my DIY spinaker sock

[RussC]

One of my winter goals was to get set up to fly an asymmetrical spinnaker I’ve had gathering dust for a couple years. I’m just a poor boy, and home made is generally my only option, so a couple weeks ago I fabricated a shorty bow sprit for my Merit 22, and this week I’ve been working on a home brew sock to make solo use easier for an old man. the hardest part was creating a decent funnel. I used up a dozen feet of pvc pipe learning how to heat and form it around my fabricated wood form but I finally did get what I think came out pretty well. then I sewed up a sleeve out of mosquito netting and a bit of hardware I had laying around. Now if it just works as well on the boat as it does laid out down my hallway I’ll be a happy camper . thoughts? I launched it out of a bag, in very light wind, on my Mac 25 a few years ago but have never used a sock before. hopefully I learned enough by watching a bunch of videos to not die .

 

[Michael Davis]

Looks like it will work just fine!

 

[SteveHughessails]

That looks great. I have not flown a Spinnaker on my own vessel yet. I’m looking forward to it. I was going to try first on our Mac 25 but was told not to. I’d be interested in learning more about your Mac 25 days. Do you think the 22 would handle the same?

 

[RussC]

That looks great. I have not flown a Spinnaker on my own vessel yet. I’m looking forward to it. I was going to try first on our Mac 25 but was told not to. I’d be interested in learning more about your Mac 25 days. Do you think the 22 would handle the same?

BWY sells spinnakers specific for the Mac 25 so I have no idea why you were told not to, as long as the sail is sized to the boat.

 

[jssailem]

Sure looks good.
You DIY skills show promise.

I have a sock on my current boat.

On the 15, the sail was small enough to take down and pull aboard in the lee of the main.

 

[Project_Mayhem]

Looks great! How hard was it to heat and bend that PVC? It seems like it would be a bit of a challenge

 

[Captain Larry-DH]

Great job!
When you use it, make sure to secure the bottom end of the downhaul/uphaul control line to a cleat on your mast, and keep it fairly taught. Don’t let it flop around -
I once had an issue when my flogging sock control line snagged on the my genoa’s halyard anti-wrap collar at the upper end of the genoa furler. (Of course, it wasn’t discovered until we were in a building wind when the boat was over-canvassed, and we needed to depower.)

 

[RussC]

Looks great! How hard was it to heat and bend that PVC? It seems like it would be a bit of a challenge

It does require a good bit of patience for sure. at least when using a butane torch as I was. there's a fine line between hot enough to soften the material and cool enough to not burn it . I'm sure there must be a heat gun out there somewhere that would be easier to use, but I used what I had. once the proper temp of the material is reached it forms really easily.

 

[jssailem]

Russ, something like this might work. Controllable heat. Maybe the range is adequate. Not sure what temperature is needed.

 

[Project_Mayhem]

I think a waterbath might be the way to go. I've seen occupational therapists use them to VERY quickly make a brace out of plastic. I suspect that PVC would have a higher melting temp

 

[RussC]

I just did a little test with my infrared temp gauge to see what temp the pipe (1 1/4" SCH 40) gets workable. the material starts getting rubbery around 150*F and begins to get a "tan", blister, and generally appear damaged, around 250*F. so I'd say workable, for forming purposes, is about 200*F . interestingly, by placing a test piece in full boiling water it barely gets it soft, but definitely not workable.
YMMV

 

[JBP-PA]

I think a waterbath might be the way to go. I've seen occupational therapists use them to VERY quickly make a brace out of plastic. I suspect that PVC would have a higher melting temp

My mom was an OT and at home she would use the kitchen oven to soften plastic for braces.

 

[Foswick]

I think a waterbath might be the way to go. I've seen occupational therapists use them to VERY quickly make a brace out of plastic. I suspect that PVC would have a higher melting temp

You can definitely do this with ABS. I sometimes 3D print parts in ABS and mold them by briefly dunking them in hot water. Plus, ABS won't shatter into sharp fragments when/if it breaks.

 

[PaulK]

Nice looking sprit! And kudos on bending the plastic pipe. If you think working temperature is around 200ºF would putting the pipe in boiling water (212º) be easier & safer than using a butane torch? Since it looks like you made a form to shape it around an epoxy/fiberglass ring would have been easy to do too.
Will the mosquito netting stand much abuse? Unless you used the pet-resistant screen door version and even then it will get kinks and folds when you stuff the sail below and when you scrunch it up to deploy the 'chute. These will weaken the netting and lead to tears that may snag the sail. Some sort of nylon fabric might be better. Let us know how it goes!
Not to diaparage home-built...

