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Here's a good reference for you, Tom...
I've found Bill Seifert's new book, Offshore Sailing, to be a treasure. Bill was head of Tartan's production group for many years, then was in a similar role at TPI in RI, and finally worked for Alden. He's got a wealth of experience in a broad mix of production houses and does speak at some length about cored hulls. The book is on my local WM shelf. Take a look and, at the least, see what he has to say about hulls. His view on both carbon fiber spars and cored decks is that, even as he wrote that book (2000), there are still unresolved problems that one can't be certain s/he is avoiding. (I think that's a pretty interesting conclusion for someone who worked at TPI for some years, given their SCRIMP system). Jack
I've found Bill Seifert's new book, Offshore Sailing, to be a treasure. Bill was head of Tartan's production group for many years, then was in a similar role at TPI in RI, and finally worked for Alden. He's got a wealth of experience in a broad mix of production houses and does speak at some length about cored hulls. The book is on my local WM shelf. Take a look and, at the least, see what he has to say about hulls. His view on both carbon fiber spars and cored decks is that, even as he wrote that book (2000), there are still unresolved problems that one can't be certain s/he is avoiding. (I think that's a pretty interesting conclusion for someone who worked at TPI for some years, given their SCRIMP system). Jack
It depends on the day of manufacture...
Hello, Monday mornings and friday afternoons are very bad manufacturing times, consider this when buying your boat...just kidding... It really depends on how it was cored...most low end joints will just slap it on with adhesive and butt joints...the way I used to do it was to cut the core into smaller sheets...its bonded to a mesh and then razor cut into small cubes to take a compound curve...then usually sold in sheets the smallest I have purchased being 3 x 6 feet...for shipping and packing reasons I imagine...anyway... So I cut it into 1 x 2 foot pieces, and don't butt it up...I bond it to the hull in normal fashion but leave a gap of about a quarter of an inch between the core pieces...vacuum bagging the area and moving to another spot...the gap is then trowelled over with 'bear shit' (fiberglass paste)...the idea here being that there is a lattice of glass between the cores and smaller local areas to fix if holed...probably adds a lot to the strength of the hull shell too...and weight...roughly faired it...laid inner glass skin... This was for a pretty high end manufacturer and of course the labour cost was transfered to the final retail cost but it was a battle tank of a boat... Trouble is, unless you can talk to the manufacturer you just don't know how they do things...in many cases the capital outlay of a brand new boat warrants a factory tour if you can...if a manufacturer is not willing to give you a tour...assume they are hiding something from you...there are no industry secrets, but there are minimum standards...they just don't want you to see where they cut corners... A good rule of thumb is ABYC certification, but that is a once around and paid subscription...once they leave the plant the standards probably go back to 'bottom line'... BUYER BE AWARE is the only real measure... I would not buy a balsa cored boat...the trees are being felled too fast and not replanted...but I am not a do gooder politician either...you can argue the energy and chemicals required to manufacture foam...fact is though, in my opinion...closed cell foam is the only way to go... I blather... Cheers... SH
Hello, Monday mornings and friday afternoons are very bad manufacturing times, consider this when buying your boat...just kidding... It really depends on how it was cored...most low end joints will just slap it on with adhesive and butt joints...the way I used to do it was to cut the core into smaller sheets...its bonded to a mesh and then razor cut into small cubes to take a compound curve...then usually sold in sheets the smallest I have purchased being 3 x 6 feet...for shipping and packing reasons I imagine...anyway... So I cut it into 1 x 2 foot pieces, and don't butt it up...I bond it to the hull in normal fashion but leave a gap of about a quarter of an inch between the core pieces...vacuum bagging the area and moving to another spot...the gap is then trowelled over with 'bear shit' (fiberglass paste)...the idea here being that there is a lattice of glass between the cores and smaller local areas to fix if holed...probably adds a lot to the strength of the hull shell too...and weight...roughly faired it...laid inner glass skin... This was for a pretty high end manufacturer and of course the labour cost was transfered to the final retail cost but it was a battle tank of a boat... Trouble is, unless you can talk to the manufacturer you just don't know how they do things...in many cases the capital outlay of a brand new boat warrants a factory tour if you can...if a manufacturer is not willing to give you a tour...assume they are hiding something from you...there are no industry secrets, but there are minimum standards...they just don't want you to see where they cut corners... A good rule of thumb is ABYC certification, but that is a once around and paid subscription...once they leave the plant the standards probably go back to 'bottom line'... BUYER BE AWARE is the only real measure... I would not buy a balsa cored boat...the trees are being felled too fast and not replanted...but I am not a do gooder politician either...you can argue the energy and chemicals required to manufacture foam...fact is though, in my opinion...closed cell foam is the only way to go... I blather... Cheers... SH
And then again for a practical view ...
