Jointing Compounds for Faying Surfaces: A Comparison of Mastinox D40, CA1000 & CA1010 - Including GSA Availability

This is the fourth installment in our series covering jointing compounds and corrosion-control solutions for government and defense aviation procurers.

Corrosion is the silent killer of aircraft, especially military aircraft that fly in harsh climates constantly, or aircraft owned by federal agencies that are used in the bush of Alaska, along the hot, arid deserts of the Rio Grande Valley, and everywhere in between. 

Preventative maintenance is the best corrosion-control mechanism there is, with no exceptions and Greenwood Aerospace is devoted to equipping your maintenance team with everything you need. This series is focused on helping you get PPG Mastinox products and jointing compounds for your fleet maintenance program. 

Let’s take a look. 

1. Why Faying Surface Jointing Compounds Matter

Jointing compounds for faying surfaces play an absolutely crucial role in safeguarding metallic structures where two surfaces meet. In military and government aircraft, these compounds seal the tiny gaps that would otherwise allow moisture to enter and accelerate corrosion, especially between dissimilar metals such as aluminum and stainless steel.

These compounds are used on wing skins, fuselage joints, fastener lines, and fuel tanks, where both flexibility and ongoing corrosion protection are needed. Given that these assemblies are constantly exposed to physical conditions such as vibration and fuel contact, a non-curing, fuel-resistant mastic is a must for long-term protection and maintainability.

For depot maintenance teams, sustainment contractors, and corrosion-prevention programs, proper compound selection is absolutely key for extending airframe life and meeting the OEM compliance standards.

2. Overview: Mastinox D40 vs CA1000 vs CA1010

PPG Mastinox D40 - This is a legacy product: a non-hardening, chromate-based corrosion-resistant jointing compound widely used on OEM and legacy platforms. It’s still a go-to for programs that require materials that meet OEM specs, thanks to its barium chromate formula.

PPG Mastinox CA1000 - A one-part epoxy-capped polysulfide compound that doesn't contain any chromates. Designed for use on aluminium and other metal joints, it provides long-term corrosion protection while remaining permanently mastic after exposure to jet fuel and avgas.

PPG Mastinox CA1010 - Another one-part compound that doesn’t have any chromates - this time a polyester formula that offers similar corrosion protection to CA1000 but with a higher service temperature rating and some excellent vibration resistance.

Greenwood Aerospace supplies Mastinox D40, CA1000, and CA1010 directly through GSA Advantage for government and defense aviation programs.

Available Products:

3. A Comparison of the Technical Specifications

Mastinox Comparison Table
Feature Mastinox D40 CA1000 CA1010
Chemistry Legacy Mastinox formula; non-hardening; chromate-based (barium chromate) One-part epoxy-capped PERMAPOL® polysulfide, non-chromate One-part polyester, non-chromate
Cure Non-curing / non-hardening Non-curing; remains permanently mastic Non-curing; remains permanently mastic
Fuel Resistance Resists most hydrocarbons and greases; avoid Skydrol/HyJet exposure Remains mastic after prolonged exposure to jet fuel & avgas Remains mastic after prolonged exposure to jet fuel & avgas
Primary Use Legacy airframes, faying surfaces, fuel-system interfaces General faying surfaces, fasteners, seams; aluminum alloys & dissimilar metals Similar to CA1000, but for higher-temp, high-vibration structures
Application Brush, knife, flow; sprayable when thinned Brush or spatula; thixotropic paste Brush or spatula; thixotropic paste
Service Temperature Up to 200 °C (392 °F) −65 °F (−54 °C) to 240 °F (116 °C); 275 °F (135 °C) intermittent −65 °F (−54 °C) to 320 °F (160 °C)
Shelf Life 1 year (unopened package) ≥ 12 months (≤ 80 °F storage) ≥ 12 months (≤ 80 °F storage)

4. Choosing the Right Compound for Your Needs

The products all stand up on their own merits, but they are also not necessarily universal products.

  • D40 - Use on older platforms or when you need to match OEM specs that still call for chromate-based materials. Excellent corrosion resistance, but because it contains barium chromate, it requires special handling and disposal.
  • CA1000 - The default choice for non-chromate applications. Ideal for use on faying surfaces, dissimilar-metal joints, and fuel-contact structures where you need a balance of performance and environmental compliance.
  • CA1010 - The better option for higher temperature or high vibration areas like engine nacelles, control surface interfaces, and areas that get exposed to prolonged heat cycling.

Considerations for Selection:

  • Chromate-based vs non-chromate chemistry
  • Operating temperature range
  • Fuel exposure severity
  • Structural loading & vibration
  • OEM or engineering specifications

5. GSA Procurement Guide (Greenwood Aerospace)

Where to Buy
All three jointing compounds are available on GSA Advantage through Greenwood Aerospace, so you can be sure you’re meeting your procurement obligations.

Procurement Checklist

  • Confirm that the product meets the platform spec requirements. Review the shelf life and storage requirements.
  • Take a look at the SDS/TDS documentation to verify its accuracy
  • Double-check the packaging size and P/N number—we offer these in the standard 6 oz. cartridges. 
  • Check on the current stock levels and lead times for prompt shipping.

Why You Should Do Business with Greenwood Aerospace

  • We're the go-to people for all your military and government flight ops and maintenance consumables needs
  • We're a GSA-approved supplier for defense and sustainment programs, trusted to get the job done.
  • Because we know how time-sensitive some of these orders can be, we make sure to get your parts to you as quickly as possible, whether for fleet or depot-level needs.

ITAR Status: U.S. Department of State ITAR-registered; eligible to support exports of ITAR-controlled items for large defense programs.

IDs/Certifications: UEI KVSUYYSJS174 · DUNS 604006874 · CAGE 2Y735 · ITAR DDTC Export Compliant · AS9120B QMS Certified

NAICS: 488190, 336413, 332722, 336411, 336413, 481212, 532411

Contact: gsasales@greenwood.aero | 580-865-6000 | 833-GSA-EBUY (833-472-3289)

6. The Bottom Line

Mastinox D40, CA1000, and CA1010 are three key products that our customers rely on to prevent corrosion and keep their aircraft ready to fly. While D40 has been a trusted performer for years, and will continue to be used in legacy programs, CA1000 and CA1010 are newer, more modern equivalents, and we're really excited about the possibilities they offer: non-chromate, environmentally friendly, and designed for the next generation of aircraft.

All three are available for purchase right here at Greenwood Aerospace through GSA Advantage, making them ideal for federal aviation sustainment projects, depot maintenance, and a range of corrosion-prevention initiatives.

If you need extra guidance on which one to choose or need to place an expedited order, give our team a call at gsasales@greenwood.aero or dial 580-865-6000 / 833-GSA-EBUY (833-472-3289), and we'll get you sorted out in no time.

All three jointing compounds are available through Greenwood Aerospace on GSA Advantage:

This article is part of Greenwood Aerospace’s ongoing Jointing Compounds and Corrosion Control Series, covering PPG Aerospace Mastinox formulations, PRC-DeSoto sealants, and related corrosion-preventive technologies. For more insights and GSA-available products, explore the whole series on GovernmentProcurement.com.