VANCOUVER ISLAND WINDTALK • Cutting a mast down
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Cutting a mast down

Posted: Mon May 30, 2011 1:29 pm
by KC7777
Hi,

I have a 426cm HotSailsMaui RDM 65% carbon mast. 4cm had been originally cut off from 430cm when I bought it.

Ideally this mast should be approx. 416cm-417cm for use with my 5.0 Gaastra Poison wave sail (which does not have an adjustable head.)

My questions......can I cut another 10cm or so off the mast and not wreck it?

Also, what is the best tool to cut a RDM mast with (I was thinking a fine tooth hacksaw).

Anything else I need to consider here? It is in mint shape, I paid approx. $175 I think for it.

Thanks,

Keith

Posted: Mon May 30, 2011 1:58 pm
by downwind dave
I have done this to an old tidal wave SDM. prior to cutting I wrapped the section in tuc tape to prevent splinters then i clamped it in a mitre box to keep things square. After the operation it worked fine.. untill the top section broke. i think the main concern is where the boom clamp goes but on a 65% rdm its a non issue. imo. 8)

Mast cutting

Posted: Mon May 30, 2011 2:10 pm
by KC7777
hey dwd,

What did you use to cut it with?

Thanks,

Keith

Posted: Mon May 30, 2011 2:18 pm
by downwind dave
the hacksaw with the fine blade (for metal) works great. i use the same tool for chopping carbon hockey sticks.

Posted: Mon May 30, 2011 2:53 pm
by KUS
carbon does funny things where broken strands can propagate.

Sparkly our resident carbon expert may have a view on this but I would concur, 65% is lo carbon and if someone already cut it you cannot likely ruin it any more. :roll: make sure tho the insertion friction of the extension doesn't change or you may create a stress point when a large section is inserted. Also I would use three door shims around the mast in the miter box to get things square. As for the base Tuck tape may actually pull splinters from the bottom so peel it off toward the bottom of the mast when you remove it. I would perhaps expoxy a section of woven cloth around the area of the cut first to keep splinters from starting, then cut through it with a miter saw very slowly, paint it black. You may also get splintering on the inside but again, lo carbon probably not an issue......tho I think the time of cutting masts is behind us :oops:

Also your 5.0 sail is likely designed to be rigged on a 400 :idea: and this 430 tho cut down will be too stiff :arrow:

Posted: Mon May 30, 2011 3:28 pm
by downwind dave
no need to peel the tape off. alternatively, use a big KC777 sticker!

Posted: Mon May 30, 2011 3:42 pm
by nanmoo
downwind dave wrote:no need to peel the tape off. alternatively, use a big KC777 sticker!
You forgot a '7'.

Posted: Mon May 30, 2011 9:25 pm
by Gdawg
Wet tile saw. Diamond blade if you were going to do a whole lot of cutting, but a carbide will get through a mast just fine. Masking / overwrapping etc is unnecessary - let the saw do the work and it will not splinter. Geoffy can elaborate on this as he has guys / equipment who cut through a couple thousand carbon tubes every day with no splinters.

I second Kus' comment re: messing up the stiffness. I am the furthest thing from a rigging/tuning geek, but cutting 30cm off a mast will render it sufficienly stiff that even I will notice a difference (not in good way).

Mast cutting

Posted: Mon May 30, 2011 9:35 pm
by KC7777
Thanks for the tips,

Never thought of the stiffness issue......I would be taking approx. 13cm off of a 430cm mast (ie down to 417cm) but will likely not be cutting this down for the 5.0M now.

Posted: Tue May 31, 2011 10:38 am
by more force 4
Casey - if the total 13 cm cut is on the bottom, and you can use a very short extension maybe the stiffness won't be a big deal compared to the original 430. Probably more bendy than having a 35 cm extension set to 2.5 cm with all the rest up the mast - but the 430 will still be stiffer than a 400 regardless. A lot of sails are made to get acceptable performance on the adjacent size to the design mast anyway, but some aren't - I'd check the sails specs first.

mast

Posted: Tue May 31, 2011 11:23 am
by KC7777
Hi MF4,

Another good point. After the total 13cm cut (ie 430 down to 417 or so) I would have rigged it with a short Chinook RDM extension with the extension collar removed as my 5.0 has a luff of approx. 415cm - 416cm. The Gaastra specs recommend a 400cm (IMCS 19) mast for the 5.0 Poison and a 430cm (IMCS 21) for their 5.4 and 5.8 Poisons. I already have a 100% carbon 430cm for my 5.8 Poison, and a 100% carbon 400cm for my 5.0 and 4.5. I had bought this 426 as a back-up for the 430 and was thinking it could work on the 5.0 too if it was approx. 415-417 so then I could rig 4.5, 5.0 and 5.8 at the same time.

Anyway, going to stick it up for sale and see what happens. If I get my money out of it will likely just sell it and pick up another 400cm in future.

This mast is almost new and would work for someone who needs around a 430cm for a 5.5 - 6.2 sail at a reasonable price for the mast with a mast bag, RDM extension and RDM shim too

Thanks,

Keith

Posted: Tue May 31, 2011 12:20 pm
by Tom B
I have a 350 that I cut down from a 430. That is stiff! I prefer it to the recommended stiffness masts for my 4.0. More punch, less leech twist, more hang time.

I could be the only one with this opinion though.

Posted: Tue May 31, 2011 12:43 pm
by more force 4
Tom B wrote:I have a 350 that I cut down from a 430. That is stiff! I prefer it to the recommended stiffness masts for my 4.0. More punch, less leech twist, more hang time.

I could be the only one with this opinion though.
Ever try a Sailworks Hucker Tom? Sounds like you'd like them!

Posted: Tue May 31, 2011 1:34 pm
by eastside
KC 7777. Didn't think it was a good idea to remove the collar on your extension? Splitting the mast being the reason I was told.

mast

Posted: Tue May 31, 2011 1:42 pm
by KC7777
eastside wrote:KC 7777. Didn't think it was a good idea to remove the collar on your extension? Splitting the mast being the reason I was told.
Man I am learning a lot. I haven't actually ever done this (no collar on an extension), just thought it would save another 1- 2 cm from being cut off - if I did cut it. So now the cut would have to be approx. 15cm off of 430 instead of 13cm.

Maybe it's just easier if someone buys it as a 426! - Check the Buy Sell section. MAST IS SOLD!