Pot-pourrit of lessons learned from building my scarab22:
I will add to this as things come to my mind...
- It si very hard and unpleasant to finish concave joints.(cockpit joints, beam
fairings, beam stubs)
- It is even worst to finish concave corners (beam stubs, beam to float joints))
- Sanding fiberglass is not fun (whole boat...). Shaping solid fiberglass in even
worst (beam UD)
- Metering pumps for epoxy are excellent for small to medium batches. Graduated
pots are best for large jobs.
- Taping chines is slow. It is difficult to make constant radius chines. It is
slow to fair.
- It is very difficult to manipulate a float with beams attached. At least 3
people are required and you can't position it adequately for working on it. It also takes
a lot of space in the shop. This is a MAJOR issue when you are trying to fair a float.
- It works very well to glass the inside of a foam hull panel and glass the
outside on the whole boat in one go. Tapes are used on the inside (no fairing). I made my
centerhull like this and it is perfect. I would build the floats like this next time.
Float stringers (shelf) should be wood. Current design is very slow and
not adapted. It should however be designed allow water to drain to the "bilge"
of the float.UPDATE: The inside of the floats are always at 100% humidity. They
are difficult to dry. There is always condensation inside so any wood in there would rot
eventually, and it would be impossible to inspect. NO WOOD!!!
- Beam stub fairings are the worst part of this boat. Their shape is awkward and
it is very difficult to control the gap with the beam ends. Many clearance and fit issues.
Plans are of no help there.
- It is very hard to paint a cockpit without stepping in the paint!!
- Aluminum parts are super: no paint, no maintenance, light, cheap.
- Cockpit floor stiffener is not positioned correctly: it should be halfway
between the traveller and the companionway. It should be positionned to support the weight
of someone using the winches.
- Folding geometry is questionable. During folding, there is a point where all
pivots are aligned and motion is not controled. It works but should be improved. I used
numerous plastic shims and pads to keep the folding and un-folding smooth. Also, the
bushings are very sensitive to any play, so make them very tight!
- Cabin space is very good and pleasant with the pop-top open, although when full
of sails, cooler, gas stove, water bottles, and the top closed, it is good only for one
- Spray painting is difficult on vertical surfaces, but very easy on horizontal
surfaces. The cockpit is very hard to spray paint correctly.
- When spray painting, dust is not a real issue. It is easy and quick to clean the
shop enough for the job.
- When spray painting, LIGHTING is crucial. When you have your mask/goggles on, it
is very difficult to see what you are doing. White paint on white paint is not evident,
unless you can see a reflection off the surface, at any position on the boat.
- Use a primer having the same color than the top coat, or very close. This way
you will not be tempted to apply too much topcoat for coverage and runs will be avoided.
(use white primer under a white topcoat...)
- Do as much hull bottom work as possible while it is upside down. This includes
waterline and primer as far close to the deck as possible. It is very hard to do when hull
- The centerboard case is seriously weak as designed. Also, the drawings dont
specify removal of the core around the slot opening under the boat and calls for
only one fiberglass ply. The loads from a centerboard are high and need to be reacted by
- To assemble the boat, pin the folding struts on the centerhull first, then
position the floats in the deployed position to receive the outboard pivot pins.
- Have one beam detached from the floats or make 5th dummy beam to make the beam
stub fairings, verify folding struts, position hold-down bolts.
- Beams are about 6" too long to fit boat through a garage door.
- To remove core for screwing fittings it is much better to use a hole saw from
the inside than a bent nail from the outside. Just use the hole saw to make a nice round
hole through the inner skin (1" diameter) for every screw, remove ALL the foam with a
1/2" sharp chisel and fill the cavity with putty. Laminate glass or carbon over the
putty to restore the inner laminate plus extra plies acting as a backup plate. Then drill
fastener holes from the outside.
- Silicone sealant for bedding fittings or hatches is awfull. It sticks on
everything and is slippery as hell, it smells bad and cures too quickly. Maybe very slow
silicone is better. 5200 is very nice to work with but is very strong so dont use too much
if you want to remove the fitting later.
- Get a grinder with a cutting disk to cut ALL the fitting bolts and screws to the
proper length. No fastener is the standard length!
- When un-folding the boat, extend float that is away from the dock first and
install the locking nuts by standing on the beams. Then extend the dockside float by
standing on the dock and pushing the centerhull away. The tension in the trampoline makes
everything smooth. To install the locking nuts, walk on the beams until your body weight
pushes them down in the right position. I weigh 170 lbs and this is just enough.
- Raise the mast only when the boat is deployed. If raising the mast with the boat
folded you risk bending the shroud chainplates since they are not oriented to take side
loads. If the chainplates were bolted to a bulkhead inside the floats (rotated 90°), this
would not happen. It is possible to fold the boat with the mast up only if you rake the
mast a lot to loosen the shrouds significantly.