Wednesday, April 26, 2017

Odds and Ends

I'm marching toward getting the hull prepped for a primer coat and there are a ton of little details that have to be taken care of before I get there.  The big thing is spot filling and fairing any anomalies that will look bad once painted if I don't deal with them.  Ideally, when the hull is finished I hope to have a pretty clean looking hull with no cloth print through and no tape 'bulges' along the seams.

All of this makes for plenty of idle time because each batch of epoxy I make up takes a good day to be ready for sanding.  It takes 15 minutes to apply and then you wait. I've gone through several rounds now and I think I'm pretty close to being able to do the fill coat, which should take care of the cloth weave that is currently on the hull.  After that, there will be more spots that I missed and I'm considering applying a 'scratch' coat to the hull before actually priming.

Bonded, filleted, and taped, but pre-fairing compound.
A scratch coat is basically a throw away coat of paint that you apply to the hull to make a uniform color and will help highlight any imperfections. I'm not sure if this is a real term, but I'm making it one now and whatever it's called, I know that I'm not the only one who uses it.  The problem with spotting imperfections now is that the hull color is so mottled it is hard to actually see the surface texture.  I'll get a can of grey spray paint once the fill coat is done and throw it on to see what I've missed.

I have been trying to make the most of my idle time though and took care of a few things that needed to be done.  The first was to fit and mount the skeg.  I had some nice 5/4 Honduras mahogany stock that I cut down to size by scribing the hull curve on and trimming to the transom angle.  This was a four step process where I initially epoxied it in place, then waited till that kicked (not full cure), then filleted a ~10 mm radius along either side.  I left that until it was still a bit green but no longer sticky and applied a layer of 50 mm tape on the filleted sides.  Finally, I waited until that was cured enough to sand and knocked off the woven edges of the tape before applying a layer of fairing compound.  I still have to radius the edges at some point, but that will be just before paint.

The second item I knocked off the list was to clean up the bottom of the outwales.  These had a combination of drips, glops, and edges of the sheathing cloth from previous work on the hull.  They always seem to catch all the gunk that drops and then I forget to clean them up when they are still wet, making more work for me.  This took way longer that I thought and used a combination of a heat gun and sandpaper to get all the crap off.  Tedious is the word for this job.  I finished up by running a small fillet along the hull intersection and filling any imperfections between the edge of the cloth and the outwale.





Sunday, April 23, 2017

Sheathed

The process of sheathing, or any large lamination with cloth is not a difficult one, but you have to plan ahead or you'll find yourself making a huge mess of things.  Having done some pretty large layups in the past, I've learned a few things the hard way and I was determined to not repeat those mistakes again.

The first lesson that I've learned is something that I found out while laying up the decks on the Alberg 35 and has nothing to do with process or technique; it's the climate.  When I re-cored the decks of the Alberg, I pulled out the old decks and rebuilt them up with a balsa core, followed by three layers of 1708 biaxial cloth.  Each layer is much thicker than the single 6 oz woven cloth that goes on the Apple, but the same principal applies: When you lay up a section, make sure you have steady or falling temps or you run the risk of getting bubbles trapped underneath the cloth.

Back in 2011, when I did the first section on the Alberg, I started early in the morning and I was pretty proud of myself when I finished. I cleaned up and left it for the day.  I checked in on it that night and was horrified to find a bunch of small bubbles underneath the cloth, and by the time I found them, it was too late. Luckily the area was fairly small and I was able to grind out and fill all the bubbles before continuing, but I called the epoxy distributor (System 3 at the time) and the first thing he asked me was if I did it in the morning before temps warmed up.  I had.

I don't know what the chemical process is that causes this, but from then on I made sure to do laminations later in the afternoon when the temps were falling.  In the new shop, I have a few heaters where I repeat this.  I make sure it is nice and warm when I start and then turn off all heating once I start.  This ensures falling temps and no bubbles.

The other lessons learned are simply a matter of getting everything ready before you add the hardener.  Make sure the cloth is in place and smoothed out, dispense each batch of resin up front before adding in the hardener.  I measured out 3 eight oz batches of resin (it turned out to be a good guess).  Then I double checked that my spreaders and brushes were ready and there was nothing in my way.

Then I mixed in the 4 oz of hardener into the first batch, mixed it up well and then went to work. The 6 oz cloth is nice in that it lays down better and conforms to curves better than heavier weight cloths, but if you just randomly apply epoxy, it will deform and crumple up (making a disaster).  Since I was doing one side at a time (with the center line overlapped about six inches), I started from the highest point, which is the center line and worked down carefully.

