Inflate the boat to ~200 millibar.
Trace the patch on the boat with a pencil. Center the hole in the patch. Mask around your tracing, leaving a 1/16 - 1/32 inch gap to account for if you don't lay the patch 100% in the middle of the masking tape (no glue = no stick)...excess glue will be removed later.
Sand the patch, sand the boat until dull with 60-100 grit sandpaper. Wipe both surfaces with toluene. Wait 5 min for evaporation. Repeat two more times.
Deflate the boat.
Follow your glue instructions for mixing and application.
1.) When laying up, start at the bottom edge of the patch, lightly laying the patch. STOP WHEN YOU GET TO THE SEAM. DO NOT LAY THE TOP EDGE OF THE MATERIAL YET.
2.) Use your burnishing tool, burnish the seam edge to edge to form a nice 90 degree cliff in the patch
3.) Continue laying the top of the patch down, burnish the whole patch down.
Once you are done, remove the masking tape. Lightly dampen a rag with toluene. Wipe around the patch to remove excess glue. Big globs of glue will need to be lightly rubbed with the toluene rag, then lightly scraped with your burnishing tool.
WEAR A HALF MASK RESPIRATOR WITH ORGANIC VAPOR CARTRIDGES
ONLY GLUE IF THE TEMP IS BETWEEN 55F - 85F , BELOW 65% HUMIDITY