So began the 1st structural repair I've ever had to do to her in a lot of miles and 26 years or ownership

I cut out a bit of the inner skin to find some very wet plywood mush. This was somewhat surprising, as she is a Coremat hull and divinycell decks. I did not know there was any ply in the laminate anywhere! But it turns out there were two sections - the backstay chainplate mounts. Anyway, it was more than damp - Once the skin was cut off, I removed the ply by hand and scraped the remains off with a fingernail! There was zero sign of this externally, just a slight crushed section on the inside surface. 

Anyway, removed the rotten/soggy ply and ended up with this;

I worked out that the original ply and skin was about  18mm thick. Now to replace the core. No Plywood for me! I considered 200kg foam, but really wanted G10. That seems to be unavailable in NZ, so I decided to make some. I ended up making a mold from multiboard, and hand laminating (60x200gm cloth and epoxy - yes, 60 layers!) rolling as much resin out of each layer as possible,  and then putting a lid on the mold and compressing it as it set. The result was this;

With a new backing plate as well - the original just had penny washers, which I never liked. Backing plate is 6mm 316. New core came out at 17.8mm, so that worked out well.  

Next was to glue it in with a thickened epoxy (microfibres) , and use the new backing plate bolted on to provide compression while the glue dried..

The filler also gave the opportunity to bevel the edges and fill any gaps - it was pretty hard to cut out the skin accurately in a cramped lazarette upside down! Sanded ready for next phase after this pic...

Once dried, and plate and bolts removed, and sanded, the inside skin has to be redone. 5 layers of 450g double bias was used for this, and peel ply over it all once up. After that, Epoxy painted over patch and when that dried, reinstall the hardware - new bolts/nuts and Bed-It-Tape outside under chain plate and around bolts. End results;

So that should be good for another 38 years! And Yes, checked the other side with a 6mm hole into the ply. Bone dry. This one had leaked thru the cable penetration for the SSB antenna, which is, of course, not there on the other side! Final step was to re-setup forestay and backstay, re-tension and go sailing!

So now the Forestay chainplate (Done while this was off), backstay chainplates and associated stays are done. Next will be the remaining shrouds (Caps, Intermediates, Lowers and Babystay) to replace and their chainplates to remove, polish, crack test, and replace with new bolts etc...

Boats! Work is never finished!

I have a 20 hp Beta Marine diesel which is three years old. The enhgine manual shows tht the heat exchnage should be serviced annually.  Is flushing the raw-water circuit with fresh water sufficient, or should I remove the heat exchanger and clean it with a marine-grade descaling solution?

If descaling is recommended, which products are safe to use? Should the shaft-cooling hose also be removed and cleaned separately, and are there any risks associated with circulating a descaling solution through the shaft seal or stern tube?

If the heat exchanger needs to be removed, I have heard that using a wooden dowel to clear the cooling passages is safer than using metal tools, which could damage the tubes. Is this correct? Are there any recommended cleaning techniques when cleaning the build up inside the heat exchanger tubes?

Got Hempel Globic NCT9000 at present, which doesn’t seem that good?

Used to use Micron 66, but feel that the Micron 77 wasn’t as effective? 

But now there’s no nasties in it, maybe nothing is that good?

Boating is around d Auckland, Waiheke, Barrier, then up the coast every Xmas for 6 weeks.

Sailing cruising cat, bit faster than average production apartment block but no race boat.

Cruises at 8-14 knots?

Thanks in advance, popcorn & wine at hand!

Is it good set up, could it be improved and is it worth the effort of changing over a cutter to a self tacking staysail?

Would like to hear all stories good or bad.

I can send to OZ if I have to, - it's a Maxwell 22, but I have to buy 10 of 'em and nearly $70.

DeFoul Antifoul Removal — HullWell Advanced Marine Coating Technology New Zealand (NZ)

"Ivermectin is not a legal antifouling option in New Zealand, as the Environmental Protection Authority has phased out several harmful antifouling paints, and using substances like Ivermectin in antifouling paints may not comply with regulations. Always check current regulations and consult with local authorities before making any changes."

and;

"Illegal addition or use of prohibited antifouling substances in New Zealand can be enforced under multiple laws; typical penalties include:

Infringement fines (on-the-spot): NZ$600–$2,000 for individuals and NZ$1,200–$4,000 for companies for RMA infringement offences (ranges set by the Resource Management (Infringement Offences) Regulations). environment.govt.nz

Criminal fines on conviction under the Resource Management Act: recent amendments raise maximum fines up to NZ$1,000,000 for individuals and up to NZ$10,000,000 for companies (actual penalty depends on the offence and court). duncancotterill.com1

Additional enforcement outcomes: orders to stop use, removal or disposal of products, remediation costs and liability to pay council/EPA investigation and cleanup costs; insurers cannot cover fines in many cases. duncancotterill.com1

If the issue also breaches hazardous-substances or biosecurity rules (e.g., ACVM, HSNO, Biosecurity Act), separate offences, enforcement actions and penalties may apply under those Acts. mpi.govt.nz"

Just so you know....

I'm seeking advice on etch primers to use on my stainless steel keel shoe, prior to antifouling. I'm in an estuary subject to heavy fouling, and struggle to get anything to stick adequately!

Any success stories out there please?

Will

im after boring advice on some repairs on a yacht based in bayswater, the kauri decks have some rot and I’d like to repaint the entire deck

happy to pay someone to come for a chat

cheers

does anybody know where I can get some foam core offcuts? - I need several bits about 130mm wide and about 300mm long and don’t really want to buy a whole sheet.

Positives, I can do it myself with minimum hassle. Replacing with copper probably means outside assistance. 

Negatives. Would it degrade the sensitivity of the steering? Enough to worry about?

Cost?

Who knew that 50 year old hoses would give up at the worst possible time?

An amendment to the Electricity (Safety) Regulations 2010 now cites

This came into force Nov 2025.

Primarily, what this means for eveyone here, is that you'll no longer have to put up with me and @Island Timedisagreeing on which standard applies

Anyone knows if that's normal?  Dont want to go trying to pull it out of its supposed to be like that. 

There are still some things i am yet to discover about the current setup, like where does the power come from, and why are the two seperate compasses, but what i do know is that the Speed Depth transducer is one end of the setup, which i thought was not what you wanted, and the first drop off the current system is a single cable that goes up the mast to 2 triton units under the boom (havent opened that box up yet to see what else is hiding there.

Attached is a copy of the current system, and then a copy of what i think i need to get to to do this properly.  The curreny restriction is that i cannot remove the mast cable as the current holes would not allow the cable to pass through without cutting off the ends.

Anyone see any issues with what i think i should be doing.

Very similar, if not identical, to the smallest of these:

The SSB has a wide/thin copper tie, 2" +/- wide x 1mm that connects to this. 

Why does it use a copper strip instead of just a wire?

Can I use this as my EWOF marina AC earth? 

Thanks 

I’ve currently got a B&G hydraulic ram which makes the helm feel like you’re steering an old wooden scow. Without the ram on its fingertip light which is nice. The DD15 supposedly offers no resistance when it’s in standby mode which would be nice so wanting to know if anyone has experience with them.