New 36inch castable build in Brisbane

[brissie]

Re: New 36inch castable build in Brisbane

Don't panic about it. The outer shell is only to keep the weather off. Keep giving it some more firings to see if any more cracks show up and to drive out all the moisture. Then get some of your Acratec and work it into the crack. I like to give my ovens around 10 decent firings before adding any waterproofing on the outer shell, that way any cracks show up and you are not locking the moisture in, which I think is your problem.

Thanks David s,

I have sealed the domes last render layer. It was probably not a good idea. I will fire it up again. and see how it goes. I have not used Acratex but a clear acrylic sealer. If steam is exiting the crack I will fill the crack with no-more-gaps, and seal it again after several firings.

[david s]

Re: New 36inch castable build in Brisbane

Don't panic about it. The outer shell is only to keep the weather off. Keep giving it some more firings to see if any more cracks show up and to drive out all the moisture. Then get some of your Acratec and work it into the crack. I like to give my ovens around 10 decent firings before adding any waterproofing on the outer shell, that way any cracks show up and you are not locking the moisture in, which I think is your problem.

[brissie]

Re: New 36inch castable build in Brisbane

Dam, have a hairline crack about a foot long (300mm) after firing up again. Cleared the dome and ran the fire for several hours.

Last night the oven walls where 320 c, when I put a hebel door on, this morning the oven is 250 c. It's warm on the outside towards the top, but not hot.

See the photo and crack at bottom right.

[brissie]

Re: New 36inch castable build in Brisbane

I have a friend who is a sheet metal fabricator who lets me use his special tools for my own work (like running the standing seam panels).

It is nice to see how a nice build comes together. Now that this project is nearing completion---what is next on the list?

There is "stove gasket cement" that might also work for you. If you marked the finish location of the storm collar on the chimney, then applied the cement beneath the collar--when you slid the collar down to the proper place, you would only see a very narrow line of black from the gasket cement. When it dries, it is hard like a rock and should work for your max temperature range... just a thought if the silicone becomes a problem.

Even if some water did seep by--it would only be a few drops! No big deal anyway!

You need the tools to do job properly. If you have access to sheet metal fabrication tools it makes it a lot easier, you just can't do tight bending or seaming, and waste a lot of time without them. Hope it goes well.

It's been great to work on the oven, it's been fun. I think I will shift into cooking mode, and start bread baking and other delicious food possible with a WFO. I have many interests, its probably time to get the veggie garden working again, and follow on with other projects not completed.

Gasket cement is an option, but I will wait and see what happens to the silicone. It might last a few years. I set up a temporary roof and roof penetration the had a half inch (15mm) gap all the way around the chimney. It did not leak much. Had a few drops of water after heavy rain come through. The tight fit of the SS transition will not let much water through.

[mikku]

Re: New 36inch castable build in Brisbane

I'll be facing a similar situation in the not too distant future. My oven will be under a roof and I'll have to do the roof flashing. Roof penetrations is not very common here, a large percentage of people vent their wood burning devices through the wall then transition to vertical.

The wood stove shops want an arm and a leg for any of their parts so I have fabricated my own chimney and will do the same with the roof flashing and storm cover- similar to yours. I used spiral stainless ducting (inner 150mm and outer 200mm) capped the ends and filled the inside with loose perlite. You can still feel some heat, but it will not burn you. My roof will possibly be standing seam galvalume (maybe black) .035mm and the chimney flashing parts probably .05. I have a friend who is a sheet metal fabricator who lets me use his special tools for my own work (like running the standing seam panels).

It is nice to see how a nice build comes together. Now that this project is nearing completion---what is next on the list?

There is "stove gasket cement" that might also work for you. If you marked the finish location of the storm collar on the chimney, then applied the cement beneath the collar--when you slid the collar down to the proper place, you would only see a very narrow line of black from the gasket cement. When it dries, it is hard like a rock and should work for your max temperature range... just a thought if the silicone becomes a problem.

Even if some water did seep by--it would only be a few drops! No big deal anyway!

[brissie]

Re: New 36inch castable build in Brisbane

Nice sheet metal work!

Have a question about your chimney, is it single or double wall type?

If it is single, what type of silicone will hold up to the high stack temperatures?

Did you make the termination cap as well? Looks like you have the tools, and knowledge to pattern and fabricate it! .7 is a bugger even with professional heavy duty snips! I'll be working with .6mm next week and not looking forward to the possible blisters!

Keep up the great work.. enjoying all the pictures!

The chimney is single walled. The silicon I used is 300 degree C rated. Sika brand its not recommended for external use, but hope it does work for a while. This is one reason I used the transition piece. Even if the silicon broke down it may not let much water in as the gap is almost non existent. its a tight fit metal to metal, allowing no water to pool around - it will shed most water without any sealing.

See attached photo. I also lifted the transition up to give a gap. It does not touch the dome. An air gap exists between the end of the SS chimney spigot all the way through and around the translation.

The carbon does not burn off the inside of chimney and castable flue gallery so does not get as hot as the internal dome. I am guessing perhaps 300 C.

The silicon will be at its design limit.

The chimney and china man's hat where bought from "pivot on line" in Melbourne. I think the web site has expired, so can't link to it. A 1200*150 dia pipe and china man's hat was about $130 shipped to Brisbane, from memory.

The SS at 0.7 is okay to cut with Wiss snips, and large Gilbow's for strait cuts. I would not like to do a lot of it in one go though, it's tough. I am an ex Plumber so have worked with lots of materials over the years, Including roofing, and other metal work jobs. Metal work is part of the Plumbing trade.

[mikku]

Re: New 36inch castable build in Brisbane

Nice sheet metal work!

Have a question about your chimney, is it single or double wall type?

If it is single, what type of silicone will hold up to the high stack temperatures?

Did you make the termination cap as well? Looks like you have the tools, and knowledge to pattern and fabricate it! .7 is a bugger even with professional heavy duty snips! I'll be working with .6mm next week and not looking forward to the possible blisters!

Keep up the great work.. enjoying all the pictures!

[Greenman]

Re: New 36inch castable build in Brisbane

Neat. Good job.

[oasiscdm]

Re: New 36inch castable build in Brisbane

in a word NICE

[brissie]

Re: New 36inch castable build in Brisbane

I picked up a sheet of 0.7mm stainless steal 1800*900 for about $30 on ebay. The thickness is about as thick as you can go if you use snips to cut it.

Finished the flue transition. I made the this so there is an air gap to allow for expansion movement. The transition piece has been flared both top and bottom to fit in place. Only the top SS to SS joint has silicone sealing. The bottom of the transition will not.

[brissie]

Re: New 36inch castable build in Brisbane

Damn, I want!

I must say it cooks really well. had to stop cooking to finish the render and some other bits and pieces. I will be cooking for Xmas, and have most of it completed.

Cheers,

[Lancer]

Re: New 36inch castable build in Brisbane

Damn, I want!

[brissie]

Re: New 36inch castable build in Brisbane

Nice work, have you cooked anything in it yet?

Yep... some photos from previous posts. After the flue is set up I will be cooking again.

[david s]

Re: New 36inch castable build in Brisbane

Nice work, have you cooked anything in it yet?

[brissie]

Re: New 36inch castable build in Brisbane

Nice work Brissie especially the tiles gecko etc. Love the colours to.

Thanks oasiscdm, just finished the first coat of the base. It think the colours work okay...