I see a lot of people talking about poor construction and "defective" hulls, especially when doing jobs like replacing stringers.
First off, your boat is probably not defective, those voids and air pockets you are grinding out are probably there due to the last layer being applied to the inside of the hull being very resin rich - that's to assure a good seal over the glass (water-proofing). The voids occur because this last layer is two processes being done at once and unlike structural layups, this last layer is not rolled out or 'squeeged' to eliminate excess resin and also why you may find slight puddles of resin. All that material should be ground out, especially those resin pockets. You don't want to tab in a new piece on structurally unsound (brittle) resin, but rather to the hull material.
You may also find a black or grey top coating peeling away. I know one manufacturer used to use "resin tar" as a final water proofing coating and another that used an emulsion coating not only in the hull, but to waterproof their foam also. None of these are problems or manufacturing defects.
There's also the "crappy materials" bunch. If you want a super light, carbon fiber boat, you can buy one. We can build boats that will easily last more than your lifetime and cost more than your home. Probably more than your last couple of houses. So materials is a non-issue except to those of us restoring boats to keep them in service well beyond their normal service life, abuse the crap out of them by leaving them stored outdoors, bow down, without any kind of cover, etc., etc.. Would you expect your car to last as long as your boat? Would you pound your car, neglect it and abuse it like your boat?
Then there's the "one size fits all" people. The ones who think all boat construction designs are the same and structural components are all interchangable. In a word they are not. All manufacturers are always looking for strongest possible result, using affordable materials and construction methods, which is why what is good for one, is not necessarily good and may even be detrimental in another. One good example is stringers. A stringer can be designed as a hollow fiberglass beam. The older boats we are interested in were, for the most part, not designed for that and the cores (lumber) in these older boats is usually part of the structure and the hull is formed with those localized stresses and the flexural and compression as well as other properties of the core material in mind. Substituting structural materials without understanding what they do or how they act in a given application is just plain stupid, even if you think "it works".
Before making any change, first determine whether or not it is structural. I saw in one thread someone was planning on a new deck, had ripped the old one out and wanted to use the old edge seal as the bottom and raise the height of the stringers 1/2" to allow for it. Some moron answered that as a yes without getting any other info! The answer should have been absolutly not, as apparently both these individuals will eventually find out. Hey... because you did something and for at least the time being it seems to be working for you, does not make it right.
That edge seal is just lightly tabbed into the thin hull side. In many (most if not all) production boats, the deck is structural and needs to be laid in against the chine - he may have tried to overcome this by installing bulkheads or some other bandaid fix, but why? That thin flap of fiberglass could be zipped off and ground flat all the way around in probably less than an hour on the average under 20 foot boat.
I guess what I'm trying to say here, is if you wouldn't pull a car out of the junk yard and ***** at the manufacturer about what a crappy job they did building it, why do you do it with boats? And why do you expect materials and or other critical components to be interchangeable when you'd never expect that in any other form of transportation?
First off, your boat is probably not defective, those voids and air pockets you are grinding out are probably there due to the last layer being applied to the inside of the hull being very resin rich - that's to assure a good seal over the glass (water-proofing). The voids occur because this last layer is two processes being done at once and unlike structural layups, this last layer is not rolled out or 'squeeged' to eliminate excess resin and also why you may find slight puddles of resin. All that material should be ground out, especially those resin pockets. You don't want to tab in a new piece on structurally unsound (brittle) resin, but rather to the hull material.
You may also find a black or grey top coating peeling away. I know one manufacturer used to use "resin tar" as a final water proofing coating and another that used an emulsion coating not only in the hull, but to waterproof their foam also. None of these are problems or manufacturing defects.
There's also the "crappy materials" bunch. If you want a super light, carbon fiber boat, you can buy one. We can build boats that will easily last more than your lifetime and cost more than your home. Probably more than your last couple of houses. So materials is a non-issue except to those of us restoring boats to keep them in service well beyond their normal service life, abuse the crap out of them by leaving them stored outdoors, bow down, without any kind of cover, etc., etc.. Would you expect your car to last as long as your boat? Would you pound your car, neglect it and abuse it like your boat?
Then there's the "one size fits all" people. The ones who think all boat construction designs are the same and structural components are all interchangable. In a word they are not. All manufacturers are always looking for strongest possible result, using affordable materials and construction methods, which is why what is good for one, is not necessarily good and may even be detrimental in another. One good example is stringers. A stringer can be designed as a hollow fiberglass beam. The older boats we are interested in were, for the most part, not designed for that and the cores (lumber) in these older boats is usually part of the structure and the hull is formed with those localized stresses and the flexural and compression as well as other properties of the core material in mind. Substituting structural materials without understanding what they do or how they act in a given application is just plain stupid, even if you think "it works".
Before making any change, first determine whether or not it is structural. I saw in one thread someone was planning on a new deck, had ripped the old one out and wanted to use the old edge seal as the bottom and raise the height of the stringers 1/2" to allow for it. Some moron answered that as a yes without getting any other info! The answer should have been absolutly not, as apparently both these individuals will eventually find out. Hey... because you did something and for at least the time being it seems to be working for you, does not make it right.
That edge seal is just lightly tabbed into the thin hull side. In many (most if not all) production boats, the deck is structural and needs to be laid in against the chine - he may have tried to overcome this by installing bulkheads or some other bandaid fix, but why? That thin flap of fiberglass could be zipped off and ground flat all the way around in probably less than an hour on the average under 20 foot boat.
I guess what I'm trying to say here, is if you wouldn't pull a car out of the junk yard and ***** at the manufacturer about what a crappy job they did building it, why do you do it with boats? And why do you expect materials and or other critical components to be interchangeable when you'd never expect that in any other form of transportation?
