What is the mix ratio of my product?

Always be sure to follow the mix ratio for your product for the best results.  Check out the chart below to see what mix ratio the system you’re using requires.

Resin System Mix Ratio by Volume Mix Ratio by Weight
LV or FLAG with Slow, Medium, Fast 2 to 1 100 to 45 (Fast 100:46)
Marine Epoxy with Marine Slow or Marine Fast 5 to 1 100 to 18
Marine Epoxy with Marine Clear 3 to 1 100 to 30
Aqua Zone 1 to 1 100 to 94
Table Top 1 to 1 100 to 83
Fairing Compound 1 to 1 100 to 90
Penetrating Epoxy Sealer 2 to 1 100 to 44

How much mixing is required?

Mixing is the key to a thorough cure, good films and strong bonds. One and a half to two minutes of slow mixing, being careful to avoid blending in too much air. Scraping the sides and bottom of your mixing cup is recommended. Use clean plastic or uncoated paper cups or buckets and a clean mix stick.

We also recommend taking the mixed batch and transferring into a clean container, scraping the sides and bottom and then mix again, to ensure a complete mix.

Can I speed up the cure time by adding more hardener?

Absolutely Not! Adding more hardener throws off the ratio and you end up with a gooey mess that never cures.

We recommend reviewing the estimated gel times and work life of the hardener you plan to use before starting a project to ensure you will have the correct cure time for your needs. See below for more information on hardener blending.

What is Blush and how do I remove it?

Blush is noticeable as an oily or sticky film formed over cured epoxy coated surfaces. It can be removed with warm soapy water and a sponge (rinse and wipe). It MUST be removed before sanding or re-coating your epoxy project.

While many resin systems blush, MAS Epoxies’ LV Resin and FLAG Resin with the 2:1 non-blushing hardener options will not need to be wiped clean because of their anti-blushing chemistry. This saves you time and effort on your project.

If using our Marine Epoxy system at a 5:1 mix ratio, be aware of blush and clean it using the instructions above.

What are the MAS Epoxies Cure schedules?

Resin Hardener Mix

2:1 Resin/Slow 2:1 Resin/Medium 2:1 Resin/Fast
Temp. Pot Life / Thin Film Set / Full Cure
140°F 1.5m/28m/11:15h 1.22m/16m/7:52h 39s/11.5m/4.5h
131°F 2.25m/42m/16:52h 1.83m/24m/11:34h 58s/17.25m/6:45h
122°F 3.0m/56m/22.5h 2.44m/32m/15:45h 1.3m/23.0m/9.0h
113°F 5.75m/1:15h/30h 3:32m/45.0m/21.0h 1.75m/30.0m/12.0h
104°F 8.6m/1:52h/45h 4.88m/67m/31:30h 2.63m/45m/18h
95°F 11.5m/2:30h/2.5d 6.5m/1:30h/42.0m 3.5m/1.0h/1.0d
86°F 17.25m/3:45h/3.75d 9.75m/2:25h/63.0h 5.3m/1:30h/1.5d
77°F 23.0m/5.0h/5.0d 13.0m/3.0h/3.5d 7.0m/2.0h/2.0d
68°F 34.5m/7.5h/7.5d 19.5m/4.5h/5.25d 10.5m/3.0h/3.0d
59°F 46.0m/10.0h/10.0d 26.0m/6.0h/7.0d 14.0m/4.0h/4.0d
50°F 69.0m/15.0h/15.0d* 39.0m/9.0h/10.5d 21.0m/6.0h/6.0d
41°F 92.0m/20.0h/20.0d* 52.0m/12.0h/14.0d 28.0m/8.0h/8.0d
* Not recommended
s = seconds; m = minutes; h = hours; d = days

Can I mix hardeners within the same product family to get a different cure time?

The short answer is YES! Pick any combination of hardeners within the same system to customize your cure time. As long as you keep the mix ratio indicated on the bottle or above in FAQ 1 you will get a cured product. If you want more information on why and how to mix continue reading below.

The time it takes for an epoxy mixture to change from liquid to solid is the Cure time. There are three phases –

  1. Pot life – time it will take the product in the container to gel
  2. Thin Film Set – which is open (working) time or wet lay-up time, or time to the initial gel
  3. Full cure is when the epoxy is totally solid and reached its maximum strength

The speed and the length of these phases varies relative to temperature and the hardener which was used – slow, medium, or combination of – and if additives have been incorporated into the mixture.

Cure times for the Fast hardener, combined with the low viscosity Epoxy resin can be lengthened by the addition of 35-40% by volume of the Slow hardener.

NOTE – The cure times are not directly proportional to the amount of hardener used to customize the blend. For example, if 25% Fast is added to Slow, the cure time is speeded by 12-15%. Conversely, if 50% of Slow is added to Fast, the cure time is slowed down by 25%.

