Outhaul cylinder surprises

Thu 6 May, HHN day 23: Outhaul cylinder finally submits to Captain, but then find the seal kit from Selden has incorrect components. Also, boom travels to welding shop.

Glorious day today, as forecast. Clear skies and perfect cool spring temperatures after the tropical unpleasantness of yesterday. Determined to finish the outhaul piston seal change today, I’m out removing the cylinder end fitting and draining the oil by 8am. Almost 2 gallons of it! No wonder the damn thing weighs so much.
With the end fitting slid off the rod, next is to pull the piston out of the cylinder. But it won’t budge, not even one mm. I had to screw the sheave carriage back on the end of the rod so I have something to pull on, while my feet and legs push against the cylinder (you can imagine the pose). Ray arrives the very moment the piston suddenly decides to give up this tug-of-war and I roll backwards in the gravel… the piston clearly thinks it’s a huge joke! The sight amused Ray too.

Once the piston had made its initial movement, it now comes out easily, especially with 2 of us on the job. It’s amazing just how long this piston rod is. And to think it is fully extended most of the time, when the mainsail is furled away in the mast.
We can now take a look at the condition of the seals. The wiper seal, which is fully exposed to the elements, is perished, but all the other seals that have been inside, in the oil, seem perfect. And I suddenly feel a bit silly having taken the whole thing apart. But wait …

On closer inspection, the main rubber seal on the outside of the piston shows some wear and is stiff. Certainly time to change that one. On the outhaul cylinder end fitting, the external static seals (that get no movement) are fine. But internally, where the piston rod goes back-and-forth through the end fitting, things are not so good.
The wiper seal failure has let moisture inside, and the main internal seal it clearly also just about to fail. There is rust all around it. If this had failed then moisture would have entered the cylinder and done all sorts of damage, not to mention leaking hydraulic oil raining down from the boom. So now I’m happier. It WAS the right time to do this. So let’s get on with it.

Removing the old wiper seal is a challenge as usual. And cleaning up the corrosion around the internal seal not very easy either. A Dremel wire brush does the trick. But now the problem: I open the seal replacement kit from Selden to find it both incomplete and 2 seals the wrong size.
The 6 seals for the piston end are fine, and I get them changed OK. But on the end fitting the outer seals are clearly the wrong size and the internal guide rings are absent from the kit. Hmmm. Looks like I won’t be completing this today after all.
And while my passion is high, I fire off an email to Mr. Selden in Sweden, via HR-Parts. Let’s see what they have to say for themselves. One thing is for sure, they won’t be replying for days or even weeks. They never do (Selden that is).

With the piston end seals changed, I decide to at least get that and the rod back into the outhaul cylinder. With the new seal, the damned thing needs some serious “persuading” to go in the first few millimeters. I try various sizes of knockometers right up to a 1 metre length of 4-by-2 timber. Eventually, I rig up our 4-to-1 block and tackle we use to hoist the outboard from rail to dinghy, and manage to haul it in that way. You just gotta think outside the box sometime, to get things done.

Well, only half a job done, unfortunately. However, right now I don’t have a boom to put back into anyway.
Before Ray left this morning, we took the boom for a trip down to the welding shop, using East Coast Marine Rigging’s dolly with me sitting on the tailgate of Ray’s pickup pulling the boom. One of those “accident about to happen” set ups. But we managed OK with no incidents.
Why the welding shop? We now have 2 sets of elongated holes where the vang fitting goes onto the boom, due to the huge force this powerful vang applies to the rig. The welder will fill the holes, which will allow me to re-drill and re-tap just one set. Been wanting to do this for a couple of years now.

That was my day. Not so fruitful as previous days, but you can’t win them all. Most days are 2 steps forward, 1 step back, and this summarises today.
And I am now exactly half way through this maintenance period. 3 weeks done. 3 weeks to go. I’d better get crackin’!