 

[Project_Mayhem]

I just did a little test with my infrared temp gauge to see what temp the pipe (1 1/4" SCH 40) gets workable. the material starts getting rubbery around 150*F and begins to get a "tan", blister, and generally appear damaged, around 250*F. so I'd say workable, for forming purposes, is about 200*F . interestingly, by placing a test piece in full boiling water it barely gets it soft, but definitely not workable.
YMMV

That is very interesting. I thought it would have better thermal transfer and more consistency

My mom was an OT and at home she would use the kitchen oven to soften plastic for braces.

It was impressive watching them make one so quickly for me. I immediately looked up the price of the material when I got home. The only thing that's more expensive than marine grade, is medical grade!

 

[RussC]

Nice looking sprit! And kudos on bending the plastic pipe. If you think working temperature is around 200ºF would putting the pipe in boiling water (212º) be easier & safer than using a butane torch? Since it looks like you made a form to shape it around an epoxy/fiberglass ring would have been easy to do too.
Will the mosquito netting stand much abuse? Unless you used the pet-resistant screen door version and even then it will get kinks and folds when you stuff the sail below and when you scrunch it up to deploy the 'chute. These will weaken the netting and lead to tears that may snag the sail. Some sort of nylon fabric might be better. Let us know how it goes!
Not to diaparage home-built... View attachment 236375

Thanks Paul. I can't explain the reason, but boiling water had very little effect to soften the SCH 40 pvc. If I had other uses for one I'd pick up one of the heat guns John mentioned. maybe I still will. the polyester mosquito netting I used seems pretty tough but only time will tell how it holds up. easy enough to make another one from another material but I used this because it's very light weight, and allows for any moisture on the sail to quickly dissipate.
I could certainly make a chute out of fiberglass as I built fiberglass whitewater kayaks (and molds) for several years back in the day, and have restored several early Corvettes (still own a 62) the form would have to be made much more accurately, finished in hard gel coat, and polished to a high luster etc to get a clean release. but using the pvc allows the form to be pretty crude in comparison.
nice looking yak there btw .

 

[Joe]

Well done.... make sure you practice at the dock first.

Now... I'm not try to be a negative observer, but if it's single handing you're wanting to make easier... the hoisting type of sock launcher may not help you as much as you are hoping... like I say.. practice at the dock or on the trailer ... anyplace you won't risk your safety. Not dissing the sock... it's great for larger boats with huge spinnakers... but for smaller, tippier boats under 28 ft, where the sail is not super huge... it can be more work than it's worth. Anyway, just wanted to offer an alternative that would certainly be within your building skill set.

My suggestion is to study the deck level launching tubes that beach cats and smaller racing dinghies use to manage their chutes. Essentially. the sail is stored in the tube (or sock) with its center at the rear, leaving the three corners up front. Launch and retrieval is managed by a continuous line halyard/retrieval line. It attaches to the head up front, through tack block, then up to the spin block and back down to a cleat near the crew area... then... it transitions to the retrieval line, running forward through the back of the tube attaching to a loop sewn to the center of the sail.

This set up is so cool.... once you see it in action you'll want to build one for yourself... Here's an example of one built for a Laser 2. Good Luck

 

[dLj]

Thanks Paul. I can't explain the reason, but boiling water had very little effect to soften the SCH 40 pvc. If I had other uses for one I'd pick up one of the heat guns John mentioned. maybe I still will. the mosquito netting I used seems pretty tough but only time will tell how it holds up. easy enough to make another one from another material but I used this because it's very light weight, and allows for any moisture on the sail to quickly dissipate.
I could certainly make a chute out of fiberglass as I built fiberglass whitewater kayaks (and molds) for several years back in the day, and have restored several early Corvettes (still own a 62) the form would have to be made much more accurately, finished in hard gel coat, and polished to a high luster etc to get a clean release. but using the pvc allows the form to be pretty crude in comparison.
nice looking yak there btw .

It depends upon what kind of PVC you have. 100C may be quite low for a lot of PVC formulations.

The PVC's typically used for occupational therapy I believe are soft PVC's - they do have a lower softening point so putting them in boiling water works fine.

dj

 

[RussC]

My suggestion is to study the deck level launching tubes that beach cats and smaller racing dinghies use to manage their chutes. Essentially. the sail is stored in the tube (or sock) with its center at the rear, leaving the three corners up front. Launch and retrieval is managed by a continuous line halyard/retrieval line. It attaches to the head up front, through tack block, then up to the spin block and back down to a cleat near the crew area... then... it transitions to the retrieval line, running forward through the back of the tube attaching to a loop sewn to the center of the sail.

This set up is so cool.... once you see it in action you'll want to build one for yourself... Here's an example of one built for a Laser 2. Good Luck

Fascinating..... first I've ever seen this setup. I'm not sure I'd use the spinnaker enough to be worth having the chute on the deck all the time but it is a very interesting concept. I'll have to dwell on that a wile. thanks Joe

 

[jssailem]

Joe’s suggestion is very interesting. I wonder, could it be something you rig if it is looking like a spinnaker day. No need to have it always on the deck.