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View Full Version : Masts - now I'm really grumpy



Daddles
14th April 2005, 07:02 PM
Some time ago, I needed some oregon for Redback's inwales. While I was at it, I thought I'd buy a plank big enough to make the mast as well. So I rings up the wood shop and tells the nice gentleman what I wanted to do. I was a bit vague about sizes because the only thing that really mattered was that it was at least 35mm thick for the mast. I was envisioning driving down there and picking up a thumping, great big plank.

Anyway, I arrived in me Falc-hoon to collect me timber. The bugger had gone ahead and ripped the only decent plank he had down into two 70mm bits, 35mm thick thank goodness, for me mast. I politely explained (I was polite too) that I wanted the whole plank coz I wanted to make extra bits from it and that I had the gear to do the ripping and thicknessing.

Embarrassed silence. :o

Then we went looking for another plank. We finally found one that'd do for the inwales plus a bit. I kept looking at the two bits for the mast and the grain was gorgeous, so I said I'd take them as well. The bloke was quick to make it clear that he'd stuffed up and that I didn't have to take them, but I did.

Now, a few months later, I'm making the mast. Carefully laminated the bits together. Planed one edge dead straight then popped it into the thicknesser to bring it down to the required square dimension. It looked gorgeous and I'm feeling really good.

Then I decide to work out the exact length I need. You see, the sail I'm using is off a different boat, a Nutshell, not the Tender Behind (a group of lads were getting them made up in bulk so I bought one cheap). Carefully measure this, add that, fiddle that bit, and I find I need 8'10".

The bloody mast stock has been cut to exactly 8'. The sodding thing is 10" too short :mad:

So I laid the sail out on the lawn and started messing with the mast, hoping I could get away with it, but I can't, not if I want the tack of the sail to be above the sheerline. :mad:

I guess that means I get to buy another lump of oregon (aaarrrrrgggghhhhh). Unless someone can reassure me about splicing a bit onto the top of what I've got. **insert hopeful smilie**

Serves me right for not working out the numbers beforehand, but I hadn't realised I'd need them seeing I was planning to buy one, big, long plank. Ah well, could be worse. At least the mast is still square - I hadn't gone to the trouble of rounding it yet :rolleyes:

Grumps
Richard

Gumby
14th April 2005, 07:46 PM
Can't you just take 10" off the foot of the sail ?

Daddles
14th April 2005, 07:54 PM
Can't you just take 10" off the foot of the sail ?

It's a brand new sail. This group of blokes were all making Nutshells, planning to do some 'class' racing and had teed up a local sailmaker to make them in bulk for a reduced price. Seeing my boat was the same size and the rigs sort of looked something similar, I bought one of the sails too.

Methinks I'd rather make a new stick than muck up the sail. And do you want to know the silly bit? If I hadn't bought the sail last year, I probably wouldn't bother making all the sailing bits now and just use her as a rowboat for a bit. grrrrrrrr

I always knew that learning how to buy timber was going to be a steep learning curve - this particular purchase was the first time I'd gone in to buy a plank rather than ask them to make me a series of specific sizes. I had rung earlier and asked about standard sizes for planks but it appeared there was no such thing, so I thought I'd just tell the bloke what I wanted to do. He misunderstood and I didn't check the results. The experience taught me a lot about buying timber, but I could have done without having to buy another plank to do the job.

Next boat I build is going to be made out of radiata pine pinched off the local tip. Fair dinkum.

Richard

bitingmidge
14th April 2005, 07:54 PM
A 10" scarf on that size rig won't be under a lot of load, I'd just do it (not being one to EVER use less sail than is absolutely necessary!)

cheers,

P

Gumby
14th April 2005, 08:17 PM
wasn't there a method of rejoining broken masts using a metal rod in the centre? maybe add 10" to the bottom and see if it holds. It wouldn't need to bend down that low so wouldn't make any difference to the sail shape. I see what you mean about altering the sail. Given the last poost, i wouldn't shorten it either. Racing isn't fun unless you win :D :D

bitingmidge
14th April 2005, 08:49 PM
I don't think you need to go for steel! Just a fairly long scarf, say 10:1 (just guessing, you could probably get a way with less- I'll go look up a book!) and a nice epoxy join.
Cheers,

P

Daddles
14th April 2005, 09:13 PM
I didn't think of adding it to the bottom. The mast sits in a plastic tube which, unfortunately, is in the order of about 10" dammit. It's a lugsail. How much force is there on the top of the mast? That's where I would have added the extra. I guess I can always just do it and if it breaks, make another one then. Let's face it, this is a 7' pram, I'm not going to be sailing the thing in howling gales ... well, not intentionally anyway.

And another thought is that, although I've made oars and spars before, this is my first mast, so if the thing has a shortened life (note the qualifier 'if'), it's still good experience making it. At the moment, I don't have any other use for the stick so turning it into a mast, even with a scarfed extenstion, isn't a bad move. Now, I wonder if I can find the timber to actually MAKE the extension? **insert pathetic howl**

Bloody boats. Doncha luvem?

Cheers
Richard

journeyman Mick
14th April 2005, 11:02 PM
Scarfing a mast is perfectly acceptable. I've scarfed the base of a large mast (about 300mm dia)that had been eaten by termites. The little flying ones - flown aboard, settled in the base of the mast and drank the rainwater out of the bilge.

Mick

Zed
15th April 2005, 08:35 AM
I bet the parrot on your shoulder is laughing at you arrrr.....

sinjin1111
15th April 2005, 09:33 AM
The maximum bending moment on a mast is at the base so if you have a choice scarf in a new piece at the top. Either way i wouldn't be bothered at all just scarf in the 10". Just a hint...you will need maybe 20" 10" of original length to do this....scarf length plus what you need for the short fall. As they say..."I cut the silly thing 10 times and it got shorter every time".
I had a laugh reading your post as i have done that sort of stuff up myself on some occassions. I think they call that "Thumb in bum mind in neutral". Personally i just love it when people stuff up it makes for great tales down the pub...lol
Sinjin

Daddles
15th April 2005, 10:17 AM
Thanks boys. Scarfing it is.

And as for that parrot, I jammed the cheeky sod down the centreboard case. Haven't heard a cheep since, just some muted swearing :D

Cheers
Richard

barnsey
15th April 2005, 03:25 PM
Are you making it in halves? ie are you going to rabbet a sail track in the timber? If so you could put a scarf either end. Will halve any weakness created.

Just a thought.

By the way the sabot I built as a kid had an oregon mast and I had it planing with 6' of water spouting out the plate case in a howling northerly on Port Philip Bay. If you don't sail it like that occasionally you're missin out :D :D :D
Will remove the remains of that bloody parrot too :p

You could always use it to make a boom :confused:

Jamie

graemet
15th April 2005, 08:59 PM
Richard,
I sailed 14s for years with masts 18ft above the deck. They were stayed with a diamond over crosstrees to keep em straight with 100 sq ft of sail. I had one break due to the strut folding up in a blow the day before a championship race. I scarphed the mast at the break with another bit of oregon at about 6 to 1 slope and the thing lasted for the rest of the season until I could afford the blanks for a new mast, so there's nothing wrong with a scarph! I'd put the scarph at the top as there will be much less force up there. Go for it!
Cheers,
Graeme