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Canoeing 101


IQ2 Gunwale Installation

When ordering replacement IQ2 gunwale be sure to request the correct length - order rails longer than your canoe.

  1. Canoes are measured straight down the keel line. Gunwales take a bit more circuitous route getting from end to end. IQ2 rails come in two sizes: under 15’ and over 15” (fits up to 17 ½’). All Mad River IQ2 gunwales include a "L" shaped aluminum insert to add strength and structure to the rail. 
  2. IQ2 gunwales will not fit Composite canoes. 
  3. Place orders for replacement gunwales through your authorized Mad River dealer. 

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

This will assist your dealer and Mad River Customer Service to make sure you receive the proper gunwale. If you are unsure of model or material, bring your boat to the dealer; they can usually identify the model and material. If this is not practical, the serial number on your canoe will be helpful. Serial numbers are located on the right side of the stern of the hull just below the gunwale. It will either be engraved on a small brass plate or stamped directly into the hull. If difficult to read, make a rubbing by holding a piece of paper against hull and scraping a pencil point across paper. The number should be revealed on reverse side of paper. 

A complete re-rail installation will require 2 IQ2 gunwales.

Unlike ash gunwales which utilize an inside rail and an outside rail on each side, IQ2 gunwales are a uni-body construction in which the inside and outside gunwales are molded in one piece. Gunwales are pre-bent to a curved form, which will fit most canoes. If your canoe hull doesn’t fit to the gunwales easily you may find it necessary to further bend the gunwale to fit without distorting your hull. Make any needed bends slow and gradual working up and down affected length of gunwale. Avoid creasing gunwale by bending too quickly or sharply or with all effort at 
one point. 

Gunwales are interchangeable, there is no right or left. 

IQ2 gunwales do not have entry slots pre-installed as proper location cannot be determined until gunwales are installed. An IQ2 Spreader Tool (available from your Mad River dealer) will be necessary to install the entry slots. 

You will need 8 replacement rivets to re-install your decks over top of new gunwales and a 70 pack of #8 x 1” self-tapping square head screws. Rivets can be used to attach gunwales but Mad River Canoe switched to self-tapping screws as they are faster to install and allow for easier removal and installation of gunwales. 

In most cases, the decks on IQ2-railed canoes can be saved and reused with new rails. 

The IQ2 gunwale profile is just a trifle wider than a conventional vinyl gunwale profile. It will fit the rotomolded decks that Mad River currently uses but some decks will require more modification than others. If your decks do not wrap flush around the IQ2 gunwale where they overlap, you may find it helpful to trim the “legs” of your decks at an angle to provide better fit. 

If you are switching from wood or aluminum gunwales to IQ2, you will need to order new decks.

Due to their length, IQ2 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. 


  • 2 Gunwales of adequate length 
  • 70 +/- #8 x 1” self – tapping screws (quantity needed depends on length of canoe) 
  • 8 HA/A612D Black rivets (or equivalent) 
  • 8 3/16” stainless flat washers 
  • IQ Spreader Tool 

All above materials are available from Mad River Canoe Authorized Dealers 

  • Rubber Mallet
  • Electric Drill            
  • Pop Rivet Tool
  • 7/32” and 17/64" Drill Bit 
  • 3/8" Wrench
  • 3/8" Drill Bit 
  • 7/16" Wrench
  • 13/64" Drill Bit 
  • Hack Saw 6
  • 3" C Clamps 
  • 20' Tape Measure
  • Putty Knife 
  • Duct Tape
  • Pencil/Non-permanent Marker 

NOTE: Additional hardware may be required to complete replacement or rehabilitation of your canoe depending upon model, material, age. Mad River has been building canoes for over 30 years and many changes and improvements have been made during that time. For example, until 1998-99, Mad Rivers’ used ¼” hardware to mount seats, yokes, etc. Since that time MRC has used 3/16” hardware to save weight and allow improvements such as double bolting yokes for increased integrity. While the instructions may specify specific drill bits, please be aware that other sizes may in fact be necessary as needed. 


Vinyl gunwale replacement starts with marking on the hull of the original locations for seats, yoke, thwart, carry handle, etc. Gunwales can then be removed by drilling out rivets or backing out screws used to secure them to hull. 

New gunwales are then placed over the top of the edge of the hull and clamped in place. Gunwales are next marked for spacing of new fasteners. Decks are positioned in place and gunwales are drilled for rivets or secured by self-tapping screws. Outfitting components are then installed at marks made at beginning of process. Finally, new feeder slots are installed in the new rails to accommodate IQ2 accessory modules. 


1. Run tape measure along curvature of hull below gunwale and mark center point on hull on each side. Measure new gunwales to confirm they are of sufficient length to cover length of hull. Check to make sure aluminum inserts are in place inside IQ2 gunwale and ends are flush. If re-rail requires removal of existing gunwales follow steps below: 

  1. Mark placement of seats, thwarts, and yokes on side of canoe hull with marker. This will provide a reference for proper location when replacing these parts on new gunwales are installed.
  2. Mark original rivet or screw locations on hull below gunwale. When fastening new rails in place these marks will serve to space new rivet locations. It is preferable to use new holes rather than enlarge the existing holes with the new rails. Enlarged holes can result in rails becoming slightly loose over time.
  3. If original gunwales are secured by rivets, drill out rivets using properly sized drill bit. Older Mad River Canoe gunwale rivets can be removed by using a 13/64” drill bit. Drill bit should be same diameter as the rivet shank. Drill from outside of hull positioning end of drill bit in center of rivet head. Drill until flange of rivet head separates from rivet stem. It may be necessary to poke rivet stem through hull to dislodge rivet.
  4. For wooden gunwales: Back out screws, starting at one end of hull and proceeding towards other end and continuing down other gunwale to return to end where started.
  5. Drill or unscrew fasteners securing the decks to the canoe if necessary.
  6. When all fasteners are free, pry up on decks and remove. This should also free gunwales along hull. On wooden gunwales, outwale will drop free when final fasteners are removed.

