How frequently should grp hull be out of the water/cleaned?

[Safe_matt]

Hello everyone,

I'm not sure if this is in the right place, I've had a good look around but haven't seen this mentioned elsewhere. Sorry if I missed it!

I am planning on buying a grp cruiser as a liveaboard. I have looked at a number of boats and think I'm pretty sold on a seamaster 30. 

I have seen one in particular that I really like however one thing I have just found out about her worries me. She hasn't been out of the water since 2009. Should this worry me? It seems like a long time for things to start going iffy! I've read lots of horror stories of osmosis. 

My main worry is that it points to the boat not being treated that kindly in general. Or is this fairly normal?

I would greatly appreciate any input or advice!

Cheers, Matt.

[Alan de Enfield]

We used to lift ours out every Winter, we now have 'copper-coat' on the bottom which should be good for inspection every 5 years.

It depends on the condition of the bottom and what it is anti-fouled with - but 9 years is a bit of a long time.

 

If it has not had the important bits (like the hull) maintained, what chance the other bits & pieces ?

[rusty69]

Ours comes out every tide.  

I would agree with Alan. Nine years is a long time. If you do go for it employ a reputable surveyor who knows his way around a moisture meter. 

Edited February 12, 2018 by rusty69

[Safe_matt]

Thanks guys. Yep that's what I was thinking, it just doesn't suggest it's been looked after really does it? Maybe I'll keep looking!

Cheers, Matt

[ronnietucker]

22 hours ago, Alan de Enfield said:

We used to lift ours out every Winter, we now have 'copper-coat' on the bottom which should be good for inspection every 5 years.

It depends on the condition of the bottom and what it is anti-fouled with - but 9 years is a bit of a long time.

 

If it has not had the important bits (like the hull) maintained, what chance the other bits & pieces ?

1

Can I ask what the 'copper-coat' is? And could it be put on top of an old (but cleaned) anti-fouling?

As mine will probably need some sort of treatment next year.

[Alan de Enfield]

2 minutes ago, ronnietucker said:

Can I ask what the 'copper-coat' is? And could it be put on top of an old (but cleaned) anti-fouling?

Its not cheap, from memory its about £80 per litre.

http://coppercoat.com/coppercoat-info/

The life of Coppercoat depends on a variety of factors such as water temperature and salinity. However, typically in Northern Europe one should expect effective performance for at least 10 years, whereas in the Caribbean, 8 to 10 years would be more normal. Many of the first boats treated in 1991 are still performing well after more than 20 years! With an average thickness of 250 microns of Coppercoat being applied in a treatment, and a typical corrosion rate of less than 5 microns per year, it is easy to appreciate how this coating offers such long lasting and effective protection.

 

How to work out how much you need :

http://coppercoat.com/coppercoat-info/application/how-much-will-i-need/

 

 

[ronnietucker]

5 minutes ago, Alan de Enfield said:

Its not cheap, from memory its about £80 per litre.

http://coppercoat.com/coppercoat-info/

The life of Coppercoat depends on a variety of factors such as water temperature and salinity. However, typically in Northern Europe one should expect effective performance for at least 10 years, whereas in the Caribbean, 8 to 10 years would be more normal. Many of the first boats treated in 1991 are still performing well after more than 20 years! With an average thickness of 250 microns of Coppercoat being applied in a treatment, and a typical corrosion rate of less than 5 microns per year, it is easy to appreciate how this coating offers such long lasting and effective protection.

 

How to work out how much you need :

http://coppercoat.com/coppercoat-info/application/how-much-will-i-need/

 

 

Thanks.

Not quite sure about their calculator. I have a 22x7 boat that their calculator seems to suggest 0.5Ltr would be enough for... hmmm....

[Alan de Enfield]

1 minute ago, ronnietucker said:

Thanks.

Not quite sure about their calculator. I have a 22x7 boat that their calculator seems to suggest 0.5Ltr would be enough for... hmmm....

I make it 4.6 litres if you have a 2 foot draft, 22 foot waterline and 7 foot beam.

[rusty69]

3 minutes ago, ronnietucker said:

Thanks.

Not quite sure about their calculator. I have a 22x7 boat that their calculator seems to suggest 0.5Ltr would be enough for... hmmm....

suspect 4-5 litres.

 

ETA beat by Mr Denfield

Edited February 13, 2018 by rusty69

[ronnietucker]

1 minute ago, Alan de Enfield said:

I make it 4.6 litres if you have a 2 foot draft, 22 foot waterline and 7 foot beam.

Thanks, guys. I thought that <1Ltr seemed a bit too good to be true. 

I'll probably have to stick to the usual anti-fouling paint then. Oh well.

[Alan de Enfield]

2 minutes ago, rusty69 said:

suspect 4-5 litres

 

How much Copper -Coat for this one ?

[rusty69]

1 minute ago, Alan de Enfield said:

How much Copper -Coat for this one

I would paint that with Deks Olje (can you still get that ?)

[ronnietucker]

3 minutes ago, Alan de Enfield said:

How much Copper -Coat for this one ?

1

Couple of coats of B&Q's homebrew gloss and she'd be right as rain.   

[David Mack]

31 minutes ago, ronnietucker said:

 

As mine will probably need some sort of treatment next year.

