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ContinuousWave: Post-Classic Whalers
Some Changes in Whaler Manufacturing Methods?
|Author||Topic: Some Changes in Whaler Manufacturing Methods?|
posted 03-15-2003 01:32 PM ET (US)
On page-4 of the 2003 Boston Whaler catalogue, the illustration and captions make mention of two interesting details of the construction technique used to make Boston Whaler boats.
First, in the callouts of the illustration showing the hull cross section, the outer hull skin is described as "woven glass matting."
Second, in the caption of the photograph (upper right) it mentions "predetermined amounts and types of fiberglass are laid by hand [emphasis added] into both the inner and outer hull molds..."
Compare that with http://continuouswave.com/ubb/Forum1/HTML/001961.html
Has there been a quiet revolution in Boston Whaler manufacturing techniques?
posted 03-19-2003 09:58 AM ET (US)
Jim, I think you are correct, and this may explain, in part, why the newer models are noticably heavier than the classic models.
On the final outing with our boat last October I eased up to the dock in strong cross winds and barely grazed the port side against the tire bumper installed at the corner of the dock. After getting the boat on the trailer I was surprised to find that my fuel tank vent had been pushed back and through the fiberglass outer skin. It was almost flush with the outer hull.
Once home, I was even more surprised to find that the outer hull in this area was no more than 1/8" thick. I cut a 4" diamater hole, opposite the fuel vent, on the inside of the hull to gain access to this area. The inner hull was at least 3/8" thick. I used West System and woven mat to build up this area to 3/8" to 1/2" thickness. I then drilled a hole through this to install the new fuel vent and covered the 4" diameter hole with a screw in deck plate.
From my personal experience above with a "chopper gun" manufactured Whaler, I would have to say that the use of hand laid woven mat is probably superior, from a strength standpoint, to the chopper gun technique used in the past.
posted 03-19-2003 11:08 AM ET (US)
Page 4 of the 1997 Boston Whaler catalog states nearly the same thing as what you mention the 2003 one reads. The callouts of the illustration showing the hull cross section describe the laminate near the keel line as "woven glass matting". Then in the text under the subject of Construction, it states "Next, a skin coat of fiberglass and varying biaxial and triaxial fiberglass sheets are coated with resin and rolled into place." Perhaps when Whaler redesigned their hulls in 1996 and developed the Accutrak System hulls they made the switch from chopper gun layup to hand rolled.?
posted 03-21-2003 11:17 AM ET (US)
The 2002 BW catalog also says the same thing about the skin construction. I have to admit that these “Post Classic” hulls are pretty tough. Back in November I hit a sandbar going 30 mph and ran my boat aground by the mothball fleet. (Northern California guys know where that is) It was pretty weird lurching to a complete stop and not knowing why. At first I thought my engines quit until a realized what happened 2 seconds later. At first, I really thought I screwed the pooch and broke my boat bad. As it turned out though, all I did was sandblast the paint off the bottom of my skegs. Amazingly, the hull, gelcoat, and clamshells were completely unaffected. I guess this could be construed as a BW testimonial.
To further elaborate on changes in BW manufacturing methods: The 2002 catalog also states that the foam used is “closed-cell” and the catalog also boldly states that the foam CAN’T absorb water. I think I’ve read some posts on this but I don’t think I heard the final scoop.
I keep hearing that older Whalers can absorb water. Did the foam recipe change at some point? I guess there are three possible answers: 1. Wet-hulled Whalers are urban legends. 2. The foam changed at some point or 3. Boston Whaler is stretching the truth about the foam now days. Does anyone know the real answer about the foam?
posted 03-21-2003 11:26 AM ET (US)
3. I think Chainsaw Whaler and its progeny conclusively proved that wet Whalers are not urban legends, that any changes to the foam over the years were minor, and that older foam (be it open cell or closed cell) and newer "closed cell" foam can still soak up prodigious amounts of water.
Maybe Tom Clark will weigh in on this thread.
One has to believe that the increased weight of newer Whalers is due, in part at least, to more/thicker fiberglass. The new 13 Sport weighs in at 560 while the Classic 13 weighed about 360 lbs. It can't just be foam.
posted 03-23-2003 11:30 PM ET (US)
Whaler has always used hand laid fiberglass in their construction. The first layer that gets applied is chopper because it makes the exterior finish smoother. Then layers of matt and woven were laid by hand. The laminate is thickest at the keel. Some areas, such as the sides can be quite thin.
The whaler foam will not "absorb" water unless you inject it into the foam. If you maintain your drain tubes, don't punch any holes into the outer hull below the waterline, and most important, don't run the boat at high speed with a hole or crack in the bottom, your hull will not get waterlogged.
posted 03-24-2003 03:56 PM ET (US)
I thought the whole purpose of the chopper gun skincoat under the gelcoat was to prevent "print through" Print Through is when you can see the cross hatch pattern of the woven mat in the finish of the gelcoat. I'm wondering if they are using some other kind of fine mesh fabric between the gel coat and mat? They do make a mat with randomly oriented fibers, but I have heard some not so good things about it. The main problem is that the binders used in random mat to hold the fibers in place can interfere with the absorbtion and full wetting out of the resin, leaving voids.
When I pulled the interior side panels on my conquest to install speakers, I was suprised to see the inner hull and foam cored out to the outer hull to mount the fuel tank and holding tank vents. The only thing holding them in place was the thin outer hull at those locations. But, the foam and inner core surroundg it were about 2-3 inches thick.
posted 03-24-2003 11:44 PM ET (US)
Single skin hulls require layers woven fiberglass for stength. The weaving can show up as print through if you don't apply a layer of chopped fiber.
As best as I can remember, Whaler only used woven glass in high stress areas, such as the keel and transom. I could be mistaken about the mat, however, the hull is subjected to incredibly high pressure during the foaming process, which wouldn't leave much room for voids. It's possible that there was some finely woven glass used instead.
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