Sun and rain awning

[Schooner Chandlery]

Has anyone made a boat sun awning of the type/style in these pics? I'm curious about making your patterns to achieve something of this style. Fingers crossed here that someone's done it. I have a very basic boom-tent and that's pretty easy to do. The part I'm interested in is the STYLE aspect of the two I shared photos of. See the sculpted/scallops between the grommets that make the one over the boom tight? This style is similar to the "stretch" tents that are becoming popular for weddings and such. I'm wanting to make this for rain not just sun shade so it can't be a stretch fabric, but will have to be something somewhat waterproof.

Appreciate any help

[Dartanyon]

It's a catenary cut tarp, and nice looking one. I've made several for hammock camping, but nothing quite as big as that. Usually around 12' x 5'.

You could certainly make you own. I used to use silicone impregnated nylon (sil-nylon). There are also plenty of cottage industry guys you can buy them from, and being that those are used for camping, not nearly as expensive as something boat specific. MSR makes a very nice (and spendy) one called the "wing".

[Schooner Chandlery]

How uv resistant is the sil-nylon? Did you use it for weight savings mostly? I have a suspicion that something a little stretchy is needed. Maybe not?

[JPA Cate]

I made one with Jim, similar to the one over the foredeck in your picture. Ours was not scalloped. It was a trapezoid, with depth built in, so that it could be used stably as a rain catcher, when lowered [the hose running to the fill functioning practically as the downhaul]. For sun and rain, it had an uphaul (we used the spare main halyard for it), and shed rain. It was made from Sunbrella, and for the remaining 10 yrs that we had the boat, stayed waterproof. The hems had nylon tubular webbing sewn into the corners [give the tubing 1/ turn before sewing the other leg down, and the loops stay open, it is a strong attachment point], and bungees to the shrouds fwd, and aft, to the running back stays, with light line and a hitch.

We also, at one time, made a mast to backstay awning, and it had 3 sets of pvc pipe in sleeves for spreaders, tubular webbing reinforced the sides, bungees to the lifelines, light lines fore and aft. It was good till about 25, then, we'd roll it up and take it down.

Another design, that might work better for you is one peaked like the one in the first picture, but more tent-like, It was written up in Practical Sailor, a long time ago, prior to 1986, and had 3 bolt ropes, each side and the peak. They were touting being able to keep it up also to 25 knots, but living at anchor, that's an awful lot of windage.

For what you showed, I think you wouldn't have to make your scallops quite so deep (to get better rain coverage), and the basic concept should still work, using hollow to keep the sail leech from flogging.

Ann

[Dougtiff]

Having lived aboard in the deep tropics for 20 year's, i went thru many awning design's, then a 48 foot Carlin Archer showed up in Singapore with a interesting awning, the big advantage was the ability to reef the awning, this was done due to a wide hem along each side, with a line in it, tied to the stay fwd. and aft. [main and mizzen stay's], each corner having a gromet, also a centerline tie to the mast's and a topping lift, so the drill goes like this, it's the wee hours of the morning and a strong wind comes up, your on the hook, untie the fwd. side line from the awning and retie to stay on each side, slack off the topping lift,untie the center line from the mast and it's ready to SLIDE down the lines still in place, tie off with some line and go back to bed, get up in the morning and slide it back, tie off, done, works like a charm.

[Schooner Chandlery]

Originally Posted by Dougtiff

Having lived aboard in the deep tropics for 20 year's, i went thru many awning design's, then a 48 foot Carlin Archer showed up in Singapore with a interesting awning, the big advantage was the ability to reef the awning, this was done due to a wide hem along each side, with a line in it, tied to the stay fwd. and aft. [main and mizzen stay's], each corner having a gromet, also a centerline tie to the mast's and a topping lift, so the drill goes like this, it's the wee hours of the morning and a strong wind comes up, your on the hook, untie the fwd. side line from the awning and retie to stay on each side, slack off the topping lift,untie the center line from the mast and it's ready to SLIDE down the lines still in place, tie off with some line and go back to bed, get up in the morning and slide it back, tie off, done, works like a charm.

The way we presently use the boom tent we have is with a line tied from mast to backstay and two other light lines tied from main shroud to boom gallows. The 16 x 20 rectangular tarp is then laid over this "ridge line" and we have numerous grommets along the port and starboard edges of the tarp (it's a standard rectangular tarp). Those grommets have a light weight line threaded through them which also goes around the port and starboard lines. The front and aft grommets are threaded and tied off to mast and boom gallows respectively.

If big winds come up (over 25 kts steady), we just untie the forward edge and slide the entire tarp back and secure it to the boom gallows. If we're not swinging on one anchor with the wind (e.g. we're in a river or other tidal area that keeps us pointed so we're not into the wind) that we may choose to untie the back edge from the boom gallows and slide the whole thing forward on the three lines until it's up against the mast where we secure it by wrapping a line around it between the shrouds and the mast--sort of sausage like.

Our boom tent works nicely but it has two problems: First, it can sag and collect water by the nature of those port and starboard fore-and-aft lines it's tied up to. That's because the 16' is a bit too wide for the aft section it covers. Second, it is just a rectangular tarp and doesn't meet my own (and my marina's) criteria of being boat canvas rather than a (marina contract no-no) plastic tarp. It is white and pretty and we've used it for two years off and on now, mostly at anchor where nobody cares that it's not boat canvas-- but its time for me to make something more permanent.

