What is the shelf life of your epoxy resin products?
Performance of our epoxy products is guaranteed for three years from the date of manufacture, printed on the bottom of the containers, provided they are stored properly. They will probably last much longer, but they should be tested first after the three-year period. The resin may crystallize or the hardener may darken but this does not affect its performance. Crystallized resins should be reheated in a water bath that is at least 125°F until the resin clears up prior to use on the project.
Will epoxy be damaged if stored in freezing or cold temperatures?
Crystallization occurs when the product is exposed to low temperatures for prolonged periods of time; the presence of any impurities will then initiate the crystallization process.
System Three products are formulated to resist Crystallization, but it can still occur.
Heat will bring the resin back to a usable state, and the best way to heat the resin is to place the container in a water bath with water heated to 125°F.
Avoiding Bubbles In Epoxy Applications
Bubble formation in epoxy coatings is more times than not the result of air expanding within a porous substrate and releasing into the freshly applied epoxy. To avoid this issue consider the following:
- Avoid applying epoxy on a surface that is being heated either by the sun or a conventional heater. When possible, wait till the substrate has stabilized in temperature or is in the process of cooling before applying epoxy.
The first coat of epoxy applied on raw wood should be very thin. Use a 1/8" foam roller and apply the epoxy at 1/2 fluid oz. per sq. ft. Some ultra-porous substrates may require a second seal coat. If a seal coat is applied too thick, persistent bubbles which are difficult to remove will result.
- Bubbles can also be present over a fully sealed substrate. These bubbles are the result of entrained air from mixing or the product of brushing or rolling. Most of the time these bubbles will pop naturally. Stubborn bubbles can be popped by lightly dragging a brush over the surface of the epoxy. A propane torch can be used judiciously by holding the flame 6-8" from the surface while moving quickly back and forth. Do not overwork the bubbles with the torch as scorching of the epoxy can occur.
How much epoxy do I need for my project?
The tables below are a guide for estimating the amount of material recommended, depending on the end use.
Mixed resin/hardener coverage in square feet per gallon
*Some soft wood materials will require 2 seal coats due to higher absorption.
Mixed resin/hardener coverage in square feet per gallon
4 oz. cloth
6 oz. cloth
10 oz. cloth
24 oz. Biaxial Tape
Adhesive Glue Lines
1/4” X 1/4”
1/2” X 1/2"
3/4” X 3/4”
1” x 1”
Ounces Per Linear Foot
Ounces Per Square Foot
1/8” x 1/8”
1/4” x 1/4"
3/8” x 3/8”
Quick Cure 5 & 15
*The units reflected are linear feet per cartridge.
System Three® Resins, Inc. P.O. Box 399, Auburn, WA 98071
The information contained herein is based on the data available to us and is believed to be correct. However, System Three Resins, Inc. makes no warranty, expressed or implied, regarding the accuracy of these data or the results to be obtained from the use thereof. System Three assumes no responsibility for injury from the use of the product described herein.
Do you still supply "The Epoxy Book?"
Yes. The original System Three® "how to" manual is alive and well on the website. It is available in downloadable sections, or all at once here.
How to remove cured epoxy.
Cured epoxy can be successfully removed from most substrates by using a quality paint stripper. However, care should be exercised as paint stripper can damage other surfaces. Carefully follow the manufactures instructions and recommendations.
What determines the gel time of epoxy resin products?
Gel times of epoxy resin products depends on the reactivity of the compounds in the Part B (hardener). Chemically they are amine hydrogens. The time the product takes to gel and then harden will be altered with change in temperature and mass of the resin/hardener mixture.
Every 18°F increase in temperature cuts the gel time in half, and the larger the mass of product the sooner it will gel.
Modifying Epoxy with Fillers
Please check out Section VII C - Modifying Epoxy with Fillers in the Epoxy Book for guidance on fillers.
What materials will your adhesives bond together?
System Three® epoxy resin adhesives will bond (glue) all woods, most metals, concrete, masonry, glass. They will also bond some plastics like nylon and Mylar. Following a flame-treatment surface preparation, they will bond to many other plastics including polyethylene, polypropylene, polyvinyl chloride, acrylic and polycarbonate plastics. In addition, epoxy adhesives are the best choice for bonding dissimilar materials together. If epoxy bonds to Material A and to Material B it will bond the two materials to each other. The best thing to do is to try it and see for yourself.
What materials will adhere to epoxy surfaces?
System Three® coating/laminating resins present easy-to-bond to surfaces. When these surfaces are cured and prepared properly, nearly any film-forming coating or adhesive will bond well to them. Follow the surface preparation directions on the product you intend to use over the top of the System Three epoxy product.
How much colored pigment dispersion can I add to your epoxy?
System Three Epoxy Pigment Dispersions can be added at 5-10% by volume to any of our laminating and coating epoxies.
Hot Coating With System Three Epoxies
System Three laminating and coating epoxies can be hot coated. A fresh coat can be applied over epoxy that is still tacky. Ideally, the tacky material should have developed structure, so that it cannot be deformed under pressure.
How to fix orange peel in an epoxy coating.
To help fix the appearance of orange peeling, please allow the existing epoxy to cure for about 48 hours or until hard enough for sanding. Block sand flat using 120-150 grit, vacuum sanding dust and wipe clean with denatured alcohol. You may then re-coat.
Can I use the hardener from one of your epoxy systems with the resin from another?
No. Epoxy resin systems are two-part products where each part is designed to go with the other in the specified proportions.
How to decipher the batch number or code.
