Cover a coracle frame with hide stretched over it, heavy canvas of at least 10 oz weight, or a woven tarpaulin, fixed at the gunwale by folding over and stitching, lashing or tacking, then seal it, since no covering is waterproof until sealed. A bowl 1 m across and 0.30 m deep has a surface of about 1.07 m², and with a 15 cm fold over the rim you need about 1.5 m² of cloth, so a 1.4 m square; one large cowhide or two deer hides are more than enough.
Part of Coracle & Small Watercraft
The covering is the waterproof skin of a coracle, stretched over the frame and sealed at the seams and the surface.
The Covering Must Resist Puncture; The Seal Makes It Waterproof
The carrier lists three coverings. Animal hide (traditional): one large cowhide or two deer hides are enough; soak the hide until pliable, stretch it over the frame hair-side out, pull tight, fold it over the gunwale and stitch or lash along the rim; as it dries it shrinks drum-tight. Canvas or tarpaulin (practical): heavy canvas of at least 10 oz weight or a tarp, draped over the frame, folded neatly at the gunwale and tacked or lashed, then sealed with a waterproofing compound. Plastic sheeting (expedient): several layers of heavy plastic such as pond liner or truck tarp; less durable but immediately available.
The covering takes the load of the water and of the paddler’s weight on the bottom, so its weakest points are the stitch lines and the place where it bends over the rim. A seam in the hide leaks until sealed.
What You Need
- The frame (see Frame Construction)
- The covering, cut large enough for the bowl and a fold at the rim
- Needle and sinew or cord for stitching a hide; tacks or lashing for canvas
- Sealant: see below and Boat Sealing
- A sharp knife and a flat work surface
Method: Cover And Seal
Step 1: Measure the area. Bowl surface plus the fold; see the example.
Step 2: For hide, soak until pliable (see Hide Preparation for how raw hide goes bad), stretch it over the frame, pull it tight all round, fold at the gunwale and stitch or lash.
Step 3: For canvas or tarp, drape it, work out the folds at the rim, and tack or lash it at close intervals.
Step 4: Seal. Apply the sealant hot to all seams and the entire outer surface (carrier: pine pitch mixed with crushed charcoal, about 3:1 resin to charcoal; or tar; or linseed oil on canvas).
Step 5: Let it cure, then float-test in shallow water and reseal any weep.
Worked Example: How Much Covering?
For a rim 1.0 m across and 0.30 m deep, the spherical-cap radius of curvature is Rc = (0.5² + 0.3²) ÷ (2 × 0.3) = 0.567 m. The cap area is 2π × Rc × h = 2π × 0.567 × 0.30 = 1.07 m². The rim circumference is π × 1.0 = 3.14 m, and a fold of 15 cm, 0.15 m (an assumed value), adds 3.14 × 0.15 = 0.47 m². The total is 1.07 + 0.47 = 1.54 m², about 1.5 m², equivalent to a disc of radius √(1.54 ÷ π) = 0.70 m, so a 1.4 m square will do. The canvas itself weighs little: 10 oz per square yard is 339 g/m² (1 oz/yd² = 33.9 g/m²), and 1.5 × 0.339 = 0.51 kg, so most of the boat’s mass is frame, sealant and any hide.
Common Mistakes
- Cutting the covering to the bowl area only — leave a fold for the rim.
- Sealing in a hurry — the sealant needs a dry surface and time to set.
- Mixing sealant recipes without testing — the carrier gives resin and charcoal 3:1, while Boat Sealing gives a pitch, tallow and charcoal mix of 3:1:1 for hulls and tar or pitch with fat for skin boats; test a patch of each on scrap before committing the whole boat.
- Tacks or lashings spaced far apart — the covering pulls out between them; space them close.
Safety
Hot pitch, hot tar and oiled canvas
Resin and pitch are flammable when melted: heat gently, away from structures, and keep water nearby. Linseed-oil-soaked canvas can heat itself and ignite when bunched (see Oiled Cloth & Animal Membrane); hang it flat to cure.
What’s Next
- Learn next: Coracle Paddling — getting the finished boat moving
- Combine with: Waterproofing — the family of sealant techniques