I've finally started our oven in Costa Rica Brick Oven Photos Discuss I've finally started our oven in Costa Rica in the Good Background Information forums; Carlos - I didn't want to hijack Nikki's thread. You mentioned that you want the igloo look but you get ...

[Les]

Carlos - I didn't want to hijack Nikki's thread. You mentioned that you want the igloo look but you get a lot of rain. Would it be possible to extend the cover that is in the pic's?

Les...

[carloswlkr]

That might be a good way to go. Our ranchito has a small bathroom in the back corner (visible in one of the pictures) and the walkway to it is from the side of the ranchito wrapping around behind the pizza oven. We've thought in the past about making an awning over the walkway so that people can still use the services while it's raining out. It would need to extend all the way to the wall with the bamboo, because often when it rains, there's a good amount of wind, too. But thanks for the suggestion! I'll check with the boss when I get home tomorrow!

can't wait to get back to work on the oven!

[carloswlkr]

I did some work this afternoon on the project. Hauled the rest of the bricks that I had bought back to the work area, and cut another 25. My daughter was anxious to help out, so after I cut the bricks, I let her help with the spray bottle. She kept the bricks moist.

Not much else to share. More pictures are in the photo gallery section. Meanwhile, here are a couple of our daughter playing with the oven arch.

[carloswlkr]

I cut another 30 bricks today. I've noticed that some are much more difficult to cut than others. The lighter colored bricks are supposed to be softer (less exposed to the fire in the kiln, according to the folks at the foundry), but the opposite seems to be true. When I cut into the light bricks, sparks fly almost immediately, and the diamond bit disk glows red. A molten substance comes out the cut. I'm not sure what it is, but it catches the light. I'll try to post a picture of some of it next time I cut bricks. I haven't asked for the chemical composition of the bricks, but now I think I will. Hope the Costa Rican bricks are up to snuff! Saw a post about asbestos, and am starting to worry...

Anyway, pics of todays progress in the photo gallery... All for today.

[dmun]

When I cut into the light bricks, sparks fly almost immediately, and the diamond bit disk glows red.

Wow! Stop! Diamond blades don't run hot. If it's red, it's dead. Tell us what kind of saw you're using.

[carloswlkr]

I'm using a compound miter saw (designed for wood). If I recall, it's a 'Delta Shopmaster'. A Pricesmart (costco) special. The strange thing is that on the darker colored bricks, the same blad cuts well. It rarely throws sparks and doesn't glow. To be more precise, it might not be the disk that is glowing, rather the brick around the area being cut. The disk itself doesn't glow outside the cutting track. I'll try to cut some tonight and post a picture of the molten worm that comes out the back. It stays hot for a good 15 or 20 seconds, and is very brittle.

anyway, thanks!

[carloswlkr]

Well, I've got some rather chilling news. I called the foundry to ask about the chemical composition of the bricks I'm using. They said that they are approximately 60% silica, 18% alumina and around 10% iron. I asked if they also have asbestos. He said, rather matter-of-factly, 'yes, but it's minimal'. He calculates it at no more than 5%. It's a rather wet blanket that's just been thrown over my oven project. I guess that's one of the risks of living in 'paradise'... we don't have a tradition of class-action suits like those that led to the removal of asbestos from firebricks in the States.

so, does anyone know how dangerous asbestos is in the bricks? from what I've read online, the major health hazards are posed when the fibers are airborne, i.e. during the construction phase. Worst hazard is right now while I'm cutting the bricks. But once the oven is finished and cured, am I going to be slowly poisoning myself and my family if I cook in it?

--A very sad, disappointed guy in the tropics.

[Archena]

The danger is from airborne particulate. Cutting those bricks is dangerous - buy a good respirator now and don't cut them without it. Seriously consider renting a wet saw.

Once in the oven as long as they are intact (no spalding) the asbestos shouldn't be a problem. You might consider a refractory mortar as an interior coating and I'd use stone or tile as the actual cooking surface. The tools that might scratch the surface could expose fiber. Heated air can get them airborne - ingestion probably isn't great for you but it's not nearly as risky as breathing the stuff.

It's treated as highly hazardous in the US but I'm not sure there are any firm numbers on low exposure risk. Don't freak but do treat it with respect.


Um, what did he say was the other 7%?

If you haven't bought all your brick you might want to reconsider using them. Once cut the risks shouldn't be very high but it's not exactly nil either.

[Wiley]

Carlos, I agree with the others in that the bricks and the asbestos is mainly a problem during construction and that a surface wash with high temp mortar would be a good idea on the finished interior. Obviously a good shop vac to remove all dusts in the construction area would be a good idea as well, especially if your daughter wants to play on the oven while it is under construction. And changing to a wet saw would be a good idea too.

I have to ask, do you have a paranoid neighbor? What's with the razor wire and electrified fence on top the wall? I am saying neighbor as the insulators and hot wire is on your side of the fence, if it was your fence the insulators and hot wire would be on the other side.

Wiley

[carloswlkr]

Thanks, Archena. I will buy a high-quality respirator today. All my bricks are purchased, and unfortunately, there is no alternative here in Costa Rica. We have one single foundry for the whole country. There might be brick ovens with bricks imported from other countries, but most come from the same source I'm using.