Proper Preparation Prevents Poor Performance
Preparation: If going directly over sub straight (No other coating on it) make sure it is completely dry.
Surfaces must be dry and free of anything that could adversely affect the adhesion to the surface.
If going over other products such as epoxy, it will need to be etched or roughed up with a grinder or sandpaper so Dura-Rubber can bond properly.
By nature is not only a very porous product but also has a tendency to retain moisture for an extended period of time. Although it may look dry on the surface, there actually is a lot of moisture still inside. Moisture content depends on the relative humidity. Cure time will depend on the water-cement ratio. A simple test takes an 18-inch by 18-inch clear plastic sheet and put it over the concrete and seal it on all four sides. After 16 hours, if any moisture or darkening of the concrete surface is found, the concrete is too wet for coating. Make sure the sheet does not come in contact with direct sunlight. You can also use a moisture meter. Keep in mind that moisture meters measure the top inch, and concrete dries from the top down; moisture levels need to be less than 7%.
Make sure when you apply, all your membrane terminations must be above the water line and dry.
Surfaces must be dry and free of anything that could adversely affect the adhesion of the Dura-Rubber to the surface. You should be sure to remove all loose, scaling, peeling, blistering, chipping, cracking, chalking or gravel, dust, dirt, sand, soot, grease, oil, uncured tar, wax, soap film, animal fats or petroleum-based residue, coal tar, chlorine, salts, efflorescence, or any other chemically reactive substance; and the surface to be coated must be completely free of all mold, mildew or any other living organism and COMPLETELY DRY.
You should be sure to remove all loose rust, and scaling, peeling, blistering, chipping, cracking, chalking or gravel, dust, dirt, sand, soot, grease, oil, uncured tar, wax, soap film, animal fats or petroleum-based residue, coal tar, chlorine, salts, efflorescence, or any other chemically reactive substance; and the surface to be coated must be completely free of all mold, mildew or any other living organism and COMPLETELY DRY.
Wood, by nature, tends to retain moisture. Although it may look dry on the surface, there could be moisture still inside. Moisture content depends on the relative humidity. Cure time will depend on the water-cement ratio. A simple test takes an 18-inch by 18-inch clear plastic sheet and put it over the wood and seal it on all four sides. After 16 hours, if any moisture or darkening of the wood surface is found, the wood is too wet for coating. You can also use a moisture meter. Keep in mind that moisture meters measure the top inch, and wood dries from the top down; moisture levels need to be less than 7%.
If you apply to dimensional lumber such as decks, picnic tables, and docks, you must thoroughly coat all four sides of the lumber, or the wood will swell and split the coating.
High-pressure 2,500 P.S.I. should be used to thoroughly pressure clean all surfaces before application when any of the above conditions exist. (When you use a pressure washer on concrete, it can drive water into the concrete, so make sure to check the moisture content after you wash and let dry)
Mildew and similar growths need to be killed with 5% chlorine solution household bleach in water, followed by a thorough rinse with clean water. All surfaces must then be allowed to THOROUGHLY DRY before proceeding with the application.
After all, surfaces are thoroughly dry, inspect for cracks, holes, and any surface irregularities that will need to be repaired prior to Spray, or roller/brush Dura-Rubber. We recommend doing an adhesion test before a final application.
The product must be stirred, by hand slowly for 2-5 minutes, not shaken, or aggressively blended prior to use. DO NOT THIN PRODUCT.
Repairing Crack in Concrete or Other Mediums (up to "1/4 cracks or gaps) Repairs should be made with an application of followed by an embedded reinforcement fabric, the fabric needs to be at least 4" in width, with 2" each direction from repair at all open joints, seams, cracks, holes, or areas of damage as well as at all penetrations, inside or outside corners and at any pan, or threshold that are determined by specification to be part of the waterproof envelope. Application on new wood, concrete, or ferrous metals should follow the same guidelines as repairs with all seams, joints, imperfections, or penetrations, inside or outside corners, pans, thresholds, or surfaces edges or transitions treated with a coat of embedded reinforcement cloth and a top-coat of prior to additional coats or final sprayed membrane. This preparation technique will add mil thickness and strength that is in addition to the additional coats or final top-coat - thickness determined by below Application Rate:
Rates of Application are typical:
Mixing Dura-Rubber with crumb rubber aggregate.
Mix 1-1/2 to 3 pounds of crumb rubber aggregate to 1-gallon Dura-Rubber (any color) depending on how thick you want to apply. Make sure to break up and lumps in the crumb rubber from packing. Mix well with a drill motor and paddle. Let sit for 15 min before using. If too thick, add up to 4 oz of Propylene Glycol per gallon of Dura-rubber.
Apply one coat primer at the rate of 300-400sf per gallon.
Pour the mixture around the floor and spread it with a magic trowel once the floor is covered. Clean the trowel with a rag and smooth out coating by pulling the trowel towards you. Clean trowel as necessary to prevent dragging.
If you get any cracks in the coating once dry, using a putty knife, fill the cracks with the coating mixture.
Apply coating 20-50 dry mil.
For best results, apply using magic trowel.
Additional coats can be applied depending on the thickness desired.
You can apply a coat of straight Dura-rubber for a solid color.
Apply two coats of sealer after 4-5 days cure time.
Drying times are typical:
If you have any cracks, seams, or corners, you will need to use the reinforcement fabric.
Brushed or rolled on straight Dura-Rubber over the seam and embed fabric while still wet. Apply a top before the base coat is dry.
Dura-Rubber can be sprayed with an airless sprayer.
Make sure fabric is totally saturated with rubber and tight to the surface. This would apply to corners seams and patches. this must dry 4-8 hours depending on the size of crack filled, temperature, and relative humidity
Needs to "deep" dry between application coats. This means that because Dura-Rubber is water-based, all water must evaporate out of each application coat prior to the next application coat. Otherwise, the rubber will develop small bubbles of fluid between the coats. If you have small bubbles appearing on your project, you need to wait longer between your application coats. Time to dry between applications coats is approximately 3-4 hours - depending on temperature and relative humidity SEE BELOW.
"Curing" or "Vulcanization" Times
You will notice the product is dry to the touch with-in a few hours and will be waterproof. However, the rubber is still going through a very important process called "Vulcanization" - this is the process where the rubber becomes one single membrane and can contain water on a continuous basis. The process of "Vulcanization" takes 7 days. You do not want to expose the coating to chemicals or continuous water saturation until the vulcanization process is complete.
If you have a question about your specific applications, please do not hesitate to contact us either via phone, e-mail or our live online support chat. We are here to help!
Optimal vs. Acceptable Humidity Levels
Optimal relative humidity (RH) levels for exterior applications tend to be in the 40-50% range or lower.
Levels of 70% or greater will "drastically slow drying and curing," but again will not prevent you from applying.
Applying above an RH level of 85% is strongly not recommended. The coating will remain gummy and gel-like until the RH lowers to an acceptable level long enough for it to solidify.
However, because the coating has not been allowed to "level" properly, the texture will remain wavy and otherwise unacceptable.
Temperatures Work With Humidity, Too
One tip is to time your application so that temperatures are on the rise--several hours before the day's peak temperature, which is usually in the late afternoon. High humidity will slow dry time.
You need to build in a head-start by beginning hours before you think it is time to begin:
Even though the temperature was OK at the time of application, the coating can stop coalescing. This permits moisture to get into the uncured paint film allowing certain ingredients to come to the surface when the moisture evaporates, causing surface staining and possible adhesion problems.