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Compressive Strength, ASTM C109

3 Days

7,610 PSI

7 Days

7,930 PSI

14 Days

8,110 PSI

Bond Strength, ASTM C1042

14 Days

5,270 PSI

Splitting Tensile Strength, ASTM C496

7 Days

255 PSI

28 Days

325 PSI

Length Change %, ASTM C157

7 Days

- 0.023

14 Days

- 0.047

21 Days

- 0.069

Concrete Time of Set, ASTM C403

Initial Set (500 psi)

127 min.

Final Set (4000 psi)

166 min.

Technical Information

Product Description

Subac Underwater Cement is a high-strength, easy to- mix, cement-based concrete and masonry patching compound designed specifically for tidal zones and underwater applications. When kept wet, Subac will set and form a permanent bond to virtually any underwater surface. It is resistant to chemical attack, as well as freezing and thawing, and can be used in all types of water.


Outstanding Compressive and Bond Strength > Less “smoke” for greater visibility > No temperature restrictions > Sets vertical, horizontal or overhead > Easy to mix, use and clean-up.


Use Subac to prevent and correct damage in any of the following applications: pier construction/ pile capping, bridge foundations, spall remediation, pipe line repair, marine worm protection, dams, stonework, nuclear and hydro power plant systems, seawalls, hull patching, pool repair, as well as any underwater surface where a permanent seal is required.

Mixing Instructions

Mix Subac in small quantities approximately 3 parts Subac to one part water, by hand or with trowel. Mix well to a putty like consistency and baseball size. Coat with water forming a smooth surface and apply without delay. Initial set time is approximately 8 to 10 minutes. Clean-up: Thoroughly rinse application tools and mixing equipment with water immediately after use.


One 50-lb pail of Subac will yield approximately 0.5 cubic ft.

Application Instructions

Subac is usually lowered to the diver in a pail and placed by hand. Work material firmly into prepared area or void. In high flowing areas or rapid current, maintain light pressure on patch until initial set begins and leaking has stopped.

Shelf-Life / Handling & Storage

Two years in original unopened pails; 1 year if properly sealed after initial use. Store in cool dry area.

Limited Warranty

Conditions of Sale– Subac Underwater Cement, Inc. offers this product for sale subject to, and Buyer and all users are deemed to have accepted, the following conditions of sale and limited warranty which may only be varied by written agreement of a duly authorized corporate officer of Subac Underwater Cement, Inc. No other representative of Subac Underwater Cement is authorized to grant any warranty or to waive limitations of liability set forth below.

Warranty Limitation - Subac Underwater Cement, Inc. warranties this product to be free of manufacturing defects. If the product when purchased was defective when used, Subac Underwater Cement, Inc. will replace the defective product with new product without charge to the purchaser. Subac Underwater Cement, Inc. makes NO OTHER WARRANTY, either expressed or implied, concerning this product. There is NO WARRANTY OF MERCHANTABILITY. In no case shall Subac Underwater Cement, Inc. be liable for special, indirect, or consequential damages resulting from the use or handling of this product and no claim of any kind shall be greater in amount than the original purchase price in respect of which damages are claimed.

Inherent Risks - Subac Underwater Cement, Inc. makes no warranty to the performance of the product after it is applied by the purchaser, and purchaser assumes all risks associated with the use or application of this product.