The third dimension

Truth be told, it’s been a very painful boat year since we broke the mast. Ravenswing sits at her dock looking long and wide, but NOT vertical. We chose a mast builder and made a purchase agreement within two months of dismasting, but the company got backed up on orders and delayed our build about nine months. I almost pulled the plug, but stayed with Composite Engineering because of the strong, fast, beautifully crafted masts on Skateaway and Round Midnight. These big ocean racing tris have had great success with their CE masts, and we expect the same. And so, on the one year anniversary of our crash, the new mast finally got started. The fiber layup is finishing now, and the resin infusion is to happen this week or next.

Back in June Keith and I went to visit CE to shake the trees a bit, and I needed to see the process given all the delays. I came away impressed with the product. These photos are “the one just before” ours; it’s actually for an America’s Cup class boom, but using the same carbon weight and braiding setup.

Here’s how they build them:

Start with an aluminum extrusion, coated in a release agent (yes, we could have just settled for an aluminum mast like this 10 months ago :). This is the one our mast will be shaped from.

The blank is placed on a very long shuttle table and run through this large stationary braider. Note the hundreds of spools (creels) of carbon and fine fiberglass (white thread)

The wad of fibers extending past the aluminum blank (mandrill) allows the builders to grab the fiber bundle and hydraulically stretch all the unidirectional carbon out very straight. That’s the key to building strong compression-resistant carbon fiber. But you also need “hoop strength”, ie bands of fibers running around the mast at 90 degrees. For you long time followers, remember we added all that hoop strength to the first mast in 2015(?) by doing the tight spiral wraps. At CE, they’ll add the hoops with the banding braider in yellow here:

Our mast is making about a dozen trips through this braider. Note that all of this is dry fabric, NOT pre-preg. They will remove the mast from the braiding area and then build an epoxy resin infusion vacuum bag around the whole thing. This will squeeze resin in around every fiber of that complex braiding. Immediately after the resin is fully infused, the infusion equipment is put aside and the whole works slides in to this 70′, multi-atmospheres pressure autoclave. The epoxy will be cured somewhere in the 200-300F range (I forget what exact temp he said).

After the baking process, the new spar is ready to have the aluminum mast mandrill pulled out. They have a huge chain-drive table for that, and apparently you say little shop prayers before a fantastic popping sound when the release gives way and the product separates from its mold.

At that point, we have an odd turn of events – CE is so understaffed right now that I’ve agreed to go work for them in September to help finish my own mast. We have to fabricate the crane, the rotation arm, the spreaders, the hounds, etc etc. Everything that makes a bare stick a sailboat mast. We figure that’s a couple of weeks.

The push is really on now to get Ravenswing ocean ready for this fall. I’ll try to get back in to frequent, shorter posts as all this work heats up.

We do have one nice thing done: shore boats. After fixing up the Portabote, we decided it didn’t cut the mustard for our uses. So thanks to Drew, we copycatted and got a Takacat 340 Sport like his. It’s a catamaran inflatable, extremely stable and with the 9.9hp, this thing rocks!

You all just heard Jimbo’s big sigh of relief. (Portabote sold)

The first video link shows the first run, and it gets amusing with the engine mounting not yet tweaked.

And we’ll sign off tonight from the other shoreboat, the SUP that at some point we’ll actually try to paddle surf. Stephane says he’ll show me what he learned from the Costa Rican teacher babe :)

4 thoughts on “The third dimension

  1. Nice dink. I just got a Saturn Kabote.. it’s a 14’ long narrow inflatable which planes with 2hp, Tracks/tows great behind 18’ Potter ReGale @ 10 knots. I’ve a friend who is dealer for Thundercats….with a 50hp I got crap scared out of me. 10hp is plenty! Hope to see you around. Goose


  2. One of my favorite books was “Two Years Before the MAST”. MAYBE YOU SHOULD WRITE A BOOK “TWO YEARS BEFORE MY MAST WAS BUILT”
    Rick H


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s