Foam core hull

Foam core hull. In the matter of your hull foam, it's use depends on the builders intent. When I use these thicknesses with areas, I end up the following weights for the fiberglass-foam-core sandwich building: Fiberglass density: 1500 kg per meter cube, Foam core density: 90 kg per meter cube, Deck Weight: 20. The pli-core hull was very strong and light but was very costly to build with production short lived. Betweeen this cored 1 and 1/8 inch thick hull and 3″ of factory done airex foam between ceilings and hull in the salon area it’s like living in a thermos! As the global shipping industry pursues high efficiency and environmental protection, PVC foam core, as a high-performance sandwich material, is lightweight and corrosion-resistant, which meets the needs of ship design and helps the shipbuilding industry transform towards a green direction. It can and it does. Aug 28, 2014 · 2) The vacuum bagging process for these foam strip plank boats appears to use the foam strips as an air tight (mold) surface. Apr 7, 2019 · Traditionally, it was always a lightweight core (foam or balsa etc) with strong skins of a fiber with resin, but has morphed into other combinations over time. Another popular foam core is Airex, which is made of PVC but is linear in its chemistry (not cross-linked). Jan 7, 2013 · In fact foam cored panels are a bit more versatile than ply Here is a flat foam cored panel in the process of bending it. While core shear stiffness and strength are paramount in sandwich construction, other properties are also important. Mar 17, 2013 · There may be other considerations, but from the perspective of standing up to moisture and rot, the foam/fiberglass stringers are great. Jun 5, 2009 · Foam core construction done right is very, very good, but much more expensive and labor intensive than single skin construction. 6 kg Total sandwich construction boat weight: 57 kg Jul 31, 2013 · Some boat builders also use core in the entire hull, or more commonly only above the waterline alone. Lay those areas up with cloth or possibly Coosa Bluewater 26 (see “The Multipurpose Core,” PS February 2020). The reason for the balsacore is that it is stronger. Discussion in 'Fiberglass and Composite Boat Building' started by wetRat, Nov 28, 2005. 2- Your boat is an old boat without a cored hull Regarding price of a cored hull regarding a single skin hull it seems evident that if cored hulls were cheaper to built the boats that are built as cheap as they can be, mass market production boats, they would have cored hulls Mar 8, 2019 · The hull uses different density foam in various places across the hull based on structural strength needs. End-grain balsa or foam would have limited the problem to a much smaller area than I had to deal with. It's my thinking that the hull was probably built over a wood and batten plug in which the Airex was applied to that then the outer glass would have been applied to the foam wetting out with hand rollers. Oct 30, 2016 · Re: Plywood vs foam core vs solid glass for dinghy hull Glass over 1/4in or foam, is using the material as a core, but 1/8 is not really big enough to act as a decent core, so you will end up putting quite a thick skin on it to make up for small core thickness to gain the same strength. May 28, 2019 · The main hull is 21ft mostly polycore sandwich with glass and epoxy. Enclosed & fully sealed hull The hull, foam, and liner are then cured into one cohesive and rigid Everglades boat. I believe it was 1st year for fiberglass and tolly had 2 versions. 7 kg Bulkheads plus keel weight (no stringers): 8. Aug 23, 2011 · Removing Water From Waterlogged Foam - Shop Vac Method My Scat II hovercraft developed a water logged hull (2-part foam) condition after cutting some holes in the deck (+ hull) and leaving it uncovered for the better part of a winter four years ago. It also provides an enduring, cost-effective choice for polyurethane boat interiors. But that doesn't mean it won't deteriorate. Re: Foam Core Hull I had a 1977 Tartan 37 for 20 years with balsa coring and she never showed signs of water penetration, plenty of small blisters , but no wet coring. In terms of performance, a cored or sandwich composite is better than a solid composite with respect to strength-to-weight ratio. It's lighter for the same strength so the boat sails better The foam is great insulation making the boat more comfortable in hot and cold climates. Foam Core Properties and Applications. Boat builders rely on our FR-7100 Multi-use Core series to insulate fish boxes, bait wells and marine fiberglass bait freezers. It is well suited to amateur boat building because it does not require a female mold or any special equipment. Beneath the waterline, Outremer uses a single layer, solid vinylester laminate for safety. May 1, 2017 · By your answer I can deduce: 1- you are not a composite engineer. Airex foam is not a good foam for use on catamarans as if it is heated then the Airex foam tends to get soft and this is not good for the open decks of a cat. By a variety