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Aluminum Gunwale Replacement for Royalex Hulls

As a lighter weight option on our Royalex hulls, Mad River Canoe has long offered black powder-coated aluminum gunwales. A low-maintenance alternative to the traditional ash, aluminum gunwales save approximately 3-5 pounds per canoe. It must be noted that aluminum gunwales are not as durable as vinyl or wood gunwales and will tolerate being distorted to the same degree that other gunwales will recover from. 

When ordering replacement gunwales make sure to request the correct length - order rails longer than your canoe.

  • Canoes are measured straight down the keel line. Gunwales take a bit more circuitous route getting from end to end. One piece Aluminum rails will fit canoes up to 16 ½’. Place orders for replacement gunwales through your authorized Mad River dealer. 

You can identify the one-piece aluminum gunwales for Royalex canoes in two easy ways: 

  1. The profile of the gunwale features a flat top and 90o angles at sides; forms a rectangle in cross section. 
  2. The “throat” (part of the gunwale that fits down over top of hull) is about ¼ - 3/*’ wide. Royalex hulls are considerably thicker than composite hulls and require a larger throat. 

Aluminum gunwales for Royalex hulls cannot be used on composite hulls or vice versa. They are not interchangeable. 

Specify your model of canoe and hull material when ordering gunwales to ensure compatibility. 

  • Replacement one piece aluminum gunwales were used on canoe models such as Horizons, Angler/Tahoe, Reflections, etc. The gunwales are shipped “bent” on a constant curve to facilitate installation. The bend will accommodate just about all symmetrical canoes. 
  • In late 2010, Mad River introduced new 2-part aluminum gunwales to replace the original one-piece gunwale. The new 2-piece gunwales will retrofit to any canoe using the original gunwales but we continue to provide instructions for replacement with one piece gunwale as some of our dealers may still have these in stock. 
  • If you are replacing same style gunwales your original decks will work with these gunwales. If you are replacing gunwales of other materials or a different style gunwale, it would not be unreasonable to expect to have to replace the decks. Unfortunately, we no longer have molds to fit older models and it may be necessary to proceed without decks or to modify new decks if originals do not fit. 
  • If you are uncertain of which model canoe you own, provide the serial number as an alternative. Serial numbers are located on the right side of the stern, just below the gunwale. It will either be engraved on a small brass plaque, or stamped directly into the hull. If it is difficult to read, try making a rubbing with a pencil and a small piece of paper. In the event that the model name is unknown and the serial number is completely unreadable, measure your canoe from stem to stem and width at center and we will approximate as best we can. 

Unlike wood gunwales, aluminum gunwales require only two rails per canoe. 

  • These aluminum gunwales are a "unibody" one- piece construction that incorporates inwale and outwale into one piece. 

Replacement rivets are required for both replacement and new installations. 

  • If you are removing existing gunwales the rivets will be destroyed in the process. The "average" installation requires 70+/- 5/32" diameter Buttonhead aluminum rivets with aluminum mandrels with grip range of 3/16" to 1/4". HA/A612D black rivets are available in packages of 80 from Mad River Canoe via your authorized dealer. 

Due to their length, aluminum gunwales cannot be shipped via UPS.

  • One alternative is to ship by common carrier (via truck) but this is expensive. Gunwales shipped via common carrier will be sent freight collect (payment due on receipt). The best alternative is to arrange shipment of gunwales to accompany a shipment of boats to your local dealer. If this can be arranged, there is no freight charge for the gunwales. 

MATERIALS REQUIRED 

  • 2 one-piece aluminum gunwales of sufficient length (for a complete re-rail) 
  • Up to 80 HA/A612D rivets or equivalent (actual number will be determined by length of canoe) 
  • Equivalent:  Buttonhead aluminum rivets with aluminum mandrels (5/32" diameter); grip range: 3/16" to ¼"; Hole diameter .160 to .164 
  • Hardware to secure seats, yoke, thwart, etc. can usually be re-used. If not, measure original hardware and order duplicates. 

All above parts are available via your local authorized Mad River Canoe dealer. 

