Stitch and glue 101

Do you want to build a boat but don't know where to start?
Spark Geissler pictured above was a little lost at first but ended up building a very nice V10 from our plans and kit.

The basis steps required to build a stitch and glue boat are:

• Cut the panels for the hull
• "Stitch" them together
• "Glue" the hull parts together

A modern stitch and glue boat does not uses copper stitches anymore: we show plastic tie-wraps. We don't glue the panels but instead build strong epoxy-fiberglass seams between them. Our larger boats (14' or 5m +) use structural seams and sometimes fiberglass sandwich. They are composite hulls but the name "stitch and glue" stayed, mainly because it reflects the ease and speed with which you build these boats.

Start With Good Plans:

It all starts with a good design . . .
Stitch and glue plans are different. In addition to standard dimensions and details, they must show the exact shape of the hull panels that will be cut flat on the shop floor. Most of our small boats plans include full size patterns for the sides and frames. For larger boats, it is more accurate to draw the panels from the dimensions. paper patterns stretch and shrink. Large paper patterns will introduce errors of several inches and that is why no designer supplies patterns for large panels. If patterns are listed, they refer to the frame patterns.
Read the plans drawing list to see which patterns are included.
Read more about patterns in our other HowTo files.
This tutorial shows the building of a small boat with patterns.

(Sean Gleason, one of our youngest D4 builders. Picture courtesy of Silvya Gleason)

Scribe The Parts On The Plywood:

From the full size patterns, transfer the outline to the plywood. This pictures shows a young crew working form a cut pattern but most builders prefer to use a pounce wheel or a nail to punch the shape through the paper. Some prefer to work from the dimensions given on our plans. Note the plywood: stitch and glue does not require the use of expensive marine ply.

(Picture of Sean & Elisabeth Gleason)

Cut all parts:

Cut your parts: frames or bulkheads, sides and sometimes bottom. We like to cut smooth curves with a circular saw but a jig saw is fine.

See the bottom of this page for other assembly methods

At your marks . . .

The assembly of most boats starts with the two side panels and the mid frame (or bulkhead). See the building instructions that came with your plans. Our plans and patterns show the alignment marks on the side panels.

Sides Up:

We attach the sides to the mid frame with temporary staples or dry-wall screws. One or two screws are sufficient. Note the block supporting the mid frame.

Install Transom and Bow:

The same way, we install the transom between the panels and then the bow. Here we show a pram with a bow transom but for "normal" pointy bows, the panels are just attached (stitched) together. Not show: some other bulkheads installed later in between.

 
Cover the bottom:

Install the bottom panels the same way: a couple of drywall screws will keep them in place. There is no need to realize tight joints and perfect fits: the fiberglass tape will take care of that. Flat bottom hulls require only one bottom panel.

Stitch:

The chines and bottom will show some gaps. Up to 10 mm (3/8") is acceptable but if the gap is wider, stitch the panels together with a plastic tie-wrap. We show a hull with strong curves (PK78) but still, we need only two stitches per side. Don't tighten these stitches too much: we want fairness first.

 This page shows a typical "stitch and glue" hull assembly method for small boats, sometimes called the sharpie method but other methods exist and can be used with our plans.

- Building on a jig
- Basket mold building, ideal for a small professional boat building shop
- Basket mold or cradle for larger boats (20' or 6 m +)
See the assembly methods page for more.

Optional Duct Tape:

We cover the small gap between the panels with duct tape. This will keep the epoxy putty inside and almost eliminate the need for grinding.

Ready For The Epoxy:

We flip the hull over, block it and check for symmetry before starting with the epoxy and fiberglass.

Pre coat:

A very important step is to coat all surfaces before building the putty fillets. Always saturate your plywood with epoxy resin before applying a putty fillet or fiberglass. The picture shows only the pre coated seams area but you could as well coat the whole thing at this stage: it is required anyway. See our shop manual for more details.

Build The Fillets (Putty):

Epoxy putty fillets must be built in all seams: between bottom and side panels, between sides, bottom and bulkheads, transoms etc. Your plans show the size of these fillets. We like to spread the putty from a zip-lock bag from which we cut a tip and use it as a pastry filling bag and then shape the fillets with a plastic spoon. The putty is made from epoxy resin and micro balloons or other fillers such as wood flour. See our kits for a list of supplies.

Fiberglass Tape Seams:

Over the putty fillet, we install fiberglass tape. Here we show heavy biaxial tape but in most small boats we use lighter woven tape. Other methods can be used: some prefer to apply wet tape to the seams instead of applying the resin in the hull.

Wet Out:

We wet the fiberglass tape with epoxy resin. This resin is the same than the one used to make putty. Epoxy resin looks and feel like thick paint. It is made of two parts that you mix before use and you apply like paint with a roller or a brush. The resin will become hard and cure in a few hours.

Roll It Out:

There should be no air and no excess resin in your "lamination". You can squeeze the air out with a special roller as shown here but a simple plastic squeegee works fine too. See our shop manual for details.

(Picture courtesy of Tom Seadon)

Finished Seam:

This is how it should look when finished. We show a seam located at a butt block. The fiberglass tape is completely impregnated = transparent, no air. All plywood surfaces are coated with epoxy resin.

(Picture courtesy of Eric Vanesse)

Flip The Hull:

After all your inside epoxy-fiberglass seams cure (= become dry and hard), you will turn the hull over to finish the outside seams. At this stage, the hull is becoming stiff and strong thanks to the fiberglass seams.

Grind The Edges:

You will apply fiberglass tape on the outside seams the same way than inside. We remove the duct tape and quickly grind a small radius on all edges. Do not remove the guard of your grinder as the operator in the picture!

Tape The Outside:
Tape all outside seams and coat all surfaces with epoxy resin if you didn't do it earlier. After the epoxy cure, you will have a complete hull . . . What's left is some inside work like the installation of the top of the seats, oarlock pads, rub rail etc., some grinding of the excess epoxy and final painting but at this stage you have a boat.

Sand:

Sean sanding and buffing his sister's new boat.

(Picture courtesy of Sylvia Gleason)>

Paint:

Do we need to explain that one?

(Picture courtesy of Sylvia Gleason)

Launch . . .