Passagemaker Gunter Rig - ALL Synthetic Rig DYNEEMA

Builder's Forum
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Hello All! 

I wanted to share with the community my experiences of putting together the synthetic rig for my Passagemaker Dinghy (PMD). The standing rigging is all made of Amsteel Blue, a material very similar to Dyneema which is stronger than steel of the same diameter but with very similar stretching characteristics.

Firstly, I need to head off this post with a few disclaimers- what we are talking about in this post is the rigging. My PMD was built from plans and not a kit. I decided to use Douglas Fir marine ply and not Okoume. I have zero regret with that decision. Halfway through my build I ended up selling my house that had a lovely two- car garage workshop and at the time I wasn’t sure I would have the chance to finish the boat at all. Consequently, things were rushed. The beautiful low radius fillets that held the bulk heads and seats for the initial build were hastily slopped over with 3/8” beads and not cleaned up well.  The bow seat was not cut correctly, and the front transom is a few degrees off square.  In the words of my generation- YOLO.

If you think it takes a fragile man to issue a disclaimer so that his boat-building peers don’t criticize him on the internet, you’d be right.  Please, please, please don’t tell me my fillets are sloppy, don’t share your negative thoughts on the boat’s finish, and for the love of god don’t nitpick the endearingly rough condition of some of the lumber cuts. I am well aware of the aesthetic quality issues. But I use this boat A LOT! I wanted a boat that I wasn’t going to be afraid to beat up a bit and after a full year of use and abuse she is holding her own. She is ugly AND I love her. 

That said, it’s open season on the rigging, please let me know your thoughts. Also if you folks want to see how a gunter rig on the PMD is REALLY done, check out CaptainSkully’s Passagmaker rigging posts. He did some amazing things and I would say if you want to commit to having an exclusive sailing dinghy that would definitely be the way to go. 

My approach is a bit different in that I am using the stock sliding gunter mast from CLC. I really like the ability to completely remove the rigging and only use the boat for rowing and trolling, which I do frequently.  That said let’s get into it-

Photos are here- https://photos.app.goo.gl/zNdmfsL117FSrUmG7
Sorry they are in a weird order

Mast Step- I modified the mast step because I didn’t like how the original through-hole style damages seat. I tried to pad the hole with felt but it still was doing a number on the wood.  I ended up talking a 3/8” through hole piece and then gluing that on top of identical 1/4” piece but without the hole.  I needed the mast to sit a bit deeper so I added a smaller 1/4” piece for the top that adds a bit of girth to the assembly.

Stays- I used Samson Ropes’ 7/64” Amsteel Blue product. Amsteel Blue is the name of the material and  comes in several colors and I went with red because I wanted it to complement my Douglas Fowler made tanbark sails. The rope is available from Amazon and I believe and 100’ was around $50ish dollars.

One does not simply make knots with Amsteel so you are going to need to do legit eye splices at each end. Because of the small diameter of the of the rope it is recommended to use Brummel Locks rather than the weaving required in a Class I eye splice. I also crudely stitched some flat webbing around the masthead side of the stays and then added thimbles to the lower ends that clip into the snap shackles.

I’m intentionally not giving lengths for the stays because I’m not convinced my lengths would be right for a kit-built PMD. Also when you make up your shrouds add a few inches BETWEEN the Brummel locks because the overall length will contract when you bury the tag ends. As a rule your tag ends should be around 18” for this diameter. It is for this reason I have 2” paracord loops that run through my thimbles in the pictures.

Soft Shackles-Soft shackles are the cat’s @$$h- errr- meow!  They are seriously awesome. I highly recommend this video from HowNotToHighline on how to make them up with the Brion Toss button knot. I also strongly recommend you practice with 110 paracord and make several before you attempt on the Amsteel.
https://www.youtube.com/watch?v=91_jEjQdlBU – NOTE: This video was made by rock-climbers who don’t use the same sort of discretion with their vocabularies as us honorable sailor types so be advised there may be some mildly offensive commentary including a brief reference to an inappropriate act with a Smurf. I do think it is the best video out there, though. Be sure to check out the channel for some other insightful uses of softshackles.

Poor-man’s Turnbuckles- In order to properly tension the rig I do use some less-than-marine-rated turnbuckles which are quick-linked on the ends one of which has a snap shackle. This would definitely be the weak link on the system and that’s why I use short slings to serve as a back-up if these failed.

Slings- I use slings, which are short lengths (about 14”) with Brummel Locks on each end as “back-ups” that overlay the turnbuckle and snap-shackle tensioning device.

Mast Head- I attach the forstay to the mast cap in a girth-hitch like fashion. I have found that this does not interfere with the mainsail halyard that also uses the hole in the mast cap. Under that is the first eyestrap that captures the loops of the shrouds- notice my novel abraision-reducing/anti-rotation webbing and zip-tie solution. Under that is a dedicated eyestrap and block for the jib-halyard. This because I really don’t like the “set-flying”  nature of the jib. I have posted about this in the past if you care to understand my reasoning.

