Confessional: admit to boat-related things you've never quite understood...

[Tranona]

Excellent!

I think I do understand, now. Basically, what I call a bolt, needs a female hole to screw into...no sniggering at the back there!!...whereas what I call a screw, goes into the material without needing much, if any, pre-drilling...and is therefore a self-tapper.

It certainly was not obvious, to me. I'd thought the phrase meant that when the screwhead is flush with the surface, it simply rotates without continuing in, deforming the thread.

Still makes me wonder why the phrase 'self-tapping' continues in such common and frequent usage. We don't often refer to our vehicles specifically as 'horseless' anymore, do we?

That Wikipedia page on screw-types is helpful...it accepts that the definitions and usage of the terms is quite variable and inconsistent. So hopefully no room for pedants!

Sorry, but a bolt and a screw are two different things. A bolt relies on a nut to secure it whereas a screw runs into a thread in the material. A bolt has an unthreaded portion of the shank where it goes through a plain hole in the material being attached. Usually a fully threaded screw (also known as a machine screw) can be used instead of a bolt, but often not the other way round.

Not difficult to learn the terminology, but it is not here to confuse, but exactly the opposite to differentiate between objects that have different functions or characteristics.

 

[sailorman]

I understand the racing measurement explanation thanks P. But I don' t get yours Woodlouse. Do you mean overhangs are designed to provide better fuel consuption but lower speed, when motoring with the boat level not heeled?

the yacht`s LWL is measured static, (over hangs not in the water). when she heels over the LWL gets longer = more speed due to a longer LWL

 

[jerrytug]

the yacht`s LWL is measured static, (over hangs not in the water). when she heels over the LWL gets longer = more speed due to a longer LWL

Ah yes I get that one, because it is about measurement, to get round (or 'Twist'..) some silly old rules.

But why wouldn't 'more speed' be better when she was *not* heeled?

Assuming you weren't interested in convoluted rules invented by blazer-wearing jingoes at the time of the Boer War, and just wanted the best yacht?

 

[Woodlouse]

Ah yes I get that one, because it is about measurement, to get round (or 'Twist'..) some silly old rules.

But why wouldn't 'more speed' be better when she was *not* heeled?

Assuming you weren't interested in convoluted rules invented by blazer-wearing jingoes at the time of the Boer War, and just wanted the best yacht?

For the reason I already gave you. When the boat reaches hull speed for it's water line length it starts to squat down between it's bow and stern waves which means the overhangs start to submerge and so the waterline gets longer so the boat can go faster.

 

[dancrane]

A bolt relies on a nut to secure it whereas a screw runs into a thread in the material. A bolt has an unthreaded portion of the shank where it goes through a plain hole in the material being attached. Usually a fully threaded screw (also known as a machine screw) can be used instead of a bolt, but often not the other way round.

That's a help, thanks.

Screws are usually tapered. Self tappers are straight and as said the thread is designed to cut a thread into the hard base material.

Self-tappers are straight? I thought that the ability of a self-tapper to cut its own thread, relied on it tapering to a sharp point...and that being 'tightenable' relied on screwing the broadening shank further into the limited diameter of the hole. How can that work if the screw is straight? Are wood-screws not self-tappers?

 

[prv]

For the reason I already gave you. When the boat reaches hull speed for it's water line length it starts to squat down between it's bow and stern waves which means the overhangs start to submerge and so the waterline gets longer so the boat can go faster.

So why not make the waterline that long to begin with?

Pete

 

[Stork_III]

That's a help, thanks.



Self-tappers are straight? I thought that the ability of a self-tapper to cut its own thread, relied on it tapering to a sharp point...and that being 'tightenable' relied on screwing the broadening shank further into the limited diameter of the hole. How can that work if the screw is straight? Are wood-screws not self-tappers?

The first part of a self tapper cuts a thread into a predrilled hole (of the correct size) in the base material, the rest of the ST then screws onto that thread. Traditional wood screws are not self tappers, they are wood screws.

 

[uxb]

Lee-bowing. I suspect that it's actually something bloody obvious, but every attempted explanation I have seen has just confused me.

I thought it was the lift you get from the current when beating? Sometimes when the wind is in a certain direction it will lift your bow into the wind helping you point??

I'm probably wrong about that.

