Tuesday, April 06, 2010

Fixing a Busted Old Stripper

Restoring a Damaged Cedar Strip Canoe

You’ve got damage to that beautiful cedar strip canoe of yours.  Now what do you do?  The repair job is relatively straightforward if you have a modicum of woodworking skills, but you may want to go a little farther.  You may want to consider fiberglassing the whole thing when you are done to add years to the life of your boat.  A light fiberglass cloth with an epoxy-based resin adds a beautiful thick clear coat that not only protects the hull, but also brings out the wood grain in stunning fashion.

This How-to is in two parts then.  First – replacing the cedar strips.  Second – fiberglassing the hull.  Of course, part two is optional, but it’s worth considering if you’ll be using the canoe a lot or if it’s stored outdoors.

Replacing the Cedar Strips

Step 1
Decide how badly the hull is damaged.  If it’s just a dent, you can probably sand it down or fill in the spot with a thin cedar veneer.  For this tutorial, we’ll assume a hole that damages two adjacent strips (it’s never one is it?).  You’ll have to remove them.

Step 2
When you remove the damaged strips, you’ll want to stagger the cuts as shown in the picture.  This disguises the repair and increases hull strength by avoiding the placement of end seams next to each other. 

Step 3
Once you’ve marked where you want to remove the strips, you’ll need to cut the end seams first. I use a sharp knife and score crosswise across the old strip where I want to cut it free.  Then rescore repeatedly till you are through the wood strip.  Because there are ribs and other layers of hull underneath, you can’t just take a saber saw to it as you would with one of the cedar/epoxy canoes. Now score a couple of passes along the sides between the piece to be removed and the neighboring strips. To remove the strips, score down the center and split each strip.  You can then carefully pry them up in the middle and pull the edges loose for the neighboring strip.  The strips should come apart at the side seams and lift right out.  Do everything slowly and carefully so as not to damage neighboring wood.


Step 4
Very lightly sand the edges to remove splinters.  Too much sanding can curve the straight edges along the sides and end, so go easy.  Lay a piece of butcher paper over the hole and use a pencil to shade the outline of the place to be repaired.  This will help you when cutting the replacement strips.  Be sure to measure the thickness of the strips on your canoe so you get replacements of the correct thickness.  You don’t want a dip or bump where the new repair is.

Step 5
When you cut out cedar strips for the repair, use the pattern you made to reproduce the exact shape of the hole.  Work slowly because you need the strips to fit exactly into the opening.  Use epoxy glue or other high strength water repellant glue.  Apply it to the edges, ends and back of the strip as you fit it into place.  Don’t use glue where the second replacement piece will touch the first.  Keep this area clean and dry till you are ready to install the second piece.  Press the strip into place and wipe any excess glue that squeezes out around the seams.  Apply pressure while the glue sets to hold it tight against the hull.  Depending on the spot you may be able to set something heavy on it or bungee something block like over the top. Use something that won’t adhere to the glue in case some more squeezes out of the seams.  Let the first strip dry and cure overnight.

Step 6
Take pictures to show you doing this all by yourself.  Video is nice if you can get it.  You want evidence so that when you're beating your chest over the beautiful work you did and someone calls you on it, you can whip out a photo.


Step 7
Apply the second strip the same way you did the first and again apply pressure while it is setting.  Again, allow to dry and cure overnight.

Step 8
Get some wood filler that matches the color of your cedar strips. Use 1/32 milled glass putty filler if you can find it.  Work the filler into the seams where there are any gaps or holes.  Let it dry, then sand the entire repaired area and adjacent strips.  Gradually lighten your sanding pressure as you move onto the neighboring strips.

Step 9
Now you need to make a decision.  Are you going to just varnish the repaired spot or fiberglass the hull to prevent any further damage?  If not glassing the hull, then once you’ve fine sanded the repaired area, apply several thin coats of marine spar varnish to the area.  You may find that you need to recoat the entire hull in order to blend in the patch.

