Stewart Systems Ekoprime Primer / Sealer

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With Heat Pack option adds a shipping heat pack to keep the material from freezing while in transit. It is recommended for winter months / destinations in cold climates where the temperature may drop below freezing while in transit. If the material freezes, it is not recommended for use.

Stewart Systems Primer Sealer is a high quality, water-based single component primer, not requiring any catalyzing agent. Performance obtained is equal or superior to that of two-component, catalyzed epoxy systems. Primer Sealer offers good coverage, excellent durability, and ease of application, as well as being a low VOC and EPA compliant coating.


It is a low VOC (Volatile Organic Compound). high performance production coating. It is considered non-hazardous by EPA definitions and does not contain lead or chromates. The solid and semi-solid sludge produced in spraying and clean up can be flocculated; dried and sent to a "Class B" landfill. Check with your local and state regulations for proper handling.


  • Excellent exterior durability
  • Excellent hardness/impact resistance
  • Excellent mar and abrasion resistance
  • Excellent adhesion on plastics, gelcoat and composite substrates
  • Solvent resistant
  • Can be applied in a wide variety of temperature and humidity conditions without the use of retarders
  • Distilled water is used for reduction
  • Water is used for clean-up
  • Non-Hazardous
  • Air dry or force curing preferred
  • Can be oven baked
  • Wide range of colors to promote topcoat coverage
  • Coating will not flash rust on bare metal
  • Shelf life of 1+ years
  • Unused paint can be returned to container
  • Non-Flammable


  • Steel, Aluminum, Fiberglass, Wood, Plastics, Concrete, PVC, Pre-Finished Siding, Steel Decks


  • VOC (Volatile Organic Compounds) 2.0 lb/gal; 240 gm/ltr
  • Free of lead and chromates


  • Liquid Boiling Point: 336F
  • Specific Gravity: >1
  • % Solid by weight: 43.2%
  • Vapor Density: Heavier than air
  • % Solid by volume: 40.62%
  • Evaporation Rate: Slower than ether
  • Weight per gallon: 10.36 lbs.
  • pH: 7-8.5
  • Flash Point: 150F CC
  • VOC: 2.0 lb/gal; 240 gm/ltr


  • Theoretical Coverage at I mil: 660 ft2 (1624 x 40.62% solids by volume)


  • METALS: Surface must be free of grease, oil, dirt, and other foreign matter. Oxidation material must be removed or converted with Aircraft Finishing Systems Conversion Coating.
  • FIBERGLASS: Surface must be free of grease, oil, dirt, and other foreign matter.
  • CONCRETE: Surface must be free of grease, oil, dirt, and other foreign matter.


1. Application area temperature should be between 70 and 85 degrees Fahrenheit.
2. Mix well before using. DO NOT SHAKE...STIR ONLY Make sure any solids that might have settled to the bottom are mixed back into suspension.
3. Thin by adding 10% distilled water (by weight). SS EkoPrime Primer/Sealer may be sprayed right out of the bottle for heavy build up to fill scratches.
4. Always pour mixed and thinned primer through a medium paint filter before spraying.


1. The first coat of SS Waterborne Primer/Sealer is applied as a light tack coat. Allow to dry untill tacky.
2. Apply 2nd coat to achieve solid coverage.
3. If top coating is desired, allow to dry. Lightly sand with 320 grit open coat sandpaper or ScotchBrite with red ScotchBrite pad.


For best results we advise spraying. But, if brushing or rolling is desired, you can achieve a nice finish with a foam brush or roller. Do not thin the primer with additional water unless it will not flow out.


Clean equipment immediately with water.

  • Frequently Purchased With
  • Customers Also Viewed


This is not a high build primer at all, even out of the can it is already too thin to spray. It needed several coats, to build up a sandable surface. I stirred up all the solids in the can. Otherwise I think it would be a good product.

Ulrich B Verified Purchase


November 7, 2021

Great products from Stewart Systems. Goes on smooth and covers and sands well. Best of all, no smell or harmful chemicals. This is not latex. Its only transferred with water. Love it.

Gary B Verified Purchase


August 10, 2021

Easy to use, didnt totally stink up the booth, covered scratches beautifully straight out of the can, and made for an excellent finished product!

Lisa R
May 14, 2021

This stuff cant be beat. I can prime and paint in my attached garage with no worries about fumes or harmful chemicals going into the house. The other stuff is covered wagon technology.

Gary B
May 3, 2021

Needed to fill the weave in 1.3 oz fiberglass cloth that was applied over birch plywood fuselage. Two coats did the job nicely without the need of heavy “filler” primers and then mucho sanding and contouring . I lightly sanded with 220 dry before painting, but believe I could have just painted over a smooth application of this primer/sealer. JJ Sinclair

Jj G
November 8, 2020

Goes on easy, sands easy........doesn’t clog sandpaper........GOOD STUFF !

Jj G
November 5, 2020

I used Stewarts system before on another airplane, it is water based so not toxic and or cancer causing . It works good, easier to use and not requiring a breathing device just a mask. I have not shoot this color of paint but we shall see. Again like with the cylinders I bought a few weeks ago in 10 years I will be able to tell you how good this material is, well see how long it lasts.

Jaffe L
August 10, 2019

I am using this on my Velocity. Its done a great job so far.

Chris D
July 15, 2019

Stewart primer and paint is working out great on our AT-6 tail section,its holding its Shiny finish...we will use the Stewart process again on our Stearman..

January 15, 2019

I have used this primer for about 4 years and had good results, even when the primer was well past the claimed shelf life.

July 20, 2018


Please note, Aircraft Spruce Canada's personnel are not certified aircraft mechanics and can only provide general support and ideas, which should not be relied upon or implemented in lieu of consulting an A&P or other qualified technician. Aircraft Spruce Canada assumes no responsibility or liability for any issue or problem which may arise from any repair, modification or other work done from this knowledge base. Any product eligibility information provided here is based on general application guides and we recommend always referring to your specific aircraft parts manual, the parts manufacturer or consulting with a qualified mechanic.

Q: Do you have the Stewart Systems Ekoprime in aerosol can form?

Unfortunately this material is not available in an aerosol can.

Q: Can ekoprime go straight onto 6061 skins, or must I sand all surfaces first?

You must first prep before you apply the ekoprime.

Q: Is this Stewart Systems Ekoprime primer sandable?

Yes, it is sandable.

Q: How many square feet does the 1 gal cover?

That is subjective per the vendor. Typically 300-600 sq feet, but it depends on what you are painting. Maybe less if he is wanting to fill and sand, or maybe more if he is just using it to cover EkoFill for a white base coat.

Q: is this primer compatible with ekopoly topcoat?

Yes, it is.

Q: Can I use this primer over an aircraft that is all ready painted with a little sanding?

Yes this primer can be applied to a painted surface that has been sanded.

Q: Can this be used in place of dope on fabric covering?

No, the uses are listed as Steel, Aluminum, Fiberglass, Wood, Plastics, Concrete, PVC, Pre-Finished Siding, Steel Decks.

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