I have a J30 with cored hull and the problem is that repetitive bashing of the starboard side ... after 15 years of using a launch in Newport harbor in a number of weather conditions ... the outside skin developed a few small cracks which let water into the core and spread to about a 2-3 ft area that had to be removed and replaced. So if you are really concerned buy yourself one of those moisture meters and scan every foot of the hull especially if it has been painted. and make sure that any new minor cracks that developed are sealed/repaired right away ... I thought they were stress cracks in the gel coat but they went deeper or I would have repaired them earlier.
I have a J30 with cored hull and the problem is that repetitive bashing of the starboard side ... after 15 years of using a launch in Newport harbor in a number of weather conditions ... the outside skin developed a few small cracks which let water into the core and spread to about a 2-3 ft area that had to be removed and replaced. So if you are really concerned buy yourself one of those moisture meters and scan every foot of the hull especially if it has been painted. and make sure that any new minor cracks that developed are sealed/repaired right away ... I thought they were stress cracks in the gel coat but they went deeper or I would have repaired them earlier.
Thats funny...
Hello, A good sounding hydrometer (hi-drom-met-er) will run you about $1800 and if you can interpret the readings and relate what they mean against what you see (and HEAR), well then you should sign your name onto the pro. surveyor list of backyard beer can chuckers who do boats too...and then what do you do with it...put it up for auction at E-BAY...hydrometer, only used once $500 bucks... A 'panel beater' Joe Hotrod - soft peen hammer will tell you the same things, but without an LED readout and some shit software... assuming you have good pitch, and you understand what you just heard... Look at the whole package, obviously you have, this is not a factory boat...all you can do is educate, (gah I hope I spelt that rightly) yourself as much as possible outside of your expert-tease, and make the decision... Shame you don't know a good surveyor...it really is worth the cost...really...really...really...hints on surveyors...they have to be old and a bit weird...if they are this and have a lot of hydrometer gear (they vary in probe depth) in water tight cases with foam liners, with fresh batteries AND, AND a soft peen hammer they are usually ex-engineer drop outs with more life experience than an A+ student who paid his way thru. with Daddy Senators money to pay geek boy to write his ESA's...I digress...or egress...egret...no that's a bird...I remember bird...ornithologist...I did not drop out...but damn I took to the Scotts whisky (no E)... If they knock the hull with their knuckles and ask for a cheque and are less than 30 years old...say something like 'it was a green Chevrolet with two guys in it headed North'...he will assume you are mad and leave, which in the end will save you many thousands of your hard earned greens... Practical view my... Here is my call...you are buying a boat worth thousands of dollars and when you bust it up the insurance company is going to screw you as much as they can...regardless of your premium payment consistency...your client history...who you know at the bank...who you are...who you know...SO PAY THE PRO'S and get it in black and white on paper and make copies... YABOH... Cheers... SH.
