Your probably getting sick of me butchering gear by now but does any one known of any negatives cutting down masts,say 460 to 400 cheers.

Yep, if you cut off the bottom you shift the boom reinforced area, perhaps away from where the boom is, this has the potential for a snapped mast, you also make the mast extender reinforcing shorter, or non existent, this has the potential for splitting the bottom of the mast.
If you cut off the top, you increase the stiffness of the mast top, this could result in a flatter setting sail.

Chopping off 15cm - maybe.
60cm - no bloody way. You will stuff it.

Tell us what you have and what you are trying to achieve.
Given your level you may find offers of free or very damn cheap stuff.

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Mark _australia said..

Chopping off 15cm - maybe.
60cm - no bloody way. You will stuff it.

Tell us what you have and what you are trying to achieve.
Given your level you may find offers of free or very damn cheap stuff.

Yep cutting a small bit of it is fine but if you cut too much, the diameter of the mast will get too small to accept the extension anyway...

Got a 460 need a 400

Also, danger that due to the way it tapers, the "new" bottom that you chop off will bee too narrow in internal diameter for your mast base.

I ran a chopped 430 fore a while, everything rigged like ** and was horrible.

you will not be able to downhaul a small sail on it, it will be too stiff. So it will be useless as a 400 and you will have lost the 460

Can you put a turbin cap on your sail? i.e. put an extension strap on the top of your sail - your sail may not work real well though.

Way too much to even consider....you will just ruin your current mast.

Mate just buy a 400 cm mast your sails will love you for it.

I am the same, 2 460masts for 3 sails, and a 4m2 unused sail with no 370/400mast.
I have been looking for a year at cutting one.

Someone might have one 400 mast for mort69 in WA.
Anyone with a cheap one in Sydney for me ? 370/400 for a Gun Top Wave 4m2

Who sold you all that wrong stuff ?

There is good second hand stuff out there go shopping on seabeeze , you'll find something that will work.

I'm picking my way through cheap gear at the mo,one of the things I'm loving about windsurfing,heaps of trick gear and cheap ,buyers market it would seem,I'm slowly learning what I do and don't need.some good advice here thanks again legends.

Mort, you should expect to pay $100-$150 for a good condition, 2nd hand 30%-50% carbon mast, or about $300 for a new one. They are a little heavier than higher % carbon but they are way cheaper and usually stronger, so better through the early years.

Masts are unfortunately one of the more confounding aspects of windsurfing. A couple of points to consider:

The longer the mast, the stiffer they need to be. This is measured by the IMCS number, the higher the number the stiffer the mast. Using a using a longer mast than the sail is designed for may make it feel hard and like it doesn't breathe properly. A smaller, softer mast than the sail is designed for may make the sail feel spongy and dull.

Different mast manufacturers have different mast curves. This is where it gets a bit tricky. Some have a relatively soft top, some have a hard top, and (most) are in between and referred to as constant curve. If you rig a sail designed for a soft/flex top on a mast that is a hard top (or vice versa) you can have bad problems. That's why many recommend choosing a mast made by the sail manufacturer. See www.unifiber.net/masts-selector for info on mast curves.

If you really know what you are doing there are all manner of tweaks you can make with masts but for most of us it makes sense to buy the mast that the sail was designed for.

Really, REALLY bad idea. It will be USELESS as a 4m mast! Any sail rigged on it that is designed for a 4m mast would feel incredibly rigid and be absolutely horrible to sail.

As masts get shorter they also have to get softer in their flex. It is actually more than the IMCS numbers suggest. This is because IMCS stands for Indexed mast check system. Originally, when mast stiffness testing was first developed, the system was called just MCS (Mast Check System). It didn't matter much in those days because you could have a mast in any length you wanted, just as long as it was 460cm (or very close to that). The MCS system was developed to compare 460 length masts.
Many of you other old timers will remember running 3.8m 'storm' sails on 460 masts with massively extended head turbans. We thought they were great because we could sail our WOD's in 25 knots of wind without being flattened (well at least some of the time) and we didn't know any better.
The rigs were horribly stiff though, and when the short board revolution came along it didn't take some people too long to work out that smaller sails worked much better on much softer masts. And it was nice to get rid of a meter or more of swing weight on the top as well, so shorter, softer masts were developed. To make some sense of testing, the IMCS system/standard was invented (i think by Fiberspar?) and the calculations were indexed to the mast length. This meant a 430/MCS 25 mast would actually be softer in flex than a 460/MCS 25.
Or to put it another way. If you took a 430/25 mast and added a 30cm extension to the base and tested it as a 460 mast it would test softer than the true 460 mast (actually it would test at around MCS 21!) If you took a 400/25 mcs mast and tested it with lots of extension to make it 460cm, it would test out at about MCS 19. etc, etc.

Has the penny dropped now?

BTW, the flex distribution % (Hard top, Constant Curve, Flextop etc.) is a completely different matter and the topic for another discussion altogether.

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mort69 said..

Your probably getting sick of me butchering gear by now but does any one known of any negatives cutting down masts,say 460 to 400 cheers.

Biggest negative is having everyone telling you not to do it, then missing the next two weeks of wind because you don't have the perfect mast.


I assume you are not rigging a full race sail and sailing at the edge of its performance.

I bet you don't actually need a 400. What extension does your smallest sail need ?

Why not cut some off the bottom and some of the top, but only the amount you need to cut. If your sails rigs on a 400 with 20cm extension, then cut the 460 with 20cm from the base and 20cm from the tip, and rig it with zero extension.

