Forums > Land Yacht Sailing Construction

Carbon vs aluminum mast

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Created by us123 4 months ago, 5 Apr 2017
us123
6 posts
5 Apr 2017 9:02AM
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I have a chance to purchase a sail works 520 80% carbon mast witch is lighter than my fed 5 aluminum mast but is the 520 just as strong ? Does anyone know

blake52
122 posts
8 Apr 2017 4:33AM
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There has been a rash of people capsizing and breaking their carbon masts lately. 2 mini skeeters and a mini that I know of in the last 6 months. Unless you run a roll bar, which the skeeters now do, that means your head goes on the ground if you tip over. Also As I mentioned in an email, if you are running a particular class you may not be allowed to run carbon. Aluminum as thick as a fed 5 mast can take a serious crash before it bends permanently and bend a lot before it breaks.
www.facebook.com/100011651047902/videos/273253286406371/
for example.

Hiko
1131 posts
8 Apr 2017 3:30PM
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Food for thought with the lighter masts. The lower internal stiffener would not be enough to save your head and upper body I dont think

us123
6 posts
8 Apr 2017 4:33PM
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Thanx for sharing that video Blake After watching that extraordinary video all I can say is WOW!!! Did you Crack anything...yep! I would say stick with aluminum....... that was kinda cool looking (the crash)

blake52
122 posts
10 Apr 2017 6:57AM
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Thing with a crash like that, where you end up back on the wheels, is that the boat powers back up before you brain does and you suddenly realize that someone better be driving or it's all going to start again.
No permanent damage to me or the boat. I sailed back to camp. Bent the front forks a little (easy to bend back) bent the mast only a little (I've done as much damage oversheeting). I didn't walk well for a few days but it was all strains and bruises; a testimonial to helmets and seatbelts...and to stay on topic, strong masts.

Sylk
WA, 193 posts
10 Apr 2017 3:03PM
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us123 I think you're asking the wrong question.
Relative strength is not the first consideration.
What you should be asking is does the bend characteristic of the mast match the sail I want to use on it? That is a very difficult question to answer if your talking about using a sail cut for an alloy mast on a composite mast.

If the alloy mast was a constant diameter and thickness then you should be ok using a "constant curve" composite mast but you still need to know if the amount of curve matches. Measure the IMCS of your old alloy mast and compare to the new one.

Measuring IMCS:www.sailworks.com/pdfs/MCS_test.pdf

Hiko
1131 posts
14 Apr 2017 11:34AM
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Select to expand quote
us123 said..
Thanx for sharing that video Blake After watching that extraordinary video all I can say is WOW!!! Did you Crack anything...yep! I would say stick with aluminum....... that was kinda cool looking (the crash)


I think we have to conclude that the heavy class5 type aluminium mast would be a lot safer in those circumstances

Test pilot 1
WA, 1415 posts
24 Apr 2017 10:41PM
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Problem these days is availability of the aluminium in the correct sizes

aus230
WA, 1603 posts
24 Apr 2017 11:39PM
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Or the right temper, T6 is impossible to find in Australia

bazl
WA, 647 posts
25 Apr 2017 7:55AM
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Select to expand quote
aus230 said..
Or the right temper, T6 is impossible to find in Australia


Looks like there might be a source for 50mm
www.yachtmasts.com.au/contents/en-us/d3.html

aus230
WA, 1603 posts
25 Apr 2017 9:39AM
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That's great Barry, I will see what it costs, still need to find a tube that fits inside.

Hiko
1131 posts
25 Apr 2017 10:36AM
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Heat treating aluminium to produce T6 involves oven heating and quenching.
The temperatures required are not that great
130 degrees C to 200 degrees C dependant on time
Maybe not that difficult?

landyacht
WA, 5758 posts
30 Apr 2017 6:56PM
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Select to expand quote
Hiko said..
Heat treating aluminium to produce T6 involves oven heating and quenching.
The temperatures required are not that great
130 degrees C to 200 degrees C dependant on time
Maybe not that difficult?


you also need to consider the composition that you are tempering. I recall that the 6061 T6 refers to composition and temper. a T5 would be a composition better for soft bending work

blake52
122 posts
11 May 2017 12:39AM
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last I checked, 6061-t6 tubes are still available in the US, unfortunately not in the metric sizes that slide nicely into each other. the French are using 7075 in both masts and axles. They referred to our 6061 scaffold tubing as "truck axles" with distain that than can only really be done in French.

US772
302 posts
18 May 2017 12:51AM
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Select to expand quote
blake52 said..
last I checked, 6061-t6 tubes are still available in the US, unfortunately not in the metric sizes that slide nicely into each other. the French are using 7075 in both masts and axles. They referred to our 6061 scaffold tubing as "truck axles" with distain that than can only really be done in French.


Blake, The 6.7 US Mini Guys are using Fed 5 masts. They bought all of them up from S and R marine. Since then they have found a manufacturer that will build them for about $600.00. They are all made from t6 pipe not tube. Pipe i$ cheaper than tube. Part of the process to make the pipe sleeve properly is to have the 1 1/2" pipe milled to fit inside the 1 3/4" pipe. That milling process jacks the price up. I found a way around the milling process by mixing metric tube with the pipe. I can get all materials for around $225.00 plus shipping online or at my local steel distributor. I have yet to try out the mast.The Alu mast is stiffer than the stiffest Carbon mast. It has less over bend wrinkles in the sail. I am planning a trip to Tule Valley Hardpan or maybe the Gale in mid June to test . See details here - www.seabreeze.com.au/forums/Land-Yacht-Sailing/General/Mast?page=1

With the Mini Skeeter we feel the carbon masts are different even though they have the same ICM numbers. The Naish are noticeable stiffer when comparing pictures or sailing behind one which I have experienced too much of. We think they loose there strength with use and UV's. The 80 % carbon is only being made by one manufacturer. The few exiting 520 masts being made are 100% carbon. About $900.00 and fragile. I think the carbon masts are better suited for smaller boats like the INT 5.6 minis. They have way less loads on them because the righting Moment is so much less. They also have less to travel in a capsize and the contact angle is flatter when the mast smacks the hard. I would never buy a cheapo yard sale mast. The two masts that broke on the Mini Skeeters were those type not Sailworks Masts.

US772
302 posts
18 May 2017 1:00AM
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Blake your rivaling the original "Crash King" Dave Farmer - See 4:30 in

&list=FLKqJHJ2yH8UtL89rICpofSA&index=19

KAONAONA
209 posts
15 Jun 2017 11:48PM
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If the price is right then buy it. It could be used for other things too. Booms, stiffeners, foot pedal crossbar and others. But only if it's cheap.

When I come across one, I usually buy it.



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"Carbon vs aluminum mast" started by us123