Hello, A good sounding hydrometer (hi-drom-met-er) will run you about $1800 and if you can interpret the readings and relate what they mean against what you see (and HEAR), well then you should sign your name onto the pro. surveyor list of backyard beer can chuckers who do boats too...and then what do you do with it...put it up for auction at E-BAY...hydrometer, only used once $500 bucks... A 'panel beater' Joe Hotrod - soft peen hammer will tell you the same things, but without an LED readout and some shit software... assuming you have good pitch, and you understand what you just heard... Look at the whole package, obviously you have, this is not a factory boat...all you can do is educate, (gah I hope I spelt that rightly) yourself as much as possible outside of your expert-tease, and make the decision... Shame you don't know a good surveyor...it really is worth the cost...really...really...really...hints on surveyors...they have to be old and a bit weird...if they are this and have a lot of hydrometer gear (they vary in probe depth) in water tight cases with foam liners, with fresh batteries AND, AND a soft peen hammer they are usually ex-engineer drop outs with more life experience than an A+ student who paid his way thru. with Daddy Senators money to pay geek boy to write his ESA's...I digress...or egress...egret...no that's a bird...I remember bird...ornithologist...I did not drop out...but damn I took to the Scotts whisky (no E)... If they knock the hull with their knuckles and ask for a cheque and are less than 30 years old...say something like 'it was a green Chevrolet with two guys in it headed North'...he will assume you are mad and leave, which in the end will save you many thousands of your hard earned greens... Practical view my... Here is my call...you are buying a boat worth thousands of dollars and when you bust it up the insurance company is going to screw you as much as they can...regardless of your premium payment consistency...your client history...who you know at the bank...who you are...who you know...SO PAY THE PRO'S and get it in black and white on paper and make copies... YABOH... Cheers... SH.
But what the hay...
Hello, Below is the best guy on the East USA...he painted his own van...that sold me...don't know if I am allowed to post his joint...could be some local enforced, Gates financed, bylaw restriction...cum conflict of interest...something...whatever...hope you get this before the lawyers, or the coffee table boys with a brother in the biz' do... http://www.mastermarinesurveyor.com/ http://www.directindustry.com/ Second is where we get our instuments from...mostly pre-excavation work...if you want a sounding hydrometer this is your K-mart...can I say K-mart... Can I get another one of these...who is watching my section of the bar... Cheers... SH.
Hello, Below is the best guy on the East USA...he painted his own van...that sold me...don't know if I am allowed to post his joint...could be some local enforced, Gates financed, bylaw restriction...cum conflict of interest...something...whatever...hope you get this before the lawyers, or the coffee table boys with a brother in the biz' do... http://www.mastermarinesurveyor.com/ http://www.directindustry.com/ Second is where we get our instuments from...mostly pre-excavation work...if you want a sounding hydrometer this is your K-mart...can I say K-mart... Can I get another one of these...who is watching my section of the bar... Cheers... SH.
cored
Don't know Sean Herron but before proceeding with the surveyor he mentioned check with The Society of Marine Surveyors and The National Association of Marine Surveyors for their status of lawsuits against this individual.
Don't know Sean Herron but before proceeding with the surveyor he mentioned check with The Society of Marine Surveyors and The National Association of Marine Surveyors for their status of lawsuits against this individual.
Why decks cause more problems than hulls
Decks, which are almost always cored, more often suffer water intrusion and delamination than cored hulls, because they are pierced by hundreds of holes. The builder drills through the deck to mount winches, turning blocks, handrails, binnacle, and all other deck equipment. (Let's not even bring up teak decks.) Few builders take the time to overdrill, fill with epoxy, and redrill. So only the caulking under the deck hardware keeps moisture from getting to the coring. This caulking fails over the years, especially with deck hardware that experiences a lot of strain. The result are voids or soft spots in the deck where the coring rots, typically around the deck hardware whose caulking let the water by. A hull is pierced only by a few through-hulls, and the engine and rudder logs. The coring is absent at these spots. (Or should be.) It's also absent where the hull and deck flange meet. Of course, construction problems can cause delamination in any case. A cored hull is more complex to make than one that's uncored. From what I have seen, though, hulls suffer this less frequently than decks. Many a boat ends its life when its value doesn't justify repairing its soft decks.
