Buying a Berthed Boat? Good idea??

[robm3]

Looked at a cheap Four Winns 230 on Thursday on consignment, all looked good and price was low but boat has been on a mooring for five years.
What I'd like to know is can the hull and stern drive (Mercruiser Bravo 3) be restored to look new as I'll have the boat on a trailer?
Two main things I guess:
Can the anti foul be removed from the hull leaving just the gelcoat? (can a high-power jet wash achieve this?)
Can the stern drive be sanded back and repainted?

Everything else is good and the boat is around $10k (£7k) under Market price so plenty of cash in the war chest.

Thanks in advance...

[robm3]

Oh, the boat dealer was the biggest b@llstter I'd ever met, some gems were:
"the boat lives in a dry dock" - barnacles on the hull say no.

"it's recently serviced" -open the engine hatch (he didn't know how to) to see 09/10 written on the oil filter.

Points to the mercruiser standard double clamping on the inlet houses and said "see how well it's been serviced, it's not even double clamped from the factory but is now"

When I could get the water pump working he said it was because the voltage was low (despite it being able to turn over the motor).

This guy was a major knob but the boat is basically sound so I just played along...

[scubadude]

robm3 said:

Can the anti foul be removed from the hull leaving just the gelcoat? (can a high-power jet wash achieve this?)

My experience is that Anti-foul naturally removes itself over 18-24months as its replaced by wildlife :-)

Use a Jetwash on the plantlife to reveal the hull, I also use a long handled garden tool as a scrapper to dislodge any creatures.

[danyeates]

In the past we've used a sandblasting company to remove heavy build ups/several layers of antifoul. It's often the quickest the easiest way.

The only problem is, if it's been done properly, you will have a "keyed" hull underneath. Basically you're supposed to rub down the hull with sandpaper to give the primer a "key" to stick to. This will be difficult to get back to a nice clean shiny gelcoat finish. You will have to keep wet and drying the hull with finer grades until you get a smooth surface, then machine polish the hull with cutting compounds and polishes until it's nice and shiny. A lot of work! Of course, you may get lucky and find that the hull was never rubbed down in the first place and the antifoul just flakes off!

The engine outdrive can certainly be repainted. Dealers should carry the spray paints.

[danyeates]

Oh, and one good tip. ALWAYS jet wash/steam clean the hull as soon as you take it out of the water. If you let it dry the growth will be a nightmare to get off. It comes off easily when it's still wet.

[Simpo Two]

I understand that new boats come with a layer of epoxy-something on the gelcoat to help against osmosis, then the antifoul goes on that.

Now I appreciate that antifoul gradually dissolves, thereby defeating Mr Green Slime who was attempting to get a grip on it, and that every two years you jetwash off the residue and recoat with fresh antifoul.

Question - why not skip the antifoul completely, and simply jetwash Mr Green Slime off the epoxy layer every two years?

[ALawson]

danyeates said:

In the past we've used a sandblasting company to remove heavy build ups/several layers of antifoul. It's often the quickest the easiest way.

The only problem is, if it's been done properly, you will have a "keyed" hull underneath. Basically you're supposed to rub down the hull with sandpaper to give the primer a "key" to stick to. This will be difficult to get back to a nice clean shiny gelcoat finish. You will have to keep wet and drying the hull with finer grades until you get a smooth surface, then machine polish the hull with cutting compounds and polishes until it's nice and shiny. A lot of work! Of course, you may get lucky and find that the hull was never rubbed down in the first place and the antifoul just flakes off!

The engine outdrive can certainly be repainted. Dealers should carry the spray paints.

I have self applied Copper Coat after removing 8 years worth of annual antifoul built up, this was scrapped of by hand (38ft boat) and then the hull abraded as described above. Literally just as we had finished preping the hull a chap turned up to sand blast a boat next to ours, he was complimentary of the finish we had achieved which took literally days of work. It took him about 6 hours on the same size boat, he reckoned that he sand blasted other hulls before copper coat was applied and they didn't need to abrade his finish, for the money he was charging I would probably do sand blast again infuture!

I take it you are getting a full survey of the hull for osmosis?

[MOTORVATOR]

Simpo Two said:

I understand that new boats come with a layer of epoxy-something on the gelcoat to help against osmosis, then the antifoul goes on that.

Now I appreciate that antifoul gradually dissolves, thereby defeating Mr Green Slime who was attempting to get a grip on it, and that every two years you jetwash off the residue and recoat with fresh antifoul.

Question - why not skip the antifoul completely, and simply jetwash Mr Green Slime off the epoxy layer every two years?

Couple of things there Admiral. Osmosis is actually a poor descriptive word for the damage that occurs in GRP but once coined it gets used. Put a boat in the water and within a day it has osmosis taking place as grp is not a 100% waterproof material.

