Sairset Kiln Mortar

Sairset is a wet, extreme strength, air-setting fireclay refractory mortar used in kiln building and to fix chipped or broken molds. This general purpose top selling resin based mortar can be used anywhere you need a good high temperature mortar. The maximum service temperature is around 3000 degrees Fahrenheit, which makes it great for glass fusing purposes.

Another popular kiln mortar used is called “Magic Mender”. Magic Mender needs to be heat set at a higher temperature than Sairset, which makes it not as convenient or easy to use for glass fusing purposes. Most glass fusing kilns do not fire high enough to set this mortar.

Have you purchased a mold just to find out that when it arrives, it is broken in half? Or have a favorite mold that has cracked because of continuous firings? Then you will need to look into purchasing a kiln mortar for this mold repair project. Both products are used when you have a repair mold problem. This page will discuss the difference in these two products and why Sairset is actually better for glass fusing purposes.


sairset, magic mender, repair mold, mold repair

This kiln repair cement is primarily used in kiln building. It is available through local and on line ceramic suppliers, furnace supply stores, as well as a refractory supply. When using this product, make sure there is a little moisture in the pieces to be cemented together. It is simple to shape with wet tools or fingers, but be sure to wash tools and fingers promptly.

Fixing Cracks in Kiln Bricks

This product could also be used to repair fractures in the kiln bricks. Do not distress about all the assorted cracks within the kiln walls. A kiln won't stay immaculate appearing for long. Firebricks receive extraordinary tension as they enlarge and shrink with each separate firing. Soon you'll discover fissures in the walls and deck of the kiln. This is natural and nothing to stress over. The cracks don't impact the firing outcomes. The only cracks that will impact the glass are the ones located in the lid or roof, because these can cast dust into the firing chamber.

Sairset Instructions

1. Make the edges to be joined wet.

2. Spread some kiln repair cement on the joint. Smooth while wet, and try not to get any at all on the inside of the mold.

3. Wipe off the excess with a damp cloth or sponge.

4. Back up the repair with more of the product on the back. Wash all tools used immediately or it will never come off.

5. Allow it to dry a fair amount of time. It can be sanded with sandpaper if necessary.

6. When dry fire to about 1472 degrees Fahrenheit to set the material.

7. Wash the mold and you are ready to go.

Magic Mender

Magic Mender can be used to repair cracks or breaks in a mold. Normal firing range for Magic Mender is cone 06 – 05 or 1825 degrees Fahrenheit to 1911 degrees Fahrenheit. This might need to be fired in a pottery kiln instead of a glass kiln to reach these high temperatures. Magic Mender does not spoil or go bad over time. Keep the unused portion tightly closed in a jar.

Crack Repair Instructions

When repairing a crack, use a knife tool or dermal to open the crack. The product must get deep into the crack for it to work properly. If not opened, the crack can reappear later. Use a vacuum to clean out the area.

1. Dip a brush in the mender and in some water so that you have a flowing consistency like ketchup.

2. Allow the mender to flow into the cracks, then let dry. Add a second application if needed.

3. Allow the mender to dry completely and wipe clean.

4. Once the mender is completely dry and clean, fire the piece to about 1825 degrees Fahrenheit.

Broken Mold Repair Instructions

1. Do not wet the mold that needs to be mended.

2. Magic Mender is already pre-mixed, so there is no need to add any additional water. The joint is delicate while the mender is still moist, so be very careful when cleaning the mold during this process.

3. Apply the mender to both sides with a soft brush. Don’t over apply the mixture. Press the pieces of the mold together for a minute or two until they remained joined. When the mender begins to bead out of the sides you have full coverage.

4. Let the mender dry completely on the mold, then just wipe clean.

5. When the mender is completely dry, fire the mold to about 1825 degrees Fahrenheit. The mixture must be fired to become permanent.

6. Once fired, the repaired area is stronger than the rest of the mold.

Return to Technical Terms

Return from Sairset Kiln Mortar to the homepage

E-mail Address
First Name (optional)

I keep this private.

Site Affiliate Links

Delphi Glass