Reinforcing a Bow

[bizzy]

Why on an "ocean passage " wasn't the anchor removed or securely tied to the deck ?
The skipper is responsible for checking the boat is ready to go to sea !

[Celestialsailor]

I am surprised that an anchor could actually hole a hull like that. How think was the laminate? On one of my boats a 45# CQR gave my bow an earth shattering smack during an anchor retrieval in a bouncy roadstead. A quarter size chunk, a 1/4" deep resulted. I used a 12 ga. SS sheet to cover the bow.

[ontherocks83]

Originally Posted by Celestialsailor

I am surprised that an anchor could actually hole a hull like that.

Me too. I was in a race once where the Captain of our boat (not me) T-boned another boat at the start line. Our bow rode up into their cockpit snapping off their aft stanchions. The only damage we had was a 3 foot long gouge down to the bare fiberglass about 2 inches wide along the leading edge of the bow.

Are there anymore details as far as conditions and exact situation that lead this to happen?

[laika]

Real quick question as not trying to hijack the thread:

If the thermal expansion ratios are so drastically different between polyester and epoxy resins, then is it fair to assume that epoxy barrier coatings made to replace polyester gelcoats stand a reasonable chance of cracking? Especially the thicker they are laid on?

It seems like epoxy and cloth are the standard tools today to fix almost all polyester hull deficiencies.

[Cheechako]

I'm thinking stainless will dent and thicker will be too heavy. Teak or Iron bark strips like some trawlers have would be a lot of holes in what sounds like a very thin hull. Why not laminate another 1/4"+ of glass in the strike zone.. making the hull stonger while you're at it?

[KStepman]

Originally Posted by bizzy

Why on an "ocean passage " wasn't the anchor removed or securely tied to the deck ?
The skipper is responsible for checking the boat is ready to go to sea !

One of the crew unsecured the anchor while underway and forgot to resecure it back onto the deck.

[KStepman]

Originally Posted by Celestialsailor

I am surprised that an anchor could actually hole a hull like that. How think was the laminate? On one of my boats a 45# CQR gave my bow an earth shattering smack during an anchor retrieval in a bouncy roadstead. A quarter size chunk, a 1/4" deep resulted. I used a 12 ga. SS sheet to cover the bow.

I can only tell what happened by looking at the damage. It appears that the point of the plow on the Rocna anchor was swinging back and forth, repeated striking the bow and chipping a hole-through, with repeated blows.

[Stumble]

Originally Posted by laika

Real quick question as not trying to hijack the thread:

If the thermal expansion ratios are so drastically different between polyester and epoxy resins, then is it fair to assume that epoxy barrier coatings made to replace polyester gelcoats stand a reasonable chance of cracking? Especially the thicker they are laid on?

It seems like epoxy and cloth are the standard tools today to fix almost all polyester hull deficiencies.

They are different, but not substantially so. Epoxy is the go to for repairs because poly won't stick to cured polyester. Poly has to be hot laid to itself to have any type of bonding strength.

In a practical sence epoxy to poly is prefered over poly-to-poly repairs because the bonding strength of polyester is so poor.

[KStepman]

Originally Posted by ontherocks83

Me too. I was in a race once where the Captain of our boat (not me) T-boned another boat at the start line. Our bow rode up into their cockpit snapping off their aft stanchions. The only damage we had was a 3 foot long gouge down to the bare fiberglass about 2 inches wide along the leading edge of the bow.

Are there anymore details as far as conditions and exact situation that lead this to happen?

I think that I addressed some of the answer to your question as to circumstances, above. In essence, the anchor was free, and swinging on a 4-5 foot radial arch repeatedly striking the bow.

Sea conditions were rough. Wave direction was mixed. We had 25'-30' rollers coming from astern. anchor rolled off the bow and began to swing freely, taking a nip out of the bow just above the water line with every swing. All I know is that the anchor and swivel were gone, the bottom paint is abraded at the bow, as was some of the fiberglass on the leading edge, just above the waterline. Alternatively, this damage on the hull could have been caused by the chain rubbing and striking the hull, which could explain why I did not hear any exceptional banging. It is still a mystery as to what happened to the anchor.

The crew member freely took responsibility for not resecuring the anchor to the deck inside the anchor locker, but hid the hull damage in his report. As captain, it was my responsibility to have double-checked his work. My only reason not, was that I he was an experiences crew, with his own boat, an engineer by profession, and I couldn't conceive that he would neglect to cleat the anchor back down to the deck cleat and played out chain behind the anchor, both.

