Hockey Puck Manufacture (or Epoxy is Stressful II)

Did I mention that epoxy is stressful?  To recap:  You have 15 to 30 minutes to get a bucket full of epoxy mixed, applied, and secured down before it turns into a rock-hard mistake that must be laboriously chipped, chiseled, and sanded off. 

Add to that, less than ideal conditions of 95°F days and adding a thickening filler that reduces the epoxy pot-life by a huge factor. 

During our days of mixing thickened epoxy (to adhere joints together and fill gaps), we inadvertently manufactured many hockey pucks in the bottom of our mixing containers. 

But by far the most interesting mistake I made was one one particularly hot day that I made a triple batch.  I broke the batch down into three containers, and successfully used the first batch before realizing that the other two batches had already begun to gel.  One of the three had kicked off dramatically and begun to melt through the plastic mixing container.  I set it out in the yard somewhere safe.

"Before Its Time"  2012.  Mixed Media: Plastic, epoxy resin, natural materials.

It formed an interesting, uh, sculpture as all the epoxy melting through the bottom oozed into and solidified around various bits of yard mulch.

Here is out collection of hockey pucks and sculptures we've created.  As we move to finishing the hull, we'll be mixing thin batches with no filler, so the likelihood of unexpected epoxy disasters decreases.

This is what a long day of working with epoxy does to me.

Opinions are like assholes...

Everyone's got one.

Every now and then I'll ask a boat-related question on a public forum or email list.  It sure isn't a problem getting people to weigh in with their opinion, that's for sure.  The challenge, actually, is picking through the dross of misunderstanding, inaccurate information, speculation, and completely made-up answers to find the grains of expertise and knowledge.

This is precisely why I picked the boat designer I did, because they has already provided me with a wealth of trustworthy and well-respected information about boatbuilding before I ever bought my plans (read Boat Plans: Choices Made and Not Made).

For the most part, during my build, I've hewed pretty close to the plans and the recommendations of the boat's designer.  I'm all for experimentation, but I'm also deeply respectful of the experience and expertise of those who came before me.

In the planning stages, there were boats I liked that came close to what I wanted, but differed in some way from my vision of our little shantyboat.  I definitely flirted with the idea of taking those plans and making significant modifications.

I resisted that urge, for the most part, and picked a boat design that met my needs, at least in terms of hull design.  

For the changes I did plan to make, I had the good fortune to be able to talk to my boat's naval architect and get his advice on these modifications (read Questions for the Old Man).

The opinion in boatbuilding forums is often to take this design and lengthen it, or add one of those or one of these.  And I'm sure for those experienced boatbuilders, such modifications would be a breeze.  But what about the first-time boatbuilder, the person just starting out?

I think people get excited sometimes about sharing what they know, but forget that there is a bigger picture.  Too often, I think that picture holds the very real possibility of a half-built boat collecting rainwater in the backyard of a frustrated amateur boatbuilder.

Hull Finish Work (or Correcting Mistakes III)

I like to joke that I bring Old World Craftsmanship to my work.  Old World like Neanderthal, the fine kind of workmanship you get from precision woodworking tools such as heavy clubs and sharpish rocks.  One of the things I like about building is all the layers of increasingly fine-tuned craftsmanship one brings to a project.

So all of my corners, more or less, meet each other, give or take a half inch or so.  Unfortunately, to coat the whole thing with fiberglass, the tolerances had to be a little more fine than that.  I knew all along that I was going to have to make all the edges smooth and even.

With all the lumber we ripped, we had no shortage of useful shims.  I made little shims to cover all these under or over cuts.

I didn't worry about fit that much, just that the shim covered the error.  I knew I could trim and sand the results.

I had to coat everything with a first coat of thin epoxy, then followup with thickened epoxy.

It was a lot of gooey mess and didn't look any too pretty mid-process.

I held the shims in with little brads until the epoxy had set.

After the epoxy set, I pulled the brads and trimmed off the extra.

The fiberglass sheeting calls for rounded corners to make a good bond.  I pulled out my router for the job and bought a 3/8 inch rounded bit.  That was the minimum radius that Glen-L suggested.

God, that is a scary and amazing tool.

It left beautiful rounded edges.

Next, we fill all the holes with a non-oily wood filler.  For some reason, I've always loved this process.

4 million screw holes come back to haunt me.  I filled ever one as well as various chips and dings and rough corners.

 Followed by a day with an orbital sander.

 

It slowly starts to look pretty smooth and nice.

By the time we were done, it was lovely.  Smooth and beautiful with edges that looks like magic.

Hull Ends

Oh god, at the end of every work day when we are high-fiving each other, we are always marveling at just how much more boatlike the boat looks. But today, for reals, at the end of the work day, the boat doesn't just look boatlike -- technically if you dropped it in the water, it would actually float for several minutes. Today, we attach the hull ends. 

We start by beveling the edge of the bottom sheeting. 

And since we are cutting up two perfectly good pieces of plywood with complicated angles, we draw a picture to help us.

We cut our first cut along the edge and our second cut after we snap a chalk line.  After that, we check for fit and, magic!  It fits. 

We had already put on a first coat of thin epoxy.  Now I needed to thick coat and screw the ends.  I think I did this epoxy work alone, which might have been a first.  So I was a little busy and didn't take a hundred intermediate photos.

However, when done, I took celebratory photos from almost every angle.

