Perilite concrete not setting up--normal?

[tfasz]

Re: Perilite concrete not setting up--normal?

Mine took a while to setup. I think I mixed it too dry, and every day I would spray about a liter of water over it. After about a week or two I could actually stand on it without a problem. I'd wait a bit more and see if it has strength - you just want to make sure it can hold up the weight of the oven.

Even if you do have to redo it, at least it is a really in-expensive mistake to make.

[Tscarborough]

Re: Perilite concrete not setting up--normal?

The amount of water required to mix perlite and cement is very high in relation to what is required to actually hydrate the cement. I also noticed that it required a long time to dry. It will always be soft and crumbly, but the water will dry out.

[BarryKeith]

Re: Perilite concrete not setting up--normal?

Raffy,
Thanks, I was typing while you responded, Sorry. I feels almost wet to the touch and when I chip a peice off (which is not hard to do) it feels wet. How long should I wait?

[BarryKeith]

Re: Perilite concrete not setting up--normal?

I have researched the difference between the concrete and cement. I feel like an idiot. Do you think that the perlite and concrete will set up and be useful or should I scrape it off and go again with perlite and cement?

[Raffy]

Re: Perilite concrete not setting up--normal?

I agree with Neil. Give it time to set but keep it hydrated for it to cure properly. Perlite on the surface has a tendency to chip off. It happened to me too. DOn't worry too much about it. The fireclay mixture will help smoothen the uneven surface of the perlite for you to lay the bricks on.

[BarryKeith]

Re: Perilite concrete not setting up--normal?

I used sakrete(concrete mix) from home depot, 5 parts Perlite to 1 part sakrete. Is this wrong? Should I have used something else?

[Neil2]

Re: Perilite concrete not setting up--normal?

"5:1 mixture of perilite to concrete "

Perlite to cement. Keep it damp and under cover for a few days and see what happens. It will always be a bit "crumbly" on the surface.

[BarryKeith]

I have had a great time with this project. My boys are 16 and 17 and talked me into building a smoker and a grill on each side (in firebrick) and setting my pizza oven in the middle. What a great way to spend time with my boys. We went to set my insulating concrete layer and after 3 days it is still soft. Is this normal. We used 5:1 mixture of perilite to concrete and when a peices brake off it is wet on the underside. Do I need to let it set longer? It has been in the 60s to 70s as a high. Was I suppose to add anyting to the mixture? I can't see this being effective for the outer layer of insulation, but I already bought the perilite. ANy help or ideas?