The problems that occur are based around the quality of products and workmanship, i.e. high levels of solvent, excessive catalysts, poor environmental control of workshop etc etc. The absorbed water reacts with any remaining solvents and detrious to form acetic acids and the like which then create the telltale blistering.

So new boats shouldn't need epoxy treatment to protect it as products have improved over the years and low solvent gelcoats and good workmanship are a far better approach.

It is actually possible to see osmosis purely in the antifoul layers without it having touched the underlying gel and contrary to popular belief simple moisture readings whilst helpful cannot identify whether severe osmotic action and consequent hydrolysis has taken place.

And yes you could just jet off an epoxy finish or even just the gel coat, however antifouls not only add a level of protection to the hull if applied correctly but also are active in stopping growth.

The different types work in fundamentally different ways though. A hard polishing antifoul for instance doesn't so much dissolve as provide a slick surface that relies on the boat going through the water at speed and any material will fall away. Or as is often used on slower vessels a dissolving antifoul will rely on releasing vast quantities (in comparison) of biocide to deter growth in the first place.

Both will contain biocides, generally copper based as the more effective TBT has been banned unless you own a vessel over 25m and that won't last much longer.

I am presently investigating methods of improving my own home brew antifoul however having finally tracked down a supplier capable of providing 60kg of chilli powder, I was slowed when the lady in Boots gave me a funny look when I asked for a gallon of DDT and 4 litres of copper chromated arsenic.

[hidetheelephants]

MOTORVATOR said:

I am presently investigating methods of improving my own home brew antifoul however having finally tracked down a supplier capable of providing 60kg of chilli powder, I was slowed when the lady in Boots gave me a funny look when I asked for a gallon of DDT and 4 litres of copper chromated arsenic.

Have you tried asking for Tributyltin Oxide yet?

[mickrick]

Ah Ha! the good ol' Osmossis discussion. Up there with Religion and Politics!

[Simpo Two]

MOTORVATOR said:

So new boats shouldn't need epoxy treatment to protect it as products have improved over the years and low solvent gelcoats and good workmanship are a far better approach.
And yes you could just jet off an epoxy finish or even just the gel coat, however antifouls not only add a level of protection to the hull if applied correctly but also are active in stopping growth.

Fair enough - I was just thinking that lifting and jetwashing would be simpler/cheaper than lifting, jetwashing AND antifouling. Bearing in mind this is fresh water with cruising speeds of 4-7mph, would the clag (mostly green slime from what I can tell) really beome unbearable in two years?

Apparently the new HMS Simpo has 'Epoxy SFE 2000' as standard, then Blakes Tiger antifouling. They recommend lifting every 2 or even 3 years depending on use. Does that sound sensible to you?

(sorry for hijack)

[MOTORVATOR]

Simpo Two said:

MOTORVATOR said:

So new boats shouldn't need epoxy treatment to protect it as products have improved over the years and low solvent gelcoats and good workmanship are a far better approach.
And yes you could just jet off an epoxy finish or even just the gel coat, however antifouls not only add a level of protection to the hull if applied correctly but also are active in stopping growth.

Fair enough - I was just thinking that lifting and jetwashing would be simpler/cheaper than lifting, jetwashing AND antifouling. Bearing in mind this is fresh water with cruising speeds of 4-7mph, would the clag (mostly green slime from what I can tell) really beome unbearable in two years?

Apparently the new HMS Simpo has 'Epoxy SFE 2000' as standard, then Blakes Tiger antifouling. They recommend lifting every 2 or even 3 years depending on use. Does that sound sensible to you?

(sorry for hijack)

Woohoo, let's hijack.

I think as Mick points out the osmosis discussion is one of those that will never end. But consider these facts and make your own mind up whether it is a good idea or snake oil to promote a sale.

To my knowledge no boat has ever sunk from osmosis, however the term has become very scary to boat owners.

Epoxy coatings will still allow water to pass at a molecular level albeit at a considerably lower rate than resins.

Epoxy coatings will therefore also slow down the drying out process when ashore.

Modern gelcoat resins do not absorb or retain water as much as earlier resins.

Boatbuilders have been aware of the risk of attracting hydrophilic damage to laminates through poor wetting out processes etc for many years now.

Good laminaters now restrict the amount of solvent product used to reduce the risk of future chemical action.

Epoxy coating lifespan is reckoned to be approx 10 - 20 years whereupon it will have to be renewed.

Most boats get their first epoxy coating around that age anyway.

Antifoul does not like adhering to epoxy surfaces and it will be necessary to prime any bare surfaces before new antifouling is applied.

At survey time if moisture readings are required then the epoxy coating should be removed locally or the results will be suspect.

