pool wall once the pool walls are cured the vacuum 50 is shut off also a vacuum is again drawn through vacuum lines 12 so as to draw bladder 30 tightly against the surface of male mold 10 see fig4 this draws the bladder undercut portions 33 away from the undercut in the resulting pool walls and enables one to readily remove the cured molded pool walls from male mold 10 similarly the skin 60 which is now tightly adhered to the resin and reinforcement layer is readily released from the interior of mold cavity 21 curing time can vary greatly depending on the resin mix but is typically 5 to 15 minutes as described the resin and reinforcement layer was applied over the top of bladder 30 however the process could be reversed and with female mold half 20 lying flat with its cavity 21 facing upwardly the various layers of impregnated glass cloth and the reinforcing ribs could be placed within and against skin 60 located in mold cavity 21 male mold 10 with bladder 30 held in place by a vacuum would then be closed down onto female mold 20 in yet another variation of the process the article being formed might be such that one would want the smooth film 60 to correspond to the configuration of the male mold 10 the process can be readily reversed to accommodate this variation one would form bladder 30 to conform generally to the configuration of the cavity 21 of female mold 20 bladder 30 would be held against mold cavity 21 and film 60 would be held against male mold 10 as disclosed in the preferred embodiment the process is particularly desirable in that one not only achieves a tight bubble free bond between the.