self-made stackpack

TiggerToo

TiggerToo

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Hi everyone,

I was toying with the idea of building my own "stackpack" for the mainsail. It seems like a pretty straightforward project. anyone done it? Any suggestions about what I should look out for?
Cheers
 
My wife and I have made 2, easy to make and came out really well. We've been asked to make them for friends but have declined. First one was screwed to the sides of the boom with reefing lines passing between coat and boom, a spacer and longer screws allowed the lines to pass through easily. The next was fitted with the sail foot in the boom track. The rear section of the coat is loose footed from where the reefing lines attach to the boom to the out haul on the boom. keeping a tensioning stap on the lose section stops it flying about an allows you to tighten it up when th sail is stowed. It works very well and no zips involved other than the main one for closing the whole thing up. Do leave plenty of spare zip at the outhaul end. This can be bound up to stop the zip coming apart but should leave you enough space to pack the reefing lines and sail away easily. I have also attached straps and plactic buckles so tha the sail coat can be strapped in while sailing. Have a look at other boats and pinch the beast ideas from other makers.
 
We made one. It works very well. Problems: It is too high so we will cut it down a little this year. Getting it and the mainsail into the groove in the boom is a real test of strength and I would seriously contemplate tiggertoo's idea of screwing it to the side of the boom BOL
 
Take a look at Kemp Sails website for ideas on positioning the lazyjacks and the sizing of your main. Once in the web site, look under products, stackpack, then into the measuring form for boom cover. As for the materials, you could try hawke house marine (just google). Good luck
 
Probably one of the easiest things to make!

Suggest touring marinas armed with a digital camera for ideas - there are many variations. Some use zips for the reefing lines to pass through. Use one long one each side with multiple sliders to adjust position of the hole.

Some attach the lazy jacks to the boom - most to the batten on the stack pack.

On the subject of battens I got away with using plastic waste pipe on my small boom. It has lasted one season so far! more importantly you will need to decide where to position the batten. If too high it will intrude into the sail area when sailing - too low and rain water will pool above the sail when stowed and leak through the zip. Its well worth stitching the thing roughly together and trying it on the boom.

If you have a loose footed main you can attach to the boom slot by stitching in a length of old halyard. I'd recommend though that you reinforce this with webbing particularly at the ends. If your main has a partial bolt rope at the foot like mine then you can fit both to the slot at the same time. I stitched two lines of one inch webbing say 100mm apart so that the stackpack slides on symmetrically. It IS a struggle to get on though particularly with one pair of hands. One trick that seems to help if you have reefing lines in the boom is to attach one to the clew. That way you can pull the sail along while feeding stackpack and sail in at the gooseneck. One trick I've seen is to use dacron sailcloth in the groove so that it slides easier.

BTW you can buy long double ended zips so there's no need to have a long tail of zip at the clew. I believe they can be made to measure but Kayospruce do them, I think, to the nearest 10cm which is good enough for me.

I put straps with side release buckles to both ends of the opening to take the strain off the zip. This helps doing the zip up too. I also used them to allow me to roll the stackpack up should I wish when the sails up.

One advantage of a normal sailcover is that it is at least partially open underneath so a damp sail stands a chance of drying. I did think of replicating this on a stackpack by making the sides longer and creating gaps underneath. Didn't get round to it though.
 
Just in the process of making two. A little trial and error required to get the size just right, best to err on the big side at first as it's much easier to make it slightly smaller than vice-versa...... Agree look around is the best design aid, with camera! The only materials problem I've encountered has been suitable battens. Sail batten would be ideal but no local dealer and can't send the length required by post. Settled for uPVC 40mm cloaking strip in the end but it may be a bit too soft. We'll see. Point North in Holyhead and Pennine Outdoor nr. Lancaster can supply anything you need. Ordinary machine quite ok, use denim needle and be sure and use UV resistant thread otherwise all the good work may come to nought......!

Good luck

Sparkie
 
I found the GRP batens in my Kemp stackpack were far tii floppy. Replaced with 25mm plastic conduit with much better results. It now behaves a bit like a Gladstone bag, if you know what I mean, with the battens helping to gather it all in when closing the zip.
I have made a few improvements, like adding webbing down to the boom to reinforce the lazyjack attachments in the canvas, and picked up on the battens. The original zip canvas soon rotted out, so I replaced and ensured it was covered by flaps of the canvas cover to better protect from the elements. I added velcro to the aft end opening as sunlight was getting in and starting to attack the clow.
I plan to remodel cover to try and extend it all the way to mast and avoid need for the seperate bonnet/coat (or have I missed a good reason why its needed?). This can take almost as long to fit as a sail cover - seems like its not really a complete solution otherwise!
 
Hi Surfer, interesting. 25mm conduit, do you mean the rectangular electrical uPVC or something else? I have incorporated webbing straps too that go under the boom to take the weight at the LJ attachment points, which are alu D-rings, the straps have snap buckles to adjust as required, and are seized onto the batten pocket.

I was thinking of a strip to cover the zip, and your comments re. zip rot are v.interesting, also the need to cover the clew. Will think about those some more, haven't had chance to try the thing in anger yet, as masts down for winter.

I agree the mast boot is a nuisance, quite difficult to size from scratch too, but with sail slides fitted I couldn't see an alternative. Perhaps with a luff bolt rope instead it would be possible to slightly enlarge the bag at the mast end, but it would still leave a lot of fabric to blow about when sail in use? My boot has webbing straps with velcro fastenings so I'm hoping won't be too much trouble to put on.

Safe sailing

Sparkie
 
Regarding the conduit - its standard circular cross section, slipped in the usual canvas pockets that I have now moved closer to the top zip to reduce water ponding on the top.

My thoughts on eliminating the mast coat were to extend the canvas all the way forward of the mast with either a zip or sew on hook/loops or snap buckles to join the 2 sides at fwd face of mast. Probably leave them joined but design plenty of volume for the flaked luff bunching up. I think I've seen domething like this on pics of charter boats abroad. It may need a simple elastic tie down when under sail, but may just find its own place and be partly helped with the battens.
 
If you get it to work it I'm sure it would be of interest to myself and others and it would be good to put a couple of photos on the forum.
 
[ QUOTE ]
Does one use a normal sewing machine for this operation?
Is it heavy duty enough?

[/ QUOTE ]

Apparently old Singer machines are ok. Lots of info on sewing machines on this form. Suggest google, i.e. <site:ybw.com "sewing machine">.

I bought a second hand Brother industrial on ebay. There are loads about but they require lots of room.
 
A good tip from the man in our local sewing machine shop is to use leather needles for sewing canvas. They are robust and extremely sharp, helping out home sewing machines.
 
I use an old (c.1970) domestic Brother and it's fine for acrylic canvas up to 4 thicknesses. Use a denim needle myself, it does the job, never tried leather needles, could be better still. Keep machine (and operator) well oiled.
 
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