Application Guide


Bonding and Sealing Keel to Hull

There are so many different types of keels being attached to hulls of yachts. we are only focused on bolt on static keels with and without bulbs of all different styles and configurations. Hydraulic keels such as canting keels again usually a blade type with a bulb.

Fixtech Fix190 is very well suited for bonding keel to hull connections. Fix190 adheres and seals the keel to hull joint extremely well. The keel substrate is made from materials such as cast-iron, aluminum, fiberglass, lead, carbon fiber, it will have protruding bolts that bolt through the hull and fasten and a surface area that comes together with the underside of the yacht for bearing onto.


  • It is very important not to smother all the surfaces with the Product, as this will only prevent the Product from fully curing in a reasonable period of time.
  • If using a tooth trowel then ensure the teeth are higher than the insert rubber packer you will use to ensure you do not squeeze all the sealant out when tightening.
  • We recommend applying a continuous triangular line of Fix190 around the perimeter and in decreasing circles on the keel bonding surface it leaves a small amount of air inside to ensure curing.
  • This is the best way to apply the product to the surfaces, this ensures complete bonding on all surfaces good cure and plenty of bearing capacity and very little amount of air entrapment during application. (Refer to page 2 for diagram)


  1. Dry fit the keel to mark out the perimeter of the keel and ensure a good fit with the hull and keep bearing transfer plate.
  2. Lower the keel but keep it close by or in alignment with the holes.
  3. Abrade the proposed bonding area with 80-100 grit sandpaper to take off the gel coat that is in the way and get back to the fiberglass structural substrate.
  4. Abrade the stainless steel built into the hull keel transfer and bearing plate.
  5. Abrade all surfaces, with 80 – 100 grit remove all debris and dust.
  6. Wipe the bonding area and bolts and bolt holes with 100% Industrial Alcohol Cleaner or Methylated Spirits using  a lint free cloth to remove any oil, release agent or wax that might still be present from all surfaces to be sealed.
  7. Warning: (do not use any Paint Thinners as this contains oil).
  8. Carefully Mask Tape the perimeter area again to be prepared on the vessel and the keel.
  9. Wipe the bonding surface areas and bolts and bolt holes again with 100% Industrial Alcohol Cleaner or Methylated Spirits using  a lint free cloth to remove any oil, release agent or wax that might still be present from all surfaces to be sealed.
  10. Removable keels have a number of threaded studs protruding from the keel, ensure all threaded studs have been wiped clean thoroughly with 100% Industrial alcohol cleaner or methylated spirits.
  11. Most keels have a keel plate that the keel bolts pass through and then the nuts are applied to lock down the keel plate from the inside of the yacht. Prepare all these surfaces also to ensure they are prepared in accordance to above standard procedures.


  • Apply Fix190 (MSP190) onto the bonding surface in the shape of a triangular run, with a height of 10 to 15mm. As the seal is required to be watertight, it is important that the triangular adhesive sealant run forms a continuous, closed ring, with no gaps. A few inner rings is also recommended,
  • Ensure the continuous ring of sealant applies to the adhesive sealant run around the anchoring bolt-holes.
  • Place a series of 5mm high rubber blocks internally into the line of sealant, without cutting the sealant continuous run.
  • Lift the keel into position thereby squashing the triangular adhesive sealant run of the Fix190 between the bonding surfaces, within it`s skin time. Fix190 approx 30 min depends on ambient temperature and humidity.
  • Support the keel in its position.
  • From inside the yacht, some may choose to apply more Fix190 down into the bolt cavity between bolt and outer diameter of the holes, and then again as they did on top of the keel, apply a continuous run of adhesive sealant around the top position of the keep block perimeter and around each bolt hole.
  • Carefully place the top keel plate over the bolts and allow the keel plate to contact with the adhesive sealant, use rubber packers as you did on the keel to ensure you do not over-tighten during the adhesive sealant wet stage.
  • Thread on each washer and bolt and lightly tighten each nut to the keel plate, tighten until the rubber blocks are sealed. (keep the keep supported).
  • Remove any displaced material that is not required at this time.
  • In a minimum of 2-3 days you may tighten up each keel bolt to its full torque.
  • This is the best time to apply a finishing wipe between the keel and yacht hull as it will be in its final position.
  • Most anti- foul paints can be applied over Fix190 after 1 day. Test is always best.