Getting Ahead of the Curve

Now that we are looking at two long, square pieces of plywood linguine, It's time to mark out the curves and decks to be cut out.

This is my weapon of choice.  I found this stick in the slab pile behind my dad's sawmill. I was looking for bracing material for setting posts back in August.  After it was tacked up, holding treated posts upright, I noticed that it was a beautiful, knot-free, quarter-sawn oak batten, straight as a pin- not something to be cut up for firewood.

  Here we are, encouraging the batten to take the curve we are looking for.  My lovely assistant, here, is Andrew, my grown up stepdaughter's boyfriend.  He is on leave from his little "job" in the USMC.  I call him my "pet marine."

  Letting the last bit of the batten run free, as per the advice of a prominent internet boat wiseguy.  This is supposed to make the plywood bending go better. 

Andrew looks on in awe (this is actually a yawn) 

The process is very simple, you simply hold the batten with both hands, then trace along it with your third hand.  Andrew helped with this. 

Celebrating a job well done. 

I forgot to take a picture before I started attaching timber to it, but here is the shape cut out.

More Plywood Issues

  Yet another gripe about the quality of the plywood I'm getting:  I flipped over one of these long ribbons of plywood I have joined I found this.

 An area of delamination a little bigger than my hand, right at where the warped plywood sort of came down and kissed the moist concrete floor.  As you see here, it is discolored and rising up in little swollen ridges.

  I became immediately concerned that the plywood was not what it claims to be and I have just spent several days inadvertently starting a boat project with interior plywood.

  Luckily, the piece was on the end where the corners will be cut away anyway, so I cut off a sample and threw it in a pot on the stove with a piece of interior plywood as a control to make sure I was being aggressive enough in my test.  

  The test piece held together, which was very reassuring.  Here you see it next to the bits of the control piece.

  The most surprising thing was how long it took the interior plywood to delaminate.  I boiled the stuff for over an hour and still I had to pull the interior stuff apart with my fingers.  This was several days ago and the interior piece from another pair of samples I put in cold water is still looking really good.  I have to pull pretty hard on it before it will come apart.  I see now why people do the boil test!

  My conclusion is that there are imperfections in the gluing process as just like every other part of plywood production and that these areas of delamination just have to be dealt with as they arise. 

And those Pay-sons go rolling along

 
   The Payson butt joint.  I had heard about it, but never done it until now.  Two little strips of fiberglass holding a butt joint of plywood together.  Hardly seems it should be as strong as it is reported to be, but things are not always as they seem.

  In this way, we have been joining three sheets of plywood end to end, to make each of the two sides of the hull. The technique of laying out wetted fiberglass on the floor, then pushing the plywood down into it is totally counter intuitive and I was a little bit unsure of myself, but it seems to work out well enough.

Here you see me wetting out three strips of fiberglass, two, four, and six inches wide, I drew a line down the center of my plastic and centered my glass strips on that line, hoping to use that to align the whole unit properly when I am operating blind under the plywood.

   I decided to screw the plywood together temporarily with blocks (on the back side in this picture) so that I wouldn't have to fool with the relationship of the plywood sheets to each other, just that of the wetted glass to the plywood.   I stood them up like you see here, then buttered the edges with slightly thickened epoxy.  Next, I set some of that thin foam that you use for padding under a laminate floor to sort of cushion the wetted glass and maybe provide a more even pressure than being mashed down into the flat, hard concrete.  Then I positioned the glass between sticks and flipped the plywood down on it.  This allowed me to fiddle with the alignment of the glass before finally slipping the sticks out and bringing on the weight.  

  Luckily, I had this fine person to lift up with a crow bar while I slipped the sticks out from under the plywood.  She is only in kindergarten, but she is a crack shop hand already!

  After the weight is holding everything down, I  unscrewed the blocks and applied the top layers of glass like normal. 

  We had a cold snap while we were doing the second side.  I heated some bricks on the stove.

Hey, it's freezing...let's get out our shorts and  bathing suits!!!

  Then I set them on the joints on cardboard insulators.  The glass was not wet here.  Just, slightly tacky (like me). 

  Finally, I blanketed the whole thing and hoped for the best.  

 None of this may have been necessary, I don't know.  I was using the fast epoxy, so I don't know if I saved myself a day here or not.  

Can't we just make a tricycle ramp instead of a boat?


I now reach out to my readers (both of you) to ask: 


Is this how YOU do this type of joint?  

 Please comment with any constructive criticism of my techniques here. Growing up in rural Southwestern Virginia rather than coastal Maine, I have had to be an autodidact in these matters, so I would like to use this blog to improve my game, here. 