TOOLS REQUIRED 

  • Variable Speed Reversible Drill
  • 20' Tape Measure 
  • 5/32"; 13/64"; 25/64" Drill Bits
  • Non-permanent marker 
  • Pop Rivet Gun
  • 10 Quick-Grip spring or Bar clamps or 3” C-clamps 
  • Rubber Mallet
  • Phillips head screwdriver 
  • Duct tape
  • 3/8” wrench 

SUMMARY PROCEDURE 

With rare exceptions, gunwale re-rail starts marking the hull with locations of seats and components followed by removal of components and then of original gunwales. With aluminum gunwales this is accomplished by drilling out the old rivets. This should allow gunwales to be able to be lifted off of hull once decks are removed. 

New gunwales are placed over top edge of hull and pushed down into place. Holes are drilled through the flanges on sides of gunwales and through hull. Rivets are inserted and set in holes to secure gunwales. Decks are reinstalled followed by hanging of outfitting such as yoke, thwart, seats, etc. 

STEP BY STEP PROCEDURE 

  1. Mark location of all seats, thwarts, etc. on inside of hull with grease pencil or washable marker. Once original rails are removed, the proper locations for these fittings will be lost if not noted. 
  2. Run tape measure around hull just below existing rails. Mark center point on each side of hull just below rails. These will serve as centering marks for replacement gunwales. 
  3. Remove all seats, thwarts, yokes, etc. from canoe. Label and attach all hardware so that it can be reused in original position. 
  4. Trace the bottom edge of gunwales on hull. This will give you a good reference point to make sure the new 
  5. gunwales are fully pressed down on top of hull. Mark existing rivet locations on hull below gunwale with non-permanent marker. 
  6. Remove old gunwales by drilling out rivets or unscrewing screws.
    • If you are replacing ash gunwales, simply remove all screws in the gunwales and the decks until gunwales and decks lift off canoe cleanly. 
    • If you are replacing aluminum gunwales, tape existing gunwales in place by applying duct tape in strips from outside of hull, over gunwale, to inside of hull. Position tape so that it does not cover any rivets. Taping the gunwale will keep the gunwale in position as the rivets are removed and prevent the gunwale slipping or springing free and scratching hull or striking someone. Drill out the existing rivets with a 5/32" bit. Drill from the inside of hull, centering drill on head of rivet. You will need to continue all the way through the rail and hull. The rivet should then slip out easily. First drill through the rivets which attach the decks at either end of the canoe, and then drill out the rivets which attach the gunwales. 
  7. Once all the screws have been removed or all the rivets have been drilled out, carefully separate the gunwales and decks from the hull and set them aside. 
  8. Clean exposed hull surfaces with a good household cleaner. Be careful not to wash away reference lines for gunwales or for seat locations, etc. 
  9. Set replacement gunwales on the ground next to your canoe hull. The replacement gunwales should be pre-bent. Align so that the wide part of the gunwale will be on the inside of hull and the narrow part on the outside. 
  10. Using tape measure, locate and mark the center point of the replacement gunwales with non-permanent marker. This mark will line up with the center point you have marked on either side of the hull once the rail has been slid onto the hull. 
  11. This step is much more easily accomplished if addressed by two people rather than one. Position one rail over side of hull, aligning center marks. Push rail down onto hull, starting at one end and gently sliding rail over top of hull working towards center. It can be challenging to align the top of hull with the throat in the rail. Do not attempt to start at one end and then push/slide rail down hull towards other end. This will scratch and abrade the hull. As you work your way along hull, tape or clamp gunwale down over top of hull to prevent it from popping off behind you. Do not force the rail down onto the hull and keep a close eye out for any crimping of the hull. You may find it helpful to use a putty knife to align hull and throat and encourage hull to fit into throat of gunwales. 
  12. Tamp rail down gently with mallet or palm of hand to fully seat gunwale on hull once completely aligned. Do not pound rail down with force as this can also cause laminate to fracture. Push gunwale down until bottom of gunwale aligns with line traced from original gunwale. Check to be sure center points are aligned. If you need to move the rail backwards or forwards to line up the center marks, gently tap the end of the rail with a rubber mallet until the marks line up. 
  13. Clamp rail to hull at approximately ¼, ½,  and ¾ of the length of the rail and at each end to secure in position. 
