SPEARFISHING EQUIPMENT: WETSUIT
MATERIALS, ADVICES, MAINTENANCE
ADVICES
Neoprene, is a synthetic rubber enriched with gas cells (nitrogen). This feature together with the thickness of the rubber provide a great thermal insulation and it’s for
this reason that this material is used for suits manufacturing.
The outcome of neoprene production is actually a mass of rubber to be cut in sheets from 1 to 8mm thick. This operation obviously cuts some gas cells so the result is a sheet with a porous surface called open-cell (or lined) neoprene. This kind of material provides a better adherence to the skin so a better thermal insulation that is however counterbalanced by an increased fragility.
After cutting, the sheet can be burnt on one (or both) surfaces in order to get the latter smooth by closing the broken cells. For this reason it gets called closed-cells neoprene.
It is slightly more resistant than the open-cells one and it also provide a good thermal insulation even out of the water since it dries easily.
After this burning step, an additional cover in jersey, lycra or plush can be backed on one (or both) surfaces, so the original sheet turns into a single or double backed neoprene. They are definitely the most resistant kind of neoprene and are easier to wear since there is no need to use soap, however they provide a lower insulation and their increased rigidity makes our moving in water awkward.
Today exists a variant of lined neoprene called shark-skin and it is characterized by a knurled weave made through the burning process. This material is more resistant and hydrodynamic and keeps the original adherence and elasticity features.
Among the innovations we need to quote the “sandwich neoprene”. This is a lined neoprene sheet backed with a gummy cover on the external surface providing more resistance and loosing a bit of elasticity.
ADVICES
As well as the kind of neoprene, we need to carefully consider its quality as this latter feature allows our suit to last longer.
Neoprene as our body is subjected to the same pressure and in the long run it looses the capacity to re-expand after dive compression, for this reason we need to choose the proper materials in order to avoid buying a winter suit that we will use comfortably the following august!
Another important feature is the seam gluing, in particular (clearly) for those suits that don’t have any stitching. Often the neoprene sheets are treated with a protective greasy fluid but that must be removed before gluing because the bi-component glues do not work properly on greasy surfaces and seams do open easily.
MAINTENANCE
In order to make our suit last longer we need to take care of its maintenance and here are some hints.First of all we need to wash away all the salt after every single use with fresh water and then we have to hang it out without clips in a dry place away from direct sunlight.In case we have to cope with a cut, the reparation is different whether the involved kind of neoprene is lined or backed.
In both cases however both edges should be dry and clean and we will have to use only liquid neoprene. This should be spread uniformly on the edges that must be kept distant from each other until the glue does not stick our finger when we pass it on. At this stage we need to put a strong pressure for a couple of minutes (perhaps by using a clip) on the edges in order get them firmly stick to each other. The suit cannot be used then for 24h. 
We must never use any water-resistant resin (most commonly used with non freediving suit) as when they dry they get solid and they create tears along the margins of application.
Thanks to the lycra cover the reparation of backed suits is easier and more resistant as after gluing with liquid neoprene we can sew the edges. All suggestions above are valid for backed suits too and in addition we make a an additional sewing with two different methods whether we repair single or double backed neoprene. In case of single backed neoprene the sewing (by common needles) should be superficial and go all the way through the sheet. In other words the needle should enter into the neoprene from the external side and come out on the other margin of the cut without breaking the internal surface, this method is called blindstich sewing (see picture).
This procedure repeated all the cut long should leave a seam visible only on the external surface, in case of double-backed neoprene instead the sewing can cross the material from side to side but it is strongly recommended to avoid this as the seams produced will cause scars and rashes during the movement in the long run.It’s clear that this procedure makes the relevant area more rigid then it is not recommended for large cuts.
