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.

Thursday, October 30, 2014

Transom Delamination Repair

I was just beginning to think that I may be able to get the interior primed this Fall when I discovered yet another project.  The outer skin on the transom has de-laminated from the core due to water ingress.  My suspicion is that winter freeze - thaw cycles did the bulk of the damage.


The plan is to start by sounding the hull to identify the region that has delaminated.  As you can see in the above image, I have completed that step.  I'm hoping this is the extent of the damaged area, as the taps went quickly to a dull thud in that area.

I will use my oscillating saw to to cut the interior laminate out, trying to keep things in an easily cut series of rectangles.  The core will be replaced using 1/2" Divinycell foam core, laid up with West System Epoxy.  I will then add a layer of 6 oz. cloth to re-establish the interior laminate.

I began by removing the hardware so I have a clean area to work in.  It is clear that this boat wasn't assembled with sealant anywhere, nor were any of the hardware mounts properly potted with high density filler to avoid compression damage.  The thin skins of this Lightning are great for light weight, but it really mandates proper potting for long-term durability.

The other problem I am seeing is use of plywood for backing blocks, but inadequate sealing of the wood.  To use plywood you need to either seal it in epoxy (preferably) or varnish of some kind.  The upper gudgeon's external block can be salvaged, but my preference is to replace it with a GRP block that's immune to degradation (once painted).  The interior block is rotted, and will need to be ground out and replaced with a new GRP block.  The lower gudgeon's interior mounting block is still in good shape (surprise!).  I plan to sand it, then seal with epoxy and a layer of cloth for protection.

While I'm fussing with the transom, I'm also going to properly pot the transom flap openings in order to better seal them against future water damage.  I would like to cover them with a 6-oz cloth layer as well, but that would require a radius on the openings that may not be feasible.  I need some more time to ponder how that might work.

Stay tuned... More to come!

Thursday, September 11, 2014

The Bow is Back

I know I said I wasn't going to do this, but...  I changed my mind...

After speaking with a friend about the bow, he guilted...  I mean, talked... me into making a better long term decision.  While I really didn't want to do this project, I know it's the right thing to do given that this boat will be bashing through Lake Ontario weather on a regular basis.

So, I whipped out my trusted Harbor Freight oscillating tool and made some incisions.  I used a small pry-bar and a hammer to gently tap and pry the top laminate and inner foam out.  It's a good thing my friend talked some sense into me, because the area I thought was about 16" back from the bow turned out to be the entire bow from the tip to the mast compression post.  Much worse than I'd hoped.

The foam was not properly laminated, and had split in many places.  A prior owner had "repaired" this by injecting copious amounts of resin throughout the bow.  They had also laminated nearly 3/16" of resin on the top of it all in some places.  By the time I removed all the foam, I was left with some significant resin pools that had to be removed with an angle grinder and 60 grit disc.  That was no fun inside the tight quarters of that bow.

Eventually I cleaned it all out, removed the dust and took measurements.  I then ordered one large sheet of 1/2" Divinycell foam from Jamestown Distributors, which is enough to do the entire bow if opposing triangles are cut properly.

I did some minor fairing using epoxy thickened with colloidal silica prior to laying up the foam.  I didn't want any significant gaps if it could be avoided.  While colloidal silica is a bear to sand, it's very strong, so makes a good foundation.  With careful use of the spreader I was able to minimize my final sanding efforts.  After a wash down to remove blush final sanding was completed with a 6" RO sander that has nice dust collection ability.  The 60-grit disc should provide plenty of tooth for adhesion to the foam.

Last step was to wet out the bow and foam with neat epoxy and a spreader, then mix up a pretty significant batch of epoxy thickened with colloidal silica.  I actually did this in about 6 batches because it was a hot day and I didn't want it to kick off too early.  Each batch was spread out with a notched spreader for even distribution until the whole area was covered.  I carefully put the new core in place, and pushed down on it to set in place.  The last step was laying some scrap wood battens into place to distribute the load, and then laying some sand bags on top to ensure proper form.

Next steps will be to inject thickened epoxy into any remaining voids between the foam and the existing border, and fair that transition.  Once the transition looks good, I will apply the top laminate of 2 layers of 6oz. fiberglass cloth throughout.  That should conclude the bow core repairs...  Stay tuned!

Wednesday, August 27, 2014

To Bow Or Not to Bow?

After I cleared all of the leaves and leaking water jugs (buoyancy bags) out of the bow, and gave it a good scrubbing it became quickly apparent to me that someone had done some major fiberglass work in there at some point. I suspect it was replacing core, as little else would really justify the scope of their repair.

The glass work on the prior  repair was very poor.  It was not done with epoxy, or if it was, it sure isn't the epoxy I work with.  The cloth had wrinkles all over, showing either a lack of preparation in properly trimming the patch, or a lack of care in installing it.  These wrinkles trap air, dirt, and become weak points.  With that in mind, I decided that I would hit them with an aggressive grinder to knock down the high spots and open any air pockets in the laminate.  I could then either fill them or lay in some patches depending on the size and depth.  I could then throw a quick and dirty fairing job at it to clean up the worst cases prior to painting.

As I crawled into the bow, prepared to work in a small encapsulated swirling fiberglass dust tornado, I noticed something that made me cringe a bit.  Visible, although subtle, flexing in the bilge.  It's an area about 12 inches wide and 16 inches long, tapering near the bow on the starboard side.  I can flex it about 1/8", which is 1/8" more than I'd like.

Since it's an area that's never visible, it's pretty easy to do some exploratory probing and clean it up without cosmetic impact, so I cut out a section of the bilge, thinking it would come right up.  It did not.  Even after prying on it.  Giving it a bit more thought, I decided that a small area with a narrow span at the bow is probably going to be fine, at least for a year or two.  I ground a quick 2" bevel into the cuts I'd made, filled the bottom of the cut with colloidal silica, and then laid in glass strips to repair the cuts.

With the cuts repaired, I threw a sheet of cloth over the entire area to give it a bit more rigidity, and to help fair the awful surface left by the prior glass work.  It made a big difference, and once painted it will look great.

I have so many projects to do right now that I just don't need to work on anything that's not necessary.  After everything else is done and I've had some sailing time I can make a Spring or Fall project out of laying in new core in the bow bilge.  For now, it's back to the critical path and my tight grip on scope creep.