 

[Danbury]

Sorry, but a bolt and a screw are two different things. A bolt relies on a nut to secure it whereas a screw runs into a thread in the material. A bolt has an unthreaded portion of the shank where it goes through a plain hole in the material being attached. Usually a fully threaded screw (also known as a machine screw) can be used instead of a bolt, but often not the other way round.

Not difficult to learn the terminology, but it is not here to confuse, but exactly the opposite to differentiate between objects that have different functions or characteristics.

What about coach bolts ?

...I'll get my coat...

 

[laika]

Self-tappers are straight?

Taking care of yourself, being immaculately dressed and a great dancer didn't have the same implications in mid 20th-century america

 

[Trundlebug]

Coach bolts have a domed head, almost flat so they look neat and tidy when assembled, underneath which is a square section which pulls into a square hole so it doesn't rotate when the nut is tightened at the other end.

Anyway, WTF are Lazyjacks?

If Jack's lazy, chuck him overboard and let him swim, no room for people like that on a boat.
What I do know is, I don't need any on a mobo.

 

[Seajet]

Forward sloping transoms are also known as retrousse ( with an accent over the ' e ' but my peasants' computer won't do it ).

Tumblehome on a boat looks good to me, my Carter 30 had this but I must say it was a PITA with fender scuff marks, I think there's probably a lot of truth in the explanations of favourable racing ratings and stability on the old wooden warships.

Lee bowing is quite instinctive and I'm sure an experienced sailor like Jumbleduck opts for it - maybe without realising - as it's simply going for the tack with the tide pushing one to windward rather than being set down by the tide and wind.

One phrase which I've never got the hang of - not having any wooden boat over 10' - is keelson ?View attachment 37216

 

[Woodlouse]

So why not make the waterline that long to begin with?

Pete

To save on wetted surface area in light airs. If you don't need the waterline length, it's best not to have it.

 

[onesea]

As some one else said alternators & there wiring and engine wiring looms generally...

 

[reeac]

Not to be confused with "self-threading" screws which look like mini taps.

When rebuilding an MGA many years ago I had to attach a valance to the front wings and used self-tapping screws. In such a case, where you're joining two thinnish sheets together, if you drill pilot holes of the correct size [i.e. just under the minimum diameter of the screw] the screw thread doesn't actually cut metal but distorts the metal surrounding the pilot hole into a spiral shape and produces a very powerful fastening.

 

[jerrytug]

To save on wetted surface area in light airs. If you don't need the waterline length, it's best not to have it.

How would that work with white and colour sails all up, going as fast as possible, in these light airs? You would still need to heel as much as in a stiff breeze, in that case, to get the longest WL length wouldn't you?
signed, Confused of Harwich.

 

[Tam Lin]

No doubt it does. Not only that but the engine is perfectly capable of driving a calorifier, which Volvo said it couldn't without spending a bomb on additional equipment. Do you think Volvo know how it works?

What happened when yours failed? and did it fail open or shut?

I had a couple of instances of overheating when the engine was pushed hard. When we looked at the thermostat it was encrusted and firmly shut. It failed the boiling water in a saucepan test so we assumed that it was not letting water in to cool the engine and replaced it. Those who are familiar with my saga know that subsequent head gasket failure meant that the head came off and we could see that some of the cooling channels were gunged up so it was perhaps not all down to the thermostat.

 

[Woodlouse]

How would that work with white and colour sails all up, going as fast as possible, in these light airs? You would still need to heel as much as in a stiff breeze, in that case, to get the longest WL length wouldn't you?
signed, Confused of Harwich.

No because once you reach hull speed the stern wave starts to fall off the back of the boat causing it to settle deeper in the water. The effect of this on a boat with overhangs is to increase the waterline length. You don't necessarily have to be heeling, though if there's enough wind to get you to hull speed there's probably enough to heel you over a bit too.

 

[chinita]

Bermudan or Bermudian?

Halyard or Halliard?

Cutter or Slutter?

....and my Thermos Flask; keeps hot thing hot and cold things cold. How does it know?

 

[prv]

One phrase which I've never got the hang of - not having any wooden boat over 10' - is keelson ?

I believe it's a piece of wood that forms the spine of the boat, to which the ribs are attached etc, but that doesn't actually protrude downwards very much so doesn't provide any lateral grip effect, so you can't call it a keel. You can then bolt a wooden or metal keel onto the outside of it.

But I'm not really a wooden boat person and I'm not 100% certain of any of that

Pete