How to Build an 11 Foot Alutender RIB: A Comprehensive Guide

How to Build an 11 Foot Alutender RIB: A Comprehensive Guide

If you’re passionate about boating and looking for a lightweight, durable, and easy-to-handle vessel, building an 11 foot Alutender RIB (Rigid Inflatable Boat) might be the perfect project for you. These boats combine the rigidity of a traditional aluminum hull with inflatable tubes, offering remarkable stability and buoyancy. Whether you’re a seasoned boat builder or a motivated DIY enthusiast, constructing your own Alutender RIB can be a rewarding experience both technically and financially.

In this detailed guide, we’ll walk you through everything you need to know about how to build an 11 foot Alutender RIB—from understanding the design and materials to step-by-step assembly instructions. By the end, you’ll have the confidence and knowledge to create a sturdy, seaworthy craft tailored to your specific needs.

Understanding the Alutender RIB Design

The Alutender RIB is a versatile boat design that merges an aluminum hull with inflatable tubes (called sponsons). This hybrid design offers several advantages:

• Durability: Aluminum hulls resist corrosion, dents, and impact better than fiberglass or wood.
• Lightweight: Aluminum’s light weight enhances speed and fuel efficiency.
• Stability: Inflatable tubes provide excellent buoyancy and stability, even in choppy waters.
• Ease of Repair: Aluminum can be repaired more easily in remote locations using simple welding techniques.

The 11 foot size makes it ideal for use as a tender to larger vessels, fishing or hunting boat, or a recreational craft in lakes and coastal areas. The compact length also means it can be easily trailered or stored.

Key Features of the 11 Foot Alutender RIB

• Length: 11 feet (3.35 meters)
• Beam: Typically around 5 feet (1.52 meters), offering a stable platform
• Hull Material: Marine grade aluminum sheets, usually 3-4 mm thick
• Tubes: Reinforced PVC or Hypalon inflatable sponsons with multiple air chambers for safety
• Capacity: Suitable for 2-4 passengers, depending on outfitting

What You’ll Need Before You Start Building

Building your own aluminum RIB requires careful planning and the right tools. Here’s a checklist to prepare you for the project:

Materials

• Marine-grade aluminum sheets (3-4 mm thick)
• Aluminum angle bars and flat bars for framing and reinforcement
• Inflatable sponsons (PVC or Hypalon) sized for an 11 foot boat
• High-quality marine adhesives and sealants
• Rivets, bolts, and stainless steel fasteners
• Paint or protective coatings suitable for aluminum
• Optional: Marine plywood for floors or seats

Tools and Equipment

• Metal cutting tools (jigsaw with metal blade, plasma cutter, or angle grinder)
• Sheet metal brake or bender
• Welding machine (TIG welder recommended)
• Drill and drill bits for metal
• Rivet gun and rivets
• Measuring tape, square, and marking tools
• Clamps and workbench
• Protective gear (welding mask, gloves, ear protection)

Step-by-Step Guide to Building Your 11 Foot Alutender RIB

Step 1: Acquire the Plans

The foundation of a successful build is a detailed and reliable boat plan. The 11 foot Alutender RIB plans are designed by experts and provide precise measurements, cutting diagrams, and assembly instructions. You can find a comprehensive set of plans designed specifically for this model at build 11 foot Alutender rib. Investing in professional plans will save you time and reduce costly mistakes.

Step 2: Prepare Your Workspace

Set up a clean, well-ventilated work area with sufficient space to lay out the aluminum sheets and assemble the hull. Organize your tools and materials nearby for easy access. Ensure good lighting and proper safety equipment is available.

Step 3: Cut the Aluminum Sheets

Using your boat plans as a guide, carefully mark and cut the aluminum sheets into the various parts needed for the hull, transom, and other structural components. Accuracy is crucial to ensure that parts fit together seamlessly.

• Use clamps to stabilize sheets while cutting.
• Wear gloves to avoid sharp edges.
• Double-check measurements before every cut.

Step 4: Form and Bend the Aluminum

Once cut, some parts may require bending to form the hull shape. A sheet metal brake is ideal for producing clean, accurate bends. Follow the curvature specifications in the plans carefully.

Step 5: Weld the Hull Components

Begin assembling the hull by tack welding the main panels together. Check alignment regularly before completing full welds. TIG welding is preferred for aluminum due to its precision and clean finish. If you’re new to welding, practice on scrap pieces first or consider hiring a professional.

Step 6: Reinforce and Seal

Install aluminum angle bars and flat bars inside the hull to reinforce joints and provide rigidity. Apply marine-grade sealants at seams to ensure your boat is watertight.

Step 7: Attach the Inflatable Tubes

After the hull is fully assembled, it’s time to attach the inflatable sponsons. These are fixed to the hull using a combination of adhesive bonding and mechanical fasteners. Ensure the tubes are evenly inflated and securely mounted to avoid leaks or detachment. Follow manufacturer instructions carefully to maintain the tubes’ integrity.

Step 8: Install the Flooring and Seats

Depending on your preference, you can install marine plywood floors covered with non-slip coatings or aluminum decking. Add seating or storage compartments as desired, securing them firmly to the frame.

Step 9: Paint and Finish

Protect your boat from corrosion by applying suitable marine paint or anodizing where necessary. Pay special attention to weld seams and edges. Allow the coatings to cure completely before use.

Step 10: Final Checks and Launch

Inspect every joint, fastener, and the inflatable tubes for defects or weaknesses. Test the boat in shallow water first to verify buoyancy and handling. Make any necessary adjustments before taking it out for a full run.

Tips for a Successful Build

• Follow the plans meticulously: Deviations can lead to performance issues or safety hazards.
• Practice welding beforehand: Clean, strong welds are vital for hull integrity.
• Choose quality materials: Don’t cut corners on aluminum grade or tube material.
• Ask for help: Some steps, especially welding and tube fitting, benefit from an extra pair of hands or expert advice.
• Invest time in finish work: Proper sealing and painting extend the life of your boat.

Maintenance and Care for Your Alutender RIB

Once your 11 foot Alutender RIB is launched, maintaining it properly will ensure years of enjoyment:

• Rinse with fresh water: After each outing, especially in saltwater, rinse the hull and tubes.
• Check inflation pressure: Regularly inspect the tubes for leaks or pressure drops.
• Inspect welds and fasteners: Look for signs of corrosion or loosening.
• Store properly: When not in use, keep the boat in a covered, dry place.
• Apply protective coatings: Touch up paint and sealant as needed.

Why Build Your Own 11 Foot Alutender RIB?

Building your own RIB offers several advantages over purchasing a pre-made boat:

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