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I am considering a new coat of antifoul for Cappella and being a hands on type of person would like to undertake this job myself.

 

I am sure many members have undertaken such a task and can offer insight into the process and the pitfalls.

 

Would the general consensus be to have a go or rather save the time\effort and cost and go the professional route?

 

The yacht is a 32' Whiting presently at Gulf harbour marina.

 

Cheers, Ron

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have a go, the hardest part is getting it out of the water and I assume the marina will be doing that,get them to waterblast it too, the rest is pretty simple scraping sanding masking tape and then painting with a roller. Choosing the paint to use is harder, there is one possibly jotul 60? that will last 60 months? do some research on what is working for others in your area. :)

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The sanding is a sh*t of a job, toxic so wear protective gear and use a dust extractor on the sander. Painting part is easy roll it on.

the big decision is whether to go for an hard ablative or a softer version.

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The sanding is a sh*t of a job, toxic so wear protective gear and use a dust extractor on the sander. Painting part is easy roll it on.

the big decision is whether to go for an hard ablative or a softer version.

From memory, Gulf Harbour do not allow dry sanding, only wet sanding.

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Im one of those professional (about to do three in a row).

I say go for it ! Its not that hard.

DONT dry sand. If the surface is not to bad then use 60 grade wet paper and abrade the whole surface.

I do it all by hand .

You dont have to remove the old coat if it is good and solid, just take the surface off. If you know what was on before you can probably recoat straight over. Otherwise, a tie coat of

Primocon, (International) or vinyguard (Jotun) as an example needs to be put on before your at least two coats of antifoul.

Cover up and wear a respirator.

Use disposable vinyl gloves.

Use good masking tape.

An extension pole on your roller saves time and your back.

Check the open times of your choice of product.

Some have specific recoat and in water times, others dont.

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The sanding is a sh*t of a job, toxic so wear protective gear and use a dust extractor on the sander. Painting part is easy roll it on.

the big decision is whether to go for an hard ablative or a softer version.

 

No, no, no ... DON'T EVER sand the anti foul dry. Wet sand the existing anti foul with wet and dry paper by hand. It's a nasty job and you'll probably get covered in crap, but at least you won't be breathing in the toxic dust and neither will anyone else. Most boatyards these days DEMAND that antifouling paint be only wet sanded.

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Those sanding thingies on a stick are the bees knees. (probably illegal but I used to "clean" the bottom with wet and dry the last few times before a paint job and that was the sanding done).

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Yeah just harden up and do it.

Pull out friday night.

Sand all day Saturday (or until sick of it) then mask waterline etc.

First coat sunday morning.

Second coat sunday arvo.

back in monday

Remember to get an additional coat on the leading edges of rudder and keel and waterline.

Have your ducks in a row so you can do other underwater maintenance at the same time ie annode, propspeed, whatever.

Take all the safety precautions mentioned here. The sanding (yes wet) is yuck.

If rolling use OIL BASED rollers, the finer foam ones you can get from the decorating dept at bunnings the better and chuck em out.

If you use water based fuzzy ones, your boat will look like a sheeps arse.

 

Oh, one more thing. Beer. Lots of beer.

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Practical tip: use a plastic bag as a liner for your paint tray by putting the whole tray inside it and taping up the end to stop it moving about with the roller. When done "inside out" the plastic bag and throw it away. Saves clean up.

 

NB: make sure there are no holes in plastic bag :problem:

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Anti-foul these days dont work (except for the retailer and manufacturer). Did ours in October and then a trip to the Barrier and back and the slim just won't let go (forms a nice home for the other weedy sh_t). "Seahorse" worked well (full of copper) but have gone bust?

As for sanding (a disclaimer here as this is potentially quite dangerous!!). 1/2 Moon Bay said no dry sanding. We had purchased a cheap flat bed sander and velcro stick on sheets so some thinking, some insulating and a isolation transformer(!!!).. we WET sanded!! OK, my mate sprayed water then we applied the sander. The trick was to not sand straight away as the "soup" would be too runny and clog the vibrating cam but after some trial and error, it worked very well...and I'm still alive too! :oops:

I have thought of jimmying up a weed eater??? It wouldn't be hard to rig a sanding head to one and rip into it with no problems about water zapping the electrics...or user!! Do the petrol engines run upside down?? :wtf:

We once tried adding some coper oxichloride to the anti-foul but the greeblies just thought that was sauce on their dinner. I have since learnt that adding things like extra copper...tin..radium and not quite depleted uranium etc to your ant-foul is not popular with authorities so we are stuck with the useless copper stuff or the very expensive teflon variety?? I did hear someone is working on the active component of sea sponges that keep them free of pests?? How far away??