Is to the extent of damage: it was important in consequence, but insignificant as to extent. It clearly happened over a period of time of hours, days even, if the anchor and more likely the chain rubbing across my boat's nearly vertical bow, in rough seas.

I trust that this helps your understanding. It is the case, that the boat manufacturer, on later year boats, had reinforced the bows with Kevlar.

[minaret]

Originally Posted by Stumble

They are different, but not substantially so. Epoxy is the go to for repairs because poly won't stick to cured polyester. Poly has to be hot laid to itself to have any type of bonding strength.

In a practical sence epoxy to poly is prefered over poly-to-poly repairs because the bonding strength of polyester is so poor.

When will you cease pushing this drivel?


Don't you think in the course of building a boat of any size that the manufacterer must do plenty of poly on poly secondary bonding? Or do you believe the whole boat is built in a day? The idea that poly won't stick to cured poly is just amateur silliness, and you should really stop confusing people with it. It's misleading.

[builder dan]

I have seen a lot of damage done to plumb bows on yachts by anchors and chain and have always wondered why people dont extend their bow rollers out a bit and eliminate any issues.

[Stumble]

Originally Posted by minaret

When will you cease pushing this drivel?


Don't you think in the course of building a boat of any size that the manufacterer must do plenty of poly on poly secondary bonding? Or do you believe the whole boat is built in a day? The idea that poly won't stick to cured poly is just amateur silliness, and you should really stop confusing people with it. It's misleading.

When people like you will recognize what the manufacturers tell them about the properties of the products they sell. Polyester is still used because it is cheap, not because it is structurally superior. It looses strength while wet, is brittle, has poor bond strength, has a lower tensile strength, absorbs water, but it's cheap.

Polyester resin doesn't fully cure until the final layer is applied and protected from air (typically with wax) which is why there are special poly resins to act as the final layer for exacally this purpose. This allows you to do layups in stages, but once the final layer is cured you can no longer get a chemical bond to it.

Of course polyester will bond to cured polyester, but it will be a much weaker bond than if you used epoxy, and much weaker than the original hot bond was.

[KStepman]

Originally Posted by builder dan

I have seen a lot of damage done to plumb bows on yachts by anchors and chain and have always wondered why people dont extend their bow rollers out a bit and eliminate any issues.

I have actually looked into this possibility for this and a number of other reasons. The reason that I have not personally modified my boat by extending its SS roller forward is primarily time and money. As in I have had other priorities that I needed my attention since owning my boat. To explain: when last in to modify the metalwork on Fair Wind, it was to solve the compound problems of replacing a damaged Bimini, installing solar panels, increasing the height and support strength of the davits, and finding a place to install a Wifi bullet, AIS antenna, Serius/XM antenna, a backup VHF antenna, GPS antenna, and to secure a Shortwave HF antenna. I achieved this by having a reverse SS arch welded onto my existing traveler SS arch, connecting SS tubes, topped with 3/4" Starboard, onto which the was attached two large solar panels. On the aft edge of the Starboard the antennas were then installed. The stern light was also raided to this position. The aft angled arch was joined by the davits, coming off the interior sides of the swim platform, and joined at the stern rail as a third point of attachment, which allowed for a third diagonal brace. The addition of a cross bar between and hinged at each davit heads, and criss-crossing tension lines between the davits allows for maximum rigidity when extended out, while allowing the davits to be folded back to the stern for service and when a shorter overall boat length is desired.

The time, energy and cost to do all I just described would be nearly equal to extending the bow roller forward a meaningful distance.

[zeehag]

i would trust minarets words as he is a repairer of classy boats..classier than any i will ever own.... and seems to be good at it. if he says something about poly vs epoxy , i listen as he is smart in his working.


i double tie my anchors in place so there is no mistake made resulting in unnecessary drama and trauma.

good luck with your repair.

[KStepman]

Originally Posted by zeehag

i would trust minarets words as he is a repairer of classy boats..classier than any i will ever own.... and seems to be good at it. if he says something about poly vs epoxy , i listen as he is smart in his working.


i double tie my anchors in place so there is no mistake made resulting in unnecessary drama and trauma.

good luck with your repair.

Zeehag

I expect that I will be double tying my primary anchor in the future. My secondary and emergency anchors are already double tied in place. I was lucky. I know that it could easily have been so much worse.