As for antifouls well that's another subject that noone will ever agree on. We have two pontoons moored in our river as it is reckoned to be the worst fouling river in the country. These belong to International and Blakes and they carry out their testing there.

I'm suffering really badly at the moment from barnacle growth as I still have French antifoul on and whilst it's good on the blue mussels it just does not work in our river. Out and jetted off 8 weeks ago and already I'm losing 8 knots off the top end.

Join that up with a pair of totally mismatched french props and I am using a shedload of horsepower driving a boat skywards whilst dragging along an awful lot of unwelcome passengers rather than making ground.

You obviously won't notice as marked a difference and if you are only travelling short journeys the odd litre of fuel will probably go unnoticed too. In fact I suspect you will probably notice the biggest difference on the underwater gear like rudder and thrusters.

One thing's for sure the best advice you will get is from talking to locals as what works in the sea won't work in brackish or fresh etc.

In fact the best way to clean your boat bottom is to go from one to the other for a week or two as all the growth / organisms will just drop off.

I religiously have the boat out once a year for a freshen up of antifoul and will still have to be lifted mid season at least once and that's without the occasional swims underneath.

This being the end of it's first year in my hands she will get the full treatment this year of a Soda Blast and moisture readings over a period. Subject to that she may get the gelshield or just a good clean bottom of my favoured antifoul. New props already on order, New anodes, one stern gland to replace, a rudder bearing to sort, and probably a new dynaplate as I'm pretty sure some dumb frenchman has antifouled over it without realising what it was.

Sorry for the short reply, but busy trying to organise an outing.

[Simpo Two]

Osmosis is not my concern - after the last boat (1973) it's the least of the issues. Just wondering how much slime woud build up without antifoul. Speed isn't an issue; the price of a coat of antifoul buys quite a lot of diesel.

What we need is 'epoxy antifoul' - both jobs in one.

As for talking to the locals, I think they tend to do what they've always done without applying much thought.

[MOTORVATOR]

Got no experience of the fens Simpo so wouldn't know. How much did you have on the old bus and how long was she in - should give you a clue.

The weed build up round our way is blamed on the nitrate runoff from the surrounding agriculture if that helps.

Based on your new boat, a little research suggests that if you were to simply add 22 hundredweight of ion exchange resin to your epoxy you would then have an effective antifoul.

[Simpo Two]

MOTORVATOR said:

Based on your new boat, a little research suggests that if you were to simply add 22 hundredweight of ion exchange resin to your epoxy you would then have an effective antifoul.

I fear you have lost me sir. Which ions need to be exchanged with which? Or are you tyring to turn me into a mobile water softener, HMS Permutit?

[MOTORVATOR]

The slime you refer to is algae fouling - Nutrient enrichment is the biggest cause of algae growth - Nutrients being Phosphates and Nitrates. Eutrophication. Can't do much about the phosphates unless you have some swing with the sewage authority, but....

"The simplest and most cost-effective method of removing nitrates from water is by anion-exchange, using resins operated in the chloride form and regenerated with brine."

Therefore you just require enough of this hanging off the bottom of your boat to clean up the bit of river you happen to be in and hey presto the slime is not being fed.

I am also considering some tests involving a large quantity of sulphuric acid leaking slowly out of the back of the boat in the hope that this will react with the nitrates to form a copper compound which will attach itself to my boat saving the effort of applying copperkote.

I worry myself sometimes.

[hidetheelephants]

That's nothing, I think the next big thing will be genetically engineered loaches which will be available in petshops; they will adhere to your hull and eat all the weeds'n'stuff.

[XJSJohn]

TBH ona relatively modern boat i would not worry about osmosis, scrape it down to the primer and whack a few more coats on.

My bigger concern would be the condition of shafts / rudders / stern drives if it has been in teh water that long ... any anodes left? have they been regularly replaced?

I have seen whole saildrives on yachts eaten away in 5 years because the owner did not understand about electrolysis and cathode / anode protection.

[Simpo Two]

MOTORVATOR said:

I am also considering some tests involving a large quantity of sulphuric acid leaking slowly out of the back of the boat in the hope that this will react with the nitrates to form a copper compound which will attach itself to my boat saving the effort of applying copperkote.

I worry myself sometimes.

Quite right too - there is no copper in sulphurc acid

Another idea might be a berth with V-shaped rubber blades at the bottom, like giant fixed windscreen wipers. Each time you arrive or depart, the boat wipes itself clean...

[MOTORVATOR]

hidetheelephants said:

That's nothing, I think the next big thing will be genetically engineered loaches which will be available in petshops; they will adhere to your hull and eat all the weeds'n'stuff.

Already got'em.

When you lay there in your cabin on a still night on my boat you hear those luverly slurping noises? That's mullet that is, eating all the weed hanging off the bottom.

At least that's what I tell any guests, and up to now I've got away with it.