Then go sailing. This is the most important part. It is the only way you can answer the question.

I bet if you put a 400cm sticker on the mast then 50% of people couldn't tell the difference, 49% of people would still sail worse than the 50% who couldn't tell the difference (and blame the mast) and the 1% who are sail makers wouldn't be interested in the question anyway.

If you can't swap or sell the 460 and get a 400, then cut it up, go sail, find out the answer and next time you will know.

The truth is I'm just trying to fit a rig together with limited resources and varying conditions,its becoming apparent you need multiple setups,I'm gathering equipment and getting past the need to modify gear,these replies are enlightening at the least. Cut some of the top and bottom is interesting concept,I barley know how the rig behaves as is but I'm starting to know what to look for cheers.

You don't need multiple rigs to sail.

You do need multiple rigs to stand around on the beach and talk ****e.


One minute people complain that windsurfing is a dying sport and nobody is getting into it, then the next they tell everyone that unless all your gear is tuned to 101% it is unusable.

With 3 sails, one mast, one boom, one mast foot, one board, two fins and a bit a stoke you can sail in anything worth sailing in. Depending where and how you sail it will vary what sizes and types you get, but you don't need more than that. It is nice to have more, but you don't need more.

Unless you finshed top 3 of the PWA this year then somebody somewhere can sail a door with a bedsheet tied onto it better than you can sail a brand new fully tuned rig.

^^^ true and also not true as many beginners start with a verrrry small sail and suddenly need a 6m which means another mast.

But yes agreed, once past that intial building of quiver, any intermediate can make do with one mast and slightly mismatched to sail.... not a NP / Gaastra mix for example, but a middle of the road bend curve mast lets you have a choice of many sail brands and a long extension and a very short extension can mean fitting up to 4 or 5 sails on on mast

Yes, sorry - I got distracted - didn't quite finish that.

I should say, if you are going to spend money then buy the correct sail and mast, plan your quiver early and stick to one brand. You might go different models for different sizes / conditions but if you are spending money and actually choosing things then right mast, right sail from same manufacturer.

If you do a bit of research you can quite easily get a decent usable range on one mast even if you have to have varying models from the same sail maker. Which is often not a bad idea because at 18knots you are probably wanting something different from a sail than at 30 knots.


If your mast is an old glass 460, too floppy to be any good, too old to be worth anything, then cutting something off and stiffening it up to be able to go sailing is a better idea than throwing it out and not going sailing.

If it is a new 80% carbon 460 RDM you bought by mistake then DON'T CUT ANYTHING OFF IT. Go trade it in against a 400.


Look down the page at the land yacht forum. They cut up masts and sails and then go faster with what they made than any windsurfer has ever sailed. You don't see them complaining about IMCS ratios and stretch properties of dacron as they hit 100kph.

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Carantoc said..

mort69 said..

Your probably getting sick of me butchering gear by now but does any one known of any negatives cutting down masts,say 460 to 400 cheers.

Biggest negative is having everyone telling you not to do it, then missing the next two weeks of wind because you don't have the perfect mast.


I assume you are not rigging a full race sail and sailing at the edge of its performance.

I bet you don't actually need a 400. What extension does your smallest sail need ?

Why not cut some off the bottom and some of the top, but only the amount you need to cut. If your sails rigs on a 400 with 20cm extension, then cut the 460 with 20cm from the base and 20cm from the tip, and rig it with zero extension.

Then go sailing. This is the most important part. It is the only way you can answer the question.

I bet if you put a 400cm sticker on the mast then 50% of people couldn't tell the difference, 49% of people would still sail worse than the 50% who couldn't tell the difference (and blame the mast) and the 1% who are sail makers wouldn't be interested in the question anyway.

If you can't swap or sell the 460 and get a 400, then cut it up, go sail, find out the answer and next time you will know.

This 'Advice' is utterly wrong! Following this advice and the sail will feel like S**T, probably won't rotate without kicking it and you will have a horrible time trying to sail. All you will have done is butchered a usable 460 mast.

IF you absolutely must try this, cut all the length of only the bottom. Get rid of the stiffest part off the mast and keep the softest part (the top). Far better to beg, borrow, swap or save up for a shorter mast!

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Carantoc said..

Look down the page at the land yacht forum. They cut up masts and sails and then go faster with what they made than any windsurfer has ever sailed. You don't see them complaining about IMCS ratios and stretch properties of dacron as they hit 100kph.

The sails and dynamics of a land yacht are completely different. That comparison is so far of and so irrelevant it is ridiculous!

I had this 4m2 sail in the garage for 5 years with no small 380 mast.
I finally found one, up the road at a neighbours' council rubbish collection.
I rigged it with a spare boom and base, it does look great.
My 12 YO son is so excited to go and try it (looks so much better than his kids 3.5 triangular sail).
I will have to take him after school this week.

My question: the mast is totally open at both end.
Should I plug it or fill the ends with some sort of 'no more gap' foam so it won't fill up with water ?
The important thing, is it better to be totally sealed, but then if water gets in it takes forever to empty or I should make a bigger hole so it does empty once vertical?
I understand I will have to leave the room for the base. And I know I should have got a better mast and sail and board??? But only when he wants to go faster than his dad.

Thanks for any advices.

ive got a couple of cheap SDM masts, booms and assorted stuff advertised on seabreeze!!!!! Just upgraded masts booms etc, also have some boards gathering dust...... Its cheap!!!!!