Even if the pot life and thin film set of your first hybrid mix does not fall right on the money, the mix will cure as long as the resin to catalyst ratio is 2:1 and temperatures are not severely cold.

Filleting and Bonding: Normally since users are looking for maximum strength and minimum clamp time, we recommend 100% Fast. However, if the weather gets hot (over 80 F), this mix can he controlled by adding approximately 25% Slow, or switching to Medium hardener (Remember always mix Resin and Catalyst in a 2:1 ratio, mix thoroughly). For large fillets Medium hardener is recommended.

What is the recoat time?

Since epoxies from MAS are 100% solid (no solvents), recoat time can be as short as it takes to achieve surface tack. If more than 12 hours passes between coats, do a light scuff sand. Use a cotton ball to test if a light scuff sand is needed. If the epoxy holds the hair of the cotton ball, you can recoat without sanding. If it doesn’t, a light scuff sand will help adhesion between coats. Remember the “Rule of Thumb” test (if you can press your thumbprint in the epoxy, but there’s no tack, then you should do a scuff sand, but will be getting a chemical as well as a mechanical bond.) Remember, warmer conditions make for a faster cure time. Review the chart in FAQ 5 to see an estimated cure schedule for the temperature you’re working at.

What are the temperature requirements for coating with Mas Epoxy?

We recommend using MAS Epoxy systems at ambient temperatures of 55°F and above. When bonding, MAS Epoxies Fast Hardeners can be used at temperatures 45°F and above, however the cure time will be significantly longer. Keep in mind the warmer the ambient temperature the easier MAS products will be to work with and apply.

The storage recommendation for our epoxy products is 60°F and above to prolong the life of your product. See below for more information on storage requirements and suggestions.

How does temperature variation affect epoxy?

For every 18°F the temperature falls below 77°F, the pot life will double for the mixture. The thin film set will allow roughly 130% increase in time. The exact opposite will occur as temperatures increase above 77°F. Applications allowed to cool below the freezing point must be warmed to achieve a full through cure. In the case of freezing, the solid or film must be checked for hardness to ensure full strength has been achieved. Best practice is to always work above 55°F. For more information on cure times MAS Epoxies Cure Schedules above.

What is the shelf life of MAS Epoxies products?

The stated shelf life is 1 year from ship date. However, our epoxy systems have been known to last much longer. You can prolong the life of your epoxy resin by following the best storage practices mention below. Or, if you find your product to be crystallized (solid or chunky) see details below on how to return the product to its liquid form.

What are the best storage conditions for my MAS Epoxy?

You will get the best shelf life out of your products by following these best storage practices. Store at 60°-90°F in a dry place. After use tightly reseal all containers. Store products on a raised surface off the floor during cold weather and avoid storing near outside walls or doors (this will help prevent freezing, which can compromise your product). Epoxy resins contaminated with dust or moisture, or subjected to low temperatures may crystallize and should not be used (see FAQ below).

What is Crystallization? What does it mean when my resin is solid, chunky or cloudy?

Crystallization can make epoxy resins appear cloudy, chunky, grainy, or even solid.  This is an inconvenience rather than a problem.  Once decrystallized, the epoxy resin will be good as new.  To decrystallize, heat the resin throughout the container to about 125-140°F until it turns back into a clear liquid.  A hot water bath works well to heat the resin.  Simply fill a large basin full of very hot tap water and set the tightly sealed container of resin in it until all the crystals melt and the resin clears.  Refresh the hot water bath as needed.  Shake the container or stir the resin periodically during this heating process to ensure that all potential crystals have melted and can no longer act as “seed crystals.”  Make sure caps, containers and tools are free of crystallized resin before continuing use with the epoxy.  Do not use resin that has any signs of crystallization until it has been decrystallized and is once again a clear homogenous liquid.  If heating the epoxy resin is beyond your capabilities or if you have any further questions about crystallization, please contact us.  We got your back.  Unfortunately, crystallization is something that all epoxy resins are prone to.  It is difficult to predict and can happen without warning, but happens most rapidly between 32˚F and 55˚F.  Temperatures cycles, such as the fluctuations that occur between night and day, also promote crystallization.  The crystalline melting point of bisphenol A epoxy resins is 107°F, so any time you are below that temp you run the risk of crystallization.  Theoretically, storage temperatures above 104°F could be used to prevent crystallization all together, but that’s not very practical.  Instead, try to store between 60-90°F in a dry place, at a consistent temperature.  Do not allow epoxy resins or hardeners to freeze during winter storage.  After use, tightly reseal all containers and store products on a raised surface off the floor during cold weather and avoid storing near outside walls or doors.  The good news is that crystallization is reversible and has no ill effect on the handling or mechanical properties of the epoxy resin once decrystallized and returned to a liquid state.