Again, screws every 3 inches on the edges and 6 inches in the field.  That's a couple hundred screws. 

So at the end of this day, if the boat were flipped over and plopped in a pond, it would float for several minutes before slowly settling to the bottom.  Exciting.

Sheeting the Hull

It looks easy, right?  What could go wrong?  Four rectangular sheets of plywood lined up together on a horizontal surface made to fit them, screwed down on all the edges.

But as soon as we started sheeting the bottom of the boat, we realized this seemingly simple task would be more complicated.  How do we jockey all these sheets of plywood into perfect alignment, secure them together, turn them over to apply epoxy and then put them back into perfect alignment before screwing them down.  And somewhere in there, we had to apply butt blocks to where the sheets came together.

We tried laying out the plywood correct side down and applying one of our patented temporary butt blocks to hold the ends of each sheet to its corresponding partner.   But when we awkwardly tried to turn this paired 16 foot long überblatt over, the warblinesss of it pulled those temporary butt blocks out, causing us later grief.  So we tried another tack.

The plans called for butt blocks at the place where each plywood sheet met another at its short end.  Got that?  Read it a couple more times.  (No butt blocks were needed on the center line because the sheets met in a butt along the keel stringer.)  So we realized we could install the permanent butt blocks and the strength of these would allow us to manipulate each pair of plywood sheets.

These butt blocks were a little trickier than the single butt block on each side stringer because they needed to be installed in the spaces between each of the stringers.  So installing the butt blocks looked like this:

1. Put all four sheets precisely where they needed to go, correct side up.  
2. Crawl underneath the boat and draw lines where the stringers met the sheeting.  
3. Turn all sheets of plywood upside down in place.  
4. Measure (and carefully label) each space where a butt block needed to fit.
5. Cut the butt blocks 6 inches wide.
6. Coat the butt blocks, the spaces where they fit, and the plywood ends with a first coat of thin epoxy.
7. Coat the butt blocks and the ends of the plywood with a second coat of thickened epoxy.
8. Fit the plywood together carefully.
9. Put the butt blocks in place (noting the careful labeling)
10. Screw the shit out of them with screws every two inches

Whew.  And this is only a preliminary step (but really one of the most complicated).

After this cured, we had two pairs of plywood joined end-to-end that were pretty bombproof and could be manipulated awkwardly, but safely.

Somewhere in all this, I found time and space to give all the top surfaces of the boat a first thin coat of epoxy.  Now we gave the hull sheeting a first coat where it would join to the stringers.

We gave that time to become tack-free so manipulating these long joined pieces would be easier.  We took the plywood off the top, and gave the top surface of every stringer a second coat of thickened epoxy.  We also epoxied the edge of the plywood where the two long pieces would meet each other along the keel stringer.  Then we awkwardly person-handled the sheeting into place.

We put in a few screws to hold the sheets in place, and then went around and put screws every three inches.  Kai gave each screw a little tap with the hammer to get them started.  This made my finishing the screw with my power drill that much easier and faster. 

So with screws 3 inches apart on all of edges and 6 inches in the center, it was by far our most screwy day at 448 screws. With all these screws, we got afraid that by the time we got around to the final side the epoxy would have cured, so we put in every third screw on all edges and then went back and filled in.

After this, it was kind of exciting to get up on the boat and be able to stand there.  Of course it's upside down, but still.  It felt a lot more boaty than the piles of lumber and sawdust and sticky epoxy goo we'd been playing with previously.

After the bottom sheeting cured, I was able to release the come-along which has squared the boat during this procedure.  I was relieved that slowly de-tensioning the come-long was a non-event with no creaky or poppy complaints from the boat.  Sweet.

Correcting Mistakes II: The Usefulness of Square Corners

When we went to put sheets of plywood on the top, er, bottom of the boat hull, they didn't really line up.  WTF?  It seemed unlikely that four sheets of plywood were manufactured not quite square, so we had to look elsewhere.

When we assembled the stringers with the cross beams, we had squared the pieces more or less, but little errors at the quarter inch level really add up over a 20 foot boat.  We hadn't thought to square the boat up as a whole unit.

So now we measured corner-to-corner to find that there was a difference of about and inch and a half.  Not giant, but enough to make the plywood fit funny on top, er, bottom.  We hadn't made a rectangular boat hull, we'd made a parallelogram.

That night I had a dream:  We were using a come-along to square up the boat.  Brilliant!  Thanks, subconscious!  So that morning, we grabbed my come-along and screwed big-ass eye bolts into the opposite (long) corners.

My come-along didn't go the distance, so we borrowed a hooked chain from the boat trailer and doubled it up.

We worked for a while to find the route for the chain and the come-along that when tightened wouldn't tear the building form apart.

We then started working my rusty come-along to square the boat.  Kai was working the come-along originally until she realized with horror that one of the two stops that keep the ratchet from violently unratcheting broke off and fell out.  She didn't want to have to explain to people for the rest of her life about that gnarly scar across her forehead so she passed on that job.

So I got to work the come-along.

After a half dozen clicks under tension the boat was approaching square.  Oh wait, too far.  Back off.  Whoops, too little.  More tension.  We played that game back and forth for a while.

Until finally the two corners were within a quarter inch of each other. Once we got the sheeting on the bottom screwed and epoxied down, the boat would stay square.

Next we sheet the bottom of the hull.