125
RADIAL AND BIAS PATCHES REPAIR INSTRUCTIONS
SD
SCHRADER BIAS 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 at its widest point (see figure 1).
5. Choose the required repair patch with the help of this repair chart according to
the tyre load capacity (PR) and the size of the damaged area.
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 400RPM). 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 damage 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/or regroove
the tread.
Working procedure for cold Vulcanization (skive is Vulcanized with a vulcanizing
machine in advance)
10. Evenly coat the buffed area on the tyre inside once with vulcanizing fluid JADE.
Drying time approx. 15 min. at 20°C, ); 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 (drying time approx. 15 min. at 20°C) then 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.
SD-GC
SCHRADER EM BIAS PATCHES
1. Remove the tyre from the wheel and inspect for damage and defects.
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 applying the patch or filling the skive, all damage must be
removed from the tyre injury. Any loose cords and casings must be
completely removed.
3. Once the damage has been removed, all surfaces must be buffed,
cleaned, cemented with BLACK CEMENT, prior to filling the injury.
4. The prepared injury must then be filled with
• a rubber stem, if the injury is 13 mm or less. Cement the hole with
vulcanizing fluid JADE.
• or other suitable rubber vulcanizing material such as rope rubber. If
using a spotter to cure rope rubber or filler gum into the tyre, allow the
tyre to cool to room temperature before applying the patch.
5. Refer to the Schrader bias tyre repair chart to determine the proper
patch size.
6. Pre-clean the inner liner with rubber cleaner and a rubber scraper.
7. 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.
8. Remove all the buffing dust with a wire brush and a vacuum. Do not
touch the buffed surface with the vacuum or hands.
9. Hot Vulcanization only
• Stir the solution before use. Apply BLACK CEMENT to the buffed area of
the tyre inner liner and to the back of the patch.
• Remove the cloth backing from the patch.
• Allow 5-10 minutes to dry.
• Apply a coat of BLACK CEMENT to the outside skived area of the tyre and
allow 15-20 minutes to dry.
• If body ply cords are exposed apply a second coat of BLACK CEMENT to
the exposed cords and repeat drying time.
10. After the BLACK CEMENT is dry on the back of the patch, place the
repair on uncured cushion gum and stitch from the centre outward to the
edges. The uncured cushion gum must be applied to the patch prior to its
placement on the tyre.
11. Slit the protective poly on the back of the cushion gum and expose the
centre. With the tyre beads in a relaxed position, place the repair over the
injury and press down hard at the centre.
12. Stitch the repair from the centre outward and remove the remaining
protective backing.
13. Apply liner seal coating to the edges of the repair and to all exposed
buffed areas of the inner liner.
Refer to the Schrader Bias Repair Chart for injury size and patch selection.
1...,115,116,117,118,119,120,121,122,123,124 126,127,128,129,130,131,132,133,134,135,...253