Building Molly - an amateur's view.

[DanishBagger]

I'm in Århus at the moment, so nowhere near the boat.

However, I just had a thought.

It's about the swing-keel, and although many people will warn me about using "epoxified" and varnished wood beneath the waterline, let alone for a keel, I'm thinking that I might have a usuable idea.

The thing is, in the original, the keel is a piece of iron, and I guess I could do that, and then glavanize it, connect zinks and so forth.

On the other hand, I just found out that you can buy rolls of lead, around 1.25mm (just around 1/20th inch) thick, and in any length and width I want (within reason).

Now, the idea is to build a mahogany frame, intersectioned by strips of wood to stiffen the lot. Then cut the sheet to size, melt it with a blow torch (perhaps built two framesets, one for heating and forming, the other for the actual keel), then lie another layer on top of it, heat that, and so forth, until I have a keel to the same size and everything, except that not so much of the weight of the keel will be above the cg as in the original.

Anyone think this is a very stupid idea?

I can make the lot almost as cheap as the glavanised iron and this way I won't have any metal beneath the waterline.

[Raggi_Thor]

I think a combination of wood, lead and epoxy is a good idea if it is stiff enough.

[DanishBagger]

Originally Posted by Raggi_Thor

I think a combination of wood, lead and epoxy is a good idea if it is stiff enough.

I would make the stiffeners in 7mm marine plywood, laminated together to 14 millimeter thick ones.
The keel slot is 40 mm wide, meaning I could propably make the keel 3 cm thick minus the 14 mm for two plates.


Edit: Come to think of it, even though one could laminate them to 14 millimeters, I gather that it would create more strength if I had more stringers on the inside as opposed to thicker ones.

The problem (as I see it) with these keels is the shape of them. THey're sort of like tear-shaped, with the pointy bit cut off. And when "fully" down, only about a third is in the water. So I figured that if I could get the same weight of the keel down into the water it would make for a more safe (read "fun" as that way it can go faster ...) ride.

Andre

[casavecchia]

No need to melt the lead, you can laminate the layers with epoxy in between. Be sure to provide some "keying" with the wood stucture.
Melted lead emits very noxious fumes.
Marco.

[Raggi_Thor]

That sounds like a good idea.
What do you pay for the lead?
I pay approx 40kr/kg or 5Euro/kg for lead ready cast at a local foundry. That is when i provide a template of wood or foam.

[DanishBagger]

Originally Posted by casavecchia

No need to melt the lead, you can laminate the layers with epoxy in between. Be sure to provide some "keying" with the wood stucture.
Melted lead emits very noxious fumes.
Marco.

Yeah, I was a bit worried about the fumes, frankly, but I figured it'd be a one-time thing.

The "keying" as I understand you is "to make fast", right? Because that was thereason I would melt it. in the end I would epoxy it to it, filling any gaps. I guess I might as well epoxy all the plates to stop getting fumes.

Originally Posted by Raggi_Thor

That sounds like a good idea.
What do you pay for the lead?
I pay approx 40kr/kg or 5Euro/kg for lead ready cast at a local foundry. That is when i provide a template of wood or foam.

In danish kroners it depends on how big a roll I buy - from www.olt.dk/Katalog/Bly/Bly.htm:

a 25kg roll is 400dkk/53euros, so that'll be about half a euro per kg. Of course, I need to have it transported, but so would an iron keel.

I need to figure out how much the original keel weighed, and how many cubic a wooden one can contain, minus the solid plywood at the top where the pivot pin will go.

Speaking of which, I just got an offer by mail to buy a ft of bronze for the pin at these prices (copy/pasted from the mail):

3/4" SIL/BRZ ROD @ £12.50 PER FOOT

7/8" SIL/BRZ ROD @ £18.00 PER FOOT

1" SIL/BRZ ROD @ £25.00 PER FOOT

Plus postage at cost

I still haven't figured out which diameter I need, though, thinking the bigger the better, but within reason.

It certainly depends on what weight I need.

Btw, the Khaya is beautiful, and as I'm writing this I'm trying to get hold of hardener number 207 to go with the epoxy, but the danish "branch" of westsystem is rather amateurish, or consider me a little more amateur than I am, they are trying to convince me to use another hardener (propably because they don't have it), not realising that the reason I want 207 is because of the uv-filters in it.

[Raggi_Thor]

You mean 2 Euros/kg :-)
Same here, if you buy a lot more, seems like your prices are very fair,
http://www.norskstaal.no/varekatalog...?varegr=506_1#

Epoxy:
I just sold 7.5 kg of hardener + resin at 1200kr (150Euro) +10% extra for the UV-hardener (207). That was the Norwegian brand Aeropoxy (not the same as an American brand with the same name).

[DanishBagger]

oh, haha, yes of course - 2 euros/kg - gees that was embarrassing.

7.5kg at those prices? That is a pretty good deal if you ask me. Do you have a link to the norwegian ones? SDeriously, the only reason I'm about to buy a sh-load of west system is that it seemed easier to buy here in denmark, but with the problems of getting the 207 hardener, that argument is out of the window.

[Raggi_Thor]

You can contact Trebåten as the company is called, the owner is danish I think (?).

http://www.trebaten.no/index.php?opt...d=30&Itemid=60

If you order from him, please mention me :-)

[DanishBagger]

Thanks, Raggi

And, I will - does he know you as Raggi, Ragnar, Ragnar-Thor, or Thor?

[Wellydeckhand]

From Smithsonian , it must be ancient he............. good luck

[DanishBagger]

Originally Posted by Wellydeckhand

From Smithsonian , it must be ancient he............. good luck

lol, yup, the original was built in 1867, and the lines were taken off by Hysloop in 1887.

But mine will have a plate saying

Molly

2006

I have attached a photo of the drawing of the boat - hopefully it works (it's rather big).

[DanishBagger]

I just wanted to add that at the moment there is not much to add.

My gf went to the hospital with an extreme case of astma, and has just come home. Because of this, I'm behind with work, so I have to prioritize that to catch up. As it is now, the boat is on hold for a little while.

Andre

[Wellydeckhand]

Dust problem or cold problem.......... can u post some picture of the progress I am curious.

Best Regard

Wellydeckhand