RE-CAULKING A TEAK DECK
If you need to caulk your boat, either when laying a new teak deck or because your old deck is worn (porosity, stained rubber, seams coming away, worn teak), you can follow the instructions below.
Materials to use:
1.- Latex gloves
2.- Kommerling HG92 primer
3.- Kommerling Koraflex 990 (black, grey or white)
4.- Polyester backing strip (optional)
Recommended machinery and tools
1.- Fein Multimaster
2.- Scraper
3.- Orbital sander
A) REMOVE ALL THE OLD CAULKING
First remove all the old rubber with the Fein and its blade attachment. If you do not have a Fein, the old Sikaflex can be removed with a chisel that fits in the deck seam (usually about 5mm). Take great care not to damage the sides of the teak strips, as this would cause differences in the width of the deck seams.
Once the rubber has been removed from the whole teak deck, sand all the seams with a block the size of the rebate (usually 5mm) wrapped in sandpaper, removing any remaining rubber.
B) CLEANING
Next, vacuum the whole surface so that no residue is left in the seams. The teak seams must be dry and clean before application. A compressed-air gun can be used to remove the dust. The bonding area must be degreased with ACETONE, never with alcohol.
C) PRIMING THE TEAK DECK SEAMS
For priming we use Kommerling HG92 primer. It is applied with a brush in a single coat inside the seam. Make sure the product fully covers the bonding area. Once applied, the area should look glossy. Protect the primed areas from dust and moisture while the product dries, which must take at least 30 minutes, before starting to caulk. The maximum time allowed before applying the sealant is 24 hours.
D) APPLYING KOMMERLING KORAFLEX 990
When the primer is dry and the backing strip is in place (or not), apply Koraflex 990 into the teak seam.
If the deck is large we recommend the Sika pneumatic gun, as this caulking rubber is very thick and hard to squeeze.
To apply it, rest the tip of the nozzle against the seam and hold the gun at a slight angle. Pull the trigger and move the nozzle at a steady speed along the seam between the deck strips. This way the whole seam fills evenly from the bottom to the surface, standing about 3mm proud of it.
Make sure that:
- The temperature of the wood does not exceed 25 °C.
- The ambient temperature during application is constant or falling (in the afternoon --> VERY IMPORTANT!) and between 5 and 25 °C.
- The moisture content of the wood is no higher than 15%.
- The filled seam is protected from rain and sunlight for 8 hours.
The higher the ambient humidity, the faster the deck rubber cures; as a general rule it takes about 12 hours per millimetre to dry, although we advise waiting at least 15 days before sanding the Sikaflex.
E) SANDING THE TEAK DECK
After one week, the excess deck rubber is trimmed off with a blade or with the Fein itself before sanding the teak. Take care not to damage the edges of the seam during this operation. Good results can be obtained with an industrial belt sander using a grit of approximately 80 or finer.
For any further information, please do not hesitate to contact us.