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one minute guide
building overview
• materials
• tools
marking out
hull assembly
hull assembly 2
hull completion
foils
spars
rigging
finishing
sails
signs and graphics
kits and supplies

 

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Repairs001
HOW TO REPAIR YOUR PRIDE AND JOY

Sailing's fun, but inevitably something will happen that will cause damage, and when that happens you have to think about how to keep going, and how to make a permanent repair. These two examples are at the opposite extremes, but will highlight how even a major repair isn't something to tear your hair out over.

Firstly, a small crack in the plywood. It was very cheap timber, with lots of voids, and the ply has delaminated. More of that later, but we want to keep sailing today. The easiest thing to do is to simply put a couple of screws in to reinforce it for now, this will stop the split getting any bigger. After the permanent repair, which really only means getting some epoxy into the crack, the screws can come out again.

Repairs002
DON'T FORGET THE DUCT TAPE

Duct tape, Gaffer Tape, Race Tape, Duck Tape, call it what you will, it is the small boat sailor's most important repair tool. Once you've screwed the crack together, or sometimes it works instead of a screw, you simply stick it over the leaky bits and they don't any more!

Of course it can also be used to repair sails, stop chafe, to package things, and in emergencies, to dress open wounds!

Repairs003
WHAT IF IT'S REALLY SERIOUS?

You mean what happens if some oaf kicks a hole in the bottom of your boat, and it's nearly as big as the ocean surrounding you?

Well... you could tape the bits up, and you might get away with it for an hour or two, but you'll need to do a bit better than that for a permanent repair. It's easy enough to scarf a piece of ply into the hole, or if you want to be really crude, you could put a slightly larger patch over the inside, and fill the outside with filler..... ugh!

In this case, the damage was severe because there were major flaws in the cheap ply we used, so we'll whip off the bottom and give it a new better one.

Repairs004
WHY CHEAP PLY ISN'T CHEAP

We don't like using cheap construction ply, but I admit I was swayed by all those people who reckon it's the duck's nuts, and here's the result!

The red lines that the arrows point to, are not laser lights, they are the sun shining through the voids in the ply, leaving only the decorative top and bottom veneers for structure! The centre veneer is not only missing, but it's meant to spend it's day vertically fixed to a wall, not bent on a boat bottom, and it's a very brittle ply indeed.

So brittle, that the damage above was caused by me popping my heel through the floor, while on the water! One of the issues here is that construction ply (this was 4mm thick) has only three plys, two thin outer veneers, and an inner one which is probably 2/3 the total thickness of the ply. We elected to replace this with a good quality gaboon (okume) 6mm ply, which has five plys, no voids, weighs less and was much more sturdy. So sturdy that we didn't need to put the bottom runners on once we'd finished.

Repairs005
PLY CRACKS

Surprisingly perhaps, it took a few weeks of relatively heavy use for cracks to develop along the voids. We were aware that the voids were there before launching, so watched progress carefully.

We considered simply using a fibreglass bandage over the voids, but that would only keep us afloat until something bigger happened.

And it did! :-)

Repairs006
MARKING FOR REMOVAL

Having decided to replace the bottom, we had to remove the old one, preferably leaving all of the existing structure in place. The best way to do that is to use a router, but first we need to work out where the structure is from above.

Simply drilling a series of holes through the hull adjacent to the bulkheads will tell us that with a good deal of accuracy!

Repairs007
MARKING THE BOTTOM

Once we have all the bulkheads located, we used a heavy marker pen to clearly show their position on the bottom.

Repairs008
ROUTING THE BOTTOM

Setting a router bit just a teensy bit short of the full thickness of ply, we start removing all the bits between the felt pen marks.

It won't be long before the whole bottom is just a few pieces in the rubbish bin. This job really suits kids with a destructive gene!

Repairs009
SURGERY

Like a skilled piece of surgery, only a few pieces remain to be routed or chiselled away before the panel can start coming away.

Repairs010a
CLEAR

With the aid of some judicious sawing, and a bit of chisel work, the bottom is clear, leaving all manner of scraps and glue to be cleaned up before the next one can be fitted.

Repairs011
CLEANUP

A belt sander is used to clean all the old joints of debris, and to get them back to their original profile.

Repairs012
CHECK ALIGNMENT

Use a straight edge as you go to make sure that the bulkhead all line through in one plane as you clean them up.

If you cut one back too far, you'll end up with an ugly dip in the bottom of the boat, and it won't be fast!

Repairs013
TEMPORARILY FIT THE BOTTOM

Use a couple of screws to fit the new bottom temporarily. We have to mark all the bulkhead locations again so we know where to screw, and it's probably best not to use the "holes drilled through" trick this time!

Repairs014
MARK OUT BULKHEADS

It's easy with the bottom screwed on to mark all the locations of bulkheads.

Of course it's a lot easier if you have a large pencil with a pink tassel on it.

Repairs015
PRE-DRILL FIXING POINTS

Unscrew the bottom and flip it over. TARAH!! All the positions of bulkheads appear in exactly the right spots, now predrill them so you can screw them in easily later.

If you wish, now would be a good time to start pre-coating what will be the inside with epoxy. You can save a day or so if you can glue it all down without having to wait for the epoxy to go off.

Repairs016
MASK THE INTERIOR

Because everything that's left inside the boat is finished varnish, we don't want to make more work for ourselves than is necessary.

Run around the whole perimeter with masking tape. You'll be surprised at how much there is!

Repairs017
GLUE IT ALL TOGETHER

Now apply epoxy glue to all the contact surfaces, then with the epoxy side face down, screw on the new bottom using temporary fasteners.

Repairs018
CLAMPS

Because the side tanks were originally held in place with epoxy fillets only, we couldn't screw into them, so we devised a method of clamping using packers as cauls to apply pressure in the required spots.

Repairs019
FINALLY

Turn it all over when the epoxy starts to cure, so that you can clean it up before it all gets too hard (the epoxy and the job). It's not as neat as it was originally, but it's tidy enough, and we are back on the water in a few days.

I haven't covered the painting, and so on as it's just more of what went before!

 

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