I'd pour roughly a 1.5 inch blob along a two foot section and then use the 6" plastic spreader to work it down over the keel strake and to the first two strakes.  I started at the stern and worked forward and then went back to the stern and repeated for strakes three, four, and five.  It all went well, but the last strake (five) was a bit tedious because it is almost vertical and you have to be careful not to use too much or the epoxy just runs down onto the outwale.  All told, it took about 2.5 hours per side and the better part of the last hour was spent working on making sure the glass on strake five was laying down properly.  After I finished the first side, I cleaned up and waited until the next day for it to harden so I could do the next side.

I also spent a few minutes after everything was wetted out to make sure I didn't have a bunch of pooled resin anywhere.  I didn't totally succeed, but all in all it turned out well.  I now have a nice hard shell that I gave a quick sanding to in preparation for the next step where I will fill the weave with a slightly thickened mixture with glass fairing compound.





Sunday, April 16, 2017

Taped

After the first round of seam and hole filling last week, I sanded everything down and did a much smaller fill session to take care of the areas I missed or didn't quite get right the first time. Of course, I had to wait another day to wait for everything to dry and sand this down, so it can be frustrating at times.

At this point in the build, things have started to slow down a bit (compared to the big gains of early on), and I have to multi-task to make sure I keep moving.  With that said, while waiting for the second filler coat to dry, I started building the daggerboard trunk.  I didn't get too far past cutting the 6 mm plywood to the proper dimensions (I had marked out the location and scribed the curve of the hull onto a piece of scrap before I flipped the boat), before I had to break out the epoxy again and put the first of 2 coats on what will be the inside of the trunk.  The second coat will be a layer of 6 oz cloth with a graphite coating.  Then I can start to cut out the bed logs, struts, and end pieces.  I have a few nice pieces of mahogany that will be perfect for the job.

Back to the hull once the filler was cured, I sanded it all down again and was pretty satisfied that I was ready for the next step: tape.  I started with a single seam, mixed up a 3 oz batch of epoxy and 'painted' it on the the length of the hull with a chip brush. Then I took my roll of 7 mm 6 oz cloth tape and rolled it along the seam from the stern forward to the bow, pressing the tape to the wetted out area as I went.  Then I went back with a plastic squeegee and made sure the tape was saturated.

As luck would have it, 3 oz batches of epoxy was the perfect amount for each seam (there are 10 total).  By the last seam, I had the technique down and it only took about 10 minutes.  I cleaned up and called it a day.

This morning I shaped and mounted a piece of mahogany to the bow for the stem with screws and epoxy.  Along with the stem, I also mounted the 25 x 15 mm 'keel' as far aft as the forward part of the daggerboard location.  The weather has been warm and I have been using cold weather hardener, so by late today, everything had cured nicely and I was able to start shaping the stem and keel.

Next up I will be skim coating the hull with fairing compound to keep the tape reasonably hidden once I sheath the hull.  I know I will have to do more fairing after the sheathing, but this will be a good step in making the hull fair.



Tuesday, April 11, 2017

Flipped

We had a family trip to NYC over the weekend to see the play Wicked so boatwork was not an option this past weekend, but before we left I spent a little time rough cleaning the stern lamination and knees I had glued up the night before to see how it turned out. Everything looked pretty good and there were no huge messes to take care of; it was just a simple matter of hitting everything with the sander to get rid of the squeeze out.  I left for the weekend in good spirits.

Fast forward to last night; I enlisted the whole family to come over to the shop to flip the boat. In retrospect I should have brought some beer and celebrated a bit, but logistics have never been my strong suit, so we just got on with it.  With the knees, outwales, and three frames in place the boat has gotten surprisingly rigid, but it's still very light. I'm not sure exactly, but I'd say it's still under 100 pounds, so the flip was uneventful and I had no opportunity to teach my kids salty phrases.

We set it up on blocks and I made sure the hull remained true during the flipping process and then went to town clipping off the 300 zip ties.  The novelty quickly wore off because many of them were partially glued in place when I tabbed the inside, so there were very few that came out easily.  Most I had to clip off flush on the hull and then from the inside (on my back), I would yank them out or break them off with a pair of pliers. It took far too long and I was really glad when it was done.

I did find an annoying mistake while removing the zip ties.  The cradle I used to keep the boat upright had caused a slight depression on the bottom of the hull.  It was only about 3-4 mm over a 2 foot section on the keel strake, but it was definitely noticeable from the right angle.  Unfortunately, the tabbed in frames made it difficult to remove entirely.  I reduced it as much as I could by propping up the center underneath frame 5, but there is still about a 2mm deflection along the keel strake.  I decided that I would correct it with the miracle of epoxy and came to terms with it pretty quickly. The epoxy won't add much weight, and will make the hull fair. It is not noticeable inside the boat. 

After work today, I got right to work with the low angle block plane to get rid of any anomalies between any joints in the strakes.  Other that the low spot on the keel strake everything looked great. I was able to take care of everything in about 30 minutes.  Then I sanded all the joints with 80 grit and mixed up the first of many small batches of thickened epoxy.  Since this portion of the build is not structural (that comes later when glass tape and sheathing is applied to the outside), I used a 50-50 mixture of wood flour and glass spheres to make the fairing a bit easier.  

