Brick Batter (High Temp Mortar) — Instructions

High Temperature Mortar

Directions For Use

  1. Mix contents of the Brick Batter pail to an even consistency. Then, spread the mortar on the left, right and bottom sides of a brick and wiggle it into place in your firebox. You do NOT need mortar on the back side of the brick. If mortar is too thick to spread, mix in a small amount of water.
  2. Spread the mortar in the same way for each neighboring brick until the entire first layer of brick is in place. Then spread mortar over the top of the entire layer of bricks. Note that you will be putting mortar on both surfaces of each joint. Also, there will be approximately 1/8″ – 1/4″ space between neighboring bricks.
  3. Repeat Steps 1 and 2 for each subsequent layer of brick. When all bricks are in place, go back and fill in any cracks by spreading mortar over each joint.

Brick Guides

Instructions for Corsair Instructions for Silverplate

*NOTE: Many hobbyists who are using the StarCat Evaporator want to be able to remove their bricks at the end of the season to make the evaporator lighter and  easier to move/transport. The geometry of the StarCat Arch is designed to help hold bricks in place without mortar. Only use the mortar if you want a permanent installation. For more information on bricking a StarCat, see our instructional video on YouTube.

Curing Time

  • Generally speaking, our mortar joints end up being 1/8″ thick or so. This is beneficial because the small mass of mortar makes cure times quicker.  We never mortar the back of the bricks, this helps to shorten cure times too.
  • Mortar should never be applied at temperatures less than freezing.  
  • If mortar is applied at room temperature (70°F) and it can sit undisturbed at room temperature for 48 hours, then it’s fully cured. 
  • If the mortar is applied in cool temperatures, it must be kept from freezing for an extended period of time. This cure time may be about a week.
  • If the mortar is applied at cool temperatures and the evaporator must be put into service very soon OR freezing temperatures threaten, the combustion chamber of the arch must be heated to about 100°F for a period of 1 hour. After the initial 1 hour of heat, increase temperatures in the combustion chamber to about 200°F for a period of about 3 hours. After this treatment, the mortar is considered to be cured and the arch can be fired to the extreme temperatures for evaporation or be allowed to be exposed to freezing temperatures.
  • Essentially, the user must avoid letting the mortar freeze with access water in it to avoid expansion during freezing.  Likewise, the mortar can’t be exposed to excessive temps which could cause the moisture to boil out. Think of it like making jerky; the moisture should be dehydrated out, not cooked out.


It is recommended that protective clothing be worn to prevent contact with eyes or skin. Wash exposed areas promptly. For eye exposure, flush with water immediately and consult a physician.

Safety Data Sheet
Product Spec Sheet
Manufactured by Alsey Refractories Company, PO Box 80, Alsey, IL 62610