Older fiberglass hull construction, better or not?

[snewk41]

I am looking, really, I'm just looking, at some of the older fiberglass Chris cruisers & constantly hear people say the earlier glass hulls were the best because "no one know what they were doing so they make the hulls extra thick" as if this were a good thing. Was this a good thing? What about the extra weight. Did these boats have wooden core's, or were they solid glass. How do the mid to late 70's hulls compare with later, lighter ones? Thanks, just looking! Scott.

[Peter XK19]

The early fiberglass hulls were thicker because they just didnt know enough about the fiberglassenforced resin as a material.
Chris-Craft actually tried fireing a gun at an early hull and found it held up and thought well this seems good enough Also no one knew at the time how long fiberglass hulls would last. These boats were looked upon as consumer products. Use and throw away. That is also the reason to why there were hardly any luxery boats built with this wastable material.
The Chris -Craft XK-19 was an exeption to the rule. They didnt sell very well because they were too expensive, after all it was "only fiberglass". Its strange though because all Chevrolet Corvette cars were fiberglass right from the start in -54 upuntill todays new cars. Did you ever hear anyone say that a Corvette is "only fiberglass"?
Also to be mentioned about early hulls is the fact that they were all hand laminated as oposed to beeing sprayed. Laying up a hull by hand eliminates alot of the air beeing trapped inside the material. Smal amounts of air inside the hull structure is what creats fertile ground for osmosis.
Most boats did not have a wooden core in the hull(exept for the transom). And of course the stringers were almost allways wood. So these two areas is what you would want to inspect sooner than anything else.

Hope you find answers somewhere above

[Bill Basler]

In your post you mention that you are looking at some early fiberglass Chris-Craft cruisers. Peter makes some good and accurate points about glass runabouts. Some of this logic spills over into cruisers. The first fiberglass Chris-Craft cruiser was the 1964 38-ft Commander. Perhaps this is one you are referring to. These were tremendously overbuilt. They are pretty heavy and this does affect top speed, but most Commander owners would not trade them for a newer/lighter boat.

The 38-foot Commanders actually featured a 3 piece hull. The hull bottom, up to the full length spray foils was one piece. Each hull side was a piece with the two halves joined at the stem and the vee of the transom. This method was used, not for structural or aesthetic reasons, but rather the factory did not have enough headroom to mold the boat in one piece.

The result is that the hull has seams. Not knowing how this would hold up and perhaps being a little nervous about the method and the new material the boats were tremendously overbuilt whichis why they are sought aftr today.

[Wood Commander]

I agree with most everything from the above posts. But I don't think that the Cortland, NY Corsair Sport Boat Division boats (XK's, Lancers, very small sport boat Commanders and etc.) were of the same over the top quality as the early Commanders were. And I say this from experience having owned a couple of the Cortland boats and having had to do some repairs along the way.
I do think that all of the 1960's and early 1970's fiberglass Chris Crafts have very good gel coats. If they have had any sort of care at all over the years, they seem to hold up well.

Also, later, follow on models of CC cruisers like some fiberglass Catalinas and even later 70's Commanders kind of fell of the cliff as far as quality goes. There were several company ownership changes going on in that period of time.
In some years of these boats you can look down the side of the hull and see cloth print- through from not enough resin in the mix.

Having said all of that, in comparison to some of the more modern boats out there today, almost any Chris Craft fiberglass hull could probably be considered superior.

[Bill Basler]

As a follow up to my previous post and Brett's observations. I also agree that there are significant differences between some of the Corsair Division boats and their cruiser kin.

Unlike Peter's XKs, my lowly XL175 Sunlounger, would be considered a fairly entry level boat. As such, it was manufactured in a very conservative manner.

In tearing deeply into my boat, I would not characterize the fiberglass layup as overly heavy. In fact it is quite thin in many areas. My boat has a 3/8 inch balsa cored floor, with a foam filled bilge. The foam carries the bottom load up the the floor, which is glassed in. This foam-filled "bilge triangle" is what give the hull its strength. The bottom has no glassed in stringers. Just a 5/8 plywood keel glassed in on edge. This alone differentiates my boat from Peter's XKs for example.

