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Cold weather mortar failure on a Friday job site in Denver
I mixed mortar at 28 degrees with accelerant last week, it set too fast and cracked by Monday, so now I tell every apprentice to test a small batch first and has anyone else switched to heated mixing water instead?
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spencer_gonzalez16d ago
Man, hold up. The accelerant probably isn't the main culprit here. At 28 degrees, you're already fighting the chemical reaction, and dumping extra accelerant just makes it flash-set like you saw. Heated water helps, sure, but you still gotta slow down the mix and use Type S or N, not just crank the heat. I've seen guys throw in hot water at 140 degrees and still get spider cracks because they didn't change their mix time. Test that small batch, but also check your water temp with a thermometer, not your hand. 60 to 70 degrees is plenty, you don't need to boil it.
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