Guide to buying a Rigid Inflatable Boat (RIB)
Whether it is new or second-hand, before spending your hard-earned money on a RIB a few things need to be considered and understood. This page has been compiled to help you make informed decision regard to purchasing of a RIB by equipping you with the relevant knowledge to navigate the sales pitch and empower you to decide on a suitable RIB.
Rigid Inflatable Boats (RIBs) were conceived over 30 years ago, mainly for use by organisations such as the R.N.L.I and by the military, the design met the high demand for a fast response craft that could recover quickly if swamping or a capsize occurred, thus making it reliable for operating in adverse and extreme weather conditions.
Today RIBS are still used commercially for use at dive schools, Government agencies and the military but now the Rigid Inflatable industry is big business and has been split into several sectors of which the main is the leisure market. Subsequently a wide variety and range of craft are now available. Often described as the 4Wheel Drive of the sea, the simple principle of the RIBs concept is a low centre of gravity.
Construction and Materials
Tubes. Hypalon versus PVC
Most RIBS today are constructed with Hypalon inflatable tubes, however a lot of the smaller sized Ribs & tenders aren’t and the tubes are manufactured with PVC mainly to keep manufacturers and retail costs down. There has been many debates & blog posts but in my opinion it has little to do with which material has more UV resistance (to read more about the effects of UV damage please see Here )or fabric strength . After all how good is the material if the glue which adheres the tubes fails? In my experience of fixing Ribs & Dingy tubes of both types I can assure you PVC glue breaks down much quicker when comparing with Hypalon. and when the adhesive fails on the seams & the plastic fittings, it really is time to scrap.
Guide to buying RIB
In conclusion PVC tubes have a far shorter life span than hypalon.
However the tubes are only as good as the construction, just because the tubes are Hypalon does not mean that you will be trouble free in the tube department.
When tubes are constructed, the glued sides need to be prepped (i.e.sanded) this ensures a proper bond. This is impossible to detect looking at a new rib. although this seems obvious if it does occur. If you have or are buying a rib check the bulkheads (they separates the sections of the tube) even if it’s new, this will save you doing it at sea with family on board if you get a puncture. To do this, inflate the chamber to be tested and suck out the air of the adjoining chamber with a vacuum, leave for a few hours and check pressure.
Excess glue on new ribs will not become apparent until exposed to UV light and once brown and unsightly can be pain to remove so look closely otherwise your one week old boat will look ten years old. Also, check the strips that bond the tube to the hull are stuck without creases or bubbles and that the bow has sufficient bonding material.
How are GRP hulls made?
Traditional lay ups are achieved by over lapping chop strand mats (CSM) and stitched or roven- wovings at the keel giving a double thickness. This again gives weight at the lowest possible point in the hull acting much like a sailing keel that helps keep the boat in an upright position. This also helps in an impact situation.
The best ribs will be manufactured using the best materials, check that the materials used comply with industry ISO quality standards and/or are Lloyds approved. Resins and gels vary greatly in composition and on a finished craft there is no visible difference other than the invoice. Cheap materials are usually only apparent on failure two days after the warranty runs out.
Most GRP Ribs are built in polyester resin of some type, some omit less styrene into the atmosphere and are also more user friendly to the builder but are in turn more expensive. Isophalic resins used in the first couple of layers of glass hugely reduce the risk of osmosis (the dreaded fibre glass disease) which is an important point if you wish to moor or berth the boat. Glass matting comes in many forms most commonly used is chopped strand mat (CSM) this is, as the name suggests, chopped strands of glass randomly bonded (often with emulsion) to form a matting. Although this is the main make up of most ribs, stitched or woven mats are essential to gain rigidity.