Decks, which are almost always cored, more often suffer water intrusion and delamination than cored hulls, because they are pierced by hundreds of holes. The builder drills through the deck to mount winches, turning blocks, handrails, binnacle, and all other deck equipment. (Let's not even bring up teak decks.) Few builders take the time to overdrill, fill with epoxy, and redrill. So only the caulking under the deck hardware keeps moisture from getting to the coring. This caulking fails over the years, especially with deck hardware that experiences a lot of strain. The result are voids or soft spots in the deck where the coring rots, typically around the deck hardware whose caulking let the water by. A hull is pierced only by a few through-hulls, and the engine and rudder logs. The coring is absent at these spots. (Or should be.) It's also absent where the hull and deck flange meet. Of course, construction problems can cause delamination in any case. A cored hull is more complex to make than one that's uncored. From what I have seen, though, hulls suffer this less frequently than decks. Many a boat ends its life when its value doesn't justify repairing its soft decks.
Of course caulking fails in time
And epoxy filled holes doesn't eliminate the need for it. Water damage and rot isn't the fault of builders, the blame for it rests entirely with owners who don't pay attention to the condition of the caulk and sealant on their boats and re-bed/re-caulk as needed. It's called "preventive maintenance," and neglecting it always costs a LOT more than doing it.
And epoxy filled holes doesn't eliminate the need for it. Water damage and rot isn't the fault of builders, the blame for it rests entirely with owners who don't pay attention to the condition of the caulk and sealant on their boats and re-bed/re-caulk as needed. It's called "preventive maintenance," and neglecting it always costs a LOT more than doing it.
I agree, Peggie.
I never meant to suggest that deck hardware shouldn't be caulked. Or that owners shouldn't rebed the hardware as necessary. I was just pointing out why deck coring tends to be more problematic than hull coring. Regardless of one's own practices, the buyer of a used boat has to be aware of past owners' possible sins. I would ding builders on one score: when they make the backside of deck hardware inaccessible, making it difficult to inspect or service. There are a lot of cabin top winches, turning blocks, and deck organizers whose mounting nuts are behind a permanent liner that the builder installed after attaching the deck hardware. You're right that these things need regular attention. Which makes it a design and construction flaw to build the boat so that the need is hidden and the service requires boring through a permanent part of the boat.
I never meant to suggest that deck hardware shouldn't be caulked. Or that owners shouldn't rebed the hardware as necessary. I was just pointing out why deck coring tends to be more problematic than hull coring. Regardless of one's own practices, the buyer of a used boat has to be aware of past owners' possible sins. I would ding builders on one score: when they make the backside of deck hardware inaccessible, making it difficult to inspect or service. There are a lot of cabin top winches, turning blocks, and deck organizers whose mounting nuts are behind a permanent liner that the builder installed after attaching the deck hardware. You're right that these things need regular attention. Which makes it a design and construction flaw to build the boat so that the need is hidden and the service requires boring through a permanent part of the boat.
I agree, Russ...Inaccessibility is a MAJOR flaw
in boat building. If you can't get to it, you can't maintain or repair it. It should not be necessary to take a boat apart to replace or repair anything. I wanted to add a couple of cleats to my own boat...no way to back plate 'em without tearing out the headliner. I gave up on the idea.
in boat building. If you can't get to it, you can't maintain or repair it. It should not be necessary to take a boat apart to replace or repair anything. I wanted to add a couple of cleats to my own boat...no way to back plate 'em without tearing out the headliner. I gave up on the idea.
