Inflatable Boat Materials

Inflatable boat Materials (The Hypalon PVC debate)

In this article I will try to outline some of the strengths and weakness of the two materials most
commonly used in inflatable boat construction as well as talk about several other materials on the
market. Most of this is based on the time I spent working for one of the largest inflatable boat dealers in
the US.

Let’s start with the basics of both materials.

Hypalon- Hypalon is a synthetic rubber made (or made under license) by the Dupont company. Hypalon
has been around for more than half a century proving itself to be one of the most durable synthetic
rubbers around. Hypalon is actually chlorosulfonated polyethene meaning it’s a polyethylene with
varying amounts of sulfur an chlorine added based on application.

PVC – Is essential a hard plastic converted into a flexible material through additives. PVC is short for poly
vinyl chloride. PVC was first discovered in the 1800 but the correct additives to make it into a useful
material weren’t developed until the late 1920’s.

Now on to the important parts what that means to those of us who need an inflatable boat.

In this article we will be talking about reinforced or supported fabric boats. Most inflatable boats with
the exception of Sevylor and other extremely low priced semi-toy boats have a layer of supporting fabric
sandwiched into their PVC or Hypalon hulls. This fabric creates the extra strength and form holding
ability that differtiates a well built inflatable boat from a pool toy. The fabric is rated in either Denier
or decitex; Denier is the more common method. Denier is the weight in grams of 9000 meters of single
thread of the fabric. (1gram + 1 denier) Decitex is 9/10 Denier (this is the best definition I have found at
least.) When you’re looking at inflatable boats you will often see anywhere from 800 to 1200 decitex/
Denier ratings, while these can be useful I wouldn’t go on them being the greatest indication of boat
strength. As former co worker with over 20 years inflatable boat experience pointed out these ratings
tell you nothing about the quality or density of weave that the thread was put into or the process in
which it was bonded to the outer material.

This brings us to how the two materials are actually constructed into boats.

Hypalon is calendared on to the reinforcing fabric (typically nylon) calendaring is processes where the

materials are sent through a series of heated rollers that essential bond the two materials into one.
Neoprene is often used as an additional interior layer on hypalon boats to increase their air tightness, this
is why hypalon boats are sometime referred to as hypalon/neopreme. PVC is reinforced in the same way,
except they typically use PVC for both the outer and inner layer.

Hypalon boats are assembled by hand; in fact this is one of their biggest drawbacks. Because Hypalon
boats are glued together by hand you will find that two boats of the same model may have small
differences (weight for instance is often off by a pound or two) and can even have a slightly different
shape when inflated. The hand gluing also lends itself to air leaks over the life of the boat. The hand
gluing also reduces the air pressure the tubes can hold. This reduced pressure is of no real concern until
you get into air floor models where higher pressures can result in stiffer floors.

PVC boats can be constructed with hand gluing methods in much the same way as a hypalon boat, but
building in this way doesn’t let you realize PVC’s advantages. PVC can be welded; welding can be done
in a number of different ways. The most used method is Thermowelding in which hot air is blasted at the
seam as the material is passed through a set of rollers there by melting and bonding the seam together.
There is also a similar method called wedge bonding that uses heated rollers instead of the blast of air.
The other method used primarily by Zodiac is Electro welding. In this process the material is passed
between an anode and a cathode that create a high frequency electric field that again heats and bonds
the seam together. These construction methods allow for PVC’s real advantage- airtight seems and
higher inflation pressures.

Positive and negatives of the materials

Hypalon Pros

Strong material very resilient to damage from external objects

Very stable in UV light the material may fade but it will typically retain its physical strength longer
than other boatbuilding fabrics.

Often backed by a longer warranty due to greater strength and longevity

Hypalon Cons

Hand glued seams are more likely to leak air and need mantinece over the life of the boat.

Cost because of the labor intensive nature of hand gluing hypalon almost always costs 10-25%
more than PVC

Lower air pressure because again of the construction methods Hypalon cannot hold as high
a pressure as PVC this becomes important when a boat uses air keels and air floors as the
additional pressure adds rigidity to these structures.

PVC Pros

In expensive, PVC boats because they can be assembled quickly on a production line are often
some of the least expensive inflatables on the market.

Higher pressure, because the bonded seems on PVC boats can withstand higher pressures the
air floors and keels can have a more defined shape for better performance (not all companies use
this feature so it’s worth researching Zodiac for instance bakes excellent air floor boats in PVC
while some of their lower priced competitors do not)

Every boat is the same, because they can be built through an automated process PVC boats can
be built to exacting standards (here again be careful as not all manufactures build PVC boats with
standards in mind)

Better air holding, PVC boats usual need less topping off through a season then hypalon boats
because of better air retention properties.
PVC cons

UV degradation, PVC is effected by UV light much quicker than Hypalon. When exposed to a
large amount of UV light PVC breaks down and can become stick, which I can tell you can be
mighty aggravating on a hot summer day

Cheap, this is not true of all PVC boats but because PVC is typically a cheaper material then
Hypalon many bargain basement brands have entered the market with substandard boats often
built by hand gluing PVC not to say there aren’t poorly built hypalon boats, there are just many
more poorly built PVC ones.

What this means to you.

