Thread: Duck masts!!

Originally Posted by animatedsnail

Hi All,

I'm getting to the point where I'm thinking about making the mast. I went to my local timber merchant and all they had available was 15mm thickness wood by 33mm or 19mm by 45.
I could buy a bigger plank and start cut to shape and then use the thichnesser, but, with 5m it would be a nightmare with my hobby tools!
Would it be easier just getting some aluminium tubing? If so what changes would I need to make to the mast partner etc?
Or, are there any other ideas out there? I saw someone using a length of 2x4 !!
Any help would be really gratefully received.

snail

G'Day mate, I'm surprised they didn't offer to size it for you for a small additional fee?! I mean, you're the customer and you want your timber a certain size, right?

If you do go aluminium, and it's a tube section not a dedicated mast section, remember to shop around. I recently priced a 50 mm by 3 mm wall tube in 6060 and it ranged from $90 to $130!

Howdy Snail!

Are you planning to use the lug rig or the sprit rig?

With the lug rig, the bend characteristics of the mast don't matter too much, but with the sprit rig a mast that is the right diameter for strength at the bottom will be way too stiff at the top for the boat to sail well.

So let's look at the alternatives.

Solid Timber Mast - I have drawn up a solid timber mast here.
An alternative solid mast for the OZ PDRacer|Michael Storer Wooden Boat Plans Australia, USA, UK, Hungary, S. Africa
The partner and step will have to be slightly changed to account for this.
It will suit either the sprit or the lug. Timber will have to be knot free and straight grained. It will probably need to be laminated from two thicknesses of commercially available timber.

Aluminium Mast for sprit sail - as mentioned above it would be too stiff if of one section and would take some trial and error to get right if made of a thicker diam bottom and thinner diam top. I would expect the bottom would need to be about a 62mm diameter tube with a 2mm wall - or a 1.6 wall would be OK. You would need a bit of extra length for this part to form a reinforcement where it goes through the partner. The top section could be around 45mm diameter. But I don't know if this will be too flexible and the sail design would possibly have to be modified for best performance.

This makes the aluminium with sprit sail option too complicated.

Aluminium for Lugsail - because this mast doesn't need to bend much and doesn't affect the shape of the sail if it does bend - it means you can use the same size section from top to bottom. It won't look particularly pretty, but it will work fine. It will need to be about 62mm (2.5ins) with a 1.6 or 2mm wall.

If you go this way - when you buy the aluminium - get about a metre extra length. That metre will have to be cut lengthwise to either go on the outside of the bottom metre of the mast or have a longitudinal piece cut out to go on the inside. It then needs to be pop rivetted in place - I need to give a couple more pointers which I will if you decide to go this way.

I would be going for the solid mast or looking for another timber merchant - the range there seems very narrow. If you can even find some of the right widths about 15mm wide it would be fine to go that way for the lug too.

Best wishes
Michael

Thanks for the reply,

I'm going to look for a solid piece of timber to shape. Could you please tell me what length I'm going to need though. I 've looked at the types of sail but none of them resemble the sail from the polysail company!! (I'm going to buy mine!!)
Do I still need a 5m length of wood?
Sorry, I'm not a sailor, yet!!!

Originally Posted by animatedsnail

Thanks for the reply,

I'm going to look for a solid piece of timber to shape. Could you please tell me what length I'm going to need though. I 've looked at the types of sail but none of them resemble the sail from the polysail company!! (I'm going to buy mine!!)
Do I still need a 5m length of wood?
Sorry, I'm not a sailor, yet!!!

Two points.

Firstly, you're better off laminating two pieces together to make your solid mast - that's stiffer (Mik can explain why).

The second is your source of timber. You should be able to buy timber the right size to make your hollow mast. A good timber yard will plane it to whatever thickness you need. Sure, they'll charge you for it but usually not too excessively. Maybe you're just asking the wrong questions - hell, half inch timber shouldn't be hard to find.

Your first post suggests you have a thicknesser. You then describe it as a 'hobby' tool. I'm confused. If you have a thicknesser of any level, you CAN plane your planks down, the length doesn't make any difference though you'll find it a lot easier if there are two of you. I've got a bottom end thicknesser and do all my own machining.

Failing that, you'd be amazed what you can do with a hand plane or an electric plane. Seriously. I've got a mate who searched long and hard for a thicknesser and in the end, found he was doing everything by hand (he's nuts ... and owns a No 7) and stopped looking. I regularly take up to a cm off planks by hand with my el cheapo No 4. All it needs is a sharp plane and a dose of the stubborns.

I suspect you're both underestimating the wood destroying capability you already have and that you haven't found the right timber yard.

My message is that it's too early to give up on the hollow mast.

But solid works too, that's what Redback's got ... though you'll do as much or more shaping than you'll need to do getting 15mm planks down to size.

Richard

Check out this post from my Little Black Dog thread for an indication of what hobbyist tools can do.

I recently ripped my oar blanks (19mm) using my jigsaw and the guide that came with it.

Richard

Part of my oar making. The planks are 19mm thick and 2.5m long

Here I am ripping it with my jigsaw

Attachment 122446

This photo shows me taking the blanks from 60mm (three layers laminated together) down to 44mm with my old No 4 plane.

Attachment 122447

It's amazing what you can do when you give it a go

Richard

Thanks all,

I'll phone around some more timber yards and try to make a hollow mast.

I found some!!!!!!
Thanks all. I managed to get some after many calls. They have to order it in and will take 7 - 10 days but will be the correct sizes. I had to pay £61 thats $110 autralian!!!
But still cheaper than buying aluminium and lighter than solid.
So thanks again for the advice.

Snail

Originally Posted by animatedsnail

I found some!!!!!!
Thanks all. I managed to get some after many calls. They have to order it in and will take 7 - 10 days but will be the correct sizes. I had to pay £61 thats $110 autralian!!!
But still cheaper than buying aluminium and lighter than solid.
So thanks again for the advice.

Snail

Onya mate

Richard

Originally Posted by animatedsnail

I found some!!!!!!
Thanks all. I managed to get some after many calls. They have to order it in and will take 7 - 10 days but will be the correct sizes. I had to pay £61 thats $110 autralian!!!
But still cheaper than buying aluminium and lighter than solid.
So thanks again for the advice.

Snail

Besides, you will get enormous satisfaction from making your wooden box mast

OUCH ... but at least the problem is resolved.

MIK