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I can wet sand my 34footer - a good going over with 80grit wetdry on a block in 3 hours. If I use the mesh on a pole it's quicker but not such a good job.

Two coats plus extra on edges takes two 4 litre tins.

I use hard antifoul for the first coat then put on a coat of ablative in a different colour, have been happy with altex no10 and no5.

Last time I got white no10 hard and used it for the boot topping as well as the boats on a mooring.

Yes it's a messy job but satisfying and good exercise. Cheers

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No you don't just wash off slime. You have to sand it. Frankly, I don't see the point. Stuff grows on it, you haul it once a year, waterblast it, sand it and put it back in. The only benefit is that you don't need to put a coat or two on it. Hard Antifoul works better as far as controlling growth for 12mths, but you have to coat it every 12mths. Ablative works much better for 24 to 36mths. What you have to work out is, does the cost of not Coating every 12mths for 10yrs, work out cheaper than coating every 12mths with Hard antifoul.

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has any used coppercoat?they reckon it will last 10yrs only need to wash off slim every 6 months?

yes we put it on a 40 ft cat 3 yrs ago and happy with it , yes you still have to wipe or scrub every few months and this can be done in the water or on the beach on a cat, we didn,t sand although this maybe needed annually to expose fresh copper, this is only a light scuff with fine paper or pot scrubber tho. The beauty is that you are not removing all the coating when you clean, and boats have lasted over 10 years. bit of work removing all the old antifoul before appling coppercoat and more expensive to buy. the applied finish is very smooth and fast when clean, better than any finish i have had from other antifoul. :thumbup:

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yes you still have to wipe or scrub every few months

I hear this comment often, but I don't get that. Why not have a bare Hull and scrub that every few months.

Anyway, the recommendation is to sand the surface yearly to expose fresh copper.

 

Contrary to the understanding of many, pure copper does not stop fouling growth. If you put a sheet of copper into water, it will foul up just the same as any other material you put in the water. But they used it on the old Ships you say?? yes correct. But interestingly, they also had electrolysis issues that caused the copper sheet to deplete. So one smart fellow said, why don't we put anodes on the Hull and stop the Copper wearing away. Suddenly growth appeared on the Hull and in 6 months, they had to clean the Hull, remove the anodes and allow the Copper sheet to wear away again. The fact was, the copper eroding caused a small amount of copper Ions on the surface, which was the actual stuff that stopped the growth. Hence why Copper based Antifouls have Copper oxide in it, not pure Copper.

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There are no true "hard" antifoulings sold in the market today.

 

A true hard anti foul is called a contact leaching antifouling and the last ones sold in NZ were Epiglass E Type and International Endurance.

 

Soft antifouls or "soluble matrix" antifouls started with products like Internationals Singapore and Epiglass,s Pacific. They, like Contact leaching, Antifouls were ceased from manufacture in the late eighties when products like Micron25 and Epiglass DRP were introduced.

 

Micron 25 and dRP were the first of the controlled Solubility Copolymers.

 

Every Antifouling on the market (except Coppercoat and the new silicon rubber Technology) are derivatives of Controlled Solubility Copolymer technology.

 

The only difference in hardeness is the solubility rate of the copolymer /resin used. Products like altex No10 have a resin that has a slower solubility rate than Alex No5 which has

 

A true hard anti foul ( contact leaching) has a very tough insoluble resin and leaches only the active ingredient Cuprous Oxide. When the copper is spent there is a porous "resin matrix that needs hard sanding to remove.

 

With today's modern Copolymer antifouls there is a reaction between the salt water and the copolymer resin which softens and releases the active ingredient, cupros oxide, from the film. This is controlled by the resin type. ( hard = slow release. Soft = fast)

 

Both the copolymer and Cupros oxide (and the anti slime additive ) then deplete and the remaining film is exposed and remains active until released and then the next layer... until all is gone. Thus any remaining paint is "good and active.

 

SANDING OF ANTIFOULS IS A VERY FAST WAY TO WASTE MONEY AND REMOVE GOOD ANTIFOUL. DO NOT SAND COPLOYMER ANTIFOULS

 

WITH SOFT ANTIFOULS A SOFT SPONGE IS ALL THAT IS NEEDED TO REMOVE SLIME.

