Today, fiberglass repair kits make it a very convenient way to do
those much needed repairs around our home, boat or car and so many
other things in between.
With a growing number of fiberglass products coming onto the
market it is becoming a matter of choice as many products have a
universal application, although it is
still important to know which ones will do the job and do it
There are many brands and types of resins available today just as
there are different types of reinforcements for different applications,
so how do we know what to use? Well for most, they just go out and
buy a Fiberglass Repair Kit and for most of these people that will do
So, what else do we need? For a start, we need to know what we are
repairing, the most common forms of fiberglass repair will come from
boats, personal watercraft, cars/4WD and trucks.
other thing to consider is "is it worth
repairing?", this is a very
sound question we need to ask ourselves as some items (like flares from
4WD to front fiberglass spoilers on sports cars) could be an expensive
and time consuming affair ending in "it would have been far
cheaper and quicker to buy a new or second hand one and get it
resprayed (to colour) if needed.
this as a guide, cracks/fractures or small holes should be easily
fixed using one of these fiberglass kits.
Fiberglass repair kits can vary in "what is in the box" as we will see
basically we will have our resin, catalyst, mat (which is csm-chopped
stand mat), mixing and/or measuring cup, mixing stick, gloves and
So, what about brands? is one brand better than the other? generally
speaking the difference would be the price and any extras you might get
apart from the basics.
Fiberglass materials in general have to meet a countries standard of
quality and assurance, so it will be a personal choice of what kit you
would buy. Always follow the directions supplied with the kit and make
sure you wear appropriate PPE when doing your fiberglass
Some times when we have failures we usually blame the product and
(rarely) it can happen, depending how long its been on the shelf and
the conditions it has been stored at.
But all in all the problem usually is us, so we need to follow
instructions and not make up our own to suit the situation at the time.
resins used in a fiberglass repair kit would be a general purposewaxed polyester resin (orthophthalic
our repairs get larger and require bigger quantities of fiberglass
materials or if we require a different grade, epoxies or we need
different types of mat and not just a
fiberglass kit, then we need to be looking at fiberglass suppliers who
specialize in these to suit our needs.
Some of these businesses and companies can be found here underLinks-Fiberglass suppliers
or in your local yellow pages in your telephone directory under
Fiberglass Materials depending on your country.
our next section under Getting started/Fiberglass canoe repair we will
cover from start to finish the whole procedure in detail of repairing a
crack in a Canadian style fiberglass canoe.
By the way this repair can be adopted to many different fiberglass
repairs including cracked panel work on fiberglass cars, small boats,
spoilers and body kits as examples.
So here is a list of the products that we will be using to cover this
repair, depending on your fiberglass repair you can take out or add to
you wish depending on what you may already have or the repair it self.
For more detailed information on all materials associated with
fiberglass repair and/or in construction this will activate when done. fiberglass materials and associated
products information page.
With this canoe repair that we will be doing, I will use a polyester
fiberglass repair kit to fix the
damage on the hull as this is what
most people would buy to repair it, although I would use a isophthalic
resin in the trade most people may not be able to get this grade of
to do a repair, so I will put myself where most people are.
The main difference between the two resins is that "Iso" grade is a
stronger and is more chemically resistance than "Ortho" grade which is
found in fiberglass repair kits which are used for general repair work.
I have heard some
suggesting to use epoxy resin to do the repair, if the canoe was made
epoxy, then I would use epoxy for the repair.
lets have a look at what we need in the way of tools, if you
haven't been here before you can go here for a list of tools that we
will need for this fiberglass canoe repair, we will also have a list of
tools and materials together at the end of this page.
Now, some other things we will need will be some colourant so when
we finish our repair we need to make it look and /or blend in with the
rest of the fiberglass canoe or object that we are repairing.
With our finished coating we have a choice of what we can put on it, if
canoe, boat or article is new or not very old (say less than 2-3 years
old and been garaged or undercover) and has a glossy gelcoat finish
then we will get a pretty good match in the original gelcoat colour
Gelcoat comes in a creamy liquid as a natural base (non-colour) or
white as the standard colour and can be tinted to any colour with base
a starting point (colour card), remember though that gelcoat will stay
tacky when it sets unless you add a little bit of wax and styrene to it
or spray some PVA release agent over it, so in this case we could use a
gelcoat repair putty which is gelcoat with fillers and wax added and
made into a rich, thick and creamy paste.
cracks, scratches (that cannot be cutout with polish) gouges, screw
holes example can be easily filled with a gelcoat repair putty, this
is white in colour and thick and comes in economical 375 gram tins with
catalyst supplied and dries to a non tacky finish.
the other hand if our fiberglass canoe or object is older and show
gelcoat or surface breakdown of the finish then we can paint it in a 2
pac or a single pack finish depending on our budgets and what we have
hand or whats available to you.
objects like repairing a fiberglass wheel arch flare on a 4WD or sports
car will be better off spray painting the whole unit, more so if the
is a metallic or pearl colour as this will blend in and will also save
time cutting in and polishing it to match the surrounding
So if we are not going to be using a gelcoat as our final colour then
will need the following materials to finish our fiberglass repair.
