Chapter 4 - Setting Up Frames and Building the Hull

Watch Me Build a Vagabond Plus

What follows is the procedure that I used in building my Vagabond Plus sailboat. I spent lots of time thinking about how to construct the boat and I hope that this diary will help any of you that are constructing a Vagabond or a similar stitch-and-glue boat. I will not go into minute detail but rather will elaborate on the hints that may help you. The pictures will take a while to load but should give you some ideas about how to build your boat.

Splice Sheets of 6mm. Plywood

I spliced up to three sheets of 6mm. plywood together so I could lay out the panel shapes. I coated the edges plus surfaces where I planned to apply tape and let the resin set up. I laid a layer of Saran Wrap on the concrete floor and ran a layer of blue masking tape along one edge of the sheet. I mixed 1 oz. resin and added three tablespoons of silica to thicken. I buttered the edge of the panel with the blue tape, and then with help from my assistant, we butted the next sheet on top of the tape. I placed a sheet of Saran Wrap over the joint, put a 2 by 4 on top and added lots of weights to flatten the joint. After the resin set, I removed the Saran Wrap and taped the joint with 6 inch. DB120 tape. I used about 1.2 oz. resin for each square foot of tape.

Layout and Cut Panels

Using the plans, I laid out the panel shapes on the spliced sheet of plywood. I laid down a baseline using a monofilament fishline and marked a pencil line. Using a rafter square and straightedge, I measured and penciled in the offsets. I used 1 inch brads to mark the points and then used a 1/2 by 1/2 pine 10 foot spline to connect the points. Next, I used my battery powered 3 3/4 Makita circular saw to cut out the panels. In some cases, I was able to use the cutout panel as a pattern for the similar panel. Then I rolled on a saturation coat of resin on the cutout panel and edges. I needed about 0.2 oz. of resin per square foot.

Layout Key Bulkheads

I laid out the key bulkheads B, E, and H on 9mm. sheets. Although paper patterns were provided, I used the dimensions from the plans. These layouts will be used as patterns for the construction frames. During this step, the resin on the panels is setting up hard making it easier to sand.

Sand Panels

I did a little shopping off camera and purchased about a dozen nice straight 8 foot 2 by 4 studs. When I was cleaning out the garage, I saved some other materials to make the construction frames. I also had 4 sawhorses, all the same height. I used the studs to form a platform to hold the panels during the wash and sand process. By now, I was tired of working on my knees. I washed the panel surface with warm water and a Scotch Brite pad to remove any blush. I loaded up my Porter Cable 7336 random orbital sander with 80 grit paper, connected up the shopvac to the sander and sanded all the panels. The dust collector on the sander picked up most of the dust, no itch! I purchased 100 each 80, 150, and 220 grit stickit disks. The machine came with a 6 hole pad but I replaced it with a solid pad since the 6 hole velcro disks were much more expensive. I wish Porter Cable had supplied a punch pad for the 7336 like they did for their palm sander.

Cut Out Glass

The glass fabric arrived in an 85 pound, 50 inch roll. I used three sheets of the 9 mm. plywood as a top of a 24 foot cutting table. I rolled out the glass and used each panel as a pattern. I allowed several inches around all the edges for overlapping seams. I used a large shears for most of the cutouts but also used a little electric scissors for some of the straight cuts. I rolled up and labeled each of the pieces of fabric.

Build Frames and Strongback

Using the bulkhead layouts on the 9mm. sheets as patterns, I fabricated frames for B, E, and H. I used 2 by 4, particle board and plywood scraps and drywall screws. I made a 3 foot by 20 foot strongback using the straightest of the studs.

Level and Align Frames

I drilled 6 holes in the concrete floor to anchor the strongback with shields and lag screws. One of my civil engineer neighbors suggested using a water level to set up the strongback and frames. He gave me a long plastic tube. I bought some red food color, mixed up a batch of dyed water, and used my roast basting syringe to fill the tube. We got lots of air bubbles in the tube but by tapping the tube, we got them to leave gracefully. I attached one end of the tube to a corner of the strongback with the water level 14 inches above the strongback reference level which was where I wanted the DWL to end up. I attached the other end to a stand also marked with a 14 inch line. By adjusting the levels in the tubes to be the same and then taping the tubes to the sticks, I could move the stand anywhere on the strongback and shim that position to the level. It worked slick. Now that the strongback was level and firmly attached to the floor, each of the frames was attached at the right level to the strongback. Again the water level was used to level the frames using DWL scribe marks. I used monofilament as a centerline to center the frames on the strongback. I added platforms at stations 0 and T at the DWL.

Assemble Panels

Starting with the bottom, the panels are attached to the frames, wired about every 8-12 inches along the seams. The seams are tacked between wires with resin putty. When the resin has tacked, the wires are pulled and the spaces in the fillet filled. Next, the seam is taped with 6 inch tape. The fabric is then applied over the panel and the taped seam giving a second layer of glass over the seam. If successive layers can be applied within 12 hours or so, washing and sanding can be deferred. I was able to complete the entire hull interior with only one sanding by scheduling the steps above.

I used 19 gauge annealed stove wire. Since the panel shapes were accurate, very little wiring was needed. I found that 8-10 tablespoons of silica in 3 oz. of resin provided real stiff putty. In wetting out the DB120, I achieved about a 1.3:1 resin glass ratio by weight.

I decided to fill the weave of the DB120 cloth before proceeding to install bulkheads. Rather than fill and sand after installing bulkheads and have to work in tiny spaces, I thought it would save some time doing it while the hull was wide open. I used a filler of resin, micro balloons, and silica in the first fill. It did a good job of filling and not sagging but wasn't really easy to sand. I used West 410 and a little less silica for the second fill. The second fill produced a smooth and fair surface. Before filling, I consulted both the designer and the resin manufacturer to determine that the secondary bond for the bulkhead taping would not have a problem bonding to the filled surface. Of course, I scrubbed the surface with warm water to get rid of blush and sanded vigorously with 80 grit between fills.

I wanted to keep the airborne dust to a minimum so I used my shop vacuum connected to my sander. The fine dust or continuous operation was too much for the bearings so off it went to the repair shop. A handyman working on drywall in the neighborhood showed me a system he used. He ran the sander into a bucket filled with water which was in turn connected to the shop vac. I bought a small shop vac and set up his system. It seemed to work better and kept at least part of the dust out of the shop vac. I cut out a holder to keep the parts together as shown in the picture below.

I used sticky sanding pads on the orbital sander and discovered that the pads had a very useful second life for hand sanding. I devised a "taco" shaped block to fit the pad and wrapped the sanding disk around the block for hand sanding. The rounded edge worked well to sand fillets, difficult with the power sander. The block is just long enough to give some leveling and small enough that hand pressure is sufficient for good cutting action.

This was the first milestone, the hull shell completed. Now it's time to fit the bulkheads and interior. Chapter 2 will describe the work on the interior.

Top :: Previous :: Index :: Next