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Motorcycle Parts - Carbon Fiber
Make
Your Own Motorcycle Parts From Carbon Fiber
by Vin Heron (vsheron@clara.co.uk)
Co-published in Gambalunga Magazine,
Moto Guzzi Club
U.K.Introduction - Moto Guzzi California (Jackal)
Side Cover
Carbon fiber moldings look great on a bike, are light, strong, generally
unaffected by fuels and oils - I could go on and on. They can cost a
fair bit, especially so if you buy ‘one-off’ moldings from a commercial
manufacturer.
I took up bikes again after a 40 year lay-off, ending up with a black
Guzzi California (Jackal). Having a bit of a poke around my machine, I
took off a side cover and found that the plastic had cracks round the bolt
holes. I decided I had to replace the covers and had a look to see
what was available.
After asking around, and talking to experts like
the guys at
Motorworks in the UK, it seems that although there are some carbon
replacement parts for other models, there is nothing in the UK made for
Cali’s. Because I like the look of carbon fiber, have a little
experience in laminating and molding, my mind was made up - replacement side
panels had to be made out of carbon fiber.
I know that there are people reading this who are true experts in this
kind of stuff and they will most certainly be capable of picking holes in
the fairly crude methods I have used and described below; it is however, a
pretty accurate description of how I actually went about successfully
producing the moldings and it worked for me.
The Skinning Process
This is a description of how to make a carbon fiber molding by
‘skinning’. You could, I suppose, describe skinning as a reverse of
molding; in molding, carbon fiber is applied into or over a mold and the
finish that will eventually be seen is the surface that was next to the
mold. In skinning, it is the opposite way round; you apply a carbon
fiber skin over a mold and the finish is achieved by building up successive
coats of resin and rubbing down till you end up with a smooth surface.
By using the skinning technique, you save all the work of making a mold.
With modern materials and a bit of care and practice using the skinning
process, you can end up with a finish that is as good as a commercially
molded item, you can (hopefully) re-use the part that you used for pattern
and it’s fairly simple, very quick and very cheap.
Making Patterns
One point on the molding of other bits for your bike - if you don’t have
a pattern, one can be produced in a soft, easy to shape material such as
white, blue or pink foam. Rough out the shape by carving the foam
using a bread saw, (this works better than it sounds),
coping saw or the like and then sand it to shape.
If you have an
old vacuum cleaner in your workshop it will save you, the workshop, the cat,
et al from becoming covered in small blobs of foam. Smooth things off
by sanding it with a ‘Permagrit’
sanding bar (see the ‘Suppliers and Data
Sources' section at the end of this article).
When satisfied with the general shape, finish off by filling any dents,
dings, seams etc. with something like
Polyfilla and
sand it smooth. When satisfied, paint on a coat of thinned
PVA glue
(thin it with water about 50/50) over the whole thing, which will act as a
sealer and the carbon fiber can be applied over that. When you have
completed the molding, you can either release it from the pattern or if it’s
stuck, remove the foam by either cutting it away or dissolving it with a
suitable solvent.
As with many things in life, once you have tried it, the mystery, but not
necessarily the fun, tends to go out of it and thus it is with making foam
patterns. Without going into hot-wire cutting techniques, I have seen
some very clever things done with foam and a bread knife. But I
digress...
Commercial molders generally produce carbon fiber moldings using a vacuum
box and an autoclave. They produce moldings which tend to be bit
lighter, but not really all that much stronger, than the ones we are going
to make although I don’t suppose a few grams of weight is of much
consequence to the average Guzzi owner.
Although not everyone has an
autoclave, it is possible however, to replicate part of the commercial
process by using vacuum bagging techniques, and it allows us to reproduce
fairly complex shapes.
Vacuum Bagging
The technique works as follows: you place the carbon fiber over your
pattern, wet out the weave with epoxy resin and then shove the whole lot in
a polythene bag and remove the air inside the bag using a vacuum cleaner.
Give it a good suck to remove all the air, tie-wrap the end of the bag to
maintain the vacuum and allow it to cure.
By creating a vacuum inside the bag, you are applying approximately 14.5
lbs. atmospheric pressure to each square inch of the molding, which forces
the carbon fiber to take up the shape of the pattern and without much effort
on your part.
The pattern may be a fairly complex shape but with a bit
of practice, you can achieve an excellent result. Once the first coat
of resin has cured, you have the shape ‘set’ and can apply subsequent coats
of resin without any problems.
Carbon fiber doesn’t really enjoy being forced into complex shapes or
around compound curves, and if you try and do it manually, the weave can
become distorted and spoil the look of the thing. Try it with a spare
bit and you’ll see what I mean. Using the vacuum bagging technique is
an excellent way to teach it some manners.
Materials, Properties and Handling
Resin:
- In principle, the warmer the ambient temperature, the faster
the mixed resin will cure (harden). More later.
