We would be glad to have that - so yes please if still available:  philiph(at)truro-penwith.ac.uk - as usual replace the (at) with the @.

Phil 01326 372096 Home

Phil & Kim
572
Georgie Girl

I bought direct from  sailspar  4 years ago. Its advantage over the old holt allen type is that you have a thicker, continous line, easier to handle,and will not come off the drum, but beware when dropping the mast . Protect the bowsprit with a piece of carpet, where the furler drum will touch, or disconnect the furler first.and lower using the forestay. 

Keith, 
You're quite right about the varying grades of s/s and also that they are unhappy below water - BUT I had hoped that Cornish Crabbers would be using good grade s/s and therefore preferred the possibility of the unbroken connection between engine and battery being the cause. I am more than happy that the anodes have been working well - even at £10 each they're cheaper than a new outboard. I'm interested in your copper antifouling fighting with s/s theory. Hadn't thought of that and perhaps a better barrier layer would be good. I'll have to try that as well as disconnecting the motor from the battery. 

Mind you, I wouldn't mind a couple of days of warmer weather so I can get the antifouling on!

Thanks for your input.

Cheers,
Colin

I agree with Graham - if the anodes are being eroded and there is no evidence of damage to the aluminium alloy outboard then they are doing their job.   That said, fast erosion usually means that there are currents flowing somewhere that need to be investigated.   An outboard anode should last at least a season even with the engine left in the well. 

Regarding stainless steel, it is wideley recognised that there is always a risk of corrosion with stainless underwater as it relies on contact with oxygen to maintain its anti-corrosion layer.  Commercial boatbuilders prefer to use bronze for underwater fittings, but these are often still connected to some sort of internal electrical bonding system to prevent erosion.  All this is very much OTT for a Shrimper and provided we are sensible, keep a reasonable watch on underwater fittings and turn off electrics, where possible, when the boat is not in use, everything should be fine. 

One thing you can do to help is insulate fastenings from their fittings.  I had a problem with erosion of fixing screw heads on a stainless steel pintle on the keel.  It was cured by inserting a small quantity of oil based mastic into the screw holes before inserting the screws.  When the screw is tightened the mastic spreads out across the countersink to form a thin insulating layer between screw & fitting and I also smeared a little across the outside of the screw head.  I found by experience that Silicone doesn't work for this job as it is too slippery and squeezes out and use a Wickes mastic designed for assembling conservatories.  Not sure which part actually solves the problem, but it must be doing something as for the past four years I have not seen any corrosion.

Finally, as Graham mentions, there are various grades of stainless steel and not all are intended for marine use.  A4 is the best stainless steel grade for marine use, but not all fastenings are to this grade - many prepacks contain A2 grade fittings that are more prone to rusting, even above the waterline.  If in doubt, have a look on the packaging - Marine Prepacks usually state the material spec.  You can also test for grade by magnetic attraction.  A4 is non-magnetic whereas A2 has a slight attraction.  

I do wonder, in this case, whether the problem lies in a the outboard being permanently in the water and attached to the battery via the charging loop.  Although insulated, there is always a chance of a barely detectable earth leak across the rectifier, causing current to flow back into the outboard from the battery and hence to the leg anodes.  Have you tried disconnecting the charging connection to see if the problem goes away.

Regards

Keith   

Seeing Stuart's comment, I have a log through hull but echo sounder mounted inboard since 1988. It sits in a cardboard tube which I painted for strength, and is filled with vegetable oil. It works very well.

Chaps,

Do be careful not to get too carried away by not looking at the simple things first. The outboard motor is aluminium so if this is not being attacked the sacrificial annodes are working fine. Do you have any other annodes fitted to the hull and if so are they earthed to the fittings? Don't immediatly assume the corrosion on the stainless is due to the effects of the outboard - what type of anti-foul do you use? If it contains copper and is in contact with the fittings, this could also be the cause. There are different grades of stainless, some of which are more suseptable to corrosion than others - this could be an issue if you have any 'non-standard' parts.