Originally I was just planning on making a trapezoidal Sunbrella (or similar material) boom tent/tarp that is 16' wide on the front and about 12' wide in the back and 22' long (our boom is 23' long and the 20' of the existing one isn't quite to the boom gallows) and use it in the same way that this one is used. If cut so the back is narrower, it won't be able to droop and collect water (a benefit to have the water drain onto the deck rather than end up in pockets on the tarp) and will be a better tarp. But--then while thinking about the port and starboard sides and wondering if I should put a bolt rope, a board, something interesting there, I saw the sculpted looks of the first tarp in my pics above and I decided that would really be nice if I could make something similar. Tight and hopefully more able to withstand winds than the boom tent.

We've had the boom tent/tarp up during last December for 3 weeks while in a marina that had a lot of birds. We were the tallest mast and they were all coming to sit on our wires. To avoid a filthy cockpit, we put up the boom tent and left it up through several days of stormy weather, 25-35 kts of wind where I thought it would surely blow away but because of the pools of water weighting it down on each side it was fine. A couple times the wind would blow and lift the tarp spilling the water over the sides of the boat but then it was raining and shortly thereafter the sides would fill again with water and weight it down again. Go figure the bad feature became a good one

I'm preferring this tight sided slightly sculpted tarp idea...

[Schooner Chandlery]

Originally Posted by Dartanyon

It's a catenary cut tarp, .

Thanks for the name, too!

[NoConplain]

De uma olhada

[svrevelations]

Originally Posted by Dartanyon

It's a catenary cut tarp, and nice looking one. I've made several for hammock camping, but nothing quite as big as that. Usually around 12' x 5'.

You could certainly make you own. I used to use silicone impregnated nylon (sil-nylon). There are also plenty of cottage industry guys you can buy them from, and being that those are used for camping, not nearly as expensive as something boat specific. MSR makes a very nice (and spendy) one called the "wing".

How long lasting is Sil-Nylon?
We are in the Caribbean and I'm concerned about how long it would last in the sun.

[canvasman]

Nylon doesn't do well with UV. Sunbrella is very good. If weight or storage space is a concern I would use Stamoid light or Weathermax. Both are durable, lightweight and fold up to a smaller size than Sunbrella. I don't think Weathermax will wrinkle as much as the Stamoid.

[UNCIVILIZED]

Originally Posted by Revelations

How long lasting is Sil-Nylon?
We are in the Caribbean and I'm concerned about how long it would last in the sun.

You might also run this one by some serious mountineers, or folks who make their expedition tents. As at altitude there's no where to hide from the UV, & it cooks things with regularity. Though it's been so long since I've done it that fabrics & coatings have changed. So I can't give you a numbers figure.

Without knowing what coatings you can get, or are built into off the shelf fabrics for sewing, any numbers need to be specified directly. As you can cook a spinnaker in 2 weeks from UV, easy.

Also, as stated, it's the connection points, & high load areas/load paths which are what commonly give out. Or rather, tears happen right where they're joined to the base fabric. So as with sails, & reef patches/points, how they're constructed really makes a difference.

Which, if you're going to spend 50hrs+ building the awning, where's the lifespan point of the awning fabric where it makes sense to then switch to Sunbrella, so that the invested build time makes sense?

I'm curious on this, for myself too. As it's been a while since I've done a big awning. But with some of them, it's as involved as building a sail that has loads of handwork. Especially if it has much/any actual roping on it, or say, sensible grommeting techniques & the like.

[ErikFinn]

Sailrite's website might have some tips, and they definitely have bits and pieces for your project. They also feature plenty of Youtube videos.

[Schooner Chandlery]

Sailrite's website is great in general but for whatever reason this style of awning isn't among their forte of discussion items or videos.

If I make this thing, I'll definitely take notes and share. I did google and see lots of hammock hikers have similar tarps but of course those are much smaller and tend to be put in place at night /evening and pulled in during the day as the person is hiking so the fabric need not be so UV proof. What I did learn from those sites is that if your material is NOT stretchy (so it's like Sunbrella) then you don't need the deep scallops so much. The scallops are to keep the tarp tight when there's rain or dew and the fabric sags. So--to me that means I should be able to make one really tight with not very deep scallops if I use a fabric like Sunbrella or Weathermax!

[Dartanyon]

This is exactly right. I've had my sil-nylon tarps for years, but they see maybe 6 days of sun per year (as in when I leave them up for shade) and even then, by the nature of them being over my hammock, they are mostly shaded by the trees. My guess is that the sil-nylon would NOT hold up to full time use as a function of UV degradation. There are other materials out there, sil-pro, cuban fiber, and others. I would think sunbrella would be great too. Maybe even if you are going DIY and trying to stay less expensive, cut an old sail up into shape.

The cat cut (scallops) are really to get a tight pitch on the tarp, and cut down on the flogging. I would think that they be something you'd want to incorporate, but probably not nearly as deep as the ones in the pictures you have. My guess is you'd get the advantage of the cat cut, even "scalloping" around 5-10% of the length.

Originally Posted by Schooner Chandlery

Sailrite's website is great in general but for whatever reason this style of awning isn't among their forte of discussion items or videos.

If I make this thing, I'll definitely take notes and share. I did google and see lots of hammock hikers have similar tarps but of course those are much smaller and tend to be put in place at night /evening and pulled in during the day as the person is hiking so the fabric need not be so UV proof. What I did learn from those sites is that if your material is NOT stretchy (so it's like Sunbrella) then you don't need the deep scallops so much. The scallops are to keep the tarp tight when there's rain or dew and the fabric sags. So--to me that means I should be able to make one really tight with not very deep scallops if I use a fabric like Sunbrella or Weathermax!

[toddedger]

I'm heading in a different direction with sunbrella shade fabric. This is first rough fitting. Side attachment points will hold it down and smooth it out some. Zippers will be installed to fit around rig latter when mast is stepped. Sister clips on lazy Jacks will allow fastening in between boom and lazy Jacks. Out side edges will turn up with snaps to collect water. It's made in three pieces and will take about twenty minutes to put up.