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Custom Applications
The Problems
Others Turn Away
When standard catalogs run out and competitors won’t take the call, engineering teams come to Rubbercraft. We’ve spent over a century developing one-of-a-kind solutions for the environments where conventional seals fail.
If your application doesn’t fit a product standard, this is the page.
AS9100 + Design
Approved for design
Custom Formulation
In-house compound development
ITAR Registered
Controlled technology compliance
Made in USA
Long Beach, CA
What “Custom” Actually Means at Rubbercraft
Engineering That Starts Before the Drawing Exists.
Custom Applications is where Rubbercraft engineers begin work without a part number. There’s no catalog page to pull from, no off-the-shelf alternative to retrofit, and often no finalized drawing on day one.
What there is: a requirement, an environment, and a deadline. Our team starts there.
We work with development teams whose requirements are still evolving — defining specifications, recommending material chemistries, designing geometries that mate to non-standard hardware, and prototyping in days instead of weeks. The combination of in-house compounding, in-house tooling design, and a seasoned engineering group.
Build-to-spec, not just build-to-print. We help define requirements when yours aren’t yet locked.
Compounds developed in-house — no third-party mixing house, no weeks-long lead times for material iteration.
Knowledge transfer across product lines. A solution from inflatable seals may inform a propulsion diaphragm.
Willing to take the smaller, more complex job. Where high-volume competitors decline, we take on the development work.
Fast Track available when the program can’t wait on standard lead times.
A Closer Look at Our Hardest Work
Hydrazine-Compatible Propellant Diaphragms
Space fuel systems operate in conditions where failure is not an option and material substitution is not available. Hydrazine is selected for its density and thrust efficiency, but it imposes strict requirements on every elastomer it contacts — chemical compatibility, long-term degradation resistance, and FOD-controlled cleanliness throughout manufacturing.
Our EPDM diaphragm systems regulate fuel movement within propellant tanks, maintain pressure balance, and deliver consistent fuel flow to thrusters across mission lifecycles measured in years.
Hydrazine Resistance
EPDM formulation optimized specifically for hydrazine compatibility — selected after material qualification, not adapted from a standard catalog.
Diaphragm Efficiency
95%+ efficiency maintained in collapsed configurations. IML bottle arc length preserved through repeated deployment cycles.
Optimized Geometry
4″ to 32″ diameter range. Compression-engineered for ease of deployment at low pressure. Reduced profile height for decreased tooling weight
FOD-Controlled Manufacturing
Manufactured in environments engineered to prevent foreign object debris — critical for systems where a single contamination event can compromise the mission.
It Starts With the Compound
Custom Formulation Is a Core Capability. ALWAYS IN-HOUSE
When a custom application requires a material that doesn’t exist in our 300+ formulation library, our chemists develop one. We mix and test in-house. We hold the formulation in-house and qualify it on your program. No mixing offsite or a third-party lab, and no weeks-long wait for each material iteration.
Our EPDM diaphragm systems regulate fuel movement within propellant tanks, maintain pressure balance, and deliver consistent fuel flow to thrusters across mission lifecycles measured in years.
Materials We Work With
Base Elastomers
Silicone (VMQ)
Fluorosilicone (FVMQ)
EPDM
Nitrile (NBR)
Neoprene
Butyl
Viton®
Specialty PTFE & Polymers
Virgin PTFE
Filled PTFE Variants
UHMW Polyethylene
PEEK
Filler & Loading Systems
Conductive Fillers (RF/EMI)
Iron Carbonyl (LO)
Carbon-Based Loadings
Thermally Conductive
Custom Customer-Specified
Reinforcement Systems
Fiberglass
Ceramic Fabrics
Nextel®
Polyester
Conductive Fabrics
Self-Qualify Before You Pick Up the Phone
Three Signs Your Project Belongs Here.
You’re Past the Catalog
You’ve reviewed standard product offerings and nothing fits the operating environment, the geometry, the material chemistry, or the assembly configuration. The application is genuinely one-of-a-kind.
1
Your Requirements Are Still Evolving
You have a program goal, an operating envelope, and a target schedule — but the final drawing doesn’t exist yet, and you need an engineering partner who can help define it before the part is designed.
2
A Larger Supplier Said No
You’ve approached a high-volume competitor and the response was “not enough volume” or “not enough margin in the development work.” Custom Applications is precisely the work that vendor declined.
3
What Makes One-of-a-Kind Work, Work
Why Engineering Teams Bring
The Hard Problems to Us.
Custom work fails in predictable places like material qualification stalls at the mixing house, tooling lead times balloon, requirements shift mid-program, or the vendor decides the volume isn’t worth the engineering effort. Our entire operating model is built to remove those failure points.
In-House Compounding
We mix our own materials. Custom formulations don’t require a third-party mixing house, which means no waiting weeks for each iteration when the test doesn’t pass the first time. We formulate, test, and adjust on our own schedule.
1
In-House Tooling Design
3D-printed prototype tooling for rapid iteration. Aluminum and steel production tooling when the part rate justifies it. Tool design happens alongside part design, not after it.
2
Build-to-Spec, Not Just Build-to-Print
When customer requirements aren’t yet finalized, our engineers help define them.
3
Willingness to Take the Smaller Job
Larger competitors decline custom development work because the volume doesn’t justify the engineering investment. We take it on.
4
Honest Engineering Feedback
When a requirement isn’t feasible, we say so. When a design needs to be reconsidered, we tell you. That kind of feedback saves months of program schedule — and our customers come back because of it.
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Our Products