Rigging Process- I pass a softshackle through a hole in forward bulkhead knee (make sure this hole is sanded smooth and won’t catch threads of the shackle) and loop it through BOTH the sling AND the lower quicklink in the turnbuckle assembly. With the turnbuckle at its full length, I pre-attach the assembly to the shroud thimbles before stepping the mast while the mast is still laying horizontal. I have found that the shrouds can be somewhat loose and still allow the mast to be stepped. I then step the mast and somewhat tighten the turnbuckle of the side of the boat I am standing on. Then, I grab the forstay and use a long softshackle to attach it to the front handle in the transom. At this point, the rig is loose but it won’t be able to come down. I then tension the turnbuckles on the shrouds before establishing the final tension of the forstay that gives the mast the correct 4 1/2" rake.  

PRO tip- Don’t worry about attaching the backups until the rig is tensioned fully. Also I use back-ups around my tensioning system only because I used dubious quality turnbuckles and snapshackles. If you invested in appropriately rated components this could definitely be omitted. As John Harris explains in the manual, marine turnbuckles are stupidly expensive.


Please let me know your thoughts and happy building to all!
-Pat

FIN

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Great post Pat, thanks!

Looking at a few videos about splicing Dyneema brought back pleasant memories I have of eye-splicing Samson double-braid back 40+ years ago for a stripper scow's running rigging.

That needed stainless standing rigging; I'd dropped in one Saturday morning at the Land's End shop on Elston Avenue in Chicago to inquire about whether they could make up what I was needing. Pretty soon I was watching them swage turnbuckles & chainplates on! I have those stays still, even though the boat's been gone decades now.

Been hearing rumors about developments in synthetic fibers bringing about what you're taliking here: line stronger than steel for standing rigging sure would have been nice to have back then!

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A couple points about the rig:

Standard bury length is about 40 diameters, say 5" for 7/64" line. The line in the spliced area will be about 20% shorter due to the diameter increase, so for two splices, 10" of total bury, add 2" to the eye-eye dimension before making the splices. This should get you within 1/2" of your target length. Do taper the buried tail so that there isn't a noticeable step where the tail ends.

This is obviously a very low tension rig. Consider making your side stays a fixed length (lash if you want some length adjustability), then use a hobble* to tension and hook or lash the forestay. Tensioning just the forestay will tension the whole rig. Shoot, just pulling down hard on the forestay and hooking in a snap shackle should be plenty, once the length is determined**. The hardware store turnbuckles and quick links really don't sell the look!

Consider sailmaker (closed) eyes instead of sharp-edged hardware store versions. They're available in small sizes, they're cheap, and won't collapse or cut sails or lines.

Consider using a few wraps of higher strength lashing instead of the multiple loops and loops of para-cord (nylon, inherently stretchy, opposite properties of dyneema).

Investigate other ways to secure the upper mast loops, that don't cause the line to be pulled into the acute angle formed by the eye strap and mast. Traditional "thumbs" have a rounded upper bearing surface, for instance. Or use a one-fastener loop, where the line would bear on the downward loop instead of the V of the strap.

*hobble: a way to tie off a stay while leaving the end free. Use a short length of rope, tie a loop in one end, big enough for your foot, and rolling hitch the other end a couple feet up the forestay. On the trailer, step on the loop hanging over the bow, tensioning the forestay, and hook/lash the now-dangling forestay end. Or use a trapeze cleat to get a simple and compact 3:1 purchase.
**adjustable length splice: measure your intended eye-to-eye length, do a standard (Brummel or lock stitched) splice for the top, then create a very large eye for the bottom, and insert a long rope tail for ~5", then exit the tail so it hangs out. Under low tension, the loop (and thus line length) can be slid along the tail, and it will remain secure once tensioned. 

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   It looks like you solved the problem of the jib block interfering with the fore stay. I will be using your idea of raising the forestay to the top of the mast and lowering the block like you did. The way it is set up in the manual, the halyard chafes badly on the forestay and won't even last for my maiden voyage. I also used turnbuckles to tune the rig, although smaller ones, they are rated to a working load of 350 lbs and made of stainless steel, purchased at Home Depot. As an added bonus, mine is a take-apart Passage Maker and the eye of the turnbuckle slides right over the joining bolt with a one inch piece of half inch copper pipe slid in to protect the threads. I don't have to remove anything to take the mast down, just slide the turnbuckle off the end of the bolt and tilt while lifting the mast off. 15 seconds, and it's off. I will try to enclose pictures.  Thanks for the ideas and the post. I may go to a soft rigging later, but I have a ton of 3/16th ss cable and the swage tool, so that is easier for me right now.