of means and methods. Keels would often be a solid laminate, as would other areas, like the deck cap flange, the chine crease, etc. Some guys throw old soda bottles in the bilge ( sealed plastic ). Jan 6, 2020 · The hull of the HMAS Rushcutter was realized using a 60 mm thick high-density PVC foam core and 8 mm thick GRP. ft. Primary hull construction is resin-infused vinylester with a balsa cored hull and deck. Due to the slamming and pounding of the hull bottom on the sea surface, water contained within a laminate or core will be compressed by the flexing laminate structure. @interior liners/gridpans: there a many different kinds, some grids (a grid of carlings/stringers & floors) tabbed to the hull - the tabbing can, if difficult, in general be inspected, & the much more difficult to inspect completely closed type that is glued (bogged?) to the hull (gluelines inaccessible) 2. Dec 14, 2011 · What matters then is how much water the hull displaces vs. Sep 17, 2007 · The shift toward cored hull and deck construction brought great potential for weight savings, but also introduced new challenges. Aug 27, 2022 · However the hull is foam cored, and we cut in to some of the foam core along the edge of the saildrive well. And on the impact resistance thing, I've seen (& repaired) enough collision damage to say this without much question. May 27, 2020 · Builders have a variety of materials from which to choose, including end-grain balsa wood, closed-cell foams, and honeycombs. The hull is made of 1 layer of fiberglass cloth, 1/4'' foam core and 1 layer of fiberglass cloth. May 17, 2021 · But it is a PVC foam core, heavier green grade in the bottom & lighter grade in topsides, Considering the hulls were standing outside for nearly 45 years (upside down) they have stood up remarkably well, core is still flexible & doesnt seem to be friable at all. LAST-A-FOAM ® TR-Series Marine high density polyurethane foams are specially formulated to meet the physical property demands of FRP-composite boat builders. Simply put, it is important that, in the construction process, every hull and deck penetration is anticipated and the core deleted in this area. Dec 16, 2008 · The current owner states that the hull is Airex cored with a ply cored deck. Pour foam, in my experience is a little tougher than foam formed in a factory and then cut to size. Worse there are boats like the Sabre 34 MK1 where they changed from no core to a core during the production run. Boats built with a core, being just the hull, the top sides, deck or interior or other structures can have, nowadays, a wide variety of materials available in the market, that range from Balsa Wood to modern lightweight rot free materials such as PVC, which is nothing more than a high rigidity micro balloon foam. This is, of course, tough to do if you don't understand exactly what foam cored construction is. Howevercertain areas and models break this rule in certain spots. Jun 21, 2013 · Christian & Co. We need to make sure it’s filled properly (primary question) and to make sure the screws to hold the plate are not going in to the cored area. Joined: Nov 2005 Posts: 2 LAST-A-FOAM ® TR-Marine High Density Foam Core. Finally, the resins used are better in quality than used back in the day. It has been sitting in a cyclone pit in tropical climate for 2 years and tyres were supporting it. 4 kg Hull Weight: 27. Core is available in a wide range of materials, from synthetic foam and honeycomb to balsa and plywood. Fontaine Pajot. It helps to stabilize the grid, adding to it's rigidity. The problem I have with foam is this: Balsa is balsa, and it doesn't come in 100 different formulations. 1276 Scott Street San Diego, CA 92106 Toll Free: 800-944-4789 Phone: 619-223-7380 Send us an email Cored hulls have become very popular, especially for power boat construction. Foam might seem like a great replacement for balsa, since it doesn't rot. Thus, the bottom literally becomes a diaphragm pump. Compression strength is needed to withstand localized loads such as dropping an anchor on a deck or resting a craft on trailer mounts. Its cross linkage and PVC foam core structure make it a good candidate for boat decks and flat hull areas. lets not degenerate this thread to a pissing contest please! 1. Because the core material is different from the reinforcing fabric, it’s less flexible across long panel sections and may resist conforming to the complex curves of the mold. Feb 2, 2024 · Klegecell is a cross-linked foam that is extremely rigid. Sep 20, 2023 · Foam core hull compression damage - Cruisers & Sailing Forums Hi all, I am looking maybe purchasing a Corbin 39. Explore the Benefits of PVC Foam in Shipbuilding Marine PVC foam core is a lightweight, Jun 29, 2018 · As the CAD work I've been doing stands now the total area of skin for the hull and deck is aboutish 30 square meters, the sides of hull use (preliminary) a 20mm foam core and the bottom has a 15cm thick foam core to add reserve flotation and to raise the bottom up to a level where it will be wide