It seems that Chris-Craft knew what they were doing. My Sunlounger represents the cheaper construction methods probably common in the entry level Corsairs. Working your way up the price points into the Lancers and XKs, it makes sense that you'd find better construction.

[Wilson Wright]

Not to argue with experts like Bret and Bill but my 1970 Courtland built Corsair is holding up quite well. Unfortunately the color choices that year were like Henry Ford's model Ts, in this case, red, red or red and red when exposed to the sun for 40 years will fade a tad but she still looks good.

[Bill Basler]

Wilson, I didn't mean to imply that the more entry level boats were "cheap." In fact, as equipped, I would not even say your 17-foot Ski Boat was one of the cheaper boats.

What I meant to imply was that Chris-Craft knew how to manufacture them to meet their retail price goal. Some of them were considerably beefier than others, quality generally paralleling price.

[Wilson Wright]

Bill:

I didn't get the impression you were saying the boats of the 70's were "cheap" but rather by 1970 and on Chris Craft was getting the hang of fiberglass and not overbuilding as they did in the mid 60's and my response was that my boat, while perhaps not as heavy as a '65 or '66 model was still seams to be over built.

With recent rains our lake is coming back and if I can figure out how to keep the hydrilla out of the cooling water pick up we make take it off the market.

[snewk41]

Thanks for all the info on the hull construction. It looks as tho the boatyard stories on these older hulls are true. Scott.

[Paul P]

I would have to say "older is better" when it comes to Commanders. It is true, they really didn't know how thick to make those hulls so they made them the same thickness as a wood plank, so the story goes. In many cases the Commander hull is easily 1" thick.

This makes a 38 Commander feel a lot heavier than the 35' wood Sea Skiff I had before owning the Commander, but the weight of the Commander is soon appreciated, as these hulls were designed to withstand 3X the stress of running FULL SPEED in a six foot sea.

The Corsair Division used the same gelcoat and resin, and same fiberglass, and to a degree the same construction techniques as the Commanders. Of course, CC would not put the same effort into a 17 or 20' boat as they would one of their iconic flagships, but the quality of the early boats is remarkably good. I have CC literature that overtly states the resin and gelcoats being used in the Corsair Division are the same as being used in the Commander Division. Owning one of each and doing all my own work over the years, I believe this to be absolutely true.

I have two 1966 fiberglass Chris Craft products, one is a 38' Commander Express, and the other is a Cortland built 20' fiberglass Sea Skiff. Would you believe the hull of that Skiff spent 25 years on Lake George, not real sure what happened to the boat during the other 17 years or so, but we found it up on Lake Ontario and the hull to this day has never been painted, still bare gelcoat, with no blisters.

In doing a total rebuild on the boat, I found the basic hull to be quite strong and stable, with some light weight techniques used to fix vinyl to the sides and flooring and all, but the glass part of the boat is as strong and good as the day it rolled out the doors of the plant.

The Lancers (and this Skiff) used a two piece hull, with the topsides being basically screwed or bolted down onto the bottom shell. This is an area where there can be some need for repair as the fasteners can shear if the boat is abused and flexes too much.


In 1970 the 38 Commander took on the Dick Avery aero look, and the cabin was widened to the edge of the boat and the outer walkway became an interior space. Chris Craft was beginning to realize their boats were over built at that time, but the quality really never dropped below the high standard, they just got a bit lighter.


Regards,
Paul





Here is a small boat technique of fastening a wood nailer, so to speak, onto a glass hull.





HEre is the same type of hollow fiberglass box beam construction used on the Commander, but obviously on a much smaller structural problem to solve. They didn't do to well with those wood stringers, which on my skiff were updated with a better design that would not crack.



Here is the proof that the early boats are built heavier. This is a plug from the bottom of my 20' glass Skiff, built in Cortland under the same roof as the Lancers and small Commander 19 and 23' hulls. This plug came from the hull when I installed a new high speed transducer. Note the fact that the bottom is gelcoat, unpainted. Quality guys, quality!

[/b]

[Wilson Wright]

You want us to believe the hull was 5 inches thick ?

