What successive steps does a shipwright take to caulk a hatch so that it is watertight.
Hatch caulking is the process of making watertight the gap between the various planks from which a hatch of a hatchway is made.
First we will look at the equipment that the shipwright uses for this and in the second part we shall explain the successive operations.
Successive operations of hatch caulking, in the example an old caulking tape is replaced...
The old, weathered caulking tape is pulled out of the groove (image 1).
The groove is cleaned out. A raking iron is used to scrape out the old tar and tape residues (image 2).The groove and the rabbet are coated in tar first. The tar paper is placed into the groove and tar is applied again. The tarred string is placed in the centre, above the groove (image 3).
The tape is tacked to both sides of the hatch groove using tacks (image 7).The tacks can be hammered in at an angle so that they come up against the flat bottom of the plank groove and the upright sides of the plank groove (image 8). Corroding tacks can be regarded as an advantage. Corrosion causes the tacks to expand and thus have even more grip in the timber (image 9).
After the tape has been applied it is coated in Stockholm tar until saturated (image 10).
Hammered in caulking tape before the tar is applied (image 11).