This page is intended to explain a method of building a fiberglass dinghy using "stitch and glue" techniques and plans. The idea is not mine but was developed by a German and two Austrians in Colon, Panama. I have modified their methods some for easier or better construction.

As simple as possible, what this involves is laying up flat sheets of fiberglass-reinforced plastic (what is generally called "fiberglass" construction, although really only the cloth is fiberglass), then using them as you would the plywood in a stitch and glue boat.

Polyester resin is used in the construction as it is cheap and readily available. In third world countries you can find the materials in paint or auto-parts stores.

To lay up the sheets, you need a large, flat surface with lots of room on either side. It could be done on  a reasonable smooth floor, but my back would kill me if I tried that! I did not use this method, but a simple solution would be to by a sheet of cheap 4x8 plywood, add stringers to provide support and keep it flat, and add legs (sawhorses would do). You lay up the panels, in whatever width is adaptable to the design and effecient with the width of fiberglass cloth you are using, in 4-foot lengths at a time. Cut open garbage bags to line your table. Once the panel is laid up, cover it with more garbage bags and weight it to hold it all flat (a 4x4 sheet of plywood would work. In Panama, we used sand, wetting it to increase the weight. Just pile it onto the garbage bags and spread it out evenly).

Layup will depend on the strength desired in the final hull. Mine was made out of one layer of woven roving and one layer of matte, as fiberglass cloth was not available. I then added an extra layer inside on the floor, but not the sides as the seats/tanks provided stiffness to that area. Better would be 3 layers: either matte/cloth/matte, or cloth/matte/cloth. In planning your layup, here is what to consider. Cloth adds the greatest strength for the weight. If used on the outside, the pattern will show and the boat will not be smooth. Matte gives less strength, but adds rigidity. In a dinghy, which hopefully is not crashing off of waves or having people jumping around in it, does not need massive strength. So, with thin panels, one needs to lean towards rigidity, so I would be inclined to use 2 layers of matte. If the cloth is very light, one could do four layers, with the matte on the outside and the cloth on the inside, giving a textured finish so as not to be slick when walking around. I would avoid overbuilding the dinghy to keep it light enough to carry.

When the first 4-foot section is getting pretty solid, but not fully set up, you build the next section, overlapping it with the first. If your material is in a roll, you just keep unrolling it. If in pieces, just make sure you have reasonable overlap between the layers, spreading this joint out over some space. By that, I mean do not have all the layers of the first piece end at the same place. Have the bottom layer extend the longest, the next layer end 4 or so inches short of the first, and the third another 4 inches short. This spreads the joint out. Do not leave any gaps when you butt the next layer up to the first, but do not overlap either. The three layers have overlap, but each individual layer is butted up to the previous section.

As you start on a third section, you slide the first one off the 8-foot table. You will need sawbucks other other methods of supporting this section at the same height as the table. If you are building on the floor, this is no problem. 3 sections should allow you to build up to a 11-foot dinghy. 4 sections would do for a 12-foot dinghy, keeping them a bit less than 4 feet so as not to waste material. You probably need two long sections for the sides, one or two slightly shorter ones for the bottom, and then lots of small pieces for seats, float tanks, bulkheads, deck.

I used a jigsaw to cut out the pieces. You can use either electrical ties or wire to stitch the sections together, proceeding the same as you would for plywood. Once the boat is roughly stitched together, it needs to be worked into the proper shape. The fiberglass panels are much more flexible than plywood, so take your time and use scrap pieces of wood or similar items to brace up areas. A thwart or two out of scrap wood will hold the sheer in place. Walk around it, making sure it has no twist. Once you are satisfied with the shape, you start taping the seams. The strength of cloth is great for this, but the problem is cloth does not conform to the curves and the V of the joints very easily, so I use strips of matte. Again, the strength needed for a dinghy vs. a high-speed runabout mean that matte here is adequate. I do not use any filler to fair the joints.

Once the inside has hardened, you can carefully flip the dinghy. A grinder will quickly smooth any areas where the outside of the joint has too much material that does not meet up smoothly. I put two layers on the outside. The first layer should be wider than the second, not the other way around.

Add extra reinforcement to any areas that you feel need the strength or rigidity. I used several layers of thin wood screwed together, with two outside and one inside, for the gunnels. Eventually I will wrap and glue pieces of indoor/outdoor carpet on the gunnels as a pad for the mother ship.

I put a large piece of plywood on the transom to stiffen it and as a motor pad, but would recommend using a piece the same dimensions as the transom: the little extra weight is more than offset by the gains in strength and rigidity.

You can fair and grind as much as you desire to get a smooth hull, but my attitude is that I want a functional dinghy, not a show boat. I do not care if the seam tape shows.

Prime and paint.