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Re: Jay R. Benford 25ft Fantail Launch

Posted: Tue May 01, 2018 1:37 pm
by TahoeSteam
The Beverly was a nice and stable launch, though I'm sure her Kingdon firetube boiler contributed to that greatly. Her hull had nice lines. She was not as fair or as tender as the Blaine/Leutza hulls of similar length.

She used to come to the Delta meet every couple years, though I haven't seen her in several years now.

Re: Jay R. Benford 25ft Fantail Launch

Posted: Tue May 01, 2018 1:54 pm
by Lopez Mike
No paper backing but really thin. Years ago a guy was going to make a curved deck house top and had a big stack of veneer done and then dropped the project. I'll do a test piece anyway.

Looking through many pictures I see boat after boat that seems to have coamings that look like mahogany. I don't get how they get them to curve that sharply

I'm considering a design change that would leave the coaming flush with the deck. I've done a lot of hauling bodies with my old boat and many of them have ended up sitting on the side decks. This design has a lot more seating. A raised coaming won't work for side deck seating.

There is the option of making the coaming out of vertical pieces maybe two inches wide with a top and bottom cover strip. Sort of bead and cove (tongue and groove?) only quite stout.

Time to involve Barbara in this. She's an architect and has a much better eye for these things.

Re: Jay R. Benford 25ft Fantail Launch

Posted: Tue May 01, 2018 2:52 pm
by DetroiTug
"I don't get how they get them to curve that sharply"

If the veneer is thin enough and good wood and correct moisture, it can literally be tied in a knot. On the tug I used 1/4" thick white oak lams for the arched pieces in the front of the wheelhouse. A seat I built for an ongoing steam carriage restoration shows a much tighter radii in the laminated white oak armrest and 1/8" birch ply construction

-Ron

Re: Jay R. Benford 25ft Fantail Launch

Posted: Tue May 01, 2018 2:53 pm
by DetroiTug
More pics

Re: Jay R. Benford 25ft Fantail Launch

Posted: Tue May 01, 2018 3:46 pm
by Lopez Mike
I am encouraged.

I tried cold bending some scraps of 5mm 3 ply I had around to fit the sharper coaming radii but they wouldn't take it. Steve Weaver is doing his out of 3mm door skins laminated and bent up cold with an oak cap strip.

I am not sure what the best strategy is for joining it all up to make a full circle (oval? ellipse?). Butt joints seems like asking for trouble. Maybe mold it in place with staggered joints. There's going to be 50m square backer boards under the deck and it might do for molding up 3mm layers without getting into trouble.

Re: Jay R. Benford 25ft Fantail Launch

Posted: Tue May 01, 2018 4:25 pm
by DetroiTug
I would use 3 formers and build it up to 1/2" out of three 1/8" lams

One to fit the front minus 1/2" about it's perimeter to accommodate the thickness.

One to fit the rear compensated the same.

And one to to make the two slightly arced sides. Then fit it all to the deck. That would be the easiest.

It could be formed up in place with staggered joints, but you'd need some additional framing underneath and flush fared to the proper angle to the deck surface. This would support the piece as well provide something to clamp to. And it would need lots of clamps and probably a backer of some sorts to hold it all up tight otherwise teh arc may have sharp points on it. You could try it by dryfitting all the lams to see, then just glue it up.

Four pieces butt-jointed is probably the easiest route. Slightly cut the butt joints on an angle for easier assembly.

-Ron

Re: Jay R. Benford 25ft Fantail Launch

Posted: Tue May 01, 2018 4:52 pm
by Lopez Mike
I'm still getting used to the idea that epoxy joints are so strong. Of course my old hull was built with finish nails and Gorilla glue poorly used so every time I trailer it I'm watching in the mirror for it to shed large bits.

I will soooo relieved to burn it.

Re: Jay R. Benford 25ft Fantail Launch

Posted: Tue May 01, 2018 8:45 pm
by gondolier88
Mike,

Mahogany bends just fine given a bit of effort- get plenty of steam onto it- an hour of steam per every 1/2" thickness to make sure. To make sure it conforms to the mould, back it up with a piece of thin stainless steel on the outside of the bend- this creates a sandwich of equal pressure on both sides of the board. Brass does the same, but will keep the bend in it, don't use ferrous as it will stain the mahogany. Think of it in terms of the former on a pipe bender and how a pipe will kink if direct pressure is placed in one concentrated load point.


I have seen Beverly's details online, but details are scant on her performance and what its like to sail. I am wanting to use the plans to provide a certified underwater profile that has prototype testing in order for me not to need a naval architect to pass my own design- which I do have, and is very similar underwater, though slightly less in the beam. I would remove the tumblehome midships and put an English plumb stem in with a true counter stern to suit carvel planking rather than strip. This is to 'recreate' loosely a lovely old boat from the late 1800's that used to sail on Windermere. This will, of course, be reliant on any conditions/licensing that Benford & Assoc. may wish to impose- although nothing stopping me producing a prototype including my modifications. I may contact the yard where Beverly was built and see if anyone there remembers her.

Greg

Re: Jay R. Benford 25ft Fantail Launch

Posted: Tue May 01, 2018 10:32 pm
by Lopez Mike
That's good to hear about mahogany. I have plenty of steam and time. I'll do a test piece. Luan is cheap around here in reasonable sizes. I can plane to my desired thickness.

I was planning on a male mold made of perhaps three layers of pressboard. Spaced apart enough to support the coaming so that there is no cupping. To follow the curvature of the deck I will need to bend up somewhat wider stock.

Are all coamings vertical or has anyone ever tried to get some angle for more comfortable back support?

Re: Jay R. Benford 25ft Fantail Launch

Posted: Tue May 01, 2018 11:13 pm
by gondolier88
Mike,

Yes, fit your coaming larger than required in depth, lay your deck and fair it if you haven't already, take the coaming top line off that.

If your boat has plenty of freeboard then a coaming is purely for aesthetic reasons. Never ever put a cap on the coaming- the single best way to give you bruises on your ribs! If you want a more comfortable job then finish the gap between thwarts/benches and gunwhale capping with moulded T&G staves set at an angle approximate to the comfortable seating angles convention dictates- though there's nothing stopping you adding a coaming to that if you wished, however when coupled to a well finished capping it is a very elegant finish on its own. If the coaming is fixed directly to the gunwhales it will pick up the camber of the topsides anyway, but this can make joining the fore and aft coaming joints a lot of fun.

Greg