enough to walk on it. The orange Feb 21, 2014 · When a cored hull is laid up by hand, the process is similar but with a couple of differences. Jan 2, 2017 · Re: Foam Core Hull Pound for pound, cored boats are stiffer, tougher, lighter (not pound for pound, but length for length), & have a few other perks. The foams closed-cell composition makes it water resistant, and it also possesses top-tier insulation capabilities. RAMCAP™ is the only hull construction process that utilizes a pre-molded high-density foam core that fits precisely between an Everglades hull and liner. I think it's pretty likely that if those components had been wood-cored, I would have been replacing stringers as well. @cored structures: lets Jan 7, 2022 · Lagoon 42 - Balsa core or foam core: Dirk01: Multihull Sailboats: 31: 25-07-2021 04:40: Foam Core Hull: captainstubbie: Monohull Sailboats: 162: 14-03-2021 09:30: RF Ground on Foam Core Hull: FuzzyFeat: Marine Electronics: 3: 28-12-2009 12:40: To balsa core or not to balsa core? fbchristo: Multihull Sailboats: 135: 04-02-2009 14:13 Sep 22, 2013 · For example, in a similar size hull, in sea kayaks, production hand laid up fiberglass over foam sandwich hull, vacuum bagged and hand finished, for 17 ft single sea kayak, will weight about 45 to 60 lbs (depending on the accessories, hatches, seat style, etc) as compared to an equivalent hand built marine ply stitch and glue with a single Sep 17, 2017 · I had a 1968 28' Tollycraft pli-core. Foam core comes in three flavors: styrene acrylonitrile (SAN), linear polyvinyl chloride (PVC) and cross-linked polyvinyl chloride. Oct 1, 2017 · Re: Foam Core Hull @Dockhead Apparently Magnus Rassy has stated that the new design is an attempt to attract people who never before would have considered buying a Hallberg-Rassy. ANYTHING inside the hull (even foam) will add weight and make the boat sit lower in the water. May 25, 2011 · I have wondered if when consulting on the Dreadnoughts he saw an opportunity to use balsa core above the waterline and full on glass below as a way to mitigate this problem. 130 foam cored sandwich hull structures subjected to variable water slamming conditions was developed. Soaked foam happens to weight a LOT more than dry foam (in reality you've got many gallons of water inside your boat), so it's not going to float as well. Dec 19, 2014 · Boston Whaler likely does not use foam poured into molds but foam blocks machined with a 5 axis CNC Router. Our HDU marine-grade foam serves as core material for building transoms, hulls and bulkheads. For over 60 years foam cores have been utilized in marine applications to lighten, stiffen, and strengthen everything form hull bottoms to fly bridges. Press into place with a grooved laminating roller. For cored areas, coat the sections of replacement core with resin thickened with colloidal silica to a peanut butter consistency. Jan 1, 2017 · A foam core hull is superior to a non-cored hull - unless water gets into the core. The two cores are the same thickness (18mm), but are two different densities. how much weight is in the boat. Some boats also use Divinycell, a Scandinavian version of Klegecell, or the structural foam core Corecell. I would think the foam planking would not be a good air tight surface for bagging, but I see it done Jul 6, 2016 · No hull core Tartan 37-2 Odd but true Bene 36. Resin is vinylester. It is particularly well adapted to the building of one-off hulls. Nov 1, 2019 · A hybrid computational-empirical fatigue failure prediction model for shear failure dominated C70. They do sell a healthy amount of boats as it is and the company has no debt so I don't think they necessarily need a new design to survive as a boat builder . Re: Foam core hull compression damage I agree with Captain Bill, it is true that that under high point loads the core will try to flow away from the stress and the skins act more brittle by comparison. The Density required these days by the USCG is 4# per cu. Is foam core construction a good thing when it comes to building boats? Some say yes and some say no, but boats. Oct 20, 2014 · A foam cored hull will have an inner and out skin, bonded to the foam. The surveyor discovered wet hull core with a moisture meter, and subsequently pulled hull fittings and portholes to physically reveal the wet balsa core. In addition, Divinycell foams scrim scored surface let it conform to curved surfaces. Mar 16, 2016 · The hulls are foam cored. Jul 24, 2020 · Some sections could be solid glass instead of core. I pulled wet foam out of my hull, but the stringers and bulkheads were perfect. Honeycomb is just what it sounds like: a waffle-like pattern of material to give the highest stiffness of any core of equal weight. Then to get it right around, a few ratchet straps are needed and viola, the bilge of a 35ft hull is done; The reason is that once water gets into a core, a phenomenon called hydraulic erosion takes place. And he was stuck with $95,000 worth of unsaleable boat. We will describe what is commonly called the open mold method. The