- The warmer the resin (up to a point) before mixing it, the
easier it will flow during application however to balance this, each
coat will be thinner as the viscosity is lower
- There are many different types of resin - don’t be a tightwad
and buy the cheapest. Get a good quality laminating resin - it
really is worth paying a little extra and it’s pointless spoiling
the road for a ha’p’worth (Editor's Note: A Yankee translation is
"being penny wise and pound foolish") of tar.
- Resin is exothermic when mixed with hardener i.e.: it can give
off a surprising amount of heat as the chemical reaction of curing
takes place (Note: see the bit on “volume mixed” in the ‘Note’
below - the degree of exothermic reaction can be dependant on the
amount of hardener added and the volume mixed.). I tend to mix
it up in containers such as those plastic pots you get coleslaw /
whatever in from the supermarkets. When finished applying the
stuff, sit the pot containing the excess either outside or on the
concrete workshop floor to cure and cool.
Carbon fiber cloth:
- It needs to be handled gently, in fact the less handling the
better. Be careful of the weave fraying at the edges.
- Use very sharp scissors to cut it. If you hack away with a
blunt pair, you will end up with frayed and raggy edges. A sharp
scalpel and a steel rule can also do the job.
- To prevent fraying, you will sometimes find that it has masking
tape applied to the edges. Don’t even think of peeling it off or you
will end up with a mess. Cut it off with sharp scissors.
- Work over a flat surface when you are cutting it and make sure
you have plenty of room to move it around.
Whilst I may be stating the obvious (something they tell me I am very
good at) it had to be said, as does the next bit.
Health & Safety, Furry Moldings, Stiff Trousers
I have no idea of what you know so I have had to address the basics here and
include health and safety aspects, however it really is only common sense
well applied to a specific operation.
- Resin fumes are an irritant. Make sure you are working in a
ventilated room / workshop. Don’t eat, drink or smoke whilst at
it. The fumes are pretty pungent so don’t do it in the house
unless you can afford the divorce settlement.
- Always wear latex gloves when working with resin. Dermatitis
is not nice. Wear eye protection if the possibility of splashes
exists. If you want to do belt and braces, get some barrier cream
and apply to your hands (for the person that’s bound to ask - yes,
before you don the gloves).
- Carbon fiber dust is really not good for you - wear a dust mask at
all times when carrying out cutting, filing or any other operations that
will cause dust. Wear latex gloves when handling the raw material.
- Know this: Before you do any laminating, lock up, give away or sell
the cat (the bagging technique may be found useful at this point).
The cat that owns us generally comes down to the workshop when I am in
there to keep me company and have a bit of a purr. He once rubbed
himself against a lamination before the resin had fully cured - ergo:
furry moldings. He then rubbed himself against my legs - ergo:
stiff trousers. Animal lovers please note: don’t write in whinging
(Editor's Note: "to complain fretfully") at this point or the cat gets
it.
Consumables
Carbon fiber cloth – use a woven type. There are different
types of weave / weight / thickness. You don’t need too heavy a
cloth, but although a thinner one is generally easier to mold, it means
a single thickness molding is more flexible and will need stiffening.
I tend to buy offcuts of whatever thickness I can get from a bike place
that does moldings. That way it doesn’t cost too much per sq.
meter and I can modify the methods I use to suit what I get (cut the
coat to suit the cloth?).
- 2 pack laminating resin. Within reason, get the best you can
afford.
- Mold release agent.
- Hard carnauba wax (don’t use the liquid stuff)
- Wet & Dry paper – around 380 and 600 grit size should do the trick.
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- Chopped strand glass fiber mat - (optional).
- Spray tin of automotive clear lacquer.
- Plastic mixing pots / lollipop sticks for mixing.
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Tools & other Equipment and Consumables
Rubbing down block (the rubber ones are best – flat one side and
curved on the other, they have pins to hold the wet & dry paper in
position).
Stainless steel washers for reinforcing the bolt holes or offcuts
of Aluminum sheet (16 or 18 SWG) for load spreading plates for fixing
holes (optional). (Editor's Note: SWG is (British) Standard
Wire Gauge; AWG is American Wire Gauge.
Here's a conversion chart.)
Dust masks - paper disposable type are OK (not optional).
Note: these are for protection against dust particles and NOT fumes Tac Rags - wipe down the molding after rubbing down in between
coats to get rid of dust. ‘Tac
rags’ (used in the automotive painting industry) are good as they
pick up all the surface dust – get them from car accessory dealers.
Latex gloves - disposable type (not optional) l)
Paintbrushes for applying the resin to the molding. You will
get through a few.
Acetone which is used as a brush cleaner. Note: Acetone fumes
are toxic – it should be used only in a well-ventilated place. Not
to be used to remove resin from your hands as it is a skin irritant.
Read the warning labels on the container or get the
COSHH (Control Of Substances Hazardous to Health) for Acetone.
(Editor's Note: Also Material Safety Data Sheet (MSDS) -
here's a list of MSDS's for Acetone) data sheets at the web address
shown at the end.
