Materials for Stucco Dome?

[ThisOldGarageNJ]

Re: Materials for Stucco Dome?

My understanding is that you cannot buy vermicrete

You actually can buy it,, THey use it in building in ground swimming pools, I though could not tell you if the mixture is correct, but there are posts in the forum of people have used it...
Cheers
Mark

[WaWaZat]

Re: Materials for Stucco Dome?

Aluminum foil rots out in contact with the caustic portland products.

What about galvanized steel? I ask because all the hardware cloth I've seen at the home centers are galvanized. Any reason I should not use that as my reinforcement layer for my concrete shell?

[ThisOldGarageNJ]

Re: Materials for Stucco Dome?

What about galvanized steel? I ask because all the hardware cloth I've seen at the home centers are galvanized. Any reason I should not use that as my reinforcement layer for my concrete shell?

Im not sure about rotting out, It may, My thought is that its used more as a form as well as holding down your insulation, It would be nard to put your vermicrete directly to your insulation... So it helps provide shape and something for the vermicrete to stick to, Then Stucco or SBC on top of the vermicrete..
Cheers
Mark

[dmun]

Re: Materials for Stucco Dome?

What about galvanized steel? I ask because all the hardware cloth I've seen at the home centers are galvanized. Any reason I should not use that as my reinforcement layer for my concrete shell?

Zinc is an entirely different metal than aluminum. The mesh that's designed to use with concrete, the expanded metal lath, is galvanized.
The linked article mentions acidity as a threat to galvanized steel; concrete is strongly alkaline.

[ThisOldGarageNJ]

Re: Materials for Stucco Dome?

Im not sure about rotting out, It may, My thought is that its used more as a form as well as holding down your insulation,

My point above that I may have missed is that if it does rot out, You have already gained the structural strength of your vermicrete and stucco, and it probably really wouldnt matter. I used the half inch galvanized hardware cloth,, I have about 5 months in,,, and I guess I will never be able to see if it does rot, But I have had 3-50 lb grandkids standing and climbing on my dome and between the vermicrete and Surface Bonding Cement,, still not a crack

So use it and feel food about it

Cheers
Mark

[WaWaZat]

Re: Materials for Stucco Dome?

Quikrete has a pretty good tech line. I've confirmed that I do not want to use aluminum foil even for the sole purpose of protecting my insulation blanket until the concrete cures (so I can reuse it once the oven is torn down & reinstalled after my anticipated move). The foil will react with the concrete producing hydrogen and possibly causing air pockets and cracks in the concrete.

And concrete is strongly alkaline but is not acidic therefor posing no threat to the galvanized mesh... in fact galvanized mesh is encouraged for use as reinforcement for stucco.... as Dmun's former point above suggests.

[WaWaZat]

Re: Materials for Stucco Dome?

Hey wawazat,,
I used the Quikrete SBC,, I've said it Once I will say it a thousand times,,, LOVE THIS STUFF.... covered my block foundation and dome with it. Added the Acrylic fortifier for watrproofing and terra cotta color.. I have a 42 inch dome and used 2 bags just for the dome and that gave me 1/2-3/4 inch coverage...
For a smooth finish you can just trowel it on
For a slightly rougher finish you can trowel it on and wipe it with a grout sponge
One Note, You can mix by hand, but a mixer is recommended....
I also used half inch harware cloth for my vermicrete it worked fine,,,

Is there a reason your not using the vermicrete,,, Insulation is key to an oven..

Cheers
Mark

Hey Mark... did the fiberglass fibers in the SBC bother you for using as the finish coat? I just did my 1st coat today and I've noticed that the fibers seem to stick out. Of course I didn't bother to do much smoothing, being the base coat. I'm not sure if smoothing would solve this. Just don't want to have needles protruding in case someone wants to run their hands across the beautiful finish. What are your thoughts & experience? Or anyones else's, for that matter, who has used Quikrete Surface Bonding Cement.

[ThisOldGarageNJ]

Re: Materials for Stucco Dome?

hey wawa,
I finished with a damp sponge. gives you a slightly rough finish, but i like it, I just went out to look at the oven and there arent any hairs sticking out... If you finish with a trowel, you will get a much smoother finish.. Depends on what you like, but I dont think you will have any problems with hairs,,but if you do.. You could always get the hedge trimmers out !!

Cheers
Mark

are you going to be using the acrylic on the second coat ?
are you using color ??

[WaWaZat]

Re: Materials for Stucco Dome?

hey wawa,
I finished with a damp sponge. gives you a slightly rough finish, but i like it, I just went out to look at the oven and there arent any hairs sticking out... If you finish with a trowel, you will get a much smoother finish.. Depends on what you like, but I dont think you will have any problems with hairs,,but if you do.. You could always get the hedge trimmers out !!

Cheers
Mark

are you going to be using the acrylic on the second coat ?
are you using color ??

I used the acrylic fortifier in the 1st coat & plan to in the 2nd coat. I did pick up a jar of Quikrete's red. I was really looking to finish the dome in a burnt orange. The red is closer to what I like than the terra-cotta. I wish they had yellow... I could use that to make the red more orange. I'm going to experiment a little. Maybe if I don't use so much red, I might get sort of the effect I'm looking for.

[sjmeff]

Re: Materials for Stucco Dome?

did the fiberglass fibers in the SBC bother you for using as the finish coat

I found that sponging the surface of the SBC *did* bring the hairs to the surface, but once it dried, most of them brushed off. I had to hand pick a few others off. In general, this wasn't a big deal and well worth the added structural benefit.

[WaWaZat]

Re: Materials for Stucco Dome?

I found that sponging the surface of the SBC *did* bring the hairs to the surface, but once it dried, most of them brushed off. I had to hand pick a few others off. In general, this wasn't a big deal and well worth the added structural benefit.

That's good to know. There were fiberglass fibers in my refractory casted oven dome. If you would have run your hand across it, you'd cut up your hand pretty good.

[Tscarborough]

Re: Materials for Stucco Dome?

The fibers are actually polypropylene. Glass fibers react with the alkalinity in cement, so they have not been used for many years for stucco or concrete, although they may be used in refractory applications. If it looks hairy, you can burn them off with no problem.

[WaWaZat]

Re: Materials for Stucco Dome?

The fibers are actually polypropylene. Glass fibers react with the alkalinity in cement, so they have not been used for many years for stucco or concrete, although they may be used in refractory applications. If it looks hairy, you can burn them off with no problem.

Thought about burning them off if necessary, but afraid that might leave a burn mark on the colored finish. The next choice might be a tedious once-over w/a sharp exacto.

[Roadkyng]

Re: Materials for Stucco Dome?

Thought about burning them off if necessary, but afraid that might leave a burn mark on the colored finish. The next choice might be a tedious once-over w/a sharp exacto.

you could always break out your trusty Norelco....just make sure you post a pic of you giving your dome a shave.

[WaWaZat]

Re: Materials for Stucco Dome?

No need to shave... the hairs pretty much lay down when smoothing the final coat with a trowel.

...tutti hanno finitoo!! Check out the pix