The subject of using Festool saws has come up elsewhere on this forum. I have basically made the same reply each time: DON'T.
Masonry dust can get into every port and pore. It can be terrible stuff on tools, especially tools NOT designed for masonry. Steveo and others have given good thoughts. Either rent the proper tools or find a good fabricator contractor or shop. They are equiped to handle the cutting, precision and above all, the dust.
If you do get the right tools/equipment, do the work outside: Read first sentence of second paragraph of this post.
The upcoming story (more torture on the way 8) ) is not about sawing masonry, but the described results can be common to any masonry cutting operation inside of a house.
I had run into a finnishing problem on a concrete floor I was pouring in the late November or early December. It was one of those nice warm November or early December days when the sun was warm and even tho it was expected to become extremely cold sometime after midnite, there was plenty of time to get the concrete down, finish troweling and get the mats down to protect from the expected cold long before danger arrived. The first truck arrived right on schedule. We poured, screded and struck off as we waited for second truck to arrive. It was only 8:30 am and we were in good shape, only "where is that second truck?" Pretty soon it was WHERE IN H--- IS THAT OTHER TRUCK???
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By 9:30 I was on the phone and was assured the truck was right around the corner. 10:30 and still no truck. By 2 pm the phone line was melting. i finaly called my other supplier from some 30 miles further away and explained my problem (turned out, first supplier, unknown to me at the time, was having financial problems and were more interrested in discussions with their lawyers than in actually doing business. they were out of biz by the end of the week). they promised to have a truck to me by 4pm. sure enough, they arrived as promised. Big problem was that first load had already set and we could actually walk on it. we should have been covering instead of adding a second pour. End result, We made a mess of the edge of original pour and a worse problem with second portion of the pour. I ended up troweling all nite long, finally adding the mats just before daybreak with temp down around 20?F. I was unable to get a smooth finish to the floor, but could not afford to leave it unprotected any longer.
Result: very rough finish.
Options discussed with building contractor and owners (all, thankfully, good friends of long standing):
A We could rip out and start over
B We could make second overlay pour
C We could rent a terrazzo machine (heavy grinder used for fine finishing artistic stone finish of concrete, tile or stone) and grind smooth. we could then wash down and apply a finish (won't get into that part of the story)
It was decided to try the terrazzo machine. We decided on the week between Christmas and New Years while the owners were away on vacation.. The day before renting the machine, i went over to the site and personally covered with tape, every crack and opening between the floor and the main house. i sealed everything. Everything???
The next day, i attacked the floor with the heavy machine (the builder came over to give me a hand unloading. Those things weigh a ton) There was no water on the job as the water system was in shut down as it was being added on to, or whatever. since i had closed all cracks, there was no need to wait for water to flush the surface and eliminate dust problems. Who cares if I suffocated, atleast we were protecting the rest of the house. If I goofed, my backhoe was on site and they could just bury me right there ???. In the end, the job came out perfect. The builder was happy and sure the owners would appreciate as well.
New Years Eve, i was at a friend's house when i got a phone call from the builder. He told me to call the owners.
To make a looonnnngggggg story short, i called and was greeted with an irate tale of grief (more like horror). It seems i had neglected to close off a cold air return duct (I had been unaware that the heating system had been redisigned to be hot air so airconditioning could be installed. the duct, being in an undisturbed area for my work had been somehow hidden from view and i missed covering it) it seems that every square inch of the house was coated with the white grinding dust. The downstairs rooms, uostairs rooms, closets, beureau drawers, inside and out, even the inside coverings of beds and the mattresses were covered with the fine dust.
Bill, I'm so sorry. i will come right over and give you a hand. I'll see if i can find extra help.
Tinker, If i see you anywhere near here, I'll personally kill you!!!
Well, they eventually got the mess cleaned up. By taking the advise of the builder, i took heed to the warning i had received.
Within a week, we were all back on speaking terms and the story of Tinker's Dust has been dutifully archived in the memories of all concerned. It even managed to come up in mutual conversations over the years without even a hint of pending bloodshed. Even some laughs, even tho I did squirm over the story a few times.
The point is, that whether you are using a terrazzo machine, as i had done, or any kind of cutting tool, when you cut masonry, you must prepare in advance to protect your (or their) property. Check and recheck. Once you know the property is protected, you must decide whether you and your tools are expendable. It is probably best to protect from that end also.
Tinker