  14. Repeat process with second rail on other side of hull. Make sure rail ends are even and are evenly spaced from stem of boat at each end. Confirm that end of gunwales extend past mark indicating ends of the decks. Secure 2nd gunwale with clamps when in proper position. 
  15. Make sure ends of gunwales are fully seated on hull and drill holes through cut end of each rail with 5/32" bit, within ¾" of the each end. Holes should be drilled from the outside of the rail. Place rivets through each hole after each is drilled. Once you have drilled all four go back and secure rivets with rivet gun. Slide rivet gun over rivet stud to point where head of gun is flush with head of rivet. This is most easily accomplished by making sure handles of rivet gun are fully released. Squeeze handles together to snap rivet. It may be necessary to squeeze more than once to get rivet to pop. If one pull doesn't do it, release handles and slide gun forward until head of gun and head of rivet are again in contact and then squeeze handle. Keep rivet gun aligned level with rivet. Do not attempt to "help" the process by bending or "torqueing" the rivet gun. This can result in rivet stud being jammed in rivet gun. 
  16. Slide the decks over the gunwales and mark ends of deck with marker on inside of hull. Starting from stern end of each rail (end of canoe with serial number on right side), measure and mark locations of rivet holes on flat flange of inside of rails with grease pencil. The new rivet locations should “split the difference” from the old. Do not use same holes as this can create a loose fit. Rivets should be 6 ½” apart. Measure from mark defining end of deck. If existing hole is at 6 ½”, mark gunwale at 3 ¼” and then space rivets at 6 ½”, marking location along flange extending below gunwale on inside of hull. 
  17. Step back and "eyeball" each gunwale to make sure it is "fair" and follows sheer line of hull. Gently tap down any high spots or rises in gunwales and re-clamp as needed. 
  18. Drill holes at all marked locations with a 5/32"drill bit. Holes should be drilled from the inside of rail. You may need to use a shorter bit to allow access to hole locations up in ends of canoe. If you still cannot access those locations, leave them undrilled. There are sufficient fasteners used to secure the gunwale. Holes should penetrate inside of rail and hull, but should not protrude through outside of rail. Measuring width of gunwale and wrapping tape at corresponding length on drill bit will help prevent accidentally drilling through the 
  19. outside of the gunwale. 
  20. Place rivets in all drilled holes and secure with rivet gun. 
  21. Transfer locations of seats, thwarts, yokes from hull to top of rails. The marks should be located on the inner half of the rail, such that a hole drilled straight down would penetrate the upper and lower surfaces of the rail without contacting the hull itself. Use one of the horizontal lines indented in the top of gunwale as a reference point for drill location. 
  22. Using the 13/64" bit, drill straight down through the rail at all marked locations. This should include holes for the bolt hangers for the carry handles (two holes per each handle); seats (four holes per seat); thwarts (two holes per thwart), if applicable; and yoke (four holes total). 
  23. Hang seats, thwarts, yokes, etc. from rails, and tighten all hardware. Place dimpled finish washers on bolts and drop through holes in top surface so that threaded shank extends through hole in bottom surface. Install seat or component and secure with flat washer and locknut. You will not use flanged finish washers with this gunwale system. NOTE: If you are replacing ash or vinyl gunwales, you will need kerfed trusses, (seat hangers) in order to accommodate the lip of the gunwale. Tighten hardware fully. 
  24. Insert black plastic caps into the holes used to hang seats, thwarts, etc. in the top of the gunwales. 
  25. Slide decks over cut ends of rails. Using 5/32" bit, drill holes for rivets through lower lip of deck and through hull from the outside. Each side of the deck should get two holes, one in each end. Place rivets through holes (four total), and pop with rivet gun. 

If additional information is required, contact your Authorized Mad River Canoe Dealer or call Mad River Customer Service @ 888/525-2925. 

Care and maintenance of aluminum gunwales 

Aluminum gunwales are basically care free. Over time and use, the black powder coating can be abraded, revealing the natural silver color of aluminum. This is a cosmetic issue only, the function and durability of the gunwale is not affected. If you want to restore the black finish, lightly sand area with fine grit sandpaper and paint with a flat black enamel. Multiple light coats will be longer lasting than one heavy coat. Please note this will not be a permanent "repair" and will likely need periodic repainting.