I am planning on using HeatStop50 to build my oven despite the higher cost as I plan to do mostly multiple-loaf bread baking. I read somewhere that when using it there is no need to keep the fire brick wet as specified in your instructions. Is that accurate?
Yes - you absolutely want to keep the Firebrick wet. Dry firebrick will suck the moisture from the wet mortar like a sponge and you’ll have brittle mortar once the mortar is dry.
Now, we’re not talking soaking wet… just thoroughly wet. Not dripping.
Simply place a good portion of firebrick in a wheelbarrow and fill it with water. Let the firebrick soak up the water for a good 10 - 15 minutes then place the brick under the base (shaded by the sun) for the remainder of your working time.
Here’s some pictures of firebrick soaking up water that we randomly have on our computer. In this stage, the brick are actually whistling! You can hear it!