1) First remove the old drain valve and check the drain valve hole on the transom to make sure the new drain valve matches the hole dimensions. Then clean up all the dirt from the hole. If there is water in the drain hole, wash it again and leave it dry in the air. Make sure all the condition are good before starting to install the new drain valve.
2) Put the Sealant on the drain hole surface about 1mm thickness (5-15g). Wear a glove and use a finger to push the sealant fully coated at the drain hole. Wait 30-60 minutes to let the new sealant coating stay well before putting the new drain valve in.
3) Apply about 5g of the Sealant on the valve and transom contact surface before installation. It helps the valve to get perfect water tight result.
4) Many inflatable boats come with plywood transom with wrong sealant used in the factory. The waterproof coating need to be refinished. Boat's old drain valve may have already caused some water leaking and damage to the transom. This Sikaflex sealant perfectly helps to finish the replacement.
General Instruction for Marine Sealant
Professional grade marine adhesive/ sealant used by boat builders and yards to bond and bed boat components structurally. Fast strength build-up overnight. Use above and below the waterline. Comes with nozzle. All purpose adhesive sealant, bond to hull and structural members. Bedding compound, light bonding, fast-cure polyurethane sealant.
If a partial pack remains, you can simply squeeze the air out of the tube using the included tool, thereby extending the shelf life of opened product. Includes application nozzle and dispensing/ storage tool.
Seals, bonds, repairs, mends and secures glass, metal, plastics, fabric, vinyl, weather stripping and vinyl tops
May be applied to horizontal or vertical surfaces
Waterproof and flexible
Temperature range -75°F to 450°F (-59°C to 232°C)
Waterproof seal resists cracking, shrinking and migrating
Can also be used as a gasket maker
Important Information - Drain Valve Operation
Please make sure the drain valve is closed during your boating or docking. Otherwise the sea water will get into the boat slowly, even the drain valve coming with a one-way rubber diaphragm. But the diaphragm is not enough to 100% block the water from outside of the boat.
When your boat has water to drain via the drain valve, you can drive your boat fast enough before you can use the drain valve to drain the water out. To help the drain valve function, the water inside the drain valve must be higher than the waterline right outside the drain valve, and the water will going out. usually to drain 1 L water will take about 1 minute driving. Min boat speed should be 10Km per hour to help the drain valve function.
When you docking your boat in a raining day. you won't be able to drain out the rain water by opening the drain valve. Except a heavy rain and the water line inside your boat is higher than the water line outside the boat. But you won't be able to drain out 100% water if open the drain valve without driving the boat. Or it should be better to have a electric bilge pump to solve this situation.
When you feel your drain valve could be leaking water, you can test the drain valve on the land by this way. Make sure outside the boat is dry, then you can raise up the boat and tilt up the bow, fill with flesh water by using a water hose. check if any water leaking from the drain valve or seam. 10 minutes to know if any leaking. and you can drain out all the water by opening the drain valve.
Drain valve is not easy to be damaged by itself. understand how to operate and inspect the drain valve will be important. Make sure you need a new drain valve before make a purchase.