Why?

Does a grp boat actually need any sort of coating?

[ronnietucker]

2 minutes ago, David Mack said:

Why?

Does a grp boat actually need any sort of coating?

I believe it needs anti-fouling every couple of years.

[rusty69]

1 minute ago, David Mack said:

Why?

Does a grp boat actually need any sort of coating?

We used to antifoul our sailing boat every season to prevent weed and barnacle buildup,but no longer bother, Just scrape it twice a year.

Barnacles add a surprising amount of weight to a vessel and cause a lot of drag. Not sure how much of that applies to an inland boat.

[Alan de Enfield]

3 minutes ago, rusty69 said:

We used to antifoul our sailing boat every season to prevent weed and barnacle buildup,but no longer bother, Just scrape it twice a year.

Barnacles add a surprising amount of weight to a vessel and cause a lot of drag. Not sure how much of that applies to an inland boat.

Zebra Mussels - add (literally) a ton to a NB.

[David Mack]

31 minutes ago, ronnietucker said:

I believe it needs anti-fouling every couple of years.

Nobody antifouls narrowboats. So why do it for a grp cruiser (assuming this is not a high speed boat)?

[ronnietucker]

2 minutes ago, David Mack said:

Nobody antifouls narrowboats. So why do it for a grp cruiser (assuming this is not a high speed boat)?

I think they blacken narrowboats. Dunno. Don't have one. But I'm pretty sure you have to anti-foul a GRP every couple of years.

Guys! HALP! Please tell me he's right and I can save some money next year. 

 

[Alan de Enfield]

4 minutes ago, David Mack said:

Nobody antifouls narrowboats. So why do it for a grp cruiser (assuming this is not a high speed boat)?

Bitumin is an anti-foul

[rusty69]

3 minutes ago, ronnietucker said:

I think they blacken narrowboats. Dunno. Don't have one. But I'm pretty sure you have to anti-foul a GRP every couple of years.

Guys! HALP! Please tell me he's right and I can save some money next year. 

 

https://canalworld.net/forums/index.php?/topic/84816-anti-fouling-of-grps/

[Phil Ambrose]

When we moored on the Broads on a 40' x 12' GRP we never had her out in 10 years that we owned her.  She never had any fouling issues I know because I checked under water. 

On the other hand we also had a 21' cruiser which fouled terribly with Zebra mussels and needed regular scraping off.  A similar sized day boat we had never had fouling issues. My dinghy was always fine but Chris's would produce 2 builders buckets of Zebra mussels every year.

I can only gather from my observations that the degree of fouling depends on the type of antifoul used.

Oh and don't get hung up on Osmosis, it's not the killer some would have you believe, it has been said that a boat with Osmosis will outlive it's owner. In fact the Navy has quite a few GRP boats so they must be OK with the stuff.

Phil 

Edited February 13, 2018 by Phil Ambrose

[Safe_matt]

Thanks for all the replies! Funny how a thread takes on a life of its own!

I've heard some different opinions on osmosis, I'm inclined to be a bit more relaxed about it, whilst still keeping an eye on it.

One other thing I wanted to ask is how damp should you expect a boat that has been left locked up and unused over the winter to be? I have looked at a couple of boats that have drops of water hanging from the headlinings. Both these boats didn't appear to have great ventilation, and this was after a spell of very wet stormy weather, so I thought it wasn't anything much to worry about. Was I right in thinking that or would that be another potential warning sign?

 

Once again, thanks for all your help! 

Cheers, Matt.

[Alan de Enfield]

13 minutes ago, Safe_matt said:

One other thing I wanted to ask is how damp should you expect a boat that has been left locked up and unused over the winter to be?

Due to 'family medical issues' our boat has not been used since September - it has had 'greenhouse heaters' in the engine room on for about 12 hours per day since the end of November.

Went to the boat a couple of weeks ago to top up the electric meter and on checking found that the bowls of 'cat-litter' spread around the boat were totally dry. The 'de-humidifier' chemicals in a box were also still looses and not lumpy so no water absorbed.

Doors and windows locked - covers on the outside of the windows. Ventilation only 3 'flying saucer mushrooms'.

 

I doubt the dryness is down to the heaters in the engine room as that is a totally separate closed off area. 

[Naughty Cal]

Our GRP cruiser is very dry with no condensation issues at all. But we make an effort to make sure that places like the bilges stay bone dry and we provide adequate ventilation when we are onboard.

We antifoul our cruiser every year when we have it lifted out to service the sterndrive. We do it purely because the boat is out and for the sake of a £50 tin of paint we may as well keep it looking smart throughout the year. We are not in a high fouling area so it could last two or three years if we were that way inclined. You won't have the hassle of lifting a Seamaster 30 every year as it is shaft drive so far less maintenance. 

I would be slightly nervous of buying a boat that had not been lifted for 9 years. If the previous owner has skimped on this what else have they skimped on? There are anodes to be changed even on a GRP boat and after 9 years I would expect these to be gone by now which will leave your shaft and props with no protection. 

We had friends who had a Seamaster 30. It is a very roomy boat for it's size. But they had cronic problems with damp on that boat. In the end that was why they sold it and bought a Fairline Holiday instead.