 Thanks!

                  

    

Square Boat, Un-square Plywood

  When I started laying out sheets of plywood on the floor to join together, I noticed something:  the ends weren't square!  

  Now, I have always assumed that they have these really awesome cutting machines in the plywood factory, calibrated with some kind of ultra high-tech, atomic, quantum-flux process so that every sheet comes out to a perfect 90 degrees.

  Indeed, I have built many a wall with OSB and never doubted its squareness. In retrospect, maybe I should have done.

  This Georgia-Pacific B-C pine plywood (PS1-09, I think they call it) that I got at Lowes was rife with dimensional inconsistencies.

 Of the six sheets I brought home to make the sides of the boat with, five needed some kind of correction with a hand plane.

This end, 1/8" heavy.  (except for the top veneer)

This end 1/4" heavy.

That 1/8" in 4 feet becomes 3/4" projected out over a 24 foot boat. No small error!

Even squared, they were different lengths. This one, 1/8" heavy, this one 3/16".   I mixed and matched the sheets for the two sides and they came out the same, thankfully. 

Then there is the bow in them.  I found the curviest sheets impossible to weigh down enough.  

Here they are, all glassed and waiting to set up.

  Even the amount of weight you see here was not enough to get them to lie flat.

  This caused one of my joints to come out all wonky

Luckily, it was alright on one end of the joint and didn't start to get bad until the end you see above. I had to cut that  joint apart half way and fix it

  Then, someone told me that by wetting one side and drying the other, you can induce the plywood to flatten out.   This made the second side go much smoother. 

.

Extremism in the Defense of Frugality is no Vise!

 My apologies to Mr. Goldwater...

 In setting up this new shop, I wanted a real wooden bench vise.  That is something I have always dreamed of.  They sell mighty nice hardware sets like this at a very reasonable price:

However, I can't stand to spend money on something so blatantly easy to make for free, so I decided to take a hack saw to an old jack I had lying around.

The work from here on out is basically the same, since you are building the vice itself in either case.  An oak block I had set aside for just such a purpose made the moving jaw.  

Here you see the board that will be the face piece of the work bench lying on the edge of the bench with the vise jaw hanging from the jack hardware. The inch dowels are the only bits that came from the store.  

The bar with a little ball on the end is a piece of an old metal chair that I saw bits off of for this and that.  A few threads cut into the end hold a retaining nut and the whole thing is captive.

The Boatshed

  Not having a place to build such a boat, it has been necessary to build a shelter.  Rather than go the standard route of throwing up something temporary, I decided to go ahead and build a proper boat-shed/workshop.  It is something I have wanted for a long time anyway and will serve us long after.  I started clearing land and doing some hand grading right about a year ago.

That sucker was hard to pull over.   The summer was busy, we took  the boat up to Georgian Bay, various projects.  I didn't move forward much on it until August.  Here I am with a buddy after we set the posts.

After all fall and winter working on it, here is what we've got.

That plastic was faster than building big permanent doors and it lets in light and possibly some heat,

The view inside. 

I finally have the 12 foot workbench of my dreams, with all my hand tools in reach and nothing permanently stored on the bench top.

Time to get crackin!

Getting the shape SQUARED away.

    The direction I have chosen to go in order to get what I think of as the best compromise between the design considerations mentioned in the last post is the barge hullform.    I discovered Dave Zeiger's Triloboats a couple of years ago and have been fascinated ever since at such an unorthodox approach. I will not go into a discussion of the merits of square boats here. His site is the place for that.


  I am thinking of a 24 foot hull, 7 feet wide.   The 7 foot beam does not fit Dave's ideal of using full pieces of plywood whenever possible, but he specializes in boats that sane boaters use.  The kind that live mostly in the water. If I try to trailer an 8 foot wide boat with further bits added to the sides, I feel like I may be pushing it.  It hardly seems fair to put constraints on a boat such that it has to be a creature of both water AND highway, but it is a mode that has proven effective for people living an inland life. C'est la vie.

 The cabin will be Birdwatcher style, with tinted windows and an open walkway down the middle.  A little self-bailing well in the bow will provide a handy place for anchors, rode, and children.

  Something like a bigger version of Dave's T16X4

Or Jim Michalak's Jewelbox.

Here is a childish doodle I made of the idea, complete with a scaled family:

I'm not actually as good-looking as the father in the drawing, but I was being optimistic.

The rig shown is a standard Hasler-Mcleod junk set in a tabernacle, offset to port.  200 square feet is the sail area for Jim Michalak's Petesboat, which is very similar in size and design so I drew a sail with that area. It is a starting place.  The details of the rig may change as the design develops.