Regards,

Graham

Dear Mark

I have a 2005 Shrimper and I have speed and depth transducers fitted, they are either side of the centre plate box as Richard has said.

Mine are plastic, through-hull transducers, and while it takes a bit of a swallow to drill an inch & half hole in a perfectly sound hull, I have never had any problems of leakage on either sensor.  You don't need a fairing block as the modern through-hull sensors are very low profile and can be antifouled.

If drilling a hole it too much to take, you can buy optional in-hull transducers from most manufacturers, which these days are epoxied into place, and will work perfectly well through the sort of GRP thickness on the bottom of a Shrimper.  That said, I don't have personal experience, just the advice from the manufacturer.

The oil-filled sensors went out with the trailing log.

Hope this helps
Stuart

The skin fitting can be left on the boat and the sea cock should just unscrew off the skin fitting, although there might be some thread lock or sealant which might make it difficult to remove, if you are removing the seacock try and prevent the skin fitting from turning as this will break the seal between the skin fitting and hull.

Dear All

I went along to the Farecla workshop in Poole, and found it very informative.  I also bought their 'Maintenance' kit to have another go at the hull this year.

The workshop was helpful, and explained that the finish always degrades, and is most obvious on black, green and blue hulls (mine is very dark blue), and is mostly due to the sun rather than oxidation.  They also pointed out that Farecla now have specific products available, rather than products like G3, which is primarily for automotive application.

Their 'Maintenance' gelcoat restorer worked extremely easily, and I used surprisingly little of the bottle.  I applied it with a foam disc, and found it worked very quickly.

Last year, I used car wax to cover the gelcoat, but Farecla supplied an 'Ultimate UV Wax' - this went on extremely easily, and polished off with a polishing disc leaving a fantastic finish - as good as new were it not for the deeper scratches which this sort of product does not remove.  I will have to wait until the end of the season to find out if it is really as good as they claim.

For the topsides (mine are cream), they have a combined gelcoat restorer and UV wax (not Ultimate this time), which is obviously half the work.  I have yet to apply this, but if it anything like the other Maintenance products, it should be dead easy.  I also have enough left over to do the job a number of times.

I believe that the Maintenence kit is available to any SOA member for a price of £39 - that includes bottles of gelcoat restorer, ultimate UV wax, combined gelcoat restorer and UV wax, and three microfibre clothes for removing the restorer - great value in my opinion when you see the result.

I have absolutely no hesitation in recommending these products to other Shrimper owners, and am very grateful to Trevor and the SOA team who organised this excellent workshop in Poole - thank you.

Stuart

I have a boom tent, which came with my Mk 1 shrimper, I think that it is the standard magnolia version that Cornish Crabbers supplied. I have never used it and its in pretty good condition. Its in Suffolk and for sale at £95.

Any takers?

We use our tent (standard one) to dump the detrious from the cabin and keep it dry when we sleep in the cabin. It works fine.

Paul

Oh dear. You make a very good point. I hadn't thought of the engine's being permanently connected to the battery as being a problem, but you could well be right. Particularly in light of your own experience. Many thanks. I can easily disconnect the engine. The problem is my brain and trying to remember a/ to disconnect and b/ to reconnect. I shall definitely try. Again, my thanks.

You might also like to look at the Tech Tips - Living Aboard section on the website, where there is a short item from Barry Mellor on tents.  He also shows his own, which is flat topped, vertical sided, ideal for socialising on board.  I know Barry would be happy to provide more info to anyone interested.

Regards

Keith

Ive been doing a bit of decorating today and have been thinking about this.

 I have a copy of Nigel Calders Boatowners Machanical and Electrical Manual, which I have glanced at, in it there is a 35 page chapter on the causes of electrolisis.
If you take the least case scenario, then what we have is a battery at the back of our boat, we have a passive, corrosion resistant stainless steel pintal and gudgon( and straps and screws), then we have a flowing electrolite in the form of sea water and we also have a very active metal about 300mm from the p and g in the form of an outboard motor and its anode.
According to Nigel Calder (page 200) we have a simple galvanic cell, and if an ammeter was placed between the p&g and outboard a very small current could be obtained.

