I've finally started our oven in Costa Rica

[carloswlkr]

Re: I've finally started our oven in Costa Rica

I finished another course tonight, and corrected the slight tear shape I had going. It feels like I'll have to start using supports soon.

I'm still amazed at how well my miter saw cuts with water. I only hope it doesn't kick the bucket before the build is through! I did buy a GFI extension cord, and a good respirator, so I'm taking some precautions.

Here are a few pictures of today's progress.

[carloswlkr]

Re: I've finally started our oven in Costa Rica

Costa Rica is not a bad place to live, indeed. And there are certainly worse places to raise kids! My daughter spent the night at her great-aunt's house, so I was able to get some more work done last night when I got home.

I've run out of the easier bricks to cut, so last night went to work on the ones that throw sparks. I tried using a small amount of water (with a spray bottle), and lo-and-behold, the saw cut through the bricks like butter! I made quick work of another dozen bricks for last night's course.

No pictures today, but if I can work on the project tonight, I'll snap a few.

[gjbingham]

Re: I've finally started our oven in Costa Rica

Three month old babies are easy to work around. Work fast, be productive. Sleep schedules will quickly change and then you're suddenly strapped for work time.

San Jose is a cool town. I spent a few days there in my last life. Then I got my ass kicked and broke my board on a huge rogue wave the size of a two story house down on Jaco beach. That was the beginning of the end of my 10 year career in surfing. No mas!

[carloswlkr]

Re: I've finally started our oven in Costa Rica

Thanks, Les. I appreciate the encouragement!

[Les]

Re: I've finally started our oven in Costa Rica

Carlos,

It's looking pretty good. Your tie in is not at all bad. Everyone of us has hit a snag at that point. And you are correct, no one will see it.

Les...

[carloswlkr]

Re: I've finally started our oven in Costa Rica

I finished another two courses on Saturday, and was going to do more yesterday, but it was raining, and my three-month old son was crying for attention. he's been an amazing baby, but yesterday was not a good day for him.

anyway, i've now finished the tie in with the opening arch. I'm not very satisfied with how it turned out, but will adjust on subsequent courses. I love the various gauges and tools that several of you have devised to make the perfect dome. But I'm just using a piece of string nailed to the center and some rustic give and take as I go. I thought it was going to turn out well, but as the tie-in gradually went up, I noticed that I was getting a little bit of the dreaded tear shape. I was finishing my last course on Saturday, with the center key-stone, and it cracked on me. :-( If I hadn't been pressed for time to clean up and go out with the family, i would have cut a new brick and done it over. But as it is, I think it'll be OK. I'll try to diminish the tear shape over the next couple of courses with some of the slivers of brick that I have laying around.

Anyway, all for now. I'm hoping to have this finished in time for my annual Oscar's party, but if I keep getting rain delays, it may not happen. Oh well...

[carloswlkr]

Re: I've finally started our oven in Costa Rica

Thanks for the links, JRParks. I've been reading up as much as possible. Both reassuring and worrying at the same time. I guess what's past is past, and now the trick is minimizing the rist going forward. I bought the best respirator I could find yesterday, and a much needed shop vac. will attach it to my miter saw when I'm cutting. Unfortunately, I haven't found a source for renting wet saws.

[jrparks]

Re: I've finally started our oven in Costa Rica

Do what you can to eliminate dust from cutting (wet saw) and clean up well.
Here is a web link to with info from the National Cancer Instiute that answers a lot of question regarding asbestos exposure;

Asbestos Exposure: Questions and Answers - National Cancer Institute

"Everyone is exposed to asbestos at some time during their life. Low levels of asbestos are present in the air, water, and soil. However, most people do not become ill from their exposure. People who become ill from asbestos are usually those who are exposed to it on a regular basis, most often in a job where they work directly with the material or through substantial environmental contact." NCIHope this helps. Cheers,

[Les]

Re: I've finally started our oven in Costa Rica

Unfortunately, crime is pretty common in paradise. the razor wire and electrified fence are ours, to slow the thieves down.

Thank God. I thought it was to keep the monkeys out

Les...

[carloswlkr]

Re: I've finally started our oven in Costa Rica

a surface wash with high temp mortar would be a good idea on the finished interior.

Thanks, Wiley. I'll do a good wash of the interior, and keep an eye on the quality of my floor.

What's with the razor wire and electrified fence on top the wall?

Unfortunately, crime is pretty common in paradise. We have two empty lots next to our house, with the adjacent apartment complex between the two lots (south side and west side). We've had our property broken into six times in the years we've lived here, and the razor wire and electrified fence are ours, to slow the thieves down.

[carloswlkr]

Re: I've finally started our oven in Costa Rica

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.

[Wiley]

Re: I've finally started our oven in Costa Rica

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

[Archena]

Re: I've finally started our oven in Costa Rica

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.

[carloswlkr]

Re: I've finally started our oven in Costa Rica

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.

[carloswlkr]

Re: I've finally started our oven in Costa Rica

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!