Centaur with osmosis

[Boathook]

As you already own the boat and ideally want to keep it, just attack the worst ones every winter and carry on sailing in the summer.

You could get them dry ice blasted ? to open them up and then fill and fair but they all seem small and I suspect not worth much effort at present. The other option is to leave until next October, get boat lifted and get the hull blasted. Leave until March to dry out, then fill and sand, etc.

 

[jwilson]

OK - too many to do individually. The question is do you want a very substantial project or to go sailing?

As others have said, how about finding another Centaur. I know someone who bought two write-off Centaurs and built one decent one. But if you really love this boat......

 

[Lenster]

OK - too many to do individually. The question is do you want a very substantial project or to go sailing?

As others have said, how about finding another Centaur. I know someone who bought two write-off Centaurs and built one decent one. But if you really love this boat......

I would rather not sail and get this one restored to be honest, I can always get on the water with other boats if needs be. There is a lot of sentiment in this boat to be honest. I think based on what has been said I am going to blast the hull as the surveyor recommended and get this done soon so it has plenty of time to dry out. Get her tip top ready for 2027 season. She is a very dry boat so unless this level of osmosis has damaged the integrity of the hull - which some tapping suggests it has not - I will know more when she is popped and dry I guess ? Plus I will learn some new skills and have some time to do some lovely carpentry and make her look lovely. Thanks for the advice, book is ordered and I think a peel is a step too far for on balance.

 

[Tranona]

Where are you located? £1400 is OTT for blasting - should be nearer half that. Best approach is to blast as filling and fairing is better kind of work than manually grinding out. You may well find many of the blisters will disappear anyway as it dries out . Most are likely to be in the gel coat rather than the laminate. Be aware though that despite the heavy layup it can be very poorly consolidated because of the poor methods used when laminating. One Centaur I know needed the whole of the bottom between the keels replaced because it was just like cardboard after the first blasting.

 

[Concerto]

PS: BOAT stands for Break Out Another Thousand ... regardless of age or value, if it's your pride and joy, do whatever you feel it needs .... @Concerto completely restored an aged Westerly and is as happy as a pig in sh!t I believe ... and it's a beautiful restoration job.

You forgot what PBO stands for - Poor Bloody Owner.

 

[Tamar]

I always remember on my first plastic boat the surveyor telling me that he can't ever remember a boat sinking from osmosis.

 

[Lenster]

Where are you located? £1400 is OTT for blasting - should be nearer half that. Best approach is to blast as filling and fairing is better kind of work than manually grinding out. You may well find many of the blisters will disappear anyway as it dries out . Most are likely to be in the gel coat rather than the laminate. Be aware though that despite the heavy layup it can be very poorly consolidated because of the poor methods used when laminating. One Centaur I know needed the whole of the bottom between the keels replaced because it was just like cardboard after the first blasting.

Thats interesting - my first reaction at the quote was it was very high but I have no other reference. I am based between Exeter and Plymouth

 

[Lenster]

You forgot what PBO stands for - Poor Bloody Owner.

I am a perpetual victim of Stockholm syndrome when it comes to hobbies and interest that have a disproportionate relationship to investment. I have reconciled that I live by my heart and not my head !! I rather enjoy the chase and the endless challenge - no hope for me. Part of the reason I have come to the decision to do the refit is to get to a point where I can have confidence in the boat and begin to enjoy her again.. the other part is that I have been putting off a lot of jobs that I wanted to sort out.. none of them super significant but an accumulation of them turns into an endless task.. so time to resolve those now.. knowing full well the cycle will begin again as soon as she hits the water lol

 

[dunedin]

I always remember on my first plastic boat the surveyor telling me that he can't ever remember a boat sinking from osmosis.

Precisely.

Boats are for sailing. The strong evidence from other projects is that the boat is much more likely to end up a total loss by starting on a refit project which never gets finished, rather than doing a quick cosmetic fix for the worst bits and ensuring relaunched and sailing again on 1st April. May be better only to start on a couple of minor improvements each winter for the next 10 years.
The boat won’t sink and a few tiny lumps below the waterline aren’t worth worrying about.

But if the OPs interest isn’t sailing but boat working, that is their call.

 

[Bobc]

Chuck it back in the water and keep sailing. Just ignore it.

 

[ridgy]

You might find this useful, and the two that follow.

If you drop George a donation you'll be able to ask some questions.

 

[Bilgediver]

sure - they are all quite small but there are a lot of them. This is an area stripped back to take a reading. Several popped with the vinegar smelling fluid in them

I did this job many moons ago on blisters mainly between and the keels .The areas were lighty sand blasted and the exposed blister areas were washed dailey with warm water till the vinegar smell disappeared.

