Oratex Application

Applying Oratex is straightforward and hassle-free. Its non-toxic nature means you can even tackle this task in your living room! Here’s a concise overview of the steps involved:

Preparing the Surface

When applying Oratex, proper surface preparation is crucial for a successful outcome. Follow these steps to ensure optimal adhesion:

  • Cleanliness: All contact surfaces must be thoroughly free of any grease, oil, dirt, wax, silicone, or other contaminants.
  • Glossy Surfaces: If you’re working with glossy surfaces like powder coating or gloss paint, scuff the surface to create a textured base for the adhesive. Scotch Brite is effective for scuffing most materials.
  • Wooden Airframes: Since Oratex is highly durable, an unprotected wooden airframe could deteriorate before the fabric shows wear. To prevent this, apply eco prime to the wooden surfaces and then scuff or lightly sand them for better adhesion.
  • Steel and Aluminium: For steel and aluminium surfaces, priming is essential.

Remember, proper surface preparation ensures a solid foundation for your Oratex application.

Applying the Adhesive

When working with Oratex, follow these steps for proper adhesive application:

  • Coat Both Surfaces: Apply two thin coats of adhesive to both the underside of the fabric and the contact area of the airframe. Ensure you use adhesive that hasn’t expired and apply it generously.
  • Allow Drying Time: After applying the adhesive, allow it to dry completely. Failure to do so will result in poor adhesion. Depending on your work environment’s temperature and humidity, a thin coat of adhesive typically dries in about 45 minutes.
  • Second Coat: Only apply the second coat of adhesive once the first layer has dried completely.

Remember, proper adhesive application ensures a strong bond between the fabric and the airframe.

Cutting, Fitting, and Securing the Fabric

After the adhesive has completely dried (transitioning from white to clear), follow these steps to ensure a successful Oratex application:

  • Clamp Securely: Use non-abrasive clamps, such as spring clamps with rubber-coated tips, to secure the fabric to the airframe. No special tools are necessary for cutting the fabric—good scissors, pinking shears, or a sharp knife will suffice.
  • Seam Overlaps: Pay attention to seam overlaps:
    • Leading Edge: Overlap leading edge seams by 4 inches.
    • Trailing Edge: Overlap trailing edge seams by 2 inches.
  • Tight and Wrinkle-Free: When gluing down the fabric, strive for maximum tightness and minimal wrinkles. This advice is especially crucial for those experienced with other fabric systems. Keep in mind that Oratex doesn’t shrink as much as some other fabrics. Take the time to achieve a taut fit during the gluing process—it’ll make subsequent shrinking easier and result in a polished final product.
  • Ignore Legacy System Advice: Disregard advice from those familiar with old legacy systems; their procedures may not align with Oratex’ s unique characteristics.

Activating Adhesive with Heat and Pressure

When working with adhesive, activating it properly ensures a strong bond. Here’s how it’s done:

  • Heat Activation: The adhesive is activated by heat. To begin, use a hot iron set at around 100°C. Apply the iron to the surface of the fabric and simultaneously apply pressure. As the temperature reaches 70°C, the adhesive melts and becomes active.
  • Pressure Application: While the adhesive is in its molten state, apply firm pressure with the iron. This ensures that the adhesive penetrates the fabric layers thoroughly. As you move the iron to a new area, the melted adhesive behind will set in approximately 10 seconds.
  • Stability During Cooling: It’s crucial that the fabric remains stationary while the adhesive cools. Any movement during this process can compromise the bond.
  • Curing and Melting Point: Once fully cured, the adhesive will have a higher melting point. It will still melt before the fabric (around 250°C), allowing for removal if needed. However, its high melting point ensures durability even in extreme environments, such as a black-painted airplane in scorching desert heat.

Remember, using a digital heat gun or a digital iron is recommended for precise temperature control during activation. These tools are available for purchase.

Shrinking the Fabric

After allowing the adhesive to set (usually 24 hours, longer in colder environments), it’s time to shrink the fabric. Here’s how:

  • Heat Application with a Hot Air Gun:
  • Use a hot air gun (never exceeding 250°C) to apply heat to the fabric.
  • Shrink the fabric until it becomes taut and wrinkle-free.
  • Before starting, test the heat gun on a scrap piece of fabric. If the temperature is correct, the fabric won’t discolour or get damaged, even with the nozzle close to it.
  • Our precise digital temperature-controlled tools make this process easy.
  • Final Heat Application with a Flat Iron:
  • Hold the iron “weightless” (without pressing down) and wave it back and forth over the unsupported fabric surfaces.
  • Light contact is sufficient.
  • Place a single layer of silicone paper under the iron.
  • Set the iron at 160°C.
  • Once complete, your fabric will have a taut and smooth finished surface.

Remember, it’s better to test on a scrap piece of fabric than risk damaging the final product!

Finishing Tapes and Reinforcing Tapes

When working with fabric coverings for aircraft, proper finishing and reinforcement are crucial. Here are the steps to ensure a professional result:

  • Finishing Tape Application:
  • Cover All Seams: Every seam on the fabric should be covered with finishing tape. You can use either pinked-edge or straight-edge tape.
  • Adhesive Application: The tapes come with glue pre-applied on one side. However, you must also apply adhesive to the fabric seam itself. This prevents air bubbles from getting trapped at the seam joint.
  • Bonding Technique: Apply a narrow line of adhesive (about 1/4 inch wide) in three layers. Avoid excess adhesive that might seep out at the edges of the tape.
  • Purpose: The adhesive not only ensures a secure bond but also enhances the appearance by hiding the edge of the top fabric layer.
  • Reinforcing Tapes:
  • Preparation: Apply reinforcing tapes to the fabric before performing rib-stitching, lacing, or pop riveting (based on the original aircraft design).
  • Covering with Finishing Tape: Once the reinforcing tapes are in place, cover them with finishing tape. If rib stitching is part of your design, the finishing tapes will go over the stitching. For rivets, the finishing tapes will cover the rivets.
  • Extra Adhesive: Apply additional adhesive to the reinforcing tapes (and rivets or rib stitching) to prevent air bubbles from forming under the finishing tapes.
  • Edge Tapes: After applying finishing tapes over the ribs, add leading and trailing edge tapes. Leading edge tapes should be at least 4 inches wide, while trailing edge tapes should be at least 2 inches wide. These tapes are available in one-inch increments.
  • Drain and Ventilation Holes:
  • Importance: Since Oratex fabric is airtight, you must provide drain and ventilation holes. These allow for air expansion as the airplane gains altitude and help vent and drain any condensation.
  • Maintenance and Cleaning:
  • Oratex Wax: Use Oratex wax for future maintenance. It helps protect the fabric and ensures ease of cleaning.
  • Special Cleaner Concentrate: There’s also a special cleaner concentrate available for maintaining your fabric covering.

Remember, attention to detail during the covering process ensures both functionality and aesthetics for your aircraft!