Install a grommet in 20 steps

From the inside, drill a hole with a small drill bit where you want to install the through-hull. Our example was made in the hull of a Tricat. The position of the through-hull is well marked in the mold (flat white surface)

From the outside, we start to drill using a hole saw of the diameter of the through-hull. Be careful, we do not cut the whole hull.

The drilling ends on the inside. This method ensures a good finish on both sides of the drilling.

A little vacuuming will keep things clean.

We sand the surfaces that will receive the adhesive joint. This is to ensure a good adhesion to the product. We sand both inside and outside.

With a degreaser (type acetone), we clean the surfaces that will receive the joint.

When presenting the hull pass, the space to be covered is marked on the hull.

The line is now clearly visible. It will be used to position the masking tape.

Using a cutter, cut the masking tape along the line. This tape will avoid spreading glue sealant on the hull.

To protect the grommet, apply masking tape.

If the grommet needs to be installed in a special position, as is the case with speedometer grommets, mark the position with a forward arrow for example.

Degrease the grommet.

Apply the sealant in a generous, wide roll.

Position the grommet on the hull.

Press gently, but firmly. Remember to position your arrow forward.

From the inside, come and spread the excess filler around the thread.

Position the washer and tighten the grommet with the screw. During this operation, hold the grommet so that it does not turn. Tightening it by hand is sufficient, do not use a tool to tighten it.

Come and scrape off the excess sealant on the outside.

Remove the masking tape immediately (before drying).

Once dry (at least 24 hours) you can tighten your grommet. The thickness of the gasket will then be compressed. The boat is ready to be put back in the water.