How should I clean up MAS Epoxy?

Gloves and other personal protection should always be used. If you should get any epoxy on your skin, it should be cleaned off with waterless soap immediately, then thoroughly washed with soap and water. Tools can be washed with BioSolv, white vinegar or isopropyl alcohol. Semi-gelled epoxy can be removed with acetone.

My pumps are sticky, can I still use them? How can I clean them up?

Pumps left in the resin and hardener containers occasionally will become sticky and dispense unevenly. If this occurs, remove the pumps from the resin and hardener bottles and soak for several hours or overnight in white vinegar. This should remove any resin or hardener causing them to stick. After soaking wipe off excess vinegar and allow to dry completely before using the pumps again.

How should I protect my epoxy coating from sunlight (UV Exposure)?

All epoxy surfaces should be protected from sun exposure to prevent discoloration and chalking. You can protect your epoxy with a good quality varnish or urethane with HALS protection additives. Paint is always considered a 100% UV filter. Indoor pieces do not need varnish over the epoxy as long as they will not become exposed to sunlight.

Can stain be used on my epoxy coated project?

Absolutely! To use a stain on an epoxy project, use a water-based stain on top of the epoxy coating or under the epoxy clear coat. Be sure the stain is fully dry before coating additionally with epoxy.

If you’re concerned about adhesion use the cross-hatch test. Apply the stain to a scrap pieced of wood. Let it dry. Apply epoxy over the stain and let it sit overnight. The next day, cut a tic-tac-toe image into the epoxy with a shop knife. Place a piece of duct tape on each of the nine squares. Try to remove the epoxy. If it comes off easily without any wood slivers, then there is an adhesion problem and that stain will not work with an epoxy clear coat over top. If it comes off with bits of wood attached the epoxy is penetrating the stain and will adhere well.

What safety protection is needed when using epoxy?

Although MAS Epoxy resin systems are more mild than other epoxy systems, proper safety precautions are still important to protect yourself. Follow these instructions to avoid skin irritation or other health concerns.

  • Avoid all skin contact with resin, hardeners and mixed epoxy by wearing gloves and other clothing. Clean any uncured epoxy off the skin with waterless soap immediately after contact. Never use solvents to remove epoxy from the skin. Always wash thoroughly with soap and water immediately after contact.
  • Protect your eyes from possible splashing by wearing protective eye wear. If contact should occur, flush eyes immediately with running water for 15 minutes. If discomfort continues, seek medical attention.
  • Avoid breathing vapors. Use epoxy in a well-ventilated area and wear a dust mask when you sand the epoxy.
  • Avoid ingestion. Wash hands thoroughly after each use to avoid accidental ingestion while eating or drinking.
  • Clean up spills with a squeegee and paper towels. Scrape up as much of the material as possible with the squeegee before using paper towels. Sand, clay or other materials may be used to soak up a spill. Clean residue with white vinegar or isopropyl alcohol. Always wear protective gloves when cleaning up spills or the end of a job.
  • Dispose of resin, hardener and empty containers safely. Do not dispose of resin or hardener in a liquid state. Before disposing of resin and hardener containers, puncture the corners and drain residue into clean containers for re-use. Small quantities of resin and hardener can be mixed and cured completely into a non-hazardous solid. Place pots of curing resin and hardeners outside on the ground to avoid the danger of excessive heat and vapors. DO NOT cure resin and hardener in a large mass because this will cause excess heat and possibly a fire. Follow your local, state and federal regulations for proper disposal.

What should I do to obtain the best finish possible?

Improper measuring and mixing cause most of the problems we see with epoxy products. Always double check the mix ratio of your project before pouring and mix thoroughly (see details above on proper mixing technique).

Application temperature is also critical. Cool temperatures make the epoxy more difficult to work with, which can sometimes cause adverse results. Working as close to room temperature as possible will give you the easiest application (see above for more information).

Lastly, when clamping pieces together in gluing applications be careful not to “over-clamp.” Too much clamp pressure can push out your epoxy resin and leave patchy areas which will not bond. The key to a strong bond is light pressure and using the correct filler. Allow yourself maximum clamp time and if a faster cure time is needed add heat with an incandescent light bulb.

What tools can be used to apply MAS Epoxy?

For coating and glassing a short nap 1/8” nylon bristle roller, plastic squeegee or disposable brush can be used. For bonding a glue brush or a squeegee with notches cut into the edge can be used.

What surface preparation is needed prior to applying epoxy coatings?