If you’re in the market for an inflatable what material should you choose? While there are many other
factors that can determine which inflatable is right for you when deciding on materials the biggest
question comes down to Price vs. longevity for most people. A hypalon boat will typically outlast a
PVC boat by many years, when I worked at an inflatable dealership when we saw a boat older than
15 years old come in for repair 80% of the time it was a Hypalon boat. After 15 years many of the
PVC boats were no longer repairable. That’s not to say they can’t last longer, I have also seen some
very well taken care of 20 year old PVC boats but these are typically either used on a limited basis
or were covered and regularly treated with 303 protectant. On the other hand if you’re an average
boater and the inflatble won’t be sitting out in the sun for long periods (weeks not hours) a PVC boat
can provide a lot of bang for the buck. Also certain models with desirable features can only be had in
PVC such as Zodiacs H2P air floors which are some of the best performing soft bottom inflatable’s on
the market, in fact the other PVC boat that stands out in my mind id the Zodiac Futura which again
provides a large performance gain over just about anything (other the certain military zodiacs) made
in Hypalon.

So in the end both materials have their positives and draw backs and which you purchase is largely up to
your budget and how you use it.

About Colin

Short Bio. I have worked in the marine industry since I was 15 with the exception of a brief stint working on cars and RV's.
This entry was posted in Boat stuff, Colinism and tagged , , , , , , , , . Bookmark the permalink.

One Response to Inflatable Boat Materials

  1. Anthony says:

    The new kids on the block use more modernized versions their grandmothers were built of in the form of Polyvinyl Chloride also known as PVC. So the plumbers now are happy without having to clinker over the use of metals for pipes and the PVC is tough and durable for old needs. PVC has a place in our daily lives, from electric wires, to kitchen accessories and the society has not a day been able to live without it ever since it was born. However, there are certainly a few issues with regard to the use of PVC.

    Plastic drain pipes have the same PVC material used for the making of Inflatables, with a difference in the range of plasticizers used along the way for the purpose it was meant to be used, namely flexibility and softness which is not found in the sewer pipes that carry our waste.

    The fabric with PVC is much cheaper as compared to Hypalon and can be thermoelectrically used for welding by anyone who has semi skill knowledge. Hypalon seams and boats need gluing which is done by hand using labor that is highly skilled and expensive. This is where PVC comes in as a savior to using less man force and saving tons of gold pots as an investment to building the Inflatables.

    The problems are several when we speak of PVC materials for boat building, since it is photodegradable and the breakdown of PVC under the scorching sun is but apparent. This means that the flexibility of the boat goes and the fabrics would leak air. One could like many other boat owners use an ultraviolet protective coating like the UVA while the painting and varnishing of the boat is on to keep it well protected, however it doesn’t last long considering you would want your boat to outlive you. Talking of which, the plasticizers as well are soft and the flexibility in it gets them destabilized. The quality of Inflatables made with PVC are a problematic choir when it comes to consistency, durability isn’t that great on most of the PVC made boats. The seams which are welded are undoubtedly strong but the portion where the fabrics are attached, especially the wooden transom and also the rigid bottom, they are not as strong as their counterparts made from Hypalon, because the gluing of PVC is a dissatisfying deal, making repairs and punctures an ordeal that can have tempers flaring and managing small tears cumbersome. The damage to PVC because of chemicals and hydrocarbon fuels leaves stains and marks which tears the life of a fabric in a short time apart, whereas Hypalon is known to resist the onslaught of such chemicals and hydrocarbons.

    Hypalon and Neoprene show off improvements and standards over Natural Rubber while PVC is cheaper when compared to the former two. Most cruisers and sailors with families around the Caribbean prefer boats NOT made of PVC but rather pay more for boats made of Hypalon and Neoprene. The best boats were from Avon and Achilles, with Avon bagging the most votes for reliable boats.

    Now this doesn’t mean that PVC shouldn’t be considered at all, through the surveys taken by SSCA and Jimmy Cornell, we get to know that the cruisers did most of their sea adventures in the wet tropics on PVC boats. The boats were assaulted constantly with the vagaries of elemental attacks and an environment as harsh as possible, a total nightmare for sailors and the entourage if you please. Unless a Biminis are covered and well protected on a sail set for the south of Bimini, then a PVC boat should be avoided. But the temperate regions are favored as some say for the PVC boat makes rather than the tropical weather.

    A survey by the “Practical Sailor” speaks of various geo centric locations and high for Hypalon boats, however doesn’t demean the importance of PVC made boats for temperate weather conditions. Many users who have PVC boats love it for the amount of money saved on its maintenance and the free replacement of parts and services which manufacturers provide.

    Temperate areas don’t have any threat for ultraviolet degrading to happen on PVC boats. Secondly repairs to be carried on the PVC boats were not that frequent. PVC boats if well maintained and kept clean and free without having to wait over extended hours in the blazing sun would be an ideal choice for money minded folks. The way one uses the new inflatable made of PVC will actually determine the lifecycle of the boat in question. Protection from natures wild elements, like the sun, the rain and gnash winds would keep the boat in good stead for years to come.

    Avon’s Hypalon boats come with a warranty of ten years and is applied for transfer of ownership, whereas West Marine’s PVC babies come for a 5 year. They both are known for the efficient and prompt services in warranty, however the best warranty doesn’t mean you have a mind blowing babe. Some manufacturers toying with Inflatables and those made of PVC have one thing to say on paper and another in real time terms, so you may want to check and do your bit before investing in a PVC model.

    For more information about inflatable boats please visit:

    http://inflatable-boats-kayaks-and-canoes.com

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