UK-Cherub Class

Get Your Heart Racing

Don’t Do it

There are some things that you should never do when maintaining a Cherub. At least not if you want to keep on sailing reliably and finishing even winning races

It will never hold

Never attach fittings to your foam boat with wood screws, it just does not work, they will pull out. You may say it is OK if you use a wooden backing piece and the fitting is low load, but you are taking a risk the wood will absorb water and get soft, the fitting will pull out it just takes time.

Never bolt high load fittings to a foam sandwich panel without a large washer or backing plate or at least replacing the foam with a plug of filler. The foam will crush and it will break.

It will always leak

Never fit a hatch cover to a curved deck. Hatch covers tend to leak at the best of times and if you are trying to fit it to a bit of deck that is not flat then it will always leak.

Never skimp on the thickness of the centreboard case. The centreboard case takes loads of abuse and once the boat has been built it is difficult to get to, so there is no point in saving a few grams by building the case super flimsy. Any weight you save there will more than be made up a couple of years down the line by a small leak that you can’t fix.

Never build your boat without a breather hole. When you put your hot boat down on a cold sea the air in it will contract reducing the pressure inside the hull, this will help water find its way in through the smallest hole or crack. In a bad case on a very hot day it may even damage the deck or hull.

It will not last

Never tie string to a pressed shackle or deck eye. If there is any movement in the string the sharp edges of the fitting will saw through the string, if lightly loaded it may last a few months, but heavily loaded it may not last the day! Use a forged shackle or thimble on the eyelet an it will last a lifetime.

Never attach Aluminium to Carbon, The aluminium will corrode through in no time.

It will just be heavy

Fair your boat with car body filler, it does not stick well to the epoxy and is extremely heavy. The short cure times are just not worth it.

Wetout directly onto a foam core, you are just pushing resin down into the voids in the core, margarine the core first with a lightweight mix of filler

Never stop worrying about weight, Every little bit of your boat that build adds weight and it is hard to get rid of.

It wont be strong

Never forget about triangles, Triangles make structures strong, forget about them at your peril.

Never forget about fiber orientation, Fibers are only strong along their length, at 90 degrees they have no strength. So make sure the majority are pointing in the direction of the load.

tech/dontdoit.txt · Last modified: 2013/06/25 15:55 (external edit)