VALVE CONVERSION ALI VALVE to PLASTIC CLAMP ON VALVE
Instructions for replacing "Alloy Valves" with “Plastic Valves”. eg 690NSBV
It is assumed that operators are familiar with basic boat repair methods described in repair kits and Operating Instructions.
For use with #4232 Valve Conversion Kit – Insert to 690NSBV.
1 x Hypalon patch 126mm diameter with 38mm hole (for quick method)
1 x Hypalon patch 225mm diameter with 40mm hole (for long method)
1 x Hypalon patch 195mm diameter without hole (for long method)
1 x Valve 690 NSBV
1 x Adhesive Hypalon
1x Adhesive hardener
Repair equipment such as pencil, sandpaper, paintbrush, and scissors
LONG METHOD – RECOMMENDED:
This removes the old valve from the boat by inserting a new valve into the same position. Two patches are required, one on the inside surface and another on the outside surface.
1. Deflate the boat and carefully cut a hole 135mm in diameter around the old valve. This will remove the old Valve Surround.
2. Mark a circle 225mm in diameter centred on the 135mm hole, on the outside surface of the boat.
3. Buff this area.
4. Mark in quarter points at 3,6,9 and 12 o'clock to assist in aligning the internal patch.
5. Mark a circle on the inside surface of the boat 195mm diameter then buff this area, this will allow 30mm bonding area on the inside of the tube.
6 Inside patch 195 mm in diameter. At this stage this does not have a hole cut in the middle for the Valve, as this would make alignment very difficult. On the buffed surface mark quarter points at 3, 6, 9 and 12 o’clock to assist with alignment.
6.1 Outside 225 mm in diameter. This is a donut style patch with an outside diameter of 225 and a hole of 40mm.
7. Prepare the two buffed patch’s and buffed area of the tube inside and out, then apply a layer of pre glue and let dry for at least 24 hours.
8. The valve comprises of two parts a female and male. Unscrew the female from the male and place
9. Bond the inside patch onto the inside surface of the tube. Some tips may be helpful. To prevent the tacky patch grabbing onto adjacent glue, when it is time to insert the patch, lay a sheet of polythene onto the glued patch, then roll the patch up as though you are making a cigarette, pass the patch inside the hole, then unroll the patch and remove the polythene. During this inserting process the glued boat surface must be held up in such a way that there is a void or gap to insert the “rolled up patch” into. This gap must be maintained to enable the patch to be unrolled, the polythene to removed and most importantly aligned in such a way that the matchmarking ensures that the patch is located centrally. (If this explanation isn’t clear, please request more detailed instructions on how to make an internal repair.)
10. Bond the valve patch onto the outside of the boat
11. Now cut a 39mm diameter hole into the inside patch. This ensures that the hole in the outside patch is perfectly lined up with the inner hole.
12. Glue fills the edges of the fabric in the hole. This ensures that the exposed textile in the fabric is sealed and that air cannot penetrate through the core of the fabric.
13. Assemble the valve. (Firmly grip the female Component and apply moderate force on the male component to ensure that the valve is firmly in place. To achieve a tight fit a spanner can be used on the screw cap or a couple of screwdrivers can be put into the slots in the top of the male section.)
1. Lay the tube, or the area to be worked, onto a flat surface.
2. Determine where to place the Valve and mark the centre point with a cross.
3. Position the Valve Patch over the top of the cross and mark around the outside edge. This will create a circle 126 mm in diameter.
4. Buff the marked area (126 mm diameter). It is important to completely remove the outer skin by buffing with120 grit sandpaper until the surface is free of not only the shiny outer layer but also the milky layer just under the surface. It is important to buff until the surface forms an even matt texture. If any textile appears you have gone to far and the damaged area should be sealed with a couple of coats of adhesive.
5. Cut a 38 mm diameter hole at the centre of the marked area. (Centred on the cross).
6. Unscrew the male (or upper section) of the valve from the female (lower section), and insert the female section inside the hole. This is a very tight fit and requires that the fabric is heated, with a hairdryer to soften and make the fabric more pliable. Use a little water to lubricate the surfaces. If this fails cut a 2mm nick into the hole to help it stretch. Apply heat slowly and evenly.
7. Pre-glue all areas to be bonded making sure that the raw fabric edge on the inside of the 38 mm holes is covered. Pre-glue basically means applying a primer coat of glue as though you were applying an undercoat layer. ALLOW TO COMPLETELY DRY for at least 4 hours.
8. Bond the Valve patch onto the tube. Apply an even coat of glue to both surfaces and contact after approximately 12 minutes. Refer glue instructions for more details. Ensure the patch is bonded over the whole area and then ROLL with considerable pressure.
9. Apply an extra coat of glue to inside of the hole. This is important that any textile where the fabric has been cut is coated with glue. Allow to dry for at least 1 hour.
10. Insert the Valve by screwing the male section into the female section. In order to do this you must first locate the female section, which you have already put inside the tube. Then shake or move the female section into position directly under the hole. Grab hold of the female section by gripping it through the fabric. Thread the male section into the female section and screw it up, by hand, as tight as possible.
11. In order to tighten the Valve insert two prongs (screw drivers) into the outer slots of the female section and tighten with a lever. Torque to 16 lbs, equal to 16 lbs on the end of a 12-inch lever.
12. Inflate the tube to normal working pressure.
13.24 hours later retighten the Valve as described above. This is important as the rubber can relax with the tension and must be re-tightened to the correct torque setting.
14. If a leak is suspected it can be checked by mixing up some soapy water and wiping it around the outer edge of the Valve patch – a leak can be detected by a gathering of shaving cream style bubbles known a “wicking”. Also wipe soapy water over the outer edge of the valve where it clamps against the fabric. If a bubble appears there is a leak showing the valve was not tightened correctly.
When a tube is made in a production situation the Valve patch may be placed on either the inside or the outside of the Tube, or both sides. Also the size of the patch may vary.
GENERAL INSTRUCTIONS ON HOW TO MAKE AN INTERNAL PATCH
1. Prepare the internal patch and buff an area on the inside of the tube 10 mm greater than the patch.
2. Lay the torn edges, of the tube, together and match mark both edges every 50 mm. (or quarter point for a valve replacement)
3. Place patch in position under the damaged area and trace a line along the centre line of the patch to show where the tear will lie. . (or quarter point for a valve replacement) Then transpose match marks onto the patch. This will help with the alignment of the patch when the bond is being made.
4. Allow pre-glue to dry over night. In order to insert patch inside tube without contaminating the adhesive with your fingers, roll the patch in a layer of thick polyethylene sheet. Insert it, then, using the match marks, align the patch; contact one corner then proceed to fold out the patch over the glued area.
5. After rolling, inflate and check that patch is airtight. Proceed with external patch.
ADHESIVE AND HARDENER ARE HAZARDOUS SUBSTANCES AND CONTACT WITH SKIN SHOULD BE AVOIDED. LIKEWISE DO NOT USE NEAR SOURCE OF HEAT OR FIRE.