The batch number is a 6-digit code that is associated with the product's manufacture date and is typically located on the bottom of the container.
Batch code: X(YEAR) XX(MONTH) XX(DAY) X (INTERNAL CODE)
Example: A product with the batch code #806141 was manufactured on June 14th, 2018.
Can I coat urethane (poly iso) foam with epoxy?
Silvertip, General Purpose, or Cold Cure epoxy resin will coat the foam without attacking it.
The Part B hardener has gotten darker over time. Can I still use it?
Probably. Hardeners yellow and darken over time due to contact with air and sunlight. This does not affect their performance. If the batch date is older than 3 years, to satisfy yourself do a small test and make sure it cures properly. Batch code: X(YEAR) XX(MONTH) XX(DAY) X (INTERNAL CODE).
My epoxy resin is taking too long to cure. How can I speed it up?
The only way to speed the cure of our epoxy resin products, once they've been applied, is to heat the room or the area that your project is in. Every 18°F (10°C) increase in temperature cuts the time it takes for the resin to cure in half.
Best product for coating aluminum.
System Three does not produce a paint or coating product specifically for aluminum applications. However, a number of our adhesives perform very well in aluminum applications.
Types of paints that can be used over System Three epoxies.
We have found that most two-part water based paints and primers will work well over System Three epoxies. This includes acrylic and latex paints. We usually caution oil based or alkyd enamels and primers because they can contain driers that would react with the amines in our epoxies and can cause overall drying issues. Nonetheless, ALL paints should be tested by the user in a small area to ensure the results meets their expectations.
Surface Preparation: Allow the epoxy to reach full cure before applying paint. Sand the surface of the epoxy with 150-220 grit and then wipe clean with denatured alcohol.
Are System Three products suitable for the fabrication or repair of a fuel or gas tank?
Our coating resins and adhesives are resistant to diesel and aircraft fuel, but have limited resistance to gasoline.
Get rid of bubbles in an epoxy coating.
Two methods can be used to rid of bubbles in an epoxy coating:
1. Roll and Tip Method: Bubbles that persist in the coating can be broken with a disposable bristle brush by lightly dragging it across the surface after rolling the product out.
2. Propane Torch: Quickly and lightly fan 6-8 inches above the uncured surface with a propane torch to accomplish bubble popping with greater speed. Avoid overheating an area as this could cause the epoxy film to pull away from the surface creating craters.
NOTE: When coating a porous surface like concrete or wood, overheating to pop bubbles with a torch can cause the expansion of any air in the pores of the substrate and can make the bubble situation worse.
Which product, the Marine Spar Varnish or WR-LPU, offers better long lasting UV protection?
WR-LPU offers better UV protection for epoxy resins and the surface underneath better than Marine Spar Varnish. How much better depends on the length and severity of the exposure. WR-LPU is a little more expensive, but being waterborne, is available anywhere in North America. Spar Varnish contains VOC content, and its use is restricted in some areas, but if available, offers more ease-of-application and a cost savings over WR-LPU.
Why didn't the epoxy cure?
There are two common reasons why the epoxy didn't cure: incorrect measuring and incomplete mixing. Measuring and mixing is really easy with most System Three® epoxy systems because they mix at a 2:1 or 1:1 volume ratio, but this doesn’t mean you don’t have to pay attention to what you’re doing. First , read the label or Technical Data Sheet to see what the correct ratio is for the product you are using. Customers will call our Technical Support line suggesting that something is wrong with the epoxy because it didn’t cure properly. We know of no situation where properly-mixed resin/hardener has gone bad or has been contaminated and wouldn’t cure. In the majority of cases, it turns out that the batch was either incorrectly measured or insufficiently mixed. Epoxy chemistry just will not allow it to work any other way.
If you’re working on a project that requires you mix many small resin batches, develop a measuring technique that is sufficiently accurate and stay with it. Doing it the same way each time will minimize the chance for error.
The Part A resin has hardened and turned white. Can I still use it?
Yes. The white solid or haziness is a mass of resin crystals. Crystallized resin will not cure properly. To bring the resin back to a usable state, heat the bottle up in a water bath above 125 degrees F until the resin clears up. It will then be ready for use.
Can I tint or color System Three epoxies?
Yes, we offer a pourable Epoxy Pigment Dispersion specifically formulated to be dispersed in System Three epoxy resins. They are available in 7 standard colors and can be blended with each other to create additional colors. Please check our our blog and product page for more information on these color pigments here.
All other dyes and colorants should be tested by the user to ensure it cures to their satisfaction.
- Should the contents of Silvertip Yacht Primer be stirred?
Heat Resistance of System Three® Epoxies
Cured epoxies will soften when exposed to heat, but never melt. The terms "softening point,""heat deflection temperature," and "glass transition temperature(Tg)", are often used interchangeably. Our room-temperature curing epoxies will soften in a temperature range from 120-140°F. Please refer to the specific product Technical Data Sheet for details on these, and other, physical properties.
When cooled back down, the cured epoxy will return to its original hardness. Depending on the intended use and service, exposing the product to heat or heated objects, might or might not make a difference.
Are there any fire retardant additives that can be added to System Three epoxies?
Unfortunately not at this time. Epoxy products can only be made fire-retardant at the manufacturing level. There are currently no materials that can be post-added to any of our epoxy products by end users to make them fire-retardant.
Where is Appendix A?
Appendix A is a section from The Epoxy Book listing suggested product use levels. It has been updated and renamed 2018 Product Usage Estimation, and can be found as a separate file on our website here: