CS17 masts & sails

[john moffat]

Am just about to order a kit but am unsure about which sails to go for and best method to attach to masts. Also what mast material - wood or alloy. I have seen Peter HK's beautifully built CS17 with alloy masts and larger sails.

I will be sailing mostly single handed and was most interested in the standard sails -gotta be red, I'm an ex Mirror builder/sailor - so would be interested in comments, experience etc.

My sailing area is Tasmania and our winds tend to be boisterous most of the time so reefing is a must. I think wind speed has not been below 20 knots all summer so far.

[Peter HK]

Hi John

I'll give another opinion (after our discussion after Christmas) for what it's worth.

As you note I have large roachy sails with battens...If I lived in Tasmania, with the higher average breezes, I'd certainly ditch the battens and have the smaller area of battenless sails with the benefit of easy rolling around the masts.

Reefing is vastly better with tracks- single handing you will need the option of 2 reefs.

Alloy masts are smaller diameter (less windage) and a bit lighter but wood looks prettier. If doing it again I'd use aluminium for the bottom 10-12 ft and (birdsmouth) wood for the top half and not leave a step, instead of the 3 piece mast.

I don't think red sails are faster (unlike cars)

Cheers

Peter HK

[john moffat]

Thanks for that Peter. I recall we discussed something similar.

What do you mean by 'birdsmouth'? I like the idea of a wooden top half, probably with a bit of taper.

How would you keep the tracks in line?

I was thinking of a gunter rig, is that what you mean? Am not sure how that would go with reefing with the gaff lying too far aft when the halyard is eased.

Red was more related to sailing off into the sunset, I'm sure older USA members will remember.

Regards,

John

Edited January 30, 2011 by jongo

[Tom Lathrop]

Sailing life is certainly simpler without battens. If you are considering a gunter rig, why would you be concerned about the tiny discontinuity at the diameter juncture of the aluminum mast? Those who have tracks can't even see this as a problem. The step in diameter is just not noticeable. Do a search for birdsmouth masts on this or other forums. Its a method for building a superior hollow wood mast section.

With winds continually near or over 20kts, you will reef most of the time and tracks are the accepted best way to do this although some have come up with some ingenious ideas for sleeved sails. I like the CS15 or Lapwing better for single handing than the CS17, especially with winds like you are to sail in.

[ecgossett]

Would the Cooper's way work for building CS17 masts? http://waderweb.com/plans/fauxbm/fbm_start.htm

I've been reading up on this and different sources say not to use epoxy for birds mouth or similar ways of mast building, why is this?

- Edward

[ChrisObee]

Would the Cooper's way work for building CS17 masts? http://waderweb.com/plans/fauxbm/fbm_start.htm

I've been reading up on this and different sources say not to use epoxy for birds mouth or similar ways of mast building, why is this?

- Edward

If you look long enough on the internet you will find every opinion there is. Lots of folks have made all sorts of masts and spars using the birds mouth method and epoxy.

[tom151]

If you look long enough on the internet you will find every opinion there is. Lots of folks have made all sorts of masts and spars using the birds mouth method and epoxy.

What Chris said!

But... if you choose a designer, with lots of well proven boats built - follow his lead.

Yes, there are reasons to consider varying particular aspects of the boat such as optimizing for short-handed in heavier wind ranges by going to sail tracks and proper reefing - but follow the designer's lead or his referral to specific boats.

As far as the "cooper's mast" technique... there's some good and bad stuff (my opinion) in that article, but that's a further discussion that's perfectly valid to persue.

[PAR]

The coopers mast build doesn't offer enough surface area for the glue's recommended except for PU and epoxy. This method would require exceptional fitting and stave alignment and clamping pressure to work with all glues except epoxy and alignment would be difficult at best with this method.

The birdsmouth method is self aligning, so this is a non-issue, it also has considerably more surface area within the joints. Both of these alone, make this method superior to the coopers method.

I'm not sure where you're getting your "don't use epoxy" advise, but I'll bet they don't use epoxy for much. There are still some throw backs that think epoxy is a "fad" that will wear out soon. Some of these used to be well respected restorers and noted writers. Epoxy is the back yard boat builder's adhesive of choice, in this mast building method. It far out preforms every other adhesive known.

[Hirilonde]

Epoxy is the back yard boat builder's adhesive of choice, in this mast building method. It far out preforms every other adhesive known.

It is the professional boatbuilder/restorer's adhesive of choice as well. Resourcinol works great too, but few are willing to live with purple joints.

[PAR]

Resorcinol and plastic resin will work fine for a birdsmouth mast, though considerable clamping pressure and quite precise joint fits are necessary for good results, plus temperatures during the cure are also a concern.

[Peter HK]

Hi John

What do you mean by 'birdsmouth'? I like the idea of a wooden top half, probably with a bit of taper.

I presume you have now googled birdsmouth masts.

My masts are 3 piece- 2 different sizes of aluminium and then a tapered wooden top mast. I didn't bother with birdsmouth construction for the short (6ft) topmasts as, when I did the maths, with plugs in each end and allowing for the taper and wood density the weight saving was about 100 grams (under 3 oz for the the imperialists). It seemed too much work for the benefit. For a longer, larger diameter wood section the benefits would be more impressive.

How would you keep the tracks in line?

I presume you are looking at breaking down the mast...You can mate the tracks with a V section or with a strategically placed screw (half in each track)

I was thinking of a gunter rig,

Lots of problems with a gunter on a CS17. Firstly it makes sprit booms difficult as the jaws of the gunter have to get past it.

This would mean using standard booms... OK on the mizzen (which can fit a vang) but the main has little room for a vang so sail twist would be a problem. You could fit a gnav- an ugly solution in my view. The sprit boomed standard rig is so light on the sheet and well behaved I'd find it hard to change.

Hope this helps

Cheers

Peter HK

[Tom Lathrop]

Resorcinol and plastic resin will work fine for a birdsmouth mast, though considerable clamping pressure and quite precise joint fits are necessary for good results, plus temperatures during the cure are also a concern.

Paul,

I have done birdsmouth with epoxy but don't see how other glues would work fine, especially resorcinol. Set up time and clamping pressure would rule these out for me. Assembly, alignment and clamping takes time that is in short supply with resorcinol, urea and aliphatic glues. I would only build a birdsmouth mast with epoxy. Would rather use resorcinol on a laminated mast though, where high pressure clamping is easier to achieve. You are dead right about the epoxy haters though, always looking for a way to stick in ignorant and uninformed negative comments.

[john moffat]

Hi Peter,

Yes I now know what birdsmouth refers to.

Have had feedback on gunter from Rob Askew/Barrie Armstrong and as I feared gunter would require stays and I want to avoid standing rigging. Have always liked the idea of unstayed masts.

I think you have the best idea although didn't you tell me that you only had two bottom sections because it was laying around from previous builds? And aren't your masts fixed in single lengths?

Over the years I have found slides and tracks develop minds of their own after a time and I don't fancy messing about in a slop and a blow with mast slides jamming in mast tracks so I think I will just go down the path of single length masts maybe with a top wooden section like tours.

Unfortunately have been able to get no info at all on what the designer actually recommends, apparently you have to buy the plans to see that.

Regards,

John

PS Thanks to all other respondents, has been/is most interesting discussion.

[Peter HK]

Hi Peter,

Yes I now know what birdsmouth refers to.

Have had feedback on gunter from Rob Askew/Barrie Armstrong and as I feared gunter would require stays and I want to avoid standing rigging. Have always liked the idea of unstayed masts.

I think you have the best idea although didn't you tell me that you only had two bottom sections because it was laying around from previous builds? And aren't your masts fixed in single lengths?

Over the years I have found slides and tracks develop minds of their own after a time and I don't fancy messing about in a slop and a blow with mast slides jamming in mast tracks so I think I will just go down the path of single length masts maybe with a top wooden section like tours.

Unfortunately have been able to get no info at all on what the designer actually recommends, apparently you have to buy the plans to see that.

Regards,

John

PS Thanks to all other respondents, has been/is most interesting discussion.

Hi John

The plans give several options. There is advice on 3 piece masts (2 different sections of aluminium and wood for the top) but also, and I quote " Masts to be made of aluminum{sic}, wood, fiberglass{sic}, carbon fiber{sic} or a combination of the above. Our preference would be, aluminum{sic} tubing for the bottom 8-10ft and birdsmouth wood or fiberglass{sic} tops giving a good balance between light weight, strength and economy". There are also detailed descriptions of solid and birdsmouth wooden masts. I presume you get a set of the plans with the kit...I'd demand that.

I made my masts a fixed 3 piece section (the sprit booms were leftovers). Break apart masts would be a bit harder, but not much.

Give me a ring regarding specifics.

Cheers

Peter HK

[PAR]

I used a 2 piece aluminum/birdsmouth mast, though I did cheat and made the lower piece long enough to get the birdsmouth portion from 8' spruce, I had on hand at the time. On the CS-17 this simply means a 12' 6" aluminum section for the main, with an 8' wooden section above, though 12" of this is buried in the aluminum, leaving just 7' of birdsmouth section exposed. The mizzen is the same deal, except it has an 11' 11" aluminum lower section with the same 7' exposed, 8' upper wooden piece glued into the tube. Naturally, the wooden portion is nicely tapered down leaving no step or transition between the two elements. If you had longer lengths of birdsmouth stock, you could use a 12' lower section on the main and an 11' 6" on the mizzen which would permit you to get both pieces from the same 24' piece of raw stock (tubing), further saving some money.