Mast sealing

Somehow my mast seems to have taken on water over the winter. Sounds like a gallon or two in there. Lucky it didn't freeze and crack the extrusion (at least not anywhere I can see). Quite a lot of water, definitely wasn't in there last time I stepped the mast (I would've heard it). Kinda concerning, but I can't see where it came from, and it's not leaking out anywhere when I rotate/tip the mast. I've got the rivets and rivet caps, and I'm planning on just drilling out the rivets in the mast base, pulling that out to drain the water, then riveting it back in. Does anyone know if there was any sealant used when first assembling these? I'll have to submerge the mast to find the leaks, but for now I just want to drain the water. Once I find the leaks, should I just re-rivet, or might I need a sealant? Original mast, no comp tip.

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Mike

'79 H18 standard 'Rocketman II' sail #14921 RIP
'78 H18 (unnamed) sail #14921
'08 H16 sail #114312
'97 H21SC sail #238

Mine has a rubber plug at bottom of mast near the faIrlead where the luff goes through , that is if it is still on, most have been removed . The previous owner may have drilled hole and put plug in. or drill out rivet on fairLead

It's unlikely that pulling out the mast base is going to allow the water to drain. There is a foam plug in the mast about a foot up from the bottom (I believe the rotator bolt passes through this plug). So if the water is in the main body of the mast, it will still be trapped by the lower plug even if you remove the mast base. Same goes for the top of the mast, there is a foam plug up there below the mast head casting. If your boat has a comptip, then there are additional plugs in the mast because the comptip is a separate sealed section. You would need to identify exactly where the water is trapped before starting to pull things apart.

If the water is in the main section of the aluminum extrusion, then I would remove the fitting for the mainsail feeder. This is the easiest fitting to remove since it is just two screws (unlike most of the other fittings which are riveted on). See if you can get the water to drain out through the holes for the feeder. You may have to experiment with tilting the mast at the right angle to get the water to drain. Another option would be to drill a small hole right above the foam plug to let the water drain and then plug the hole with a machine screw or a rivet.

If you still can't get the water out, then you would need to start removing the castings and the plugs, but that is going to be a lot of work.

sm

Did H18 masts always have a sail feeder? Mine is a 1979 vintage, and I don't believe it has a screwed on fitting for feeding the sail, it's just an "opening" in the extrusion where the luff track is wider. No comp tip. When the mast is tipped, it sounds like the water runs all the way to the mast head, but maybe I just can't tell that it's stopping short of the plug. I'll take another look at the "sail feeder" this evening. I'm not overly fond of drilling a new hole in my mast, though it sounds like that may be the best way to drain it.

You would know if you had a sail feeder. I believe the older boats didn't have them. A 3/16" diameter hole in the mast is no big deal, it's the same size as any other rivet hole. I would put it right on the centerline of the front of the mast. Drill and tap for a 10-24 machine screw and put the screw in with a dab of caulk. That way if you notice water in the mast again, you can just pop out the screw, drain, and re-install.

sm

Definitely no sail feeder. I didn't get a chance to drill before heading to the madcatter this weekend, so I just left it alone. After stepping the mast, I found a slow but continuous leak out of the through bolt hole/tube for the diamond wires and mast rotator. After the weekend, it seems most (if not all) the water drained back out. Any thoughts on how to seal it? Not sure if I should still try to drill a drainage hole... if the bolt goes through the plug, then water seems to be leaking past/through it. If the plug is just below the bolt, then the mast is probably fully drained. If it's a little further below the bolt, I'm not sure what height up the mast to drill the hole.

Any more thoughts on sealing around the rotator bolt? I'm thinking I may need to buy a new foam plug, maybe this one is toast after so many years?

Randii

randii, I haven't gotten any further into this issue. I take it yours is leaking as well?

I'll have to pull out the through bolt and take a look. I might just try and dab some marine sealant/silicone in the sleeve and hope that it seals. I'll have to tip my mast a bit and see if there's still any water left in it after I left it stepped to drain, to figure out if I need to drill a drain hole or anything.

I'll definitely need to figure it out before winter though, or store my mast differently so I don't have to worry about water freezing/expanding in the mast and cracking the extrusion.

Yes. On my comp-tip mast and my all-aluminum mast.