The filling. Material wasxan international material. This has stood the test of time and no further areas appeared

 

[Lenster]

Chuck it back in the water and keep sailing. Just ignore it.

I have a ton of other jobs to sort so going back in isnt an option right at this second.. however, I am very aware that my intended course of action was over the top and I will be doing bare minimum on the osmosis once I am happy there is nothing structural at play. I have two seacocks which are old and need replacing as well as some cosmetics.. so its refit time for the short term and after a 15 year sprint on the water with very minimal work on her, its overdue to be honest.. anyway after the last comment from Dunedin I am going to leave this forum.. thanks to those who provided some practical advice..

 

[dunedin]

you sanctimonious prick - my boat has been sailed for 15 years, I was after some advice on the engineering not my approach to boating..

And a Happy New Year to you too.
Not been on the forum long ?

 

[Refueler]

If the blisters are small - what are usually termed 'Micro-blisters' ...... then I would not blast the hull.

I would look at doing a sand, wash, fill and antifoul job .... cheaper and basically better ....

I reckon it would be hard to find any Centaur without similar or worse case of boat-pox. In the days they were built - the resins used were less resistant to the 'pox'.

I have a 25ft Sunrider Motor Sailer - a direct competitor to the Centaur - it has high moisture readings .... (I used to survey yachts in UK and have the meters etc) .... have I treated it ? No. The value of such a boat and OP's Centaur are well below the full cost of peeling / drying out / barrier caoting / finishing off.
As another says - the boat has taken ~45yrs so far and will last another 45yrs ....

To illustrate the hull and if any reduction in strength .............

My SR25 struck concrete block at reasonable speed entering harbour ... this caused the stbd bilge keel to crack at fwd and aft joint to hull .... boat was lifted and repairs started ... first entire keel joint was ground back to see how far the cracks extended ... second measurements of alignment / flex were taken to determine if the 'wet hull' had deformed ...
The cracks were limited to the joints fwd and aft - with main run OK. Deformation of hull was zero and only normal when stood on keels.
Repairs were carried out - costs well exceeded value of the boat agreed - but I have owned the boat many years and have an affection for her - it has proven solid in storms and events that make me feel I owe her ...

This is for a hull that has no treatment since it was built in 1973.

I can only suggest to OP .. consider carefully what it will cost ... will the boat really benefit from such work ... and something that is rarely mentioned :

It is extremely hard and difficult to work on a bilge keel hull such as Centaur ... you need to raise the boat high on blocks to get round behind keels and to the central hull. It may not seem much - but it really does add to the overall work load.

 

[Stemar]

From the photos, those blisters don't look deep in the laminate. Maybe between the gelcoat and the layup at worst, but it's possible a lot of them will disappear when you strip off the antifoul. I'd be inclined to get that done - quite enough to do in one winter - then grind out anything particularly nasty and let the rain wash it all for a couple of weeks. Now add a few of coats of epoxy. I can't remember the name, but there's one that has green and grey coats, so you can see where you're putting it, antifoul and go sailing.

It's likely that blisters will reappear. If they do, deal with them on an ad hoc basis when you can be bothered. While it isn't pretty, and it would slow down a racing machine, a Centaur won't care. The only real issue is that it's one more reason for a buyer to negotiate a reduction in price when you come to sell.

 

[Refueler]

From the photos, those blisters don't look deep in the laminate. Maybe between the gelcoat and the layup at worst, but it's possible a lot of them will disappear when you strip off the antifoul. I'd be inclined to get that done - quite enough to do in one winter - then grind out anything particularly nasty and let the rain wash it all for a couple of weeks. Now add a few of coats of epoxy. I can't remember the name, but there's one that has green and grey coats, so you can see where you're putting it, antifoul and go sailing.

It's likely that blisters will reappear. If they do, deal with them on an ad hoc basis when you can be bothered. While it isn't pretty, and it would slow down a racing machine, a Centaur won't care. The only real issue is that it's one more reason for a buyer to negotiate a reduction in price when you come to sell.

As I suggested as well ... sand back the antifoul ... which likely will pop most blisters .... wash ... fill any that need it ... epoxy and antifoul.

Go enjoy the boat and use the saved money to invest in other gear you might want ...

 

[PaulRainbow]

you sanctimonious prick - my boat has been sailed for 15 years, I was after some advice on the engineering not my approach to boating..

Uncalled for.

 

[Refueler]

Glad to see that you have stayed with us ... I don't think anyone really was having 'a go at you' .... sometimes just reads that way ...

 

[Refueler]

Uncalled for.

Isn't it better to leave it alone ... lets not rake it up ??