Hartley TS18 wood selection?

Hello all,

I've a set of plans for a Hartley TS18 - after years of dreaming about a wooden boat, I'm going to have a go.

I'm just not sure about a few things and would appreciate some guidance.

1. I've decided to build the frames from laminating ply. Is modern exterior grade ply to BS1088 from the local hardware shop going to provide adequate water resistance for a boat that will live on a trailer during the week.... or do I spend the few extra quid on marine ply?

2. The plans mention "hardwood or good clear semi hard materials" for stringers. Which woods should I use for stringers and bearers that can easilly be sourced in the UK?

3. The plans show copper nails pinning the ply onto the frames - should I use these, staples or given modern epoxies, do I need them at all?

4. If not too complicated, I'd like to fit bilge keels instead of a dagger board to help increase room inside. Is there any way of calculating the size/position based on the dagger board/fin drawings? - I want the boat to balance and remain stable but don't need brilliant performance.... I'm not going anywhere in a hurry! (Any recomendations on books that may help)

Thanks

 

There must be a Hartley association somewhere in your area - they would be the best to ask.

If you put twin keels on you might miss-out on some plane-ing action, which would be a shame. With no spinnaker (as I can remember seeing in Sydeny Harbour, Drummoyne Yacht Club) the Hartley (was it the 16'?) still has enought sail area to get up on the plane in reasonable wind.

While I am a fan of twin keels - you will have more difficulty trailering, beaching (nearer the shore), go slower - and you will enter the unsure world of 'deviating from the designer's plans' thereby effecting performance, resale value...........etc.

 

I just finished refurbishing a hartley 16 an would recommend that you use marine ply. I have replaced about 10% of the hull and from advice recieved here the exterior builders ply will not stand up to the immersion. The middle layers will rot out even if the outer layers are in good condition.

For stringers I used western red cedar (very light) 2 x10mm x 30 mm strips glued together to provide laminiated stringers. And bearers were appox 20mm x 150mm, again 2 10mm boards glued together. Western red cedar siding boards are an easy source of this size buty don't know about the UK. Other 6than that maple is often used but it is a bit heavier and don't know you availability.

I also used copper nails to attach the hull to the stringers but was only necessary to hold the ply in place until the glue had dried. Stainless screws are another method and are quite cheap (down here) these days do not oxidise under the paint, The copper nails will oxidise if you dont seal the heads with resin.

No opinion on the bilge keel and have never seen one in Australia but would not think that they are easily trailered.

 

One of the difficulties in designing for backyard construction is the knowledge that the builder WILL change things around a bit and the design should be able to tolerate this to a degree.

I'd be quite careful about making the structural changes you've had in mind, without a through design evaluation by a person skilled enough in the processes necessary to make these types of changes and not screw up the structure and qualities of the design.

Making a centerboard or daggerboard boat a bilge keel boat can be done, but only a designer or NA can get it done correctly.

Red western cedar is a very soft wood and worked in the system done by John-ts16 by using a lamination, making the stringers much stronger then solid stock. Again be very careful making material substitutions as the properties and qualities must be near the same for the substitute to work in the same location, under the same expected loading issues.

As a rule Marine grades will easily out perform the exterior grades. Typically the best material on a wooden boat is the hull planking and not a place to skimp, after all it is the thing that keeps you separated from the long swim back to shore.

You are building a trailer born boat and this will permit the use of less expensive fasteners. Stainless steel doesn't like to live in wet wood, but will do fine on a dry sailed boat and be a bunch stronger to boot. The key to long life on dry sailed craft is to keep the hull coatings intact, be they 'glass set in epoxy or just paint. Make it a point to examine the bottom every few times you splash her and quickly address any and all breaches in the coatings.

Lumber substitutions can be made easier if you contact the local forestry service and ask for the qualities of the locally available lumbers. They will have the types of lumber available and the qualities and the properties of each. This makes making a switch in materials reasonably fair and reliable. The AG section of the local collage may be of some use here as well as the local boat builders and saw mills.