Thru-Deck Holes
One area where the manufacturers SHOULD epoxy seal is where there are thru-deck holes: Genoa tracks, furling lines, hatches, etc. When these holes are open and the deck material is clear and clean it would take comparitavly little time in a production environment to properly epoxy-seal these holes. The cost from water infiltration and damage in these areas is probably a thousand time what it would cost to build the boat properly. One poster said it cost something like $10 or $15K (exact amt??) for him to repair the damage on one side of his boat from a leaky genoa track and furling line holes. The January 2003 issue of Seaworthy, "Why Fiberglass Boats Sometimes Fail – a Primer on Boat Construction", http://www.boatus.com/seaworthy/swhigh.asp, says that "whenever a hole is drilled through a core below the waerline, it should be tightly sealed with an epoxy paste and then caulked to prevent water penetration". BoatUS says this because when wood rots the member looses strength. Wonder which builders do/don't do this? Also, even above the waterline, if water sets or is impeeded in flow it can easily find it's way into the deck through the smallest of cracks. My boat has recessed genoa tracks, probably for safety to prevent stubbed toes, where the water can sit just waiting for a chance to leak into the core. Resealing all the thru-bolts on just one side is about a two-day job for two people. The genoa track has LOTS of holes, to be sure, but there are large loads on the track which, if sealant was the only thing keeping it water tight, tends to fail easily. To expect the new owner to come behind the manufacturer and dismantle everything, clean out all the sticky sealant and do the job right is expecting a lot. Either they should have solid impervious fiberglass or build it right. In many areas Hunter apparently has put solid fiberglass with aluminum plates for things like winches, sheet stopers, etc., which is as it should be. To For a manufacturer to say they are a "production boat" to avoid appropriate use of epoxy is a cop-out. I just can't believe it would cost that much. Once epoxy is mixed the shelf life can be extended greatly by puting it in a freezer so they could mix up a batch and draft out of it during the course of several days. The Owners Manual for my boat is totally silent with regard to any resealing requirements but has information for many other things. Gotta leave now and put on my flak jacket!
One area where the manufacturers SHOULD epoxy seal is where there are thru-deck holes: Genoa tracks, furling lines, hatches, etc. When these holes are open and the deck material is clear and clean it would take comparitavly little time in a production environment to properly epoxy-seal these holes. The cost from water infiltration and damage in these areas is probably a thousand time what it would cost to build the boat properly. One poster said it cost something like $10 or $15K (exact amt??) for him to repair the damage on one side of his boat from a leaky genoa track and furling line holes. The January 2003 issue of Seaworthy, "Why Fiberglass Boats Sometimes Fail – a Primer on Boat Construction", http://www.boatus.com/seaworthy/swhigh.asp, says that "whenever a hole is drilled through a core below the waerline, it should be tightly sealed with an epoxy paste and then caulked to prevent water penetration". BoatUS says this because when wood rots the member looses strength. Wonder which builders do/don't do this? Also, even above the waterline, if water sets or is impeeded in flow it can easily find it's way into the deck through the smallest of cracks. My boat has recessed genoa tracks, probably for safety to prevent stubbed toes, where the water can sit just waiting for a chance to leak into the core. Resealing all the thru-bolts on just one side is about a two-day job for two people. The genoa track has LOTS of holes, to be sure, but there are large loads on the track which, if sealant was the only thing keeping it water tight, tends to fail easily. To expect the new owner to come behind the manufacturer and dismantle everything, clean out all the sticky sealant and do the job right is expecting a lot. Either they should have solid impervious fiberglass or build it right. In many areas Hunter apparently has put solid fiberglass with aluminum plates for things like winches, sheet stopers, etc., which is as it should be. To For a manufacturer to say they are a "production boat" to avoid appropriate use of epoxy is a cop-out. I just can't believe it would cost that much. Once epoxy is mixed the shelf life can be extended greatly by puting it in a freezer so they could mix up a batch and draft out of it during the course of several days. The Owners Manual for my boat is totally silent with regard to any resealing requirements but has information for many other things. Gotta leave now and put on my flak jacket!
Answer to Russell
You had some good and practical questions and here are my "quick" answers (not intended to cover every detail or situation): New piece doesn't have the same bolt pattern as the old? Drill straight through then epoxy-seal the raw material and install new item with sealant. Epoxy seal the old, unused, holes. Drill hole larger than needed for bolt. If you tap into aluminum then be sure to use aluminum taping oil and not steel taping oil. Your view that there should be no inaccessible spaces in a boat - I agree. And a removable headliner is far preferable to an interior fiberglass liner.
You had some good and practical questions and here are my "quick" answers (not intended to cover every detail or situation): New piece doesn't have the same bolt pattern as the old? Drill straight through then epoxy-seal the raw material and install new item with sealant. Epoxy seal the old, unused, holes. Drill hole larger than needed for bolt. If you tap into aluminum then be sure to use aluminum taping oil and not steel taping oil. Your view that there should be no inaccessible spaces in a boat - I agree. And a removable headliner is far preferable to an interior fiberglass liner.
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