 

With hard (copolymer ablative/ antifouls) that are slimed up then a soft abrasive pad to remove just the slime layer is all that is needed to expose the next "fresh" layer of antifoul.

 

Coploymer antifouls work by the first exposed layer softening and exposing cuprous oxide to the elements until spent. it then releases( by weight of contamination on it or by water movement)( soft above 4-5 knots hard typically above 10... depending on brand) and exposes the next layer.

 

Commercial ships get 5 years plus because the have calculated the level of release and wear and put the correct film build (coats) to allow product to wear down during movement and expected life cycle of ships "between docking" immersion time. Also these boats move constantly and thus the cleaning is more effective.

 

Sainding of Modern antifouls is unnecessary. Any antifouling left on a boats bottom is good product until spent. If youslip your boat and after clean down there is a good film of antifoul left then just remove slime and contamination and recoat. In theory you could just recoat the worn areas and leave the built up areas and all would be fine. But in practice this is not practical.

 

If you are getting slime easily on the surface and it is hard to clean. I would suspect your brand of antifouling is either poor quality, applied/dried poorly, or is the wrong type for your craft/environ.

 

Most racing guys buy a hard antifoul so they can scrub/burnish for a hard fast finish ( Plus think the soft Antifouls are slow/wear off to fast). While this feels good it is a easy way to get faster slime build up. Remember these Harder ablative copolymers were designed for motorboat's and craft that travelled at speed and thus cleaned them selves. Most race yachts will not do the speeds necessary to "self Clean" and the owners end up scrubbing every weekend.

 

A good solution is to put a harder AF on first in one colour then two coats of soft of another colour. This shows the wear areas and level of ablation and thus determines the level of recoat.

 

The biggest issues with premature failure of antifoulings are...

 

1. Cheap product with low levels of Cuprous oxide or poor quality CO.

 

2. Wrong product for intended purpose

 

3. Low film build applied.

 

4. Inadequate drying time before launching. (Solvent entrapment)

 

5. Launching into dirty/oily water

 

6. Over zealous cleaning

 

6. Failing to fresh water clean all the salts way a before recoating ( guys on the grids). Painting over salt contamination will guarantee poor performance of AF by allowing the product to fail from the inside out.

 

Finally. Most boaties fail to really examine their boats when they slip. They do not examine where it is fouling and where it is clean. Common things like ..

 

Why is one side / area fouled more than the other? Is it the northern side (sunny side) that is dirtier... or the side next to a fresh water outlet clean.

 

Experts can quickly determine what the issues are by easy examination and logical analysis.

 

If your boat come out with clean areas and dirty areas then try to understand what happened and why. I. Can gaurantee the fouled areas are 100% not a product issue and the clean areas prove this.

 

Yet most will blame the product.

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Sailor x, any ideas / recommendations re antifoul for alluminium application?

 

 

Hi Steve, this is a good question.

 

In NZ The usual Products like Altex's Vivid and Internationals Trilux are safe but very average performers.

 

The other option I know of is Trilux® 33 from Interlux. This is a copper based paint but it is copper thiocyanate, which Interlux say is safe for properly barrier coated aluminum boats.

 

The term " barrier Coated" is to use a 300 micron coat/ film (dry) of good quality epoxy primer (for underwater) between the Antifoul and the alloy.

 

The correct system would be to clean the Alloy back then 2 pack etch the alloy followed by a good 2-3 coats of epoxy primer. then antifoul.

 

The alloy has to be 100% encapsulated.

 

There are some interesting commercial systems that allow the use of normal Cuprous (Cu2O) oxide antifouls. These system involve application of a Specialized epoxies containing a Zinc derivative and are very successful.

 

I think Altex Coatings in NZ has used this system in the past with great success.

 

By far the best is the silicon rubber (this is interesting link - http://www.google.com/patents/US3702778) products as used on the ferries that travel the worlds harbours. i think your smaller Fullers ferries have this on?

 

These require constant movement but for legs is great and lasts for years if done properly.

 

also of interest is this commercial product.

 

Intercept®

Intercept® is a brand new patented biocidal antifouling that will revolutionise predictability in

hull coating performance.

 

Intercept®8000 LPP

Featuring brand new patented Lubyon® polymer technology, Intercept®8000 LPP

provides consistent, predictable linear polishing performance.

docking cycle, for in-service periods of up to 90 months.

 

hope this helps?

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