124
RADIAL AND BIAS PATCHES REPAIR INSTRUCTIONS
SRR
SCHRADER RADIAL REPAIR PATCHES
1. Remove the tyre from the wheel. To find out if the tyre can be
repaired, carefully check the whole tyre inside and outside and mark
the damaged area with chalk. Do not repair the tyre if it shows any sign
of run flat and/or under inflation, has casing separation (visible, bent
or broken bead wires), sidewall or tread cracking deeper than 2 mm
(3/32”), weather cracking deeper than 2 mm (3/32”) or sidewall scuffing
that exposes the cords.
2. Before repair, all damage must be removed from the tyre injury. The
prepared injury must then be filled with a suitable rubber vulcanizing
material. Refer to the Schrader radial tyre repair chart to determine
the proper repair size.
3. Pre-clean the inner liner with rubber cleaner and a rubber scraper.
4. Place the patch on the inner liner centred over the injury. Mark a
perimeter 10-15mm (1/2”) beyond each side of the repair and buff the
inner liner to an even velvet texture with a low speed buffer. (Max 4,500
RPM) and the appropriate rasp.
5. Remove all the buffing dust with a wire brush and a vacuum. Do not
touch the buffed surface with the vacuum or hands.
6. Stir the solution before use. If the repair is being applied cold,
apply vulcanizing fluid JADE to the buffed surface and allow to dry for
3-5 minutes. If the repair is being applied hot, BLACK CEMENT may
be used. Drying time for BLACK CEMENT is 15-20 minutes. Allow
additional drying time in cold/humid conditions.
7. Remove the protective backing from the centre of the repair. With
the tyre beads in a relaxed position, place the repair over the injury and
press down hard at the centre.
8. Stitch the repair from the centre outward and remove the remaining
protective backing.
9. Apply liner seal coating to the edges of the repair and to all exposed
buffed areas of the inner liner.
Refer to Schrader Radial Repair Chart for injury size and patch
selection.
SR
SCHRADER RADIAL PATCHES
1. Remove the tyre from the wheel. To find out if the tyre can be repaired, carefully check
the whole tyre inside and outside and mark the damaged area with chalk. Do not repair
the tyre if it shows any sign of run flat and/or under inflation, has casing separation
(visible, bent or broken bead wires), sidewall or tread cracking deeper than 2 mm (3/32”),
weather cracking deeper than 2 mm (3/32”) or sidewall scuffing that exposes the cords.
2. We suggest using “Schrader PRP” for injuries up to 6 mm (car) and 10 mm (tractor /
truck) (see instructions for use).
3. For larger injuries, buff back the damaged area at a maximum of 45° on the outside of
the tyre (
see figure 2
). Do not enlarge the damaged area more than necessary. Cut and
grind away exposed steel filaments.
4. Measure the injury size (
see figure 1
):
a) Crown injuries:
- Measure Ø “C” on the tyre tread’s most damaged working ply = 1st patch choice.
- Measure “A” and “R” on the casing ply = 2nd patch choice.
- Choose the larger patch.
b) Sidewall:
- Measure “A” and “R” on the casing ply and choose the patch.
c) Shoulder:
- Measure Ø “C” and choose the patch.
5. Choose the required repair patch with the help of this repair chart according to the tyre
size and the size and location of the injury.
6. Moisten an area significantly larger than the patch with the chemical buffing solution
to remove all contaminants.
7. Mark a cross through centre of injury, larger than patch and position the patch centrally
over injury with arrows pointing to tyre beads. Mark an area, at 10-mm larger, all round
the patch.
8. Evenly buff the inner liner within the marked out area (Max 4000 RPM). Do not buff
through the inner liner.
9. Remove buffing dust dryly, if possible with a vacuum cleaner. Do not soil the buffed area
any further. Do not clean the area with a chemical buffer.
Working procedure for the subsequent hot Vulcanization
10. Shake the solution before use. Evenly coat the buffed area on the tyre inside once with
vulcanizing fluid JADE or BLACK CEMENT. Coat the buffed, clean skive area twice with
hot vulcanizing fluid BLACK CEMENT. Let the first coat dry thoroughly, then apply the
second coat. (drying time approx. 15 min. at 20°C, according to weather conditions). On
this occasion turn the tyre with the repair area a little upwards.
Remove the patch’s protection foil, coat the bonding layer once with hot vulcanizing fluid
JADE or BLACK CEMENT (drying time approx. 15 min. at 20°C) then only as necessary
apply and stitch firmly a layer of Self-vulcanizing Cushion Gum to the patch’s bonding
layer, if the patch is cloth-backed only.
11. After drying is complete, return the tyre to its initial position. Centre the chosen repair
patch on the buffed/coated area and press the center of the patch firmly. Take off the
first part of the protection foil and firmly stitch the patch with a small stitcher from the
centre to the outside. Then remove the remaining part of the protection foil and stitch the
remaining section.
12. Fill the damaged skive with hot cure filler compound, avoiding air bubbles and stitch.
Overfill the skive by approx. 3 mm in the centre.
13. Then Vulcanize the repair area in an appropriate vulcanizing machine at min. 100°C.
(Curing time approx. 4 min per mm of skive at approx. 125ºC). After the Vulcanization
and cooling check the tyre and seal the patch rim with linerseal coating, covering all the
buffed area.
14. Mount the tyre and, if necessary, buff the exterior of the tyre and regroove the tread.
Working procedure for cold Vulcanization (skive is Vulcanized with a vulcanizing
machine in advance)
10. Shake the solution before use. Evenly coat the buffed area on the tyre inside once with
vulcanizing fluid JADE. Drying time approx. 15 min. at 20°C ); then turn the tyre with the
repair area a little upwards. Remove the patch’s protection foil, coat the bonding layer
once with hot vulcanizing fluid JADE (drying time approx. 15 min. at 20°C) then only as
necessary apply and stitch firmly a layer of Self-vulcanizing Cushion Gum to the patch’s
bonding layer, if the patch is cloth-backed only.
11. After drying is complete, return the tyre to its initial position. Centre the chosen repair
patch on the buffed/coated area and press the center of the patch firmly. Take off the
first part of the protection foil and firmly stitch the patch with a small stitcher from the
centre to the outside. Then remove the remaining part of the protection foil and stitch the
remaining section.
12. For the Vulcanization of the repair patch let the tyre rest at a min. ambient temperature
of 18°C for 24 hours at least. Finally check the tyre and seal the patch rim with linerseal
coating, covering all the buffed area. If the tyre is a tube-type tyre, it can be mounted in
advance and filled with max. 2 bar air pressure.
13. Mount the tyre and, if necessary, buff the exterior of the tyre and/or regroove the tread.
1...,114,115,116,117,118,119,120,121,122,123 125,126,127,128,129,130,131,132,133,134,...253