I started by spreading out a reasonably thick course over the deflected area and then moved on to filling all the seams and holes left from the zip ties.  I also spent some time filling in the partially lapped strakes at the bow.  All told it took about 2 hours.  Tomorrow I'll sand it down and find what I missed and do it all over again (but hopefully not as much).
Zip ties clipped, everything faired and ready to epoxy

Note the filled deflection

It's finally warm again and I can open things up a bit.





Thursday, April 6, 2017

Knees

So even with my screw up yesterday when I somehow cut the starboard outwale too short, I'm pretty pleased with the way it turned out.  The 5 inch piece I fitted on after I got the rest of the piece on is blended pretty well even though it's just butted, not scarphed.  Once it's sanded down it won't be too noticeable (except to me).  The best part of last night's work is that the boat has really stiffened up a lot now that both outwales are on and the curve of the top strake now seems totally fair.

I wanted to pull the boat and flip it today, but it was raining so hard I didn't dare. I'm sure it would be fine since it is BS1088 marine plywood that should have waterproof glue, but I didn't see the point. Instead I decided I would fit the quarter knees and the outboard stern rail (the trim on the back of the boat, not sure what it is called).  I thought it would be quick, but it ended up taking a ridiculously long time to get everything nice and tight.  It was fairly satisfying though, I love shaping wood and a low angle block plane and my shinto rasp are some of my favorite tools for hacking up wood.

I started with the stern rail and the low angle block plane to sneak up on the cambered line and when I was close, I went to the rasp to get the last bit.  Once I was satisfied with the general shape, and that it matched the slight camber of the inner one I moved onto the quarter knees which should also help stiffen up the boat even more once they are glued and screwed into place.

For the knees I found a nice piece of wide Honduras mahogany board and transferred the general angle of the transom to strake intersection onto the soon to be knee.  I oriented the board so that the grain was diagonal across the knee for the best strength and then used a compass and ruler to make the curves that will be exposed inside the boat.

It took a few test fittings to get the initial angle (there are 2 dimensions; fore - aft, and up - down), but eventually it sat perfect in the crook between the strake and the transom.  I cut out the rough inside shape with my band saw, but could cut the tight curves with the blade I have on it right now, so I settled for close, and made multiple passes at different angles to get most of the waste wood cut away. Then it was back to the shinto rasp for final shaping and some 80 grit paper to cleanup and radius the edges before epoxying it all in.  I didn't have any screws long enough to go through the rail and solidly into the knees so I will have to do that after it all dries up and I can get to the hardware store from some 2.5 inch SS screws.

Unfortunately, I won't be able to do any work on the boat this weekend so the boat flip will have to wait until next week when the weather gets a little better.  The shop is long overdue for a serious cleanup and I want to be able to move the boat out for a few hours so I can clean and sweep before moving it back in and starting on the bottom.




Wednesday, April 5, 2017

Sticky Bits and Stupid Mistakes

Morning in the shop
So now I have reached the inevitable stage in a build where the big pieces are together and things start to seemingly slow down because the parts get smaller and require careful setting and epoxying. It's not that I've stopped doing work, it just feels that way sometimes because you don't see as many big changes.

With that said, I did reach a milestone earlier this evening and finished gluing up both sides of the outside gunwale (outwale).  The reason it's a milestone is that I've finished the first stage of the build and now it's time to turn the boat over and start glassing up the bottom.  I should thank Tom, who commented on my last post.  I was lamenting the fact that I didn't have enough spring clamps to glue on all the spacer blocks for the scuppered inwale and Tom pointed out that I could just slice up a length of PVC pipe and cut them lengthwise to make a super cheap spring clamp.  I had enough PVC pipe on hand to make 20 and that allowed me to move forward much faster.

Mini miter box
Scarph goodness
While the spacer blocks were curing in place, I cut out the 20 x 20 mm outwale pieces and cut 8:1 scarphs to get the lengths I needed. To do so, I built a mini miter box to do the cut and it also served as a jig to glue them up.  Once the epoxy had cured and I sanded them down the glue lines looked really good.

Next, I milled a 6 x 8 mm rabbet in both of the scarfed outwales.  It's a little hard to see in pictures but I epoxied the spacer blocks about 8 mm proud of the top plank. I did this so when the outwale was set, the rabbet would cover up the plywood edges. I never liked the looked of exposed plywood edges and figured that sealing those edges with epoxy and then covering them with the outwales would help keep out moisture.

