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acreew

Finding centerline of mast/attaching hardware to masts

10 posts in this topic

Hello All,

Any pearls for finding the centerline of the mast (CS 17) for installing sail track. Also, any insights into sequence, process, pitfalls, etc. of attaching hardware on mast would be appreciated. Also any thoughts on painting vs. not painting.

 

thank you very much,

Will

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I strung a chalk line from tip to base, then lightly marked its placement with a sharpie.  It is reasonably straight with no hangups either hoisting or dropping.  Luff looks fine.  sharpie comes off with denatured alcohol.  

 

I painted my masts with Rustoleum aluminum spray paint.  I am not pleased with the results as it still peels off way too easily.  PAR had a thread on this if I remember correctly.  You need to scrub the aluminum with steel wool or the equivalent, and then prime immediately prior to painting.  I will redo it in a few years.  I think that the most important thing to remember when working with the aluminum spars is that they are not anodized, and will crumble in a salt environment if water can enter and sit inside the aluminum.  coating with a thin coat of epoxy in and out may have some good benefits here.  

 

 

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Make up a jig like this out of scrap. Angle it so the two legs contact the mast and the pencil will be on top of the mast. Move it down the mast, keeping it level.

Sorry about the lousy sketch in MS Paint

Mast Jig.jpg

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I zip tied the track to the mast, made adjustments until it was straight, then used a sharpie to mark the holes.

 

Fastened the track with stainless steel rivets. A good source is boltdepot.com.  They are reasonable, fast, and you can buy any amount. I dipped the rivets in 3m 5200 to try to keep a barrier between the stainless and the aluminum. I also laid the track down on a bead of 5200.

Pay attention to deburring the track, rounding the corners on the ends, and getting excess caulk off.

 

I primed the masts with a bright yellow spray, name of zirconium oxide (?). It is common at hardware stores. Then painted with enamel. I didn't paint the section that went down the support tube. The paint is not the best and there are some wear marks.

 

I attached the hardware with stainless steel bolts, using a long stick with a gob of caulk to hold the nut. Then the edge of the stick against the nut to hold it while tightening. There is a description by roguepaddler somewhere on this site. In some cases I used rivets.

 

Remember to put a cap on the top of each mast. Water could get in during a capsize.

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I set this jig up on either end so that my line did not wander, put a small kerf in the tube at the plumb mark either end then strung a piece of mason line.

 

I used PPG self etching primer and sprayed with rustoleum, 4 sailing seasons and it seems to be sticking (I need to put some leathers on my sprits to stop wearing paint at that junction)

 

Hope that helps

 

Sorry pictures are in reverse order. There are more pictures in my build pics in the signature link below.

 

Jim

IMG_20111218_142325.jpg

IMG_20111218_132512.jpg

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I used a chalkline for the initial lineup, but then put the sail track out and eyeballed it straight, held it in place with clamps, drilled/screwed a few holes, unclamped, re-eyeballed, re-clamped, drilled a few more.  I found the track could tend to wander as I was drilling holes if I did not stop and re-align and reclamp every so often.  There are still a few variances from dead straight, but no more than 1/16 inch or show.  It shows up looking down the length of the mast, but I don't think it will make any difference to either hoisting or setting the sail. 

 

I used #6 stainless pan head sheet metal screws.  I got that idea somewhere, can't quite remember where, but I think it was from the sail track specs.  I drilled the smallest hole possible, and then essentially self-tapped the screw in.  I could use a smaller hole if I drove the screw with the power driver, set on high torque, than I could driving by hand.  You need to use care, of course, or you'll end up with a half-driven screw and a busted head or a ground-out phillips slot.   I used a slightly larger hole in the thicker aluminum in the lowest mast section, then smaller holes in the lighter aluminum aloft. 

 

I laid the track on a layer of plastic tape, and I dipped each screw in sealant before driving. 

 

Each 69" section of track took me at least an hour to install.  as someone mentioned, I paid special attention to making sure the track ends match at joints.  I'm curious to see how the sails will hoist; may need to do some addl smoothing.  This is the old traditional Schaefer flat track, not the new B&B track.

 

I have the luxury of sailing almost exclusively on fresh water (nearest salt 1,000 mi away) so did not paint the entire mast.  I painted only the areas around the fiberglass ramps and collars.  (Color coded so I can tell main from mizzen at a glance; sprits with a color band to match.)  If I find somehow that I will be on salt water, I'll explore priming and painting.  I used the delrin caps that B&B provides, they're slick.

 

For other hardware such as cleats and straps, I used s.s. #10 pan head or flat head sheet metal screws where no access is available (middle of mast) and 10-24 machine screws with locknuts where it's possible to get in back to put a wrench on the nut.  Most of that is shown on the plans.  Also used tape and sealant to try to seal the hole and isolate the stainless.

 

I base this in part on using similar methods on aluminum mast on the big boat with good results, again in fresh water.

 

Finally, for the little "keeper" at the bottom of the sail track, I tapped a 10-24 hole (#25 drill) and will use a ss machine screw, with locktite.  Seems to be what the plans want.

 

Edit:  I uploaded this picture, linking it showed more than it does.  Here I have the mizzen, with its track, in the main step, and I'm using the partially assembled main to help position the foot of the mizzen step.  So, picture doesn't really have anything to do with the question at issue, but I couldn't find a way to delete it.

 

 

 

Spars up.jpg

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I aligned a laser level along the edge of the lower tube, then slid the laser over to a pre-marked centerline. Marking top and bottom of the mast would have worked as well I'd guess, connecting the dots with a laser.

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Thank everyone for the very detailed responses...got the centerline and will be painting the masts. 

 

Tonight got the idea to use epoxy thickened with micro balloons to fill in gap at joint of the mast around the entire circumference instead of using the fiberglass wedge. I have done only one joint and then began to have doubts.... is this a stupid thing to do.? Will the epoxy crack with movement of the mast? Any other reasons why this won't work?

 

anyway... hoping for a reply tonight if I need to undo it.... thanks in advance.

 

will

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Acreew,

I used thickened epoxy to fair the circumference of the joint between sections. It created a "shoulder" for the wider section to butt up against. After one season no problems. 

 

However, the gap under the mast track, which can be filled with a wedge, extends beyond the area I filled with epoxy.  When bedding the track in 5200 I  just used extra caulk to fill the remaining gap. When installing rivets I skipped a few holes until the caulk hardened then went back and added them. No fiberglass wedge.

 

I hope this helps.

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Thanks beacher.... good to know it worked out... thanks again for the fast response

 

will

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