I need to know the depth of mast step for my 2 passenger twin. Going to use 6.5 sailworks sail with 520/75% carbon mast. That leaves about 40 cm of the mast showing on the bttm.
Thanks Windcrazy
I wouldn't go any less than 220mm for a mast tube. I think the LLM is 250mm,Mini-promo (FL1) it's 400mm and blokart is 150mm?
There is no right or wrong answer have a go if it looks right do it. You can make stronger and longer if you are worried about breakages. I wouldn't be concerned about weight as you aren't racing. If you want to go faster you can always kick your co-pilot out.
Don't forget to reinforce/make a mast stiffener or your lovely carbon mast will split/crack.
You can also make mast extension that also useful if you don't have enough clearance under the boom. Just make sure it is suitable aluminium.
I have made a couple and bent one (wrong material).
Deisgn it, make it, break it then make it stronger.
Ben.
what do you mean by a mast stiffener? On my old set-up, my mast went down inside a 2 1/4" ID aluminum tube 16". I don't have enough mast left to go that far down on my new set up so I have to figure out how I'm going to rig the new sail. I was running a 40% carbon 460 on my old windsurfing sail but it was getting to be a pain in the ass to rig as I got older. The performance wasn't that good either. Need to get some input from US772, he's been kind of quiet since the worlds. Have to try and get ahold of him.
Thanks Windcrazy
Im using a 5.2m 100% carbon mast on my Class 5 my mast step is 320mm deep.
Wind surfer masts should be reinforced if they are only supported by a mast step, remember on a winsd surfer they are supported at shoulder height by the boom, there is no lateral force at the base of the mast.
I inserted the top half of a second carbon mast into the base of my main mast. Start by pushing a tight non porous foam plug down the base of the main mast about 50mm further than the length of the mast top top insert. Set the plug in place with about 100ml of 2 part urethane. Once your plug has set pour about a 1L of urethane into the mast then insert the mast insert. This process will stiffen the mast quite a bit up to a point just a bit highr than where the boom would attach on a wind surfer. The base of the mast insert is floating free inside the base of the main mast but the clearance is only about 3mm between the outside of the insert and the inside of the mast.
Next you need to reinforce the base of the mast around the mast step. I wrapped my mast with a double layer of 50mm glass tape overlapping by 25mm I.E 4 layers of glass. Starting at the base of the mast up to about twice the height of the mast step. then sanded the finished product for a smooth fit.
This method is still a bit experimental I only finished my yacht about 6 months ago but it seems to be going ok so far.
The original IMCS of the mast was 35, haven't tested it after reinforcing.
Here is one of my mast extensions/stiffener.
By using this I can use my favourite 430 mast on my land yacht.
Can't use it on my class 5 because of cams but should be a good mini sail. Been working hard on my seat b
