PCUK
Well-Known Member
I wonder how many others are in the same boat, as these make a professional finish easy.
Sikaflex at Screwfix
- Thread starter Greenheart
- Start date
I wonder how many others are in the same boat, as these make a professional finish easy.
Greenheart
Well-Known Member
I know you're right Shiny, thanks. Unfortunately the rubbing strake is attached round the boat with literally hundreds of M5 bolts, whose inside ends (and the holes through which they are screwed) show no sign of moisture even after heavy rain...so the owner is reluctant to take on this considerable low-season job at this time.
When the strake was first fitted, presumably it butted-up snugly against the gunwale. I don't see what damage or other cracking can be responsible for rainwater ingress except the M5 holes, but eliminating that large gap through which heavy rain obviously pours by the pint, would seem to make an immediate-term improvement...
...although I daresay the same holes will leak much worse, when the boat heels and the gunwale dips into wave crests. The fact that the strake is so battered and misshapen (and must have as many openings at the bottom, as at the top) would seem to prevent the problem of holding moisture behind the sealant - the sealant will only keep rain out, not prevent movement below.
VicS
Well-Known Member
I assumed they were something the ladies usd :encouragement:
Greenheart
Well-Known Member
I assumed they're some sort of chemical-infused part-plastic non-recyclable throwaway convenience that can be dug up from landfill utterly intact after thirty or forty years.
Blue Sunray
Well-Known Member
You make it sound like a bad thing!
Greenheart
Well-Known Member
I had a long look at the task in hand again today, and I'm afraid my friend has chosen the wrong end of the summer to make the fix.
The top of the rubbing strake is badly bashed and deformed from its original shape, so rain pours into the crack...but the bottom of the rubbing strake is still firmly pressed against the gunwale. So as some of you gents said, if we just pump sealant into the crack, the moisture of recent rains will be locked in there to do mischief at its leisure.
If the same job had been done during the baking dry weeks a month or more ago, the Hippo sealant might have made a permanent waterproof seal. As it is, I don't know what can be done short of blowing hot air into the crack to dry it out, inch by inch.
The top of the rubbing strake is badly bashed and deformed from its original shape, so rain pours into the crack...but the bottom of the rubbing strake is still firmly pressed against the gunwale. So as some of you gents said, if we just pump sealant into the crack, the moisture of recent rains will be locked in there to do mischief at its leisure.
If the same job had been done during the baking dry weeks a month or more ago, the Hippo sealant might have made a permanent waterproof seal. As it is, I don't know what can be done short of blowing hot air into the crack to dry it out, inch by inch.
LittleSister
Well-Known Member
Are you perhaps overlooking the possibility of the joint between the hull and deck mouldings being behind the rubbing strake and somehow involved in the leakage? (Some boat designs were known for this issue.)
Greenheart
Well-Known Member
Yup, definitely a possibility. I think if the owner gutted the interior lining, he might find answers.
It's odd though, that the incoming moisture - not a deluge, but a significant dribble after heavy rain - accumulates where the outer bulkhead meets the settees and V-berth forward, without appearing anywhere near the hull-deck join or the rubbing strake bolt-holes.
I guess it's trickling unseen down a layer of glassfibre added behind the shelves, and only emerging at the bottom of the lining below.
Whatever the reason, I still think the Hippo sealant will make things much better, even if it doesn't wholly eliminate the problem. If the gunwale-strake crack can be (somehow) sheltered to keep further rain out, how quickly in mild September weather is the moisture that is already in there, likely to dry out?
It's odd though, that the incoming moisture - not a deluge, but a significant dribble after heavy rain - accumulates where the outer bulkhead meets the settees and V-berth forward, without appearing anywhere near the hull-deck join or the rubbing strake bolt-holes.
I guess it's trickling unseen down a layer of glassfibre added behind the shelves, and only emerging at the bottom of the lining below.
Whatever the reason, I still think the Hippo sealant will make things much better, even if it doesn't wholly eliminate the problem. If the gunwale-strake crack can be (somehow) sheltered to keep further rain out, how quickly in mild September weather is the moisture that is already in there, likely to dry out?
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LittleSister
Well-Known Member
Could it be coming in through a deck/coachroof fitting, and then through some internal path to the bulkhead? (Beware of deck/coachroof leaks if it got a balsa sandwich top, which is common.)
What is the boat?
Greenheart
Well-Known Member
You may be right about the deck fittings, which are numerous and didn't look recent to me.
Anyway, while I discussed it here, the owner went ahead with the Hippo sealant so the rubbing strake is now 'sealed' to the gunwale.
It looks like a wet day in the Solent tomorrow, so he'll find out if it has closed the door on rainwater leaks. The boat is an Achilles.
Anyway, while I discussed it here, the owner went ahead with the Hippo sealant so the rubbing strake is now 'sealed' to the gunwale.
It looks like a wet day in the Solent tomorrow, so he'll find out if it has closed the door on rainwater leaks. The boat is an Achilles.
PCUK
Well-Known Member
They burn just fine!
But if you're a tree hugger then you'll find it hard to find anything that can be used on the boat without some "green" cost.
Greenheart
Well-Known Member
October 14th
Well, it seems the Hippo sealant isn't anywhere near as good as the enthusiastic salesman at Travis Perkins had me believe.
The stuff is just letting go of the inside of the gap between the rubbing strake and gunwale, and popping out in places.
Maybe I ought to have stressed the importance of the product adhering to the surfaces it was hopefully sealing...
...there seems to be a balance that isn't always understood (or made obvious by the manufacturers) between whether these sealant products are basically rubbery glues, or just sealants...although if the cured product doesn't adhere to the surfaces either side, it is very difficult to see how it can act as a sealant.
So, I am brought back to the widely praised CT1...but is there more than one grade of CT1? The job in question doesn't need adhesive, but the product has to adhere in order to seal effectively.
Well, it seems the Hippo sealant isn't anywhere near as good as the enthusiastic salesman at Travis Perkins had me believe.
The stuff is just letting go of the inside of the gap between the rubbing strake and gunwale, and popping out in places.
Maybe I ought to have stressed the importance of the product adhering to the surfaces it was hopefully sealing...
...there seems to be a balance that isn't always understood (or made obvious by the manufacturers) between whether these sealant products are basically rubbery glues, or just sealants...although if the cured product doesn't adhere to the surfaces either side, it is very difficult to see how it can act as a sealant.
So, I am brought back to the widely praised CT1...but is there more than one grade of CT1? The job in question doesn't need adhesive, but the product has to adhere in order to seal effectively.
Poignard
Well-Known Member
Correct.
ffiill
Well-Known Member
second that
Greenheart
Well-Known Member
Sounds terrific. Is there any difference between the red-ink printed 250ml bottle (£14.95 on Amazon)... https://www.amazon.co.uk/Captain-Tolleys-Creeping-Crack-sealer/dp/B00JQ6XHWC
...and the identically marked, blue-ink printed 250ml bottle, only £10.95 at the usually extortionate Force 4? https://www.force4.co.uk/cpt-tolley-creeping-crack-cure-250ml.html