All surfaces should be cleaned of any contaminates, such as oil, grease and pooled water. Light sanding is recommended. A clean cloth moistened with denatured alcohol or plain water may be used to clean surfaces and remove dust. DO NOT use acetone or a tack cloth to clean the surface.

How much coverage will I get from one mixed gallon of MAS Epoxy?

Generally, you can cover 500 square feet, 3 millimeters thick with one gallon of mixed epoxy. See the chart below for an estimate on cloth wet out.
Cloth Wet Out Chart

How do I choose between LV (Low Viscosity) and FLAG resin?

Users who have chosen the benefits of our 2:1 Non-blushing Epoxy System will find they have two options for their base resin. How do you know which one to choose? Well a lot of it is in the name.

LV Resin (or Low Viscosity Resin) is a thinner resin that will wet out fiberglass and other knitted reinforcements with ease. It is best used on horizontal surfaces where it will absorb into your fabric and not run off your project.

FLAG is an acronym as well, which means Filleting, Laminating and Gluing. We recommend this product for laminating on non-horizontal surfaces where a thicker-bodied resin will not run off of your project. We also recommend this product as a base resin when fillers will be added because it’s starting viscosity is higher. Fillers are typically added for processes such as filleting and gluing which is how FLAG got its name.

Do you have any recommendations for glassing with knitted reinforcements?

Click here to read our article on glassing with knitted reinforcements.

What are best practices for blister repairs and barrier coating?

To understand how to repair blisters you should learn what causes them and before you apply a barrier coat on a new surface, learn more about how to prepare it.
Click here for more information on blister repair and barrier coating.

What filler should I use for my particular application?

Over the years we’ve had a variety of fillers available to use with our non-blushing system that allow you to fill and fair your project as need. Today, we still offer these options, but have developed new products that make these types of projects easier. The following charts show you your options.

Pre-Filled Options & Time Saving Solutions

Fairing Compound Try our new Fairing Compound that comes in tubs with a 1:1 mix ratio by volume and let us do the work to make sure your fairing compound has a consistent weight.  Pre-filled with microballoons.
Gluzilla Pre-filled with resin, hardener and colloidal silica to provide a Vaseline like filleting compound that mixes itself as you dispense
Gluzilla Fast Pre-filled with resin, hardener and colloidal silica to provide a faster Vaseline like filleting compound that mixes itself as you dispense
Woodzilla Pre-filled with resin, hardener and wood flour to provide a peanut butter-consistency filleting compound that mixes itself as you dispense

Resin & Filler Options

Do you have any other application suggestions for my project?


Recommended Product

Bonding Porous Woods Any of our Resin and Hardener mixes may be used with Cab-O-Sil or Wood Flour to thicken.
Bonding Dense Woods Pre-coat pieces to be bonded with MAS FLAG Resin/Slow Mix, bond with Cab-O-Sil filled mixture.
Bonding Iron and Steel Pre-coat with MAS FLAG Resin/Slow mixture. Rub mix into clean surface with scotch brite pad.
Bonding Aluminum Pre-clean and treat with DuPont 225-S cleaner. Convert with 226-S (Bond like dense wood).
Bonding Foam and Core Same as dense wood.
Laminating Wood Structures All products, depending on the size of the structure for dense wood. MAS LV Resin/Fast mixture or Medium mixtures are good for deck deck beams, stringers, etc.
Filleting (structural) MAS FLAG Resin/Medium Speed Hardener thickened with Cab-O-Sil (1 part) and then filled with Wood Flour until looking just dry.
Filleting/Fairing (cosmetic) Same as structural, but substitute low density filler (i.e., Microballons for the Wood Flour).
Laminating Fiberglass MAS Resin mixed with Fast or Slow Hardeners. Use Slow for “No Blush” and green stage next day – the surface will be ready for more work while requiring no prep.
Osmotic Barrier MAS LV Resin and Slow Hardener. 5-9 coats (optimal temperature while curing is 70 degrees F.)
Vacuum Bagging MAS LV Resin and Slow Hardener

What are the differences between Epoxies, Vinylesters and Polyesters?

Epoxies, Vinylesters and Polyesters represent two resin families. Epoxies can be cured with amine agents at room temperature to form excellent adhesive and composite resins. Vinylesters and Polyesters contain an unsaturated polyester or hybridized vinylester backbone which is catalyzed with a peroxide to condense into cross-linked solid resin. While there are benefits to using both types of systems, in general epoxy resin systems provide a better shelf life and physical properties than their polyester and vinylester counterparts.

Do you have information on the Tg for your products?

The amount of heat your epoxy resin can withstand can be reported by two different numbers which are closely related, HDT and Tg. The data sheets for our products is reported in HDT which tells you how high of a temperature your finished project can withstand. Below is a graph of the Tg curve for LV with our Medium Hardener.

tG Graph