[Paul P]

Wilson, you had me going for a minute. I thought I must have had a typo! Hey, all the best to you, hope to see you somewhere soon where there are boats and water.

regards, best, Paul

[snewk41]

That is a great post Paul, I appreciate the information. Scott

[Paul P]

Hi guys,

Here is another tidbit from history outlining the quality of the early Chris Craft Corsair Sport Boat Division gelcoat and resin, same as being used in the Commander series.


Regards, Paul

[Bruce Reynolds]

G'day all,

I realise that this thread is rather old, but still VERY informative, and I have one question.

How much heavy weather (seas) are the 1972 Seasport 16's designed to take?

My Gullwing with its' 155HP OMC Stern Drive had been put through some pretty heavy short waves, in as much as the bow is burying 6" under water, and still comes up, with the resultant water flowing over the Screen and getting in the nooks and crannies.

It has even "fallen" off a few peaks and even though I personally, and my passengers, have survived the crunching, this is not when travelling too fast, but just getting caught in some confused swells, which we encounter down here in the Southern Hemisphere.

Does anyone know just what sort of testing the Chris Craft factory did.


Calmer water


And this is Salt Water


In the trough, travelling across the waves to limit the drenching.

It is a bit difficult taking pictures when trying to hold on. But, thankfully the Windscreen Wipers work, and the Side Curtains and roof keep those seated a little but drier.

Bruce.

[Thommyboy]

Chris-Craft purchased the molds and tooling of Evinrude. That's where the Gull Wing models originated. Ted Thompson, Jr. remembers going to Illinois with his brother Bob to make the deal with OMC - Evinrude's parent. Everything was moved to Cortland, NY. I don't think Chris-Craft ever changed the hull design.

Don't have an answer to your question.

Andreas

[Bruce Reynolds]

G'day Andreas,

Thanks for that info, and I was aware of the history and I have totally rebuilt the interior of mine, removing all the rotten timber (Plywood) that was rotten and full of Carpenter Ants when I purchased it in 2008 in NY.

Were these boars built in NY, or Florida (which I was told)?

I have reinforced the internal framing, and replaced the Stringers, and made it stronger than before, but the noise that emanates from the water hitting the fibreglass sides, especially as the fuel tank is up the bow, and supported by the forward floor, sometimes is a bit disconcerting.

But then, I haven't done the same seas in "tin dish" so I can't compare the experience. My previous "small vessel" sailing/sea voyages have been in Clinker Built timber open boats, and Lightweight Sharpies. This boat is my first at anything over 4 HP, engine wise.

Bruce.

[Thommyboy]

The tri-hull Gullwings were built at Cortland, NY. They may have also been built at other plants.

Andreas

[Bruce Reynolds]

Thanks Mate,

I love it when I learn new things.

Now I just have to remember them.

Bruce.

[Peter M Jardine]

There is some chemistry involved here. Older fibreglass boats were laminated by hand with heavy rollers inside the mold. Modern boats use a chop gun which sprays glass fibre onto a layer of wet resin. This does create voids, which allow osmotic blistering to start.

The reason that osmotic blistering occurs in the first place is based on the type of resin used in the the construction of the boat. American Cyanamid, Celanese and Dupont did extensive research in the 30's 40's and 50's and finally produced a heat setting air cured polyester resins that we associate with fibreglass boats.

The first commercially produced resin was ORTHOPHALIC resins, and it is still used heavily today. All of the 60's fibreglass boat used this type of resin. It has one problem: It isn't waterproof. It absorbs water over time, and if that is combined with a construction method such as a chop gun, you can see where problems could start. The fact that early CC hulls were rolled laminations of cloth and roving meant that voids were few. Add an excessive hull thickness, and you have a very strong and long lasting hull, despite the drawback of the resin type.
Despite the water permeability issue, this is one of the most common resins used.


The second generation of resins were ISOPHTHALIC resins, invented by Amoco oil. It was less water permeable. Finally, there is VINYLESTER resin, a Glidden/International Paint coeffort, which is quite waterproof and lighter than previous resins. It did have some problems with UV, and was typically used underneath the waterline.I haven't kept up, but I suspect that problem is now gone Hatteras and Catalina have used Vinylesters since the 80's. Epoxies are used as barrier coats, are almost entirely waterproof, but suffer from breakdown if used unprotected above the waterline.