1. Fibreglass

2. Fibre Reinforced Plastics…...
FRP....Fibreglass

3. Safety and Composites Respiratory protection Skin Protection
Eye protection
Hearing protection
Consideration of others
Strand magnified at 1000x

4. Tools and Materials Grinders Sanders Cut-off saws Die-grinders
Air chisel
Blow gun
Heat gun
Pneumatic/manual adhesive applicator guns
Masking materials
Repair materials
Glass cloth
Clamps/fasteners
Cleaners
Safety equipment
Clean up materials

5. Surface Preparation
The first step in any successful repair is the appraisal of the surface
Wash the panel with warm soapy water to remove water soluble contamination then rinse clean
Once dry, clean all panels with the appropriate wax and grease remover so as to float all (solvent soluble) contaminants to the surface

6. Tools, Equipment and Abrasives

8. Cleaning
Acetone
Brushes
Containers
Safety!

9. Sanding & Grinding

10. Grinding Disc Grits
50 grit
40 grit
36 grit
24 grit

11. Differences in Sandpapers
Aluminum Oxide
Garnet
Aluminum Zirconia
Silicon Carbide

12. Grinders / Sanders

13. Single Action vs. Dual Action

14. Sandpapers And Their Application
36-50 grit is used for damaged material removal, as well as primary shaping and beveling prior to repair procedure
grit is used for shaping of the repair bevel, primary featheredging
grit is used for back sanding, final smoothing and featheredging prior to primer surfacer application

15. Fibreglass is a Plastic?

16. Fibreglass Fibreglass is made up of three basic ingredients:
fibreglas mat
resin (polyester or epoxy)
catalyst

17. Reinforcing fabric must
be of loose construction
to allow repair adhesive
to penetrate and ‘wet’
the fabric

18. Types of Fibreglass Mat
CHOPPED STRAND MAT (CSM).
- The most common fibreglass reinforcement, is made up of randomly arranged glass fibre strands, pressed and held together with a binding agent.
- Available mainly, in three different weights, one, one and half, and two ounces per square foot. Metric equivalents are 300g, 450g, and 600g per square metre, or GSM CSM lends itself ideally to most laminating jobs including, boatbuilding, car body, roofing, ponds, etc.

19. Chopped strand
Continuos strand

20. Woven Cloth
Glass fibre filaments, spun into a yarn then woven to make cloth, provides great strength with minimal thickness, is usually used as an alternate layer between CSM, giving added strength without substantially increasing laminate thickness.

21. Uni-directional E-glass
Bi-directional E-glass
Woven Roving

22. New Technology
Kevlar
Carbon Fiber

23. Production Application Methods
Chopped strand roll
for use with chopper gun

24. Gel coat Gel coat is used as a finish coat
To add colour to the product
Is UV protectant
Can be multi colour
Applicator Gun

25. Epoxy Resins

26. Resins
Polyester resin is usually available as a two- component system, with resin in one container and the hardener often known as the catalyst in the other.
Some systems use a catalyst and a promoter to activate the resin. It is important to note that these two products should not be mixed together prior to mixing with the resin. Fire or explosion may occur
It is important to note that FRP resins cannot be used on SMC repairs!

27. Resins continued...
Resin and catalyst (hardener, activator) are mixed by quantity (ounce or milliliter)
Rule of thumb: 1 oz. resin requires 10 drops of catalyst to cure correctly
Incorrectly measured resin will have adverse effects on the repair

28. Not following
recommended curing
guidelines can lead to
product failure
Assuming one manufact-
urers procedures will
work for others can be a
costly mistake
Never cure any repair
Above 225° F. Curing
Fibreglass is ideally done
At 140° F for minutes

29. One Sided FRP Repair

30. Two Part Repair Materials

31. Damage Identification
One of the most
critical steps in
assessing damage
to FRP is to note
where the damage
ends.
Great care must be
taken to note all
cracks and fractures
are removed

32. One sided repair materials
- Cleaner
- soap and water
- wax and grease remover
- Repair material
- cosmetic
- panel patching adhesive
- Abrasives
- 36 to 50 grit grinding disc for beveling
grit for featheredging damage
grit for shaping and smoothing

33. Preparation
-When beveling the
damaged area, make
sure all of the scratch
or gouge is removed
and the bevel is 2-3”
away from the centre
of repair area and all
paint material is re-
moved from the
immediate area

34. Follow manufacturers
guidelines as to drying
and recoating times
Always finish imperfec-
tions (pinholes etc) off
with same material or
if acceptable use a high
density cosmetic
filler

35. Two Sided FRP Repairs

36. Types of two sided damage
- damage that penetrates the panel and breaks the
reinforcing fibres
-large crack
-fracture
-hole
- damage results in pieces missing
-broken or missing pieces