A small tin of car body filler that is suitable for fiberglass
and that will go under 2K paint (2 pac), a cork or rubber sanding
block, some sandpaper of 80grit, 150grit and 320 grit, a spatula,
paint scrapper or a plastic disposable bog spreader and a clean plastic
lid from a 2 litre ice cream
bucket or something flat and clean
to mix some filler up on and some clean cotton rag.
with this we also will need some primer, all this can be obtained from
a hardware shop and/or a auto paint place.
Septone is one of many top brands that work well and come in handy
spray tins and is easy to use and sand, always follow the directions on
the can before using.
Now, we will need a mixing container of sorts to mix up the resin in
unless one came with your kit, so a clean tin that will hold enough
resin to do the job will be fine (mixing containers).
Make sure it is clean and dry before use, a flat stick like a wooden
ruler (fiberglass repair kits usually come with paddle pop sticks) or
something similar to stir the catalyst through the resin when you mix
Next we will also need some sandpaper to level the gelcoat or car
for gelcoat a sheet of of 80grit, 150gt, 240gt and 320gt in dry paper
and a sheet of 600gt, 1200gt and 2000gt in wet n dry, plus a rubbing
The reason for so many different grades is that gelcoat is a hard
coating and requires many grades to bring it up to a very smooth
surface for easy polishing with a cut and polish.
For car filler we will need one sheet of 80grit, for the primer one
sheet of 320gt STOP? hang on!! why do we need so many sheets of
sandpaper for gelcoat compared to the paint system? Well gelcoat
remember is made to go into a polished mold hence why fiberglass
production items come out so shinny.
So now we are using gelcoat in a different situation, so we would
either spray, pour, brush, roller coat or spread the gelcoat over the
outer surface of the fiberglass repair and depending on how good we are
it could be quite rough or very smooth or anywhere in between but
either way it will require many grades of sandpaper to achieve the
Gelcoat is a very hard product and thats why it can shine up to a very
luxurious finish, but it takes effort to do so unless we put it in a
mold or lay it onto something that is shiny and prepared for gelcoat
e.g. a mold.
Now back to our paint system, if we are going to use a 2pac gloss paint
we will need our 80grit for our filler, 150gt and one 320grt for 2pac
or and a 600grt wet n dry for lacquer for the primer.
Some guys use acrylic lacquer, and others a 2pac paint and that will
also depend on what we are repairing, depending on your budget one
could use a enamel if you wasn't too concerned on its durability.
In our case we will be using a 2pac in a spray can and you read
correctly, these days and for quite some time auto paint shops that
deal in 2 pack paint for the auto trade can make you up a spray can
tinted from your colour chip pre mixed with hardener and thinners, in
the old days one would have to use this up well before the day was up
as it would start to thicken and set and become unsprayable.
But now and for some time the spray can has a little button on its
bottom so when we get it mixed at the shop we have at least a week or
two to activate this button to release the hardener into the paint,
afew minutes of shaking the can and we are ready to spray.
it is also a good idea to look at other areas around the car,
the object that we will be spraying cause it is on the cards that there
will be some left over, so if there are any other areas you find it
beneficial to prepare those areas as well so they can be touched up.
Some masking tape and paper may come in handy if your spray area is
near another colour, near the opposite door or guard of the car or
gunnel of the boat, I think you get my idea here we do not want to get
overspray on our undamaged shinny surfaces unless you are spraying the
So, lets recap on the on the basic material and tool list here,
of course you can take out what you don't need or what you may have
already at your disposal and also your method of finishing.
for a typical fiberglass repair.
to protect ourselves from dust/fumes or resin.
grinder with a backing pad and sanding disc/s.
A number of
sheets of sandpaper to prepare for our topcoat.
or something suitable to apply filler or Gelcoat paste.
container for resin.
mixing board for filler or gelcoat.
repair kit or fiberglass materials to do the job.
A tin of
Gelcoat repair putty. (if using this system)
A spray can
of primer filler or undercoat suitable under 2pak paint.
A spray tin
of 2pac or your desired paint system.
A tin of
polyester based auto car filler. (if using a paint system)
Some wax and
A roll of
newspaper to protect the surrounding surfaces from overspray.