solid glass version was built thru 1974 I'm A premolded fiberglass grid is bonded to the hull and then filled with foam. . But it has not adhered to the paint? underneath. Cored composites yield lighter, faster and more fuel-efficient boats. Jun 29, 2018 · As the CAD work I've been doing stands now the total area of skin for the hull and deck is aboutish 30 square meters, the sides of hull use (preliminary) a 20mm foam core and the bottom has a 15cm thick foam core to add reserve flotation and to raise the bottom up to a level where it will be wide enough to walk on it. Aug 6, 2003 · The weight difference from Airex to balsa is minimal. One being solid glass and other being what they called "pli-core" which was foam cored. Picture from installation on Sadler 34 with a foam core hull construction Ultrasonic transducers must make direct contact with the outer skin of the hull. Oct 7, 2017 · agprice22: Catalina did not use end-grain balsa or foam core in 1988. It looks like most of the lower part of the boat has delaminated. Honeycomb. For hulls constructed with a foam sandwich or other core, a small area of this material must be removed to expose the outer skin. C&C in general no hull core below 33 and full of balsa above 33 feet. With the foam strips all being epoxied to adjacent strips, there's a lot of seal area that could allow air into the bag. Oct 15, 2020 · With a carbon fiber inner skin, Catana also uses Twaron aramid fibers in the sandwiched hull over a foam core. These marine polyurethane foams provide structural strength with moisture resistance, enabling boat designers to replace wood components RF Ground on Foam Core Hull: FuzzyFeat: Marine Electronics: 3: 28-12-2009 12:40: To balsa core or not to balsa core? fbchristo: Multihull Sailboats: 135: 04-02-2009 14:13: different core types (foam pvc, divinicell vs balsa) schoonerdog: Multihull Sailboats: 56: 22-07-2008 09:56 Jun 21, 2017 · Beyond that, plastic foam core materials are more common in hulls than decks. She had solid glass where bulkheads were tabbed into place as well as through hull fittings. Nov 28, 2005 · moldless foam core High Performance hull. Oct 31, 2008 · Re: Wet foam core, rotten stringers There have been pro's and con's over the years about adding new foam. Tim returned the deposit to the buyer, who left angry. And I have heard this:However, some foam cores are expensive, such as Airex. The newer closed cell foam is pretty watertight so if you decide to go that route you should have no further worries about it getting waterlogged again. Jan 5, 2016 · If you're looking at new boats, one of the things you'll have to consider is whether or not to buy a boat built with foam core construction. This was prior to the high-density, close-cell, PVC foam core such as Divinycell, commonly used today for both topsides and decks. Oct 18, 2007 · Composite material boats are either built with or without a "sandwiched" core. for floatation but structural areas are likely 8-16 pounds. Revealing a variety of foam cores on the outside of the polycore It looks like the foam was used to created a wider profile at the waterline. they used exterior grade plywood. The white, pin hole laden stuff is cloth, in the laminate. But what exactly is foam core? What type do I use, and where can I use it? Should I use it instead of balsa or plywood? Foam sandwich is a well proven material, light and strong. These have varying engineering properties, but from the owner’s viewpoint all are essentially the same. In a previous Troubleshooter column, I wrote about how to detect core moisture intrusion, and how to prevent the intrusion from happening. Moulding boats using thin veneers for boats is actually an old system that goes back at least 75 years. Outremer. Epoxy vs polyester means entirely different risks of having water penetration in the first Sep 11, 2013 · Both balsa and foam cores can be well produced and last for years. Mar 27, 2024 · Between the 1970s-90s many boats had balsa-cored sandwich decks, partly to make them stiffer, and partly to help reduce the boat’s weight above the waterline. 7 no hull core. Foam Cored Decks. The most popular core materials are balsa and PVC cross-link foam, including Klegecell, and Divinycell. In core construction, a low-density material is sandwiched between high-modulus, fiber-reinforced-plastic (FRP) skins, resulting in a strong, but light panel. The premium for using epoxy vs polyester is not so significant on a foam cored hull and there will be less in the layup since there will be less weight of higher modulus laminate. com Senior Editor Lenny Rudow explains why fo Jan 25, 2019 · It failed. The model combines numerical results from FE stress analysis with experimental core material characterization published in the literature. More specifically, the skin panels were manufactured combining chopped strand mat and woven roving reinforcements, in order to maximize the bond strength, fire resistance, and interlaminar shear strength. ibpn xutjdf uawxec hpc zim ghrhe rigmk qdzbx fvyhr feqvs