Interesting Duck Boat Build

Their is so much I like about that boat. The quasi offshore bracket is the only way a motor should be mounted in my less than humble opinion. If your gonna encapsulate everything in glass, and can afford it, closed cell structural foam makes way more sense than wood. Other than the fact that it doesn't have a stem or keel, I like it a lot.

Ron
 
Why cheap out and use drywall screws, not stainless or at least exterior grade? I doubt that foam was cheap.
 
Andy,
the screws serve no structural purpose once the glass and resin cures. They are only to hold the shape as the fabric is wet out and laid up. Some fab shops glue it all together with hot melt glue to get the shape.

The foam is only acting as a core and all the strength is from the two skins of glass and resin hardened up after cure.
 
Andy,
the screws serve no structural purpose once the glass and resin cures. They are only to hold the shape as the fabric is wet out and laid up. Some fab shops glue it all together with hot melt glue to get the shape.

The foam is only acting as a core and all the strength is from the two skins of glass and resin hardened up after cure.
Click to expand...

My thought is that they will eventually rust even encapsulated in the resin. Moisture will migrate even if only very slowly. This might not effect the boat to have tiny pockets of rust in it. A better screw probably wouldn't get enough moisture for the life of the boat. Why not spend the few extra dollars? That foam makes marine ply look cheap. Is it really that expensive to manufacture?
 
Corecell is not just foam core for substrate. It is structural and different types are used for different parts of the boat depending on application. You can put a boat together without glass and walk on it and even jump up and down on it.

It is the same difference as foam core engineered panels for sheathing timber frame panels and SIPS that can make a free standing house.

This particular foam is so expensive because of it's complexity of manufacture and amount of material used. Sure does make a nice boat though.

ROn
 
Andy,
my misunderstanding of your question was that your concern was structural. The rust is up to the builder. But the foam will still do its job with a screw that is totally rusted because of the skins bonded to the core after the build, acting to hold the structural pieces together.
 
I like everythign about the boat, very nice. One thing I would change is to use something other than Mantex. While the Mantex is a good product, I believe there are other, better, products very similar. Specifically, I would use Penske Composite material (I think they were just sold to BASF) as the product is better and in my opinion, the people running the business are first rate.

Cool thinkg about these composite boards, they can be made to any density of one's chosing. Different densities for different locations on the boat. These boards also have some wonderful sound damping characteristics which I think would be beneficial on a duckboat.

Cool design.

Mark W
 
This is my buddies boat, yes the dry wall screws where removed they were just holding the foam together. Actually it's about ready for paint. I thinks he's using FME I gave him from Lou Tish. Next time I get out to his shop I'll take a few pic's....John
 
Please guys!! Before anyone has heart failure over the drywall screws, they only hold the foam together till the glue dries (bondo, corebond or hot glue). You then pull them out before you glass the boat and put them back in the bucket to use again. A little green wax on them makes sure none of them get stuck in the epoxy if that is what you are using to hold the foam together. I explained this on United Waterfowlers. By the way Ron Jones, you have more than a passing understanding of this construction! Any relation to the legendary Ted Jones?
 
No relation to Mr. Ted. Just a guy who grew up on a 42 Californian. One brother sells boats from time to time, another is a service / parts manager at a dealership and I live half my life welded in a boat underwater. I've been messing around in small boats for 38 years, and I'm 38 years old. I aint absolutely comfortable if I don't know when the next time I'll be on the water or fishing again.

Thanks
Ron
 
TO: Mark W

On the other site I stated that the high density glass impregnated foam core used to be called "Mantex" - we have used this for years- never a problem. Today i was told by my supplier that they don't make Mantex anymore. What we are using now is called "Bluewater Okoosa". Looks, feels, tastes exactly like Mantex. Same rock-hard feel. Absolutely no compression factor, great for transom boards, rub rails, cleat locations, etc. Perfectly good for this application. We recently built an 86 ft. triple engine sportfish out of Core Cell, e-glass, Kevlar and carbon in select places. In critical areas like keels and chines we used the super high-density Core Cell, not Mantex, Okoosa or even Penske board. The latter don't have anywhere near the shear resistance of the high-density Core Cell. Still perfectly good for a transom that only needs to hold a 24 hp longtail. I see your point but in this boat built mostly out of leftovers and giveaway stuff, an overkill in the transom would be impractical.
 
Last edited:
Hey Rich -

Sorry if I came off critical which wasn't the intent. I've worked with most of these suppliers over the years and had some issues with the Mantex Corporation. Penske was using some very advnced construction in their boards and they had some charateristics that made them unique in the Urethane fiberglass reinforced board world.

Love the boat.

Mark W
 
You must log in or register to reply here.
Back
Top