a little mist

Since my polyurethane glue is moisture cure, I mist the edge of the last plank before positioning the next plank. Again, the strip of plastic keeps the hull foam from sticking to the mold stringers. ....oh, when I position the plank with the glue on it, I try to slide the two planks together so that the glue really makes full edge to edge contact and works its self into the other ,slightly moistened, edge. .....for anyone building in the South, you can skip the "mist"; just glue the planks after an afternoon thunderstorm.

a line of glue

I squirt a line of polyurethane glue along the edge of a plank.......( I take a flat stick and spread it evenly; trying to keep the bulk of the bead in the center of the edge so that when it mates with another plank it will "foam cure" from the inside out towards the interior and exterior )

dressing the plank....walking the plank comes later

I dress the plank edge.......( the thermo-forming process flares out the inner edge a little in the curve so a few passes w/ an electric planer set @ 1/32in. produces a nice square edge)

a twenty plank day.....

Here's a pretty good run of planks.....Now that I'm working on the last hull section, I've really settled in on an easy way to lay down the foam. Here's what works for me:

1) Rip 10 inch corecell planks on a table saw.....( when using 4x8 sheets you end up with a 5 or 6 in. plank that can be used towards the bow.

2) Thermo form plank......( 5 min in my 160 deg convection / radiant hot box... ten seconds before it starts to droop )

3) climb up and over my mold and quickly lay it over the stringers.

4) Since I'm flying solo, I found it easy just to put a few sheet rock screws through some plywood squares here and there till it cools. ( make sure to put little sheets of plastic under the wood tabs so the glue dosen't stick )

5) after setting about twenty planks, I numbered them all with a sharpy and began fitting and gluing them in place starting from the center and working alternately towards the bow and then the stern.....beginning with the middle #10....then......#11, #9, #12, #8 etc.

6) .......more to follow

a nice vacuum pump rig

So here's an improved vacuum rig that I built while I was waiting on my corecell foam order. Rather than keep my vacuum pump running all night long when bagging panels, I built a proper set-up for my pump. Joewoodworker.com has a nice set of plans for adding a vacuum reservoir and switch so that the pump can rest most of the time.

http://www.joewoodworker.com/veneering/downloads.htm

With a proper system, the pump will only need to switch itself on every once in a while during the cure process.

ripping up foam

If your reading this from top to bottom, this is what happens when you rip a few sheets of foam across a table saw..........it doesn't take too long to lay waste to a fortunes worth of corecell foam. I've chosen to work with 10 inch wide planks mainly because it allows me to dial in the temperature/ "toast" time of each plank. I've found that if I keep the temperature, the "toast"time and the plank width consistent, it allows me to keep my forming technique under control while I lay each plank into the mold.

fresh foam

Nothing like opening a fresh box of Corecell foam.....

exotic temperature curing chamber

To see whats under this blue tarp, go down to the botom of this post and follow through a vacuum bag process. .....since it's a little cool now, I covered my bulkhead vacuum bag layup with a tarp and placed a small heater under it......

ssssssssssss

turn on the vacuum pump.....

in the bag..

cover the whole deal with a vacuum membrane

breather

top with breather material. Notice the extra breather leading to the vacuum port

layers and layers and layers

then wet it out with resin, lay in the foam piece,wet the foam surface, lay down the top layer of triaxial glass, wet out with resin, cover with another layer of peel ply, then top with perf sheeting....

glass

then the glass.....

peeeeeel ply

lay down the peel ply.....

baggin the starboard side aft bulkhead

So here's a method of vacuume bagging bulkheads: I stretched a rubber sheet of "pond liner" over my 12ft. x 8 ft. surface so that I only need to apply a membrane over the top of my layups. the first step is to apply the mastic. Do not remove the paper tape just yet.

starboard side outer hull half mold

Here's a little progress running stringers over the starbord side mold forms....

When working on a multi year project, I find it helpful to knock out an occational smaller project just to give me a since of accomplishment and gain a feeling of completion..... the shark hanging up in the back ground is actually a gravity bike that I designed and built to compete in the IGSA ( International Gravity Sports Association ) "Marryhill festival of speed". I used some of my scrap triaxial glass, epoxy and some blue foam from home depot to make a 3/4 fairing gravity bike....won the race and then hung it from the shop roof so I could get back to the boat.

unapproved modifications

When working with a partner, it's a good idea to discuss any modifications or changes to the mold. While I was attaching battens over the stern mold forms, tang took it upon himself to modify the starboard side bow mold stringers without consulting the designer Ian Farrier.

If left alone, Tang could reduce the entire starboard side mold to a twisted pile of splinters in an afternoon.

Guide stick

I found it handy to make a guide stick that I could use to insure all of my forms were the same distance apart. I just cut a stick the proper spacing minus the 3/4 in. thickness of my forms. I pin the stick between the forms ;holding the loose form with my knee while I run a screw through a joining stringer and down into the edge of the form.

converting the mold

In order to free up a little shop space, I decided to re configure the mold by re-attaching the deck and cabin form sections back onto the strongback. Once complete, this will allow me to start laying the foam for the last hull half ( starboard outer ). Thank Ian Farrier for this clever use of materials and technique. (note: the lone stringer is there to prevent another domino disaster and once I have aligned and checked the forms for accuracy, I will attach smooth flowing battens to finish the mold )

fitting the port side hull halfs

Here's a picture taken of the bow bulkhead before the hull bonding process and obviously before the addition of the sacrificial hull foam end.

creating a hull

I've dropped the port side inner hull section down onto the outer hull half and I'm spending some time trimming, cutting and preparing for the joining process.

another view

Here's another view of the port side inner lift.

lifting the port side inner hull

Here I am lifting the port side inner hull form from the mold. Since the port side outer hull is in the cradles right next to it, I'll somehow figure out a way to flip it over, set in place with 2x4 spacers and prepare it for bonding.

You can see the plastic strips that I used to keep the foam joints from sticking to the stringers.

port side hull cradles

Rather than wait until I finished the last hull half so that I could use mold forms 4,7,10 and 13 for cradles, I decided to cut a set of plywood cradles so that I could position the port side outer hull in preperation for mating it to the inside section. This will allow me to free up more shop space once the two halves are joined to become the port side hull.

fish eye view

Here's a picture of the outer port side hull taken from under neath looking towards the bow. ( I think that's the mast bulk head with the door opening that is visible) The lamination was accomplished with a continuous length of 60 inch wide 34 oz stitched Triaxial glass 42 feet long. I ran the zero degree strands lengthwise against the foam with the two 45 degrees towards the outside. I layed the glass from bow to stern , laying down resin sufficient to allow me to cover one sectional width of peel ply at a time. ( about 1500cc per batch ) Once I was happy with the saturation, applied the peel ply and had worked any excess resin forward, I mixed my next batch and continued the methodical process. I find it nice to listen to some soulful music or a good public radio station while I work.......or, maybe I will try to find an MP3 file of screaming cicadas to remind me of the sounds of an Alabama southern night.

This simple hand layup technique has resulted in a surface that will not require much final faring at all.

(for scale, that's a 16ft. sea kayak hanging up behind the hull)