Just looking at my Shrimper for a moment, I had a 5hp Honda with a charging facility, connected to a battery with an isolator, I found that my motor to battery connection was live all the time regardless what the isolator was doing, with the battery connected to the outboard and the outboard in the water then I had an oppitunity for discharge leakage.
By disconecting the outboard from the battery when not in use this resolved the problem.
What I ultimatly did was buy a Mariner 5hp and take it off the back of the boat and put it in the aft locker when not in use.

Hope this helps

You're clearly thinking as I have - but it's left me puzzled. Boat on swinging mooring. Outboard engine provides tiniest amount of charge to single 12v battery, which is mainly charged by solar panel. Outboard remains in water - don't know if that's significant. Anodes on cavitation plate are perhaps 1ft from the stainless straps on the rudder. The worst corrosion of a screwhead is, bizarrely, on the opposite side of the rudder. 

Any of that help a diagnosis? Much appreciate your interest.

What electrical systems do you have on board?
Are you in a marina or mooring?
How are you charging your batteries?
I understand that electrolisis can be caused by dissimilar metals being in contact with each other, as well as earth leakage, caused by very small amounts of current through poor wiring, switches or connections reaching earth (sea).

Has anyone else suffered surprisingly high levels of electrolysis? I have an outboard and have fitted two (smallish) extra anodes to the cavitation plate. These have gone almost completely in the last season and some of the stainless steel straps and screws holding the lower gudgeon and pintle on the rudder have been attacked. I'm surprised by the speed of loss from the anodes and of the level of attack on the stainless steel fittings.

Thank you for this.

A further problem

As part of winter laying up I filled the fuel tank, I should say overfilled  - fuel was coming out of the vent on the transom. I have also had to pump fuel out of the bilges.

I have now with the wooden dowel you suggest measured the fuel in the tank it measures 10 cms on the stick, the depth of the tank measured on the stick to the collet for the dip stick is 18 cms. It would appear from this that the tank is only half full.

Should I be checking for a leak?

Thanks for any guidance.

Martin

anyone having problems with this product...

I've now found out that the Holt Allen gear is now supplied by Chris Holman at Chichester Marina 01243514000 - if anyone is interested - Julian

hi brian

do you know who made your large tent?

thanks

alex

Graham,

Was it Batt or Arun by any chance?

Julian

Thanks Graham,
Since BB is currently living in Chichester Harbour ( Bosham ) and I live close-by this may not be too difficult - thanks for the heads-up.

Julian

Julian,

The spar was made by Holt-Allen but they no longer produce them. Manufacture has been taken over by a sailmakers in Chichester, but the name escapes me (old age) and I am a long way from home and my info at present. I have provided the name to several people, but if no-one else replys suggest you phone around the local saillmakers - there can't be that many.

Regards,

Graham

I should really get a new roller furling foil this season - the present one is a bit clapped out ( actually very!)
Who apart from Crabbers themselves might supply these - any thoughts?
 
Thanks - Julian Biggs ( Bybyn-Bubyn 384)

Martin,

The most common method on ships is to use a piece of chaulk and put this on your dipstick or measuring tape.
This gives a clear reading of the level of fuel in the tank.
More practical is to have a piece of wood, diam 5 mm, approx 40 cm long, and a piece of waste cotton.
Make your choice!

Regards,
Krijn, (Grace, S996)

Moonfleet Sail 920 inboard

I use road diesel and I am unable to see any mark on the stainless dip stick

Is their any way to make the wetted section more visible?

With thanks for any advice

Martin

Hi Peter 

I had a similar problem with my 17 year old mariner. I used Hammerite non ferrous metal primer followed by Mariner spray top coat.
The first year wasn't so good, so I redid it. I also put on a new anode. This helped alot and now I change it more regularly. The paint is now lasting well.

Hope this helps
 Richard Smith

Paul/Malcolm

Thank you both.

Trevor