Monday, July 11, 2016

Glassing The Ribs

Riding the momentum of getting the ribs installed, I was able to start glassing over them as well.  I'm just shy of half way through this phase at the moment.  Many nights were spent while falling asleep trying to figure out how best to wrap the cloth smoothly on those bends.  I think this is where vacuum bagging would be nice, but I'm not equipped for that kind of thing so I needed a lower-tech approach.

The small ribs had a larger radius on both sides, so I was able to massage the cloth into shape and then trim it even.  The fit ended up perfect, and I'm really pleased with the result.

The inboard ends of the ribs along the centerboard trunk were cut off square with an approximately 1/2" round over that proved a bit more difficult.  I ended up slicing it down the center and wrapping.  It worked OK on one, and got rough on another.  I may just sand the rough spot and add a small layer to cover it.  The structural element is really my concern here, but having the top open to the weather allows water inside the piece, and will encourage expansion and contraction of the cedar.  A good laminate will better seal it, and extend its life.

Despite my best efforts I had a few spots which I couldn't seem to keep firmly pressed against the wood, visible in the above picture as being lighter colored.  I kept brushing resin into them, but it didn't seem to work.  I think the 8oz cloth is just a bit stiffer than the 6oz which seems lie flatter.  I suspect this will go away if I add a second layer, which I'm still debating.

Which leads me to the laminating schedule.  The original ribs I removed seemed like about 3 layers of 8oz cloth in thickness.  Possibly two.  Definitely thicker than the single layer I have on now.  The other observation I made was that the ribs appeared to not be bonded to the hull, and definitely had no fillet, so the laminate was all that was holding it.  I used a much stronger bonding approach, which would reduce the laminate's structural responsibilities.  I've also observed a bunch of Lightnings who had a single layer of 6oz cloth over the ribs, certainly less than what I've got now.  So what to do?

I suspect that structurally the single layer I've installed is sufficient to the task at hand, and after checking with the Classic Lightning Yahoo Group my suspicion was confirmed.  It sounds like the glass is really optional for a properly bonded rib.  At this point I plan to make sure I've got good coverage on the 8oz cloth, clean the blush off, and give it one more light resin coating to help fill the texture and ensure full moisture blockage.  We'll stick with one layer of 8oz cloth.

Sunday, July 10, 2016

Ribs Are In!

I made some great progress over the last week with installing 10242's new ribs.  I rough-cut them to a template made from the original ribs, but discovered that there was some variation in their match to the boat's profile.  With a bit of custom sanding on each I was able to get them within 1/16" on average, which should mean less glue and a better joint.

After spreading neat-epoxy on the hull (traced the outline of the rib first) and the bottom of the cedar rib, I placed about 1/8" of epoxy thickened with colloidal silica along the edge.  Thickening was just enough so that it didn't run when a glob is pulled out.  Somewhere around ketchup consistency, maybe a bit thicker.  I then pressed them into their original positions which were still very easy to discern on the hull.  The oozed epoxy was then used along with some extra to make a perfect 1/2" fillet with the back of the West System plastic spreader paddle.  That 1/2" radius is important because any less will cause the fiberglass cloth to lift, weakening the laminate.

The results were great, and all pieces are now in place.  The mast sitting on-deck in this picture isn't centered and makes things look asymmetric, but rest assured I measured twice and glued once.

The next phase will be glassing over the ribs to protect them from damage and further stiffen these structural members.

Friday, July 1, 2016

New Ribs Fabricated

After a way-too-long sabbatical from Lightning work, I finally finished fabricating new ribs for Anyela.  They are made from 5/4 western red cedar planed down slightly to match the original boards.

After removing the failed fiberglass laminate, I traced the original ribs, then cut templates from cardboard, and laid them out on the fresh lumber.  A jigsaw was used to cut the pieces out.  The pieces were then gang-sanded on a belt sander, and drum sander until more or less even.  My last step was to hit them with a 1/2" round-over bit on the router table.  This will allow the fiberglass cloth to have a nice surface to adhere to without the sharp corners which create pockets in the laminate.

My next step will be to thoroughly clean the hull that's been sitting for a while, wipe down with acetone, and then start bonding these ribs are right-angles to the centerboard.  I'll put in a 1/2" fillet at the base, which would have gone a long way towards durability on the original ribs.  Finally, I will cover them with a layer of 6 ounce fiberglass cloth.

I wish I could capture the smell of my barn in words...  Cutting cedar is a real sensory treat!

Where You Been, Man?

So yes, I dropped off the face of the Earth for a bit.  When we purchased #10242 I sailed a 1977 CS27 called Ravat which I'd just completed a 3 year refit project on.  The boat was essentially done, and required very little time other than, well, sailing!  Unexpectedly, my wife caught the sailing bug and decided that she wanted a boat with bigger side decks and more living space below decks.  We ended up selling Ravat, and purchasing a gorgeous Beneteau First 310.

As with just about any new boat, even the ones in excellent condition take some time to get into the sort of shape and configuration that you want.  I've been really busy doing just that, as well as keeping her pretty busy with a 30+ race per year schedule.  This has cut into my Lightning time.

The good news is, I'm pretty deep into this new boat's to-do list, and am starting to get some time back to return to Anyela.  Hoping to have some progress to report shortly as I get back into nibbling off pieces of the Lightning project list.