Eliminating Boats with Liners - Advice

[sailorboy1]

there is a difference between a liner and a pan

[Adelie]

Originally Posted by Wavewacker

Interesting opinions, but what is a liner? I was thinking there was a sheet of goods laid between the hull and the interior tub, I don't think that's what was meant now. Is the liner a molded interior tub or structure that is fitted inside the hull during construction and capped with the deck? Sorry to be so ill informed, but I'll be looking at older boats and need to address such an issue if it is really a concern. I will be making interior mods I'm sure of it, so if this linner thing is a limitation, I'd sure like to know too....

A liner is one or more fiberglass pieces molded to create the interior furniture or parts of the interior furniture in a boat. The smooth gelcoat surface faces in to give a finished look that does not require nearly much additional work as wood furniture.

Generally a boat is 2 moldings minimum, 1 for deck and 1 for hull with the interior looking unfinished. Liners are additional moldings.

The liner may provide a little, some or a lot of added structure to the hull depending on how it was designed and installed.

A liner may obstruct access to the hull or deck or parts thereof depending on the extent of a liner and how it was designed and installed.

[Wavewacker]

Adelie, thanks, yes, now I am totally on track, especially after awakening from my morning nap! I have often wondered why access was so limited in some areas, knowing there could be some cubby holes. Someone mentioned finger holes to remove a pannel, wonder too if they allow some ventilation to air out such cavities from any condensation. There are caps and grommets for holes too.

I studied the McGreggor X a bit years ago as I was interested in them, but lost interest after speaking to an engineer at the factory, telling me the deck connections were not designed for off shore use and the "liner" keeping you from bulking up the rigging/chain plates & hull for any modifications or adding amenities.

[FecklessDolphin]

It seems like the best ocean-going boat builders (like Shannon) and the those who do the most ocean sailing (like John Neal) prefer not to have liners. Building boats is certainly more expensive without a liner. The debate here is probably how much value is added (such as structurally), what other things are lost (such as asthetics and money in your bank account) and whether that trade off works for your individual plans for the boat

[Cheechako]

Wauquiez, Passport, Valiant, Hans Christian, Tayana, Lord nelson, CT, Formosa, Westsail, Cape George, older Swan & Hallberg Rassy are a few without liners. They may have small areas like shower pans that could be called a liner. I think there are many more but not sure. Full/ near full liners make production easy. What you dont know and cant see well is how well the liner fits the hull. You also have to have faith that the "glue" used to attach them will act as advertised. It is awfully tough stuff...

[sailorboy1]

Originally Posted by FecklessDolphin

It seems like the best ocean-going boat builders (like Shannon) and the those who do the most ocean sailing (like John Neal) prefer not to have liners. Building boats is certainly more expensive without a liner. The debate here is probably how much value is added (such as structurally), what other things are lost (such as asthetics and money in your bank account) and whether that trade off works for your individual plans for the boat

That's really because for builders that will cutomize your interior it is more expense to make a pan/liner for each customer than just stick building the interior.

I have faith in the glues used and believe the liner probably makes the boat stronger not weaker.

[Bash]

You're going to disqualify more than 95% of fiberglass boats currently being produced, and you'll ultimately limit yourself either to semi-custom builders or very old boats. You will not end up with boats with greater storage space, nor will these boats have stiffer hulls.

We all have something different we're looking for in a boat. I remember swearing, at one point, that my next boat would be designed from the refrigerator out, and that I wasn't going to purchase from any manufacturer that didn't understand how to insulate an ice box properly. Yeah. Right. What do you suppose the chances are that there's someone out there insulating to my high standards?

Seems that liner-free design is going to be a tough starting point from which to begin a boat search.

[Dockhead]

When well done (like for example Beneteau) a liner adds a lot of stiffness, which is a very, very good thing. My boat does not have a liner, but she was made in the inefficient, old, labor-intensive way and thus was unreasonably (read, outrageously) expensive for what she is. Modern production methods are much more efficient, meaning you get a much better boat for a given amount of money. That is also a very good thing.

[Adelie]

DonLucas touched on the point of liners making the hull stronger.

From a structural stand point a liner that is bonded to the hull will make the hull stronger at the locations where the bonding occurs. The amount of improvement will depend on the thickness and depth of the liner in those areas, the quality of the bonding.

The question that remains is whether a bonded liner strengthens the hull as much as similarly arranged stick building that is also bonded to the hull?

My guess is that they are comparable for most manufacturers.

Things to watch for would be are all edges of the liner bonded to the hull and is the bonding done with resin and fiberglass tape or was the bond done with thickened resin squirted into the joint?

[sailorboy1]

Just a note - just because a boat has a liner or a pan doesn't mean the bulheads etc aren't fibergalss tabbed to the hull also. Some even have the deck designed in such a way that the bulkheads fit into a designed slot inside the boat (you know that much trashed "H" boat).

[four winds]

I've been looking around my boat because of this thread.

The floor pans or liners in my Pearson are port and starboard halves. And they appear to be more than an inch thick. I assume they are cored. They feel strong under foot. They appear to make contact with longitudinal stringers or stiffeners at the waterline on the hull. (edit,.. actually below the waterline, and appear to be there as a mounting point for the pans.) I'm not able to determine if or how they are bonded along the outer horizontal edge yet. I'll wait till I need to remove panels for other reasons for a look. My guess is glassed with woven roving along the entire length, considering the bulkhead attachments as evidence.

These pans are formed with "slots" for the bulkheads to fit into. The bulkheads are fully glassed to the hull sides with woven roving on both sides. The bulkhead at the mast appears to be the most substantially constructed. The bulkhead at the v berth appears to be a quarter in less in thickness but still fully glassed with roving. These are plywood bulkheads.

The settee and dinette structures are about one quarter inch fiberglass.

I have some formal training in structures and strengths of materials and it's my opinion that this setup is strong. I've never heard any groaning or creaking in the boat while underway.

A comparable stick built construction can be strong of course, but considering the greater number of pieces involved, the many, many connections, the possibility of these to be compromised by various means, makes me think that overall strength is not really the issue to focus on.

I'm currently evaluating access issues to all areas of the hull. .

edit, to clarify, I think traditional wood structures can be and are strong, but takes more skill to do correctly, and might need more diligent maintenance to preserve integrity.

[avb3]

Great comments and educational; but I've come to expect that from CF users

I ran across this article today about hull/deck marriage, which has some relevancy to this discussion. A good read.

[mitiempo]

I saw that yesterday on Wavetrain (Charlie`s blog).

Most boats of any size have the inward flange with either an aluminum or teak toerail on top.

[Billy Higgins]

Several times a "soft liner" is mentioned. What exactly is that?

[sailorboy1]

Originally Posted by Billy Higgins

Several times a "soft liner" is mentioned. What exactly is that?

Would need to see more of the description for how it is used. But it probably is just talking about the foam backed sheet vinyl liners used for insulation along the hull and deck.