Inflatable Boat Repair (Hypalon)

Small repairs and the addition of small accessories may be attempted by the owner if factory gluing instructions are followed closely. Rips or holes larger than 2.5cm (1") in the air chambers or within 5cm (2") of a seam should be repaired with both internal and external patches by a professional repairer at a certified repair facility. A quick patch repair may solve your problem for a short period of time, but we recommend you have it redone by a professional. We further recommend that major repairs and the addition of large accessories such as row locks, seating or towing rings be done by a professional repairer at a certified repair facility.

Recommended solvent: The solvent used at the factories is called Toluene or Toluol. It is often available at paint, hardware or plumbing stores as a cleaning solvent. You can also use MEK (methyl ethyl ketone). It is often available at paint, hardware or plumbing stores, sold as a cleaner for PVC pipes or lacquer thinner. For non-critical bonds you might substitute acetone.

Recommended glue: Zodiac #7097 Universal Glue. You can also use Avon Adhesive (one or two part), Bostik®, or other Hypalon glues.

Environmental conditions: Glue with humidity less than 70% (as low as 40% is better) and away from direct sunlight. A temperature of 18°C (64°F) to 25°C (77°F) is best. This is very important, as bond strength drops rapidly with heat or high humidity. Take your boat indoors rather than attempt repairs on the dock, near the water, or in direct sunlight. Professionals use a specially built, climate controlled room, and still don't attempt to work on a rainy day.

1. Preparation: You will need rags, glue, brush, solvent, and stop watch. Make sure all the old glue is cleaned off; have your patch cut to size, position noted and marked. It always leaves a neat tidy finish if you tape off the perimeter of the patch area with masking tape to avoid over-gluing.

2. Mix the accelerator and glue thoroughly while waiting between the solvent wipes below. Note that accelerator is toxic, so keep it off your skin. Keep mixed glue covered (foil or wax paper) when not in use. Pot life for glue is about 1 hour - it may still look liquid after that, but will have lost effectiveness.

Impotant: you must abrade/scuff the fabric to remove any oxidation and to allow the glue to attain a mechanical bond to the scuffed area. Use 100 grit sandpaper or a Dremel tool. Do not cut into the threads under the protective coating. You just need to cut through the surface to allow the solvents and glue to penetrate. The surfaces of some accessories have been prepared and do not need abrading, in this event rub just the boat fabric. Wipe clean to remove grit and residue.

3. Scrub both surfaces (boat and patch or accessory) with solvent on a rag to clean surface. Wait 10 minutes after the first solvent wash, then repeat. This is important, as you are preparing the surface for proper glue adhesion. Mix glue and accelerator while waiting, if you not done so already.

4. Apply a thin layer of glue to both surfaces with a stiff brush, working it aggressively into the fabric. If it looks too thin, it is probably correct.

5. Wait 20 minutes. If glue still looks wet, wait longer. With your knuckle, check there is no tackiness; no adhesive should stick to your skin. Humidity control while the glue is drying is critical. Keep the door closed. Don't breathe on glue area while inspecting.

6. Repeat steps 4 & 5 (total of 2 layers with 20 minutes wait between)

7. Wait 10 minutes after second layer of glue.

8. After 10 minutes, join the parts together. If you have waited more than 10 minutes, or if the glue has spots of white haze, the glue will have picked up moisture and you should try to "reactivate" it. With a clean rag wet the glue surface with solvent but do not rub the glue off (one quick swipe is sufficient). Then assemble immediately, starting from one edge and slowly laying the patch or accessory down onto the glued area. Press hard. Squeeze out all the air bubbles and wrinkles, working from from the centre to the edges. On the deflated boat rub as hard as possible with smooth tool, e.g. the back of a large tablespoon - you must force all the air out from between the boat and the patch. Be careful not to scratch the fabric.

For davits and hard based accessories, first deflate the boat and press through from other side to make sure of adhesion. Wipe off excess glue with solvent.

9. Wait at least 48 hours before use. A mechanical and chemical bond will continue to strengthen over the next 7 days. Don't be tempted to shorten the process. Don't cut this curing time short - your patch could peel off at an inconvenient moment.

10. Pressure test if you want to be sure. Inflate your boat to full pressure and leave it overnight.