Glassing the Hull

Step 1
For this you’ll need the following:
Epoxy fiberglass resin and hardener
Disposable small bucket or can and stirring stick for the resin
Flat edged spreader (plastic or metal wide putty knife will work).
4-6 oz. E-glass Fiberglass fabric - Plain Weave Thickness: 0.0093"
Fine grades of sandpaper and a few course sheets for the edges.
Steel wool fine to extra fine
Acetone
Latex or rubber gloves
Respirator, especially if working indoors.

Step 2
Use a 4 to 6 ounce E-glass fiberglass fabric that is lightweight and works well with the epoxy resin. You’ll need a piece large enough to completely cover the boat.  It should overlap by a couple of inches, as the cloth will shrink up when curing.  Use heavy-duty scissors to trim the fabric along the gunwales all the way to the ends of the canoe.  You may need to cut notches out of the fabric to accommodate curves in the hull, bow and stern.  If you do, tease a few threads from the fabric along where the edges of the cuts will meet so they blend together better when you apply the resin and you don’t get that overlap “bump” when you are done.  I use duct tape to tape the fabric in place while trimming and remove it as I apply the resin.

Step 3
Put on your gloves and respirator.  Mix up a small batch of epoxy resin. Starting at one end, pre-wet a section of the hull with the epoxy resin.  Pull up the fiberglass cloth.  Pre-wet the area by brushing it with the epoxy coat.  Now lay the fiberglass back over the wet resin and push it into place with your fingers.  Brush more resin on top to saturate the fiberglass fabric till the white threads and any bubbles disappear.  E-cloth is harder to saturate than regular fiberglass cloth, so be patient.

Step 4
Use the spreader to smooth the surface of the section, to press the cloth firmly against the hull, to make sure the resin fills all the spaces in the fabric and to remove any remaining air bubbles. A low viscosity resin helps the E-cloth soak up the resin better.  You can also warm the resin before lay-up. This helps make the repair completely transparent.

Step 5
Proceed section by section from one end to the other. When you’re done, go back to the parts that have already set and tap the surface with a quarter. If it sounds hollow, the fiberglass has delaminated from the hull and will need to be removed and replace.  If you’re careful, however, this should not be a problem.

Step 6
Allow the fiberglass resin to cure overnight.  Then crank up the sander and smooth the edges where the fiberglass may have overlapped the edges or created bumps or burrs.  Sand the entire hull thoroughly first with light sandpaper and then two or three more times with progressively lighter sandpaper.  Finish by rubbing the whole thing with fine grade steel wool.

Step 7
Brush or spray on an epoxy based clear coat.  A sprayer works better, but either way use thin coats and apply several allowing them to dry and cure between coats.  Lightly scrub each coat with fine steel wool and wipe clean before spraying the next coat.

Step 8
Get out the buffer and polish the hull to a high shine.  Your beautiful shiny canoe will slip so quietly through the water you won’t believe it.  It will be a little heavier to carry, but let’s face it.  You aren’t likely to be taking this beauty into any whitewater rock gardens are you?  You’ll just want to stand there in the garage and look at it, but don’t be afraid.  Take it out on the water and make everyone jealous.  Cedar canoes are the Rolls Royces of the canoe world.  Show your baby off!

(c) 2010 by Tom King:  Rights Reserved.  Feel free, however, to link to this website.

Monday, April 05, 2010

Canoe on a Shelf

How to Build a Shelf-Style Canoe Rack

Introduction

An easy way to store your canoe is to build a canoe shelf on an empty wall either inside or outside the garage, tool shed or other handy structure. It takes just a few simple tools, some shelf brackets, padding and a pair of two by fours. A canoe shelf keeps your boat up off the ground and allows you to store the boat without a lot of bending of your back and knees.

Materials:

2 large metal shelf brackets at least 18 inches wide
2 pressure-treated two by fours, 4 feet long
A bag of 2 inch galvanized screws
2 pieces of thick pile carpet 8 inches wide by 28 inches
Drill and bits
Saw
Stud-finder
Stapler and 1-1/2 inch staples

Step 1
Find a wall with cleared space long enough for your canoe.  If you have an 18-foot canoe, you’ll need a wall with at least 22 linear feet of open space. Remember you need room for the folks carrying the canoe to get around the ends to hoist it up onto the rack.

