IS SPRAYWALL AN EPOXY?
No. Most common epoxy resins are produced from a reaction between epichlorohydrin and bisphenol-A. SprayWall is polyurethane that is produced from a reaction between a polyalcohols and an Isocyanate.
HOW ARE SPRAYWALL'S POLYURETHANES DIFFERENT FROM EPOXY PRODUCTS?
Polyurethanes cure much faster than epoxies and therefore can be applied much thicker in one application. Typically, an epoxy must cure for 6-10 hours. Sprayroq’s polyurethane products begin curing in about 10 seconds. They reach a tack-free state within 2 minutes and full cure through within 4-6 hours.
SprayWall has the ability to return a structure to water service 30-60 minutes after application, based upon the thickness of the application.
IS A POLYUREA AND POLYURETHANE THE SAME THING?
No. Polyurethanes are generally the reaction product of polyalcohols and Isocyanate. Polyureas result from reacting polyetheramines and Isocyanates and usually require a primer. Sprayroq products normally do not require primers.
WHAT TYPE OF SURFACE PREPARATION IS REQUIRED BEFORE USING SPRAYWALL PRODUCTS?
Surface prep is the key to any successful polymer application. Generally, power washing with 3,000 psi water pressure will address most cleaning needs. Sometimes, higher water pressure and/or the use of a biodegradable cleaner may be needed for more difficult cleaning jobs.
After the power washing is complete, inspect the structure for infiltration. If you discover even a small degree of infiltration, use a very good chemical grout system such as Quadex and/or Strong Seal to seal off the infiltration.
If point repairs are necessary, a calcium aluminate based cement or strong Portland cement should be used to rebuild the profile of the structure. Use the cement to replace any missing mortar between bricks or to fill in voids from poured or precast structures.
Once the cement has dried by ambient temperatures or by an accelerated process, you may begin the spray applied rehabilitation process.
Caution: Be sure that your surface area is both clean and dry. This is true for any polymer you may use.
HOW STRONG IS SPRAYWALL?
One of the measures of SprayWall is known as “flexural modulus”. That is the point in which the sample of material yields under the pressure of a testing device. The rating, measure in pounds per square inch, tells the engineer what the strength of the product may be. Sprayroq uses the most conservative numbers to represent flexural modulus. That number is 735,000 psi.
Let’s compare that to a well know product called cured in place pipe, CIPP. Most resin filled fiber liners have a flex modulus rating of 360,000 psi to 400,000 psi, which is a very strong product. Some other newer materials will go higher, but compared to the most common felt liner, SprayWall is tested out at nearly twice that of CIPP with the same 50 year design life that accompanies CIPP products.
HOW LONG DOES IT TAKE FOR SPRAYWALL TO CURE?
The curing process of Sprayroq products begins in about 8-10 seconds with what we call “gel time”. A thin skin is formed on top of the freshly sprayed surface which quickly continues to solidify throughout the application. In about 2 minutes, a “tack free condition exists where the product is able to support the weight of the applicator safely while the spray application continues.
Within 30 minutes, the initial cure is complete and the structure is capable of accepting flow* while the complete curing process continues for the next 72 hours.
The majority of structures may be returned to active service within 30-60 minutes after the application*. Thicker applications may be returned to service even sooner. This is due to the accelerated curing that takes place in a larger mass of spray applied material.
* Potable applications require a 72-hour cure time in order to meet WQA standards
WILL I GET A FAVORABLE ROI WITH THE USE OF SPRAYWALL?
Indeed! This product, in a structural finish, has a 50 year design protocol. Other technologies may not have that same service life expectancy. When municipal funds are being used for rehabilitating vital infrastructure, the taxpayer is entitled to the longest lasting, comprehensive solution available. With its 50 year design life, SprayWall will continue working 24/7 while other technologies may have to be reapplied anywhere for 3 to 15 times on that same structure over a 50 year time span.
DOES SPRAYWALL COME IN OTHER COLORS?
The natural color of SprayWall has a golden tone to the finished product, thus we use the phrase, “the Gold Standard” as part of our marketing initiative. As this is part of our identity, we will not change the color of our core products.