37. Two sided repair materials
Cleaning
- use recommended
cleaners
Adhesive
- panel patching
adhesive
Filler
-cosmetic
-structural
Reinforcing fabric
Appropriate abrasives

38. Cleaning Fibre reinforced parts
Soap and water
-removes water soluble contaminants
-use a wash mitt or sponge
-rinse thoroughly with water
Wax and Grease remover
-may be needed on heavily contaminated parts
-use of scrub brush may be used
-should not be applied to the damaged area

39. Plastic cleaner
-Liquid or aerosol
-can be called a “mild” wax and grease remover
-may contain alcohol
-do not apply to the damaged area or broken fibres
Using cleaners
-do not use a solvent soaked rag
-apply solvent to the surface of the panel so as to float
contaminants to the surface
-pour or spray on
-always use clean cloths to wipe solvents
-always wipe in one direction to prevent recurring
contamination

40. Repair procedure
-clean area as to manufacturers recommendations
-on the exterior side of the panel, create a bevel with
appropriate grinding disc, making a gradual taper 1 1/2”
wide, leaving no sharp edges
-remove all loose material
-prepare the back of the
panel by removing any
loose material
-sand the area to re-
ceive the reinforcement
patch
-wipe, then blow the panel
clean

41. Reinforcing the panel back
-the back of the panel is reinforced to provide strength to
the panel and the repair
-a backing patch can be used
-built up from layers of reinforcement material and
adhesive (pyramid patch)
-made as thick as the panel to be repaired
-backing panel can be used
-cut from scrap SMC or FRP having a similar contour
to the damaged panel

42. Front reinforcement
-proper reinforcement of the front of the panel will allow
repair to remain hidden through temperature change
-try to copy the amount of reinforcement in the original
panel
-reinforcing strips should be cut according to the position
they assume in the
cavity, from the
smallest to the largest

43. 1. Cut several pieces of
of reinforcing fabric
large enough to overlap
the damaged area by 2”
2. Use as many pieces as
deemed necessary to
duplicate the thickness
of panel to be repaired
3. Lay out a piece of wax
paper or aluminum body
tape larger than the
reinforcement patch will be
4. Mix repair adhesive

44. 5. Sketch out the rough dimensions of the patch on the wax
paper or body tape
6. Apply adhesive to the wax paper or body tape to a
uniform thickness is achieved with a plastic spreader
7. Begin laying out reinforcing fabric, applying more adhesive
between each layer to achieve saturation, stopping between
layers to use wax paper and a saturation roller to remove
any air pockets (do not leave wax paper between coats)
8. Alternate this procedure until appropriate layers of cloth
and repair material have been achieved to match thickness
of panel being repaired
9. Apply patch panel, and allow to cure in place, heat may
assist in cure time

45. A backing panel can
be made of scrap SMC
with a contour match-
ing the panel being
repaired

46. Making a backing panel
1. Cut a piece of SMC which overlaps the damage about
2-3” all around
2. Grind or sand off paint or primers from the front of the
backing panel and wipe or blow off
3. Clean and sand the backside of the panel that will receive
the patch approx.. 3” all around
4. Apply a 1/2” bead of adhesive
all around the edge of the
backing panel
5. Press the backing panel into
place until the adhesive has
100% contact all around
6. Smooth out excess material

47. Completing the repair using a bridging strip
- A bridging strip is usually needed when sectioning a panel
- Adds reinforcement to
the repair
- Helps minimize shrinking
caused by changes in
temperature

48. Making a patch panel
-patch repair can be
made if a similarly
shape panel is avail-
able
-uses a square or
rectangle hole
-requires bonding strips

49. To make a patch repair: 1.clean the damaged part
2.cut out the damaged area keeping the cuts as straight as
possible
3.cut bonding strips about 2” wide and fit them around the hole
4.remove all paint from bonding strips
5.clean and scuff backside of panel where the bonding strips
will be applied
6.apply a 1/2” bead of adhesive to the bonding strips
7.secure the bonding strips in place with screws or clamps
until adhesive cures
8.cut and fit patch panel, leaving at least 1/2” gap all around
9.clean and scuff sand the back of patch panel
10.apply adhesive to the bonding strips and secure panel into
place

50. 11. remove the screws
12. use a grinder to make
a 2-3” bevel on either
side of the gap between
the damaged panel and
the patch
13. blow or wipe clean
14. cut enough reinforcing
material to fit into the
taper
15. apply adhesive to the
taper, then lay reinforc-
ing cloth, more adhesive,
more cloth, until height
is achieved. Finish with saturation roller and wax paper