2. Place decks onto hull, making sure end of deck fits snugly against the bow and stern (see diagram 1). Tamp point with rubber mallet to seat properly. With non-permanent marker, mark outside of the hull at rear edge of the deck on both sides. Also mark point on hull of deck where deck will overlap the gunwale. Remove decks after making marks. 

3. Run tape measure along top edge of hull following outside surface of hull. Start measure at the mark defining end of gunwales under the deck overlap and measure to mark at opposite end defining same location. Double check measurement as this will be length you will cut new gunwales. 

4. Cut new gunwales to measurement made in step 3. Mark center point on each new gunwale. 

5. Position new gunwale on hull, matching center point marked on hull to point marked on gunwale. Narrow side of gunwale goes to the outside of the hull and wide side to inside to provide mounting point for hanging seats, thwarts, and yokes. Start at center and push gunwale fully down onto hull, working towards one end. Tamp gunwale down with mallet to fully seat onto top of hull and use clamps to hold gunwale down in place. Once you have one end on hull, return to center and work towards the other end. You may find that slipping a putty knife up under edge of gunwale will help it slide over the top of hull. You can also use duct tape to help hold the gunwale down. Leave about the last 3’ of the gunwale free to be able to be raised. 

6. Lift the ends of the gunwales from the hull and start ends into decks. Do not fully insert to equal the measurement of overlap made earlier. Push ends of gunwales down onto hull and allow end of deck to seat over end of hull. Use rubber mallet to tamp deck back onto hull until end of deck is flush with stem of canoe. 

7. Step back and "eyeball" the gunwale. Look for any rises or humps that would indicate gunwale is not seated completely on hull. Tamp down and secure any section of rail necessary with additional “C” clamps and/or duct tape gunwale firmly down onto top of hull. 

8. Along gunwale sections, refer to the marks locating the original rivet locations. Place evenly spaced marks along the indented line on the lower external flange of gunwales between old rivet locations. These will be new fastener locations. At decks, mark locations as described in following step. 

9. At decks, mark point on the outside edge of the deck 1" from point where gunwale is inserted. Make next mark 3” towards end of canoe from first mark. Move to end of canoe and make a mark 1" from end of deck. Make a fourth mark 2" from tip of deck. Repeat on other side of deck. This will provide 4 fasteners (2 self-tapping screws and 2 rivets) on each side of deck. Check to make sure that the two marks at wide end of deck are positioned to engage the overlap of the deck and the gunwale. If necessary, adjust position slightly to engage both gunwale and deck. 

10. Confirm that gunwales are firmly seated against top of canoe hull. Beginning at center of hull, insert self-tapping square drive screw onto drive bit and place tip in groove running down center of gunwale flange on the outside of hull. Drive screw through flange, hull, and into interior gunwale box. Be careful not to drive head of screw through the flange. If this occurs, back screw out and install a flat washer on screw and re-drive. 

11. Working towards one end of canoe, drive screws at each marked location, pressing down on top of gunwale at each position to make sure it is fully seated on hull. 

12. When you reach the deck, drive self-tapping screws at marks where deck overlaps gunwale. 

13. Return to center and proceed to fasten other half of gunwale in same fashion. 

14. Repeat for gunwale on opposite side of hull. 

15. Install 13/64” bit on drill and drill through each deck at remaining two marks on each side. 

16. Insert rivet into each remaining hole. Place flat washer over end of rivet on inside of canoe and push washer flat against inside of hull. 

17. Place rivet gun over shank of rivet and pull trigger. Make sure to keep head of gun pushed firmly up against outside of deck to get best attachment. Do not try to hurry things along by bending or twisting rivet gun. This can result in rivet stud being jammed in gun. 

18. Using marks as reference, re-hang seats, thwarts, yokes, etc. Drill 7/32” holes to accommodate current Mad River Canoe mounting hardware. 

19. After all gunwales and fittings are installed access slots need to be installed in the IQ2 gunwale. Factory installation includes: 

  1. Exterior gunwale channel: total: 4 (2 per gunwale, one at each end approximately 2” from end of deck)
  2. Interior gunwale channel: total 8 to 12 depending on number of interior fittings (yokes, thwarts, seats, etc). Object is to provide access to all usable sections of interior gunwale. Includes: 2 slots 2” behind bow deck and 2 slots 2”in front of stern deck, 1 slot on each gunwale on either side of center yoke, approximately 2” from yoke. If your canoe has an additional thwart, install slot in each gunwale either behind or in front of thwart to allow access to all internal areas of canoe.

20. To create feeder slots: 

  1. Heat gunwale section to be opened with hair dryer on high or heat gun on lowest setting. Keep heat moving and heat until gunwale is warm to touch, not hot. To protect hull, you may want to shield the hull from the heat source. Normally gunwale is properly heated well before any threat is posed to the hull material.
  2. Align slot in edge of spreader tool with upper edge of channel in IQ rail and slide slot over edge of channel. Slowly and with steady pressure lever the tool head gradually upward until tool is in horizontal position to open slot. Do not bend gunwale quickly as this can crack the gunwale.
  3. Align slot in edge of spreader tool with lower edge of channel and slide slot over edge. Slowly and with steady pressure lever the tool head downward slightly to further open the slot. It is not necessary to fully open the bottom edge of slot. It is sufficient to flare it slightly to make entry and exit of components easier.

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