We do have the ability to modify the colors of our polyurea products to virtually any color. The standard colors are either black or blue, but we can color the polyurea to meet your specific job requirements.
HOW MANY MOBILIZATIONS WILL YOU NEED TO MAKE IN ORDER TO BUILD UP TO 300 MILS (3/10")?
Will that take multiple mobilizations and extra bypassing?
One! The beauty of our products is that we can build up to about 500 mils (one-half inch) or about 13 millimeters in a single application. This unique feature of our product allows our SCP’s to keep their cost in line by minimizing mobilizations to only one trip, reducing expensive bypassing requirements and returning the structure to service sooner than other technologies.
HOW DRY DOES A STRUCTURE HAVE TO BE BEFORE APPLYING SPRAYROQ PRODUCTS?
Bone dry! But, our SCP’s understand the nature of drying out a structure by the effective use of grouts and special techniques to assure that the structure is in perfect condition for a spray applied application of Sprayroq products.
DOES SPRAYWALL CONTROL THE CORROSIVE EFFECTS OF H2S?
Hydrogen Sulfide is converted to Sulfuric Acid in sewer systems. SprayWall is resistant to the corrosive effects of Sulfuric Acid. However, in its Hydrogen Sulfide state, Spraywall’s polyurethane formulation controls the destructive nature of the gas.
WHAT IS THE KEY TO A SUCCESSFUL COATING OR LINING PROJECT USING A SPRAY APPLIED RESIN?
The key word in any structure is to start with a clean and DRY surface. This applies to any polymer. In other words, the quality of the surface prep should reflect the quality of your finished structure.The next issue, and equally critical, is to have a dedicated, manufacturer trained applicator team who have the ability to address the wide area of conditions they will encounter when using any polymer product for rehabilitation linings or corrosion coatings.
HOW LONG MUST I WAIT TO PUT MY NEWLY REHABILITATED STRUCTURE BACK INTO ACTIVE SERVICE?
With Sprayroq’s quick curing polyurethanes, you can return a structure back to active water service in 30-60 minutes. If there is a thicker mass of material sprayed, you may return it to service even sooner due to the accelerated curing process that accompanies the heat of that thicker mass of material.
WHAT IS THE DIFFERENCE BETWEEN THE VARIOUS SPRAYROQ PRODUCTS?
All Sprayroq products are quick curing polyurethanes, Polyureas or hybrids; with one exception, SR6100 is a trowelable, high strength epoxy used for spot repairs or for coating structures where our SCP’s spray rigs cannot access.
SprayWall is a structural, spray applied polyurethane with a flexural modulus of 735,000 psi and 4% elongation. This unusual combination of performance factors is part of what helps SprayWall achieve a 50 year design protocol. As well, SprayWall is NSF certified for use in potable water applications. It is excellent for use in infiltration control, high hydrostatic loading and structural reinstatement of deteriorated water structures.
SprayShield is polyurethane as well, but is highly elastomeric with excellent tear strength. It is designed to use in applications where thermal cycling and geological events are commonplace. SprayShield I has the same corrosion resistant qualities as SprayWall and is NSF certified for use in potable water applications as well.
WHEN POLYURETHANE IS APPLIED TO A WET AREA IT WILL BLISTER AND FOAM - WHY IS THIS GOOD?
If our products are applied to a wet surface, they will react violently to contact with water. This “hydrophobic” condition affects different polymers in different ways. The reason that foaming and blistering is a good thing is that the applicator realizes within a second or two that they have not dried the substrate surface properly. If this condition occurs, they can stop, address the moisture issue and re-spray within the 15 minute time window to allow the new spray and existing application to meld together.
Other polymers, like epoxies, may not react at all when they come in contact with a wet surface. This may also diminish the quality of the bond and lead to problems in the years ahead.
HOW DOES SPRAYWALL ADDRESS HYDROSTATIC LOADS?
To address hydrostatic load, we use the modified Timoshenko Equation to determine the lining thickness of the SprayWall throughout the structure. This is an equation similar to that used by CIPP installers to determine the thickness of the tube they are installing in your wastewater collection and storm system pipes.