What can be done when blistering is occurring?
Blistering does not always show up on the first troweling but when blisters occur they usually are visible before the second troweling. It helps somewhat to delay the second troweling as long as possible. Delayed troweling will depress the blisters, even though it may not establish a complete bond. On the second or third pass, when the trowels are pitched at more of an angle, entrapped air is forced ahead of the trowel blades under the surface skin until it is concentrated enough to form blisters. Switching to flat troweling when this occurs can reduce the problem.