Phantom Phoam

It's official, there is only one more step before the boat will be technically legal by the USCG regulations. That sounds huge, and it feels great but there is still a TON of work to do before the first shake down cruise.

To get to this point Dad and Captain Dave came out again last Monday to finish off the stringers and prep the glass on the deck pieces.

This is a shot of the starboard stringer glassed in and ready to go

After we got the stringers in and the first layer of glass on the middle deck piece we ran out of resin. Looks like I'll need to head down and get another 5 gallon barrel. Not too great for the old pocket book but we're on a roll and being finished next month will feel sooooooooo good.

When the stringers and glass were finished the next step was the floatation foam. The Coast Guard requires all boats under 21' to have enough floatation material to create neutral buoyancy when swamped. The forums have multiple ideas and solutions for this from the two-part polyurethane foam to multi-colored pool noodles. The main characteristics that all the solution share is high buoyancy, light weight, and closed cell. I decided a while ago that since the old foam had so much rigidity in the stern I wanted to stick with the firm polyurethane expanding foam. But this stuff is expensive. Most local retailers sell it for $75-$100 per cubic foot. So how many cubic feet do I need you ask yourself? Well through the magic of math we can figure that out. The formula I found is for salt water. But fret not! There's a coefficient to compensate for the difference in fresh water:


Hull weight: 750lbs
Specific weight of fiberglass in salt water: 1.5
Positive buoyancy: 500
Negative buoyancy: 250
Engine weight: 250lbs
Specific weight of cast iron in salt water: 7
Positive buoyancy: 35.71
Negative buoyancy: 214.29

Total negative buoyancy: 464.29
Fresh Water coefficient: 1.025
Fresh water buoyancy: 475.89

Flotation factor of foam 60lb/cu foot

Total cubic feet of foam needed: 7.93

So at $100/cubic foot that's $800 worth of foam! Fortunately I found an online retailer that sells it for a much more reasonable price.

This is my 16lb kit of two part foam from US Composites out of Florida.
This stuff is ridiculously tricky. You mix equal parts of A and B for 20 seconds then there is only 45 second to pour it before it begins to expand. Then there is the issue of ambient temperature. For optimal expansion 80 degrees is required. Since this has been the worst spring in the history of humanity, our neighborhood hasn't gone above 70 on the best day. And yesterday was not the best day, it was only 65 in the sun. To overcome the heat issue I used my wife Rachele's hair dryer to blow hot air down the length of the boat, it actually worked quite well.

It took ten small batches to get it all in but here it is all foamed up:

You can see the blow dryer in the right side of this picture

Next we need to get the boat off the trailer to patch and paint the underside. I want to get this done before we lay in the deck, it'll be much lighter this way.

So big thanks to Dad and Captain Dave. Another couple weeks and she'll be ready to sail!

Sometimes you get the holes

Whoo, big updates. On Friday my father in-law David Wirrick (Captain Dave) came out to help me get the two smaller side stringers  cut, glued, built, sanded, anchored, and laminated. After the main stringer was in I assumed the two smaller ones would be a piece of cake. Couldn't have been more wrong. As mentioned in my last post, these two pieces were still anchored in well and took a fair bit of grinding, sanding, and grunting to get out. Because the transom and bilge area were still new enough to not require replacement the rear most deck piece is still intact thus covering the rear most foot of the stringers. What I decided to do ended up being pretty simple. Since the wood hasn't rotted, nor can I get it out, I cut it where the wood was best and removed the forward 6' to be replaced, then re-glassed the rear sections. However, while performing this seemingly simple task I made the mistake that all boat builders probably make at one time or another: I cut through the hull. I was so busy sanding off the last half inch of wood I wasn't paying attention to the vertical edge that I was whacking into. Thus, TWO holes ground right through *sigh*

Captain Dave and I started by ripping 6x 2 1/8" pieces of 3/4 ply. Since my only circular saw is battery operated we used his older Sears corded saw. As it turned out "older" meant "time to retire." We did the best we could but the saw just wasn't up to the challenge of quick cutting. As a result it took us over an hour to get the pieces cut, which unfortunately set the pace for the day. After we finally got the four pieces cut it was time to glue them together. Because we had unfinished CDX plywood, it had a pretty severe warp. As such we had to paste them together at opposite curves so they would cancel each other out to be strait. Dave drilled shallow holes for anchors while I mixed up the putty and hardener, we slathered a layer on, and clamped them together to harden. While that hardened I laid up two layers of glass on the holes I had cut in the hull. After everything hardened and Dave had sanded a bevel in the top of the first stringer I laid it down, filleted the edges and we laid up two layers of glass over it.

So here we are, two of the three stringers are in. One more to go, then floatation foam and the deck then it will technically be seaworthy according to Coast Guard regulations. However, it will still need a bunch more work before I am actually willing to take her out again. There's another big work day scheduled for Monday when Captain Dave and my Dad are both coming over. Soon it will be ready to outfit with paint and interior fittings. We may not make the 4th but dammit it will sail this summer!

All glass and no play...

Big update! This weekend with the assistance of the unsinkable Kate Jordan-Rivera we got the main stringer glassed in. I have to say multiple layers of fiberglass mat takes a ton of resin. But Kate and I worked out a good flow once I realized how much material it would take. We started by filleting in the base of the stringer with Fiberlay structural putty to create a smooth and rounded bottom surface to laminate to. From there I laid on two layers of 1.5oz Chopped Strand Mat and poured catalyzed resin on it. We started by mixing up 1.5 pints of resin per each 36" section. We quickly realized this was not nearly enough. So I would lay out the mat as Kate mixed resin and we would swap out cups as I used it up. The trick being that we only had about 15 minutes of working time before the resin "kicked" and began to harden. It took us about two hours to do the entire length of the stringer on both sides. It was messy, sticky, gooey, and most importantly SMELLY. Thank god there was a breeze, that stuff stinks.

I let the base glass harden and cure overnight. On Sunday I prepped and laid over two more layers to cap in the top. This was considerably easier since I had worked out a flow. This being the last coat on the stringer I mixed the resin with a wax additive. Polyester resin is oxygen inhibitive meaning that if it's exposed to air it won't harden completely. So on your last coat you add wax to the resin which separates to the top and seals it from the air and allows the plastic to harden completely. And harden it did, wow, it is like steel.

From there I bean removing the two small side stringers which I had left in for working structure. Now that the main stringer is in I can get those out. Unfortunately that turned out to be easier said than done. I'm guessing that since these are higher in the hull they were never soaking in water like the rest they haven't rotted to the same extent. The anchoring material is still like a rock, and as such they are a huge pain to chip out. I only got about half way through one before I had to bail to cook dinner. I hope to get them out tonight after work.

It's a thing of beauty. Yes it's messy but hey, I'm an amateur.