Step 2. 
Find two wall studs to screw into. They should be about a third of the length of the canoe from either end. If you have an 18-foot long canoe, position the shelf brackets about 4 to 6 feet from the ends (no less than 4 feet).  If the shelf is on an outside wall this keeps the sun from heating a composite or plastic boat and making it sag in the middle.

Step 3
Screw the shelf brackets to the wall so the top of the bracket is 3 ½ inches below where you want the gunwales of the canoe to rest.  Back the screw heads with washers. Use 3 ½ inch galvanized screws and predrill the holes.  You can make the rack high so the boat will be up out of your way – if it’s, say, inside a garage or shed.  Just remember, you’ll have to lift the boat up onto the shelf.  Don’t make it so high so that racking the boat is difficult. You can make the shelf waist height and avoid lifting altogether. This is great for an outside rack and saves on the old bones if you’re not 22 anymore.

Step 4
 Measure the beam of the canoe amidships.  This is the width from gunwale to gunwale at the center.  Add two or three inches to this measure and cut your two by fours this length.


Step 5
Set the two by four’s on edge on top of the shelf brackets.  Predrill the holes from underneath and up through the shelf brackets.  Use 2 inch galvanized screws backed with washers and screw the boards into place.


Step 6
Cut out the carpet pieces so they are 8 inches wide and about two inches shorter than the two by fours are long. Lay the carpet strips over the top of the two by fours and staple them into place.

Step 7
Screw large eyelet screws (1 inch or more wide across the eye) into the ends of the two by fours.  Screw a second pair of eyes in the face of the two by fours on the sides of the boards facing the bow and stern of the canoe (away from the center of the rack).  Place those two up close to the wall.  This gives you a pair of handy hook up points to which you can attach bungee cords or tie-down straps.  You’ll thank me later. 

Tips:

  • Don’t paint pressure treated lumber.  Leave it the natural color. 
  • If you can get plastic astro-turf style carpet, use that.  Regular carpet will eventually rot. Artificial grass will last longer, tolerates being wet and protects just as well.
  • Keep metal brackets and screw heads painted to reduce rusting and this setup will last nearly forever.
  • You can bungee lifejackets and paddles up underneath the canoe for easy storage and transport, so that everything is together.


Warning:
  • If you forget to tie your boat down, a good windstorm can leave your boat in the branches of a nearby tree or you can push it off onto the garage floor when you’re dragging tools around the garage. A friend of mine dented his aluminum canoe while trying to pull an electric cord loose.
  • Make sure you have plenty of room for loading and unloading your canoe safely from the rack. Keep obstructions out from under foot.  Dropping a boat on your toe can be painful.
Rogelio Hernandez of Kennesaw, Georgia sent me the picture below of the canoe shelf that he built.  He could only find an 18 inch wide shelf bracket, but the weight limit was more than adequate, so he re-engineered the design a bit.  He screwed the 2x4s to the top of the shelf bracket, making them long enough to support the width of his very nice-looking Mad River canoe and then added a 2x4 brace out to the end of the support arms. The shelf brackets each have a 600 pound weight limit which would support the canoe fine even with the leverage on it from the extended support arms, but like me Rogelio is more comfortable over-engineering stuff.  Frankly, if I had a nice Mad River like his, I'd do the same.  It's a neat way to support the overhanging arms and, as a bonus, you can screw hooks to the wooden supports for hanging lifejackets and other canoe equipment.

Note how the shelf allows room for the cars to park up close to the back garage wall AND places the canoe at a perfect height for lifting.  No bending over to hoist the canoe up off the floor. Allows you to keep your back straight while loading and unloading the boat.  Also, there are no dark places underneath the boat where rats, cats and the odd chihuahua can hide or collect things.  Crisp, clean and neat. Good job Rogelio and thanks for sending the picture.

© 2013 by Rogelio Hernandes, Kennesaw, Georgia
used by permission


Friday, April 02, 2010

Fix a Ding in Your Canoe

How to Get a Dent Out of a Super-linear Polyethylene Canoe

Sounds kinda heroic don't it? 