Last night I lured my wife over to the shop to help butter and bend on the first rabbeted outwale. I mixed up two small batches of wood flour thickened epoxy and had my wife start 'painting' the outwale with the mayo consistency epoxy while I did the same on the outboard side of each spacer block.  Once done, we simply mashed it into place and worked our way forward, clamping it onto the curve of the hull as we went.  I needed to use a few c-clamps along the way because just using spring clamps wasn't enough.  It went great and once it was on, we spent 20 minutes or so cleaning up all the squeeze out before quitting for the night.

The last few days wasn't without it's trials though; I managed to get an extremely large cherry sliver in the palm of my hand when planing down one of the outwales.  My wife managed to get it out with some serious digging, but it ended my work for the night.  I also knocked over four ounces of unmixed resin on the shop floor and didn't notice it until it spread out all over and I had walked in it. My wife managed to drag her hair in thickened epoxy when we were moving the boat a few feet. She was not happy.

I also managed to screw up the length on the starboard outwale we finished tonight and didn't notice it until we bent it on after we buttered the whole thing up with wood flour thickened epoxy. Earlier in the day I cut the forward end at an angle so it would match up with the one we did the night before and didn't realize that I cut too much off and as we pushed it into place, it was about 5 inches short of the stern.  WTF...

There wasn't anything to do at that point but get it clamped down because getting all the epoxy off the hull that we just spread just wasn't an option and I don't want to go through all the work of scarphing and milling more cherry stock. I found the piece I cut off and glassed that in place at the aft end where it was short.  Not ideal, but it's the last 5 inches on the stern, not on curve and it fit into place nicely.  Obviously there will be a seam that is not as elegant as my nice scarphs, but strictly cosmetic. Oh well,


Saturday, April 1, 2017

The April Fool

The 50 and 75 mm glass tape and wood flour showed up Thursday afternoon so I spent two marathon nights in the shop getting sticky.  After more hours than my back was really happy to be on duty, I finally finished up last night.  It's not that the work is difficult, but leaning over the gunwale of the boat, reaching down to spread out the seemingly endless supply of 180 mm fiberglass tape pieces just go old.  
I started out by measuring and cutting 100 pieces of 180 mm fiberglass tape from the 50 mm wide roll.  I came to the the 180 mm number simply because the zip ties are spaced at 200 mm and 180 would give me a little leeway on either side (first pass lays the tape between the zip ties).  Once cut, I vacuumed out the boat to get any debris out that would prevent the tape from laying flat.  

I layed out all the pieces of tape next to the spots they would soon occupy permanently and then it was just a matter of mixing up a batch of unthickened epoxy and painting in between the zip ties.  I would generally paint out a row, going from the stern forward to frame 5 and then place and smooth out the pieces of tape in an orderly fashion.  Then I would move onto the next row, do the same, and then circle back to the first row (which by that time had a bit of soak time), and brush a thin layer of epoxy over them to make sure they were fully wetted out.  Repeat... again and again over the course of two days.  

Once those were all done, I mixed up a batch of epoxy and thickened it to peanut butter consistency and spread it into the frames and transom; first with a putty knife, and then followed with my finger which is the perfect filet radius.  After taking care of that, I cut a small piece of mahogany and planed it down so that it fit nicely in the inner stem to tie the strakes together.  This isn't called for in the plans, but I can't see how it would hurt (other than add about 6oz of weight) and most boats do have this 'feature'.  I fileted that in place and called it a day.

This morning I woke up to a fine April Fool's joke complete with 10 inches of snow and the power out.  Fortunately, the shop is well insulated and it only got down to the 40 degree F range.  The power came back on this afternoon and I started working on the scuppered inwale that needs to go in place before flipping the boat over.  This is also a deviation from the standard plan, but I know others have done this and I have found in the course of messing around in boats that scuppered inwales make nice places to tie something off anywhere along the rail of the boat.  Very handy and I think it looks nice too.

I have a couple of nice black cherry boards that I had bought for the gunwale/inwale job so I sliced off a few 3/8" (~10 mm) pieces and cut them to 2" (50 mm) lengths to use as spacer blocks.  I marked out the placement and found that if I have the 50 mm spacer block spaced every 100 mm they will be nicely staggered the entire length of the boat.  A note on the metric measurements: the plans are all metric and while I still have a little trouble visualizing how long say 125 mm is (whereas if I think about 5 inches, I can visualize how big that is), it is WAY better going metric.  The math is dead simple and I wish all my tools were calibrated in metric.  I did buy a full on metric tape measure and I have a metric straight edge that I've been using as well.  I wish we could convert everything over.

Anyway, I mixed up a batch of thickened epoxy and spread it onto each spacer block and positioned them with spring clamps.  Unfortunately, the saying 'you can never have enough clamps' is very true in the case of doing scuppered inwales; I have about 20 or so, but probably need a good 30 to do one whole side (let alone the whole boat), so I did one 20ish clamp section and will wait till those kick before getting the rest of the side done before going to bed tonight.