ok, folks, everyone has spoke of this... you're talking about 40 boats out of 200
"My space is limited and I do need to discuss the blistering concerns. So, I’m not going to go into the usual details of construction other than to say the hulls are solid fiberglass and plastic resin, the decks are cored, and the method of construction has been in line with what should be expected of an offshore yacht. It is the materials of construction not the method that have caused problems with a number of Valiant 40 hulls.
Often the Valiant 40 problems have been more severe than the typical osmotic bottom blistering associated with many production boats of the 1970s and 1980s. My experience has shown a number of Valiant 40 models built by Uniflite between 1976 and 1981 to have severe blisters of the fiberglass laminates, some as large as eight inches in diameter.
Initially the blistering problem was blamed solely on fire retardant resins used by Uniflite. Later research has shown that a combination of sizing used on fiberglass strands chemically reacts with the fire retardant resins resulting in the blisters. This has the potential to be considerably more serious than typical osmotic blisters restricted to areas near and below the waterline. The Valiant blisters affect the entire hull. Most attempts at repair I am familiar with have been unsuccessful, and blisters have redeveloped in as little as two years.
I have heard of several successful repairs, although the solution is very expensive and the last I know of done professionally cost in excess of $60,000. On the positive side, there were 200 Valiant 40s built, and less than 20% have been reported to have severe blistering problems. I do not know of any reported sinking or catastrophic failure resulting from these blisters."
"But the original Valiant 40 does have its warts, or I should say, its blisters. According to Stan Dabney, who has owned hull number 108, Native Sun for 28 years, the well-known account of Valiants blistering because Uniflite switched to fire retardant resin, is only part of the story. Dabney claims that the blisters occurred when Uniflite switched to an inferior resin. “Like other builders, Uniflite was already using a fire retardant resin, but during the energy crunch in the mid ‘70s, some resin wasn't up to snuff.” Dan Spurr, the former Editor of Practical Sailor, wrote in his book, Heart Of Glass, that the questionable resin had a trade name of Hetron.
For a run of over 100 hulls, the Valiant 40's builders used inferior resin, leading to the need for substantial aftermarket repairs on those boats. Here one victim of those circumstances sits in the builder's yard near Lake Texoma after having had its gelcoat stripped.
The results of boats molded with this flawed resin were not pretty. While some Valiant 40s were horribly scarred with deep, structural fiberglass blisters up to 10 inches in diameter and requiring relamination, others experienced cosmetic blemishes restricted to the gelcoat layer. Still, you should be aware that boats built between 1976 and 1981, or hull numbers 120 to 249 all had some degree of osmotic blisters. As a result, a 1975 used Valiant 40 is often more valuable than a 1980 model. Worstell solved the problem for good in 1984 by switching to an isophthalic resin.
So does this mean you should avoid Valiant 40s built during this period? Absolutely not. Although most marine surveyors claim that only way to permanently fix a badly blistered boat is to completely peel the hull and re-fiberglass it, in most cases the blisters are simply unsightly. Blistered Valiant 40s are in some ways, one of the best values on the used boat market. And besides, by now many of older 40s have been properly repaired at some point. "