Thank you so much for post your pics. They are a really big help. As for having a perfectly flat hearth; it's definitely not too late. I'm just now digging the foundation.

Your second picture also helps me see how people are building the dome around the outside of the cooking surface. Your detail work is super. I found the thread about wet saws and tapering bricks. Looks like I need to find a wet saw!

Ken

[RTflorida]

Rental is a good option for the saw, if you are well planned and can get all of you cuts done in a day or two. Many of us non professional masons have opted for the Harbor Freight 10" wet saw for $199. Surprisingly, I have only heard of good experiences with this inexpensive saw.......mine include. Bought their $30 blade with the saw...cut as well on the last brick as it did the first.
Probably not suited for daily heavy use.....but for a pompeii oven build, is plenty of saw

RT

[Ken524]

Originally Posted by RTflorida

Many of us non professional masons have opted for the Harbor Freight 10" wet saw for $199. Surprisingly, I have only heard of good experiences with this inexpensive saw...
RT

Is this the saw you are referring to?:
Harbor Freight Tools - Quality Tools at the Lowest Prices

I'm definitely going to purchase as I'm not organized enough to knock out all the cutting in one day.

Thanks!!
Ken

[RTflorida]

Ken, thats the one. You may want to double check the price.......this saw always seems to be on sale at $199. I purchased mine from an actual HF store location which had "extended" the previous month's sale prices. It was listed online at $219 or $229, but the store was selling it at the "sale" price of $199

[Les]

Ken - this is pretty good saw for the price. I advise purchasing the extended warranty. They have an in house replacement for 2 years and I recall it only cost me $36.00. I fried the start capacitor on mine a couple of months ago. They were out of stock so I fixed it for less than $6.00 and it's still running strong.

Les...

[Hendo]

Ken,

I've just read ihughes' recent post on the possibility of insulation sheets getting wet, and I should have mentioned that I am planning to enclose my dome with red brick cladding on all four sides and a corrugated iron roof. So I'll end up with insulation blanket over the dome and loose-fill vermiculite between the dome and walls (and on top of the un-trimmed Cal Sil sheets).

Had I elected to stick with a 'feature' dome like many others on this Forum, I would have cut the sheets around the perimeter of the dome. So in the second photo above, you wouldn't see any insulation, but it would have extended under the dome brick course.

I think with a good render coat(s) of stucco over the dome, the likelihood of water absorption into the Cal Sil sheets would be minimal, if not zero. There's been plenty of posts recently on the 'waterproofness' of stucco coats, so I'll leave you to track them down, should you be going this way.

Cheers, Paul.

[Ken524]

Originally Posted by Hendo

Had I elected to stick with a 'feature' dome like many others on this Forum, I would have cut the sheets around the perimeter of the dome. So in the second photo above, you wouldn't see any insulation, but it would have extended under the dome brick course.

Paul,

Thanks for the clarification. I do indeed plan an igloo style with stucco. I'll probably trim the SuperIsol as you suggest, but leave 1 or 2 cm extra sticking out from under the dome. I'm thinking that this might prevent any heat from sneaking out into the hearth concrete. Probably overkill (can't have too much insulation!).

Ken

[Ken524]

Originally Posted by Les

Ken - this is pretty good saw for the price. I advise purchasing the extended warranty. They have an in house replacement for 2 years and I recall it only cost me $36.00. I fried the start capacitor on mine a couple of months ago. They were out of stock so I fixed it for less than $6.00 and it's still running strong.
Les...

Les & RT: Thanks for the super lead and advice on the saw. HarborFreight has a store here in Louisville. That'll be my research field trip for tomorrow if I don't get caught up at work.

Ken