Technical Tips & Hints

 

 

the hull

restoring that colour

When I first saw 'Lucy'(235), it was love at first sight because not only was 'Lucy' a hard-to-find inboard, she was, as they say, 'immaculate'. Stored under cover all winter long her three year old dark blue hull gleamed. Three years later the dream was beginning to fade, not in my heart but in the hull, for Lucy's gleaming gel-coat was becoming dull, dull, dull. Fellow owners in David Whitehead's Mylor 'Shrimper Sanctuary' looked on sympathetically as I bemoaned Lucy's plight and then the helpful suggestions began to flow. Try this polish, that polish, colour restorer, meths, T-cut, abrasive paste, Owatrol, I tried them all - and they all worked the miracle, Lucy gleamed again, for hours, days or at best, a few weeks!

In desperation, I summoned an expert in GRP. He informed me that dark pigment equalled maxi fading and that Lucy's only hope was a serious heavy-duty buffing by a professional like himself. Six hours later, Lucy was gleaming again, yes, you've guessed, for about three months.

Then, towards the end of the 1998 season with Lucy fading fast, David Whitehead mentioned that John Ashworth, our [then] esteemed ex-Hon. Sec. had painted his beloved 'Daisy'. Intrigued, I interrogated John. What type of paint was it? Where was it done? How shiny was it? and, now for the big one, How long did the shine last? Epoxy, Mylor Yacht Harbour, brilliant and YEARS were John's replies.

Next day found me in Mylor Yacht Harbour's offices. They recommended the AWLGRIP paint system involving preparing and repairing Lucy's hull above the waterline, spaying with epoxy primer, filling any pin holes and then spraying in premium urethane in a deep, brilliant blue. Lucy looked stunning right through the winter and into the Spring. Her appearance in the first Mylor race brought cries of 'You're blinding us' from fellow competitors.

The cost? Around £1000 in 1998.

For a second view of how to do it yourself read a short story by Roger Lowe who has done it himself, more..

antifouling

We are all aware of the scare stories regarding osmosis, fortunately in a Shrimper the possibility is practically nil. Good housekeeping and a sound boat design/build keep us all in a fairly comfortable state. However, each year we look forward to cleaning, improving and maintaining our craft. When it comes to re-varnishing there is great joy in preparing and finishing wood, fittings can be removed oiled and replaced if necessary, but antifoul removal - what a chore!
There are a number of reasons to remove antifoul and these can best be summarised as follows:

1. Checking for hull damage or osmosis.
2. Checking hull fittings (See John Benge's article 'Corrosion' Spring Newsletter)
3. Removing numerous makes and specifications of anti-foul that has built up over the years.

Generally it makes sense to remove anti-foul to the gel coat every four/five years. This enables the above to be incorporated in a routine maintenance programme, and on a practical level allows for the re-application of a type of anti foul that you the present owner has chosen. The bottom sides are as important as the topsides. Now the problem of removal, I like others considered scarping. A long laborious job this is never 100% and has the potential for damaging the all important gel coat. Unless you have a desire to spend countless weekends hand scraping then avoid this at all costs. Then there is high pressure wet blasting. This satisfies the desire to use brute force and a nifty piece of kit. The process involves directing a high-pressure stream of water at 2000-3000 PSI, with grit being added at the lance end. The system is effective and quick, but uses way to much water, and can (because of the high-pressure) lead to damage to the hull. With these two options the choice then comes down to, well lets just apply another coat of anti - foul and leave it for another season. There is a third option, the SPS system that utilises low pressure, typically 05-115 PSI. The grit is added to the water before being propelled to the hull surface resulting in a misting procedure that gently removes all anti-foul down to the gel coat. The resulting surface is keyed for re-application of either gel shield or if not required anti foul. The process is quick and efficient and takes about 4 hours to complete. The result is a Shrimper that moves through the water with even greater ease. The added advantage of having all fittings and rudder stripped allows for greater piece of mind.

It would be of interest to hear of any member has had any osmosis problems. My feeling is that we are clear of the dread.

bow-eyes

When did you last see your Bow-eye? I know, you see it all the time. But when did you last really check it? For - be warned - hidden dangers lurk within this small fitting. Consider for a moment; not only does it have to withstand the upward pull of the jib and forestay, transmitted via the bowsprit: it also is subjected to repeated jerking and snatching if used as a mooring point as per the Shrimper handbook. Indeed its condition is crucial to the health and safety of your Shrimper. To find out how to get at the bow eye and read of the experience of two members on this subject go to the bow-eye's own page. more..

centre plate wires

I have owned my Shrimper (60) for 15 years and periodically changed the centreplate winch wire with no difficulty. However at the end of the season 2 years ago with the boat out of the water on it's trolley, I decided that after some 5 years the wire should be changed.

Having removed the cabin step, the inspection hatch on the starboard side of the centreplate case and released the tension on the wire, I was horrified to find that the wire would not pull down through the centreplate. A week was spent pouring easing oil onto the top of the centreplate where the wire entered the plate. I gripped the swaged end of the wire with a variety of pliers and endeavoured to hammer the wire down. All to no avail except that the swaged end of the wire parted. I was left with wire coming from the top of the centreplate with which I made a loop with 2 small wire clamps. More easing oil and pulling on the loop and still the wire would not budge. Eventually with an experienced engineer's help, a block of wood was placed on the bridge deck aft of the cabin entrance. This was to act as a fulcrum to scaffolding passed through the loop in the wire. At the aft end of the cockpit I bore down on the pole with a series of jerks while my engineer expert (545) hammered the wire to keep the pull straight in line with the wire's hole in the centreplate. One more jerk and the wire came out and I collapsed in the bottom of the cockpit. Before I could replace the wire the narrow hole in the centreplate was cleaned out with a watchmakers file. This entailed drilling a small hole through the top of the centreplate case.

Why the wire jammed, I am not sure. The wire had been in place for some time, so it could have been electrolytic action between the wire and the plate. The wire should be well greased before threading it through the plate. In addition I now take our Hon Secretary's advice and change my wire every second year.

centreboard case distortion

Robin Whittle had some trouble with the centreboard travelling correctly in his 1983 Shrimper and found that corrosion of some of the ballast was to blame. This is the full story of how he cut out the old and replaced with the new, more..