<aside>
I am reconditioning an all-aluminum mast, and had some leakage at the masthead cap and between the mast and SS ring-catcher. I popped them both off and did a lot of cleanup... I had several issues:
- the foam piece inside the mast had cocked in the bore (compressed only on the rivet sides)
- the aluminum plate was akew
- corrosion between the SS ring-catcher and the aluminum mast had pitted the mast
- one of the rivet holes was nearly torn out (perhaps because of the pitting)
After a lot of cleanup (way too much silly-cone had been expended in the area, a previous owner may have used a caulking gun to fill?):
- I used 3M 5200 sealant to build up a small shelf inside the mast to backstop the foam
- inserted the foam plug
- put a bead of 5200 around the inside of the mast between the foam and the plate
- inserted the aluminum plate
- put a bead of 5200 around the inside of the mast sealing the plate
- cut multiple layers of polyethlyene foam to fit inside the masthead and keep the stack (masthead, poly, plate, foam) evenly compressed
- tapped the masthead in
I know I pulled more stuff out than I put back in, and it should be less weight at the tippy-top of the mast.
</aside>

I am in the process of epoxying the pitting, and will sand that back fair and then seat the ring-catcher with more 5200 as a sealant, barrier, then redrill and re-rivet with rivet casings. I put a low-profile aluminum valve stem up top and drilled a narrow air hole through the valve stem (with the core removed) and then through the foam and plate, and I can now pressurize the mast slightly and soap-bubble test the other fittings without needing to submerge the mast to check for bubbles.

Much leakage occurred at the mast rotator bolt. I have thrown several solutions at it at once (unintentional result: I'll never know what actually worked!), and I'm unsure of the result until after finishing up the ring-catcher sealing/attachment. My spacer seemed a little short, so I have o-ringed it on either side. With creative goopery, I managed to do a pretty thorough coating of 5200 inside the mast, along the bolt hole through the foam block. I seated the O-rings in 5200, then did a small bead on top of them, and sandwiched it all flat with a couple of 1/4" nylon fender washers, with the diamond-wire keepers on either side, held fast by the through-bolt.

If none of these work, then I'll pull out the foam and metal plate and try with new foam and a lot of cleanup -- the same caulking-gun style approach appears to have been used here as was used the the PO at the masthead.

Randii

Update -- the all-aluminum mast is water-tight now, and pressure-tested to >5psi (I didn't go past that).

After the above, I had a tiny leak between the ring catcher and the mast. I pulled a slight vacuum on the sealed mast through the valve stem I added, and put a small bead of 3M 5200 along the bottom of the ring catcher alongside the mast. I can see a slight dimple in that bead when I look close, and it matches where the bubbles were exiting. Simple fix.

I drilled for a masthead eye strap for a spinnaker halyard and a mast base eye strap. I used rivet caps and a dab of 3200 at the masthead (they sealed up nice) but not at the base, as I wrongly imagined the mast would be sealed at the foam block through which the mast rotator bolt inserts. I should have drilled the rivet out and re-popped another with a casing, but instead, I did the vacuum/5200 trick detailed above, and will look to changing out that rivet and adding a cap when I redo the mast rotator foam, at a later date.

My 5200-intensive solution to the leaking at the mast rotator bolt works for now, perhaps with the belt-and-suspenders support of adding O-rings. We'll see how that all holds up, the mast rotator pivots on the through bolt and sees various directional forces as the mast steps or as the boom moves whilst sailing.

For now, I'm done sealing and need to re-commence sailing!

Randii

Glad your mast is all sealed up, randii! So you just coated the mast rotator sleeve with 5200 sealant? I'm thinking of doing the same with mine, probably put it on the end of a zip-tie and use that to coat the inside of the sleeve.

Installing a spinnaker? Sounds like a blast! id love to try it, but I think I have other priorities for the time being, and my trailer setup time is long enough as it is

Yeah, I put some 5200 on the outside of the sleeve hoping to seal any leaking between the foam and the spacer and to hold it in place... but that's not what I think causes the majority of the leakage. The air comes out right alongside the 1/4" through-bolt, and I used an O-ring on either side which sits outside the sleeve and in the depression formed by the end of the sleeve, the outside of the through-bolt, and the inside of the mast wall (and the riveted reinforcement plates). That O-ring is then sandwiched in by a nylon fender washer on each side, and the whole shebang is compressed together by the through-bolt, squeezing together the ends of the rotator and diamond wires.
I suspect it would have been waterproof just like that, but I put a small bead of 5200 around each O-ring nonetheless, so the mast is goo-ed to the fender washers with the O-ring goo-ed in the gap between the spacer tube, the nylon washer, the inner diameter of the mast and reinforcement plate, and the outer diameter of the through-bolt. The 5200 has set up nicely, and none of that moves relative to anything else, but the mast rotator still has sufficient swing up/down within the lower terminal ends of the diamond wires.


Haven't tried it yet, will save it for light wind entertainment. Right now, I agree -- getting off the trailer and onto the water is the priority and I'm choosing better wind days! It has been a good season thus far in Northern California... summer will find me bobbing around with limited wind on local lakes (playing with a spinny, perhaps?) or driving further to get to good wind in the mountains or near Rio Vista.

Randii