Canoes with  lightweight hull designs made of a flexible super-linear polyethylene material sometimes get dents in them.  Fortunately, the material they are made of remembers its shape.  You can use this to help you repair minor dents and dings and even some major crinkles.  Mad River Canoes (tm) uses SLP construction to integrate the hull and deck structure of their Mad River Adventure canoes to provide rigidity, durability, excellent abrasion and impact resistance. Integrated polyethylene hulls balance a modest price against a very tough and virtually maintenance free design. But dents do happen. Here's how to save your boat from early retirement if you hit a rock or leave something heavy sitting on the hull in the sun! The instructions here are for dents, not holes, cuts or cracks that breach the hull. That's a different article.


Things You'll Need
  • Heavy leather gloves
  • Hair dryer or heat paint stripper
  • Patience and sunshine

First
First try putting the canoe in the sun and applying gentle pressure to the inside of the hull once the sun heats it up. The SLP hull of the Adventure series canoe has some "memory" and if gently heated may let you pop the dent out and restore your canoe to its original shape.

Second
Set the canoe up on a flat spot in the sand or soft lawn. For more stubborn dents, this technique works best on a very hot summer day. Fill the canoe with water. Water is very heavy and provides the "gentle pressure" you need to push the dent out. As the sun heats the water, it also heats the hull. When heated the hull may "remember" it's original shape and pop back into shape. You may also have to press the warm hull with your hand to get the dent to pop out. Be careful putting your hand in. Sunlight heated water can get surprisingly hot. Keep an eye on the temperature to avoid distorting the shape of your canoe.

Third
If pushing by hand doesn't work, install a brace inside the hull that presses outward against the dent. You can cut a piece of wood to size or slightly longer and wedge or duct tape it in place against the dent. You might want to place a wide square wooden foot on the undamaged side under your brace so it doesn't create a new dent where the brace presses against the side opposite the dent. Leave the brace in place for a week or so and let the sun heat up the water every day. Don't cut the brace so long it pushes the hull out of shape. Watch out for distortion of the hull. Make sure every part of the hull touches the ground firmly.

Fourth
If the dent resists repair by the above described methods, you can dry out the hull and string a heavy-duty extension cord out to the canoe and plug in an ordinary hair dryer to heat the hull at the site of the dent. You have to keep the dryer moving and don't touch the heating element to the canoe. Heat the dent on the side where the dent is and gently press from the opposite side with your hand. You might want a heavy leather glove for this part since the hull will be quite hot.

Fifth
If the hair dryer doesn't work well, you can use a hot air gun of the sort that's used to remove paint and wallpaper from walls. This requires even more care than with the hair dryer. If you heat too aggressively, you might melt the hull and cause a hole to form. Keep the gun moving quickly at all times in a circular motion at least 1 inch from the hull. Watch closely for glistening and melting of the hull surface.

Preventing Dents

On the Rack
Do not suspend your canoe by it's ends. If it gets hot, it could sag and warp the canoe in the middle. Support racks should support the canoe at either end about a third of the length from bow and stern.


In the River
When in moving water, try not to hit rocks. Scout your path and avoid large rocks or shallow bottoms. You may have to get out and walk your canoe around such spots in the river. Be careful not to drop your boat while launching or unloading. Get lots of help when loading or launching.

In the Drink

If the canoe turns over in fast water and fills with water, do not get in front of it. Guide it quickly to shallow water, turn it over to drain the water and pull it out.. Full of water a canoe is as heavy as the car I used to drive in college and if it hits a rock with that mass and momentum, there WILL be a dent!

In the Sun
Do not leave the canoe tightly tied down, especially in the sun. This could pull a dent into the hull from the pressure of the tie down straps. Especially, be careful of heavy duty crank down straps as they can exert serious force on the hull and cause a warm hull to buckle.

* Don't overheat the hull. You can melt a hole in the hull if you're not careful.
* Repair the dent as soon as possible to prevent it from becoming permanent.
* Don't overload the canoe either in the water or on the rack.
* Don't forget your life jacket and an extra paddle.


(c) 2010 by Tom King