Methylated spirits which is used as a (safer) brush cleaner. Also
use it to get any resin off your hands. Has a very low flashpoint and
consequent fire hazard. Try not to smoke when using it unless you are
keen on self-immolation.
Molding
Pattern Preparation
Relax. If you screw anything up in the following stages,
don’t worry about it. Have a good swear at the cat (it’s
probably stuck to the molding anyway), a cigarette / mug of tea /
coffee and start again. This particular molding is so small
that you can easily start again from scratch which won’t waste too
much time, certainly won’t break the bank and as a further bonus,
you are adding to your experience and skills all the time.
Worst case scenario is if you screw up the molding and get it stuck
to the pattern however to do that, you really have to try hard.
Ensure that the pattern surface finish is as good as you can get
it. In this case, the plastic cover normally has an excellent
finish that needs no additional work other than waxing. If you
need to, fill any pinholes with filler, finish off with fine wet &
dry used wet. Polish out any minor imperfections with ‘T Cut’.
Apply a good quality hard wax. Any make that contains a
high proportion of ‘Carnauba’ wax is the business but tends to be
more expensive, however for the amount you will be using, hang the
expense - chuck the cat another canary. Apply a coat of mold
release agent. Allow it to dry, polish with a soft cloth and
apply another coat. Repeat in accordance with the
manufacturers instructions. You can reckon on between 3-5
coats of release agent. The release agent should be applied to
the pattern both inside and out for reasons that will become
apparent later.
Applying the Resin and Molding the Carbon Fiber Cloth
Don’t do molding if the temperature where you are
working is less than about 15 degrees C (59 degrees F); the ideal
range is about 15-25 C (59-77 F). If it gets cold, I usually
shove the molding in a cardboard box with a small hole cut in one
corner and poke a hairdryer into the hole and go and have a smoke
and a cuppa (Editor's Note: be careful doing this!). This
gives you a very crude, but very effective curing ‘oven’.
This
technique also helps maintain matrimonial (or should that be
matriarchal) harmony - I was once read the riot act when I tried to
lightly bake a molding in the oven – only in the interests of
science and technology you understand. The riot act was also
read when during a wet season, I once tried to dry our Walnut
harvest in the tumble drier but that’s another story (the noise by
the way, was pretty awesome).
Shape the carbon fiber cloth gently over the pattern making sure
you leave about 15mm (or ½” in old money) or so overlap hanging over
the edges of the pattern which will be trimmed later. Don’t
pull it as you will stretch it out of shape and it will spoil the
uniform look of the weave. Trim the edges of the cloth to
size, using a set of very sharp scissors taking care not to fray the
edges too much. Have the Hoover, the poly bag and a couple of
poly bag ties on standby (V. large sandwich bags work well).
When satisfied that the carbon fiber cloth fully covers the pattern,
mix up some resin.
Ideally, you are looking to get an even coverage of resin over
the carbon cloth - you can always rub down any runs later.
Make sure when spreading the resin that you don’t pull the weave,
raise any individual strands of carbon or stretch it – we need to
try and keep the weave looking even and flat. The method that
works for me is to make sure the resin is warmish before I mix it
(reasonable ‘runny’). I pour it on the cloth and brush it out
very gently and only as much as absolutely necessary. The
objective of this stage is to wet the carbon fiber right through the
weave with resin and provide a hard ‘shell’. You should have
no problems with air bubbles doing it this way.
Vacuum Bagging the Molding
 Apply the resin carefully and gently spread it evenly to cover
all of the carbon fiber cloth including the overlap. Use
enough resin to wet-out the fiber but don’t put great dollops of the
stuff on. Shove the whole lot into a plastic bag, taking care
not to alter the position of the carbon fiber over the pattern.
Gently shape the carbon fiber over the mold through the bag and
shape the overlap around the edge of the pattern (this is why we
applied release agent to the inside: the carbon fiber should curl
round the edge & the overlap will mold itself to the inside of the
pattern).
I would recommend that if you have any doubts about
this part of the operation, don’t grasp any of it (and given my
writing technique this is understandable), or even if you do - try a
dummy run without the resin. It only takes a minute or so and
will give you a better idea of how it is done.
When satisfied that the carbon cloth is in the right position,
turn the Hoover on, open the air bleed so that it isn’t sucking too
much, gather the opening of the poly bag and stick it into the
Hoover nozzle. Have the bag tie ready and when the Hoover has
sucked all the air out and starts to ‘redline’, tie the bag end.
Make sure that the vacuum is holding. If it is not, give it
another good suck with the Hoover. I had a problem holding a
vacuum with one bag and just left the Hoover running until the resin
cured (the Hoover motor re-build didn’t cost too much).
Anyway, sit the whole lot somewhere warm and it should cure within
about 20 minutes.
Hardening times vary a bit with resin types,
manufacturers and temperatures so that I can only give you a guide.
With an ambient temp. of around 25°C, I was working in the open air
and the resin I was using was going off within 15 - 20 minutes.
When the resin hardens, remove the molding from the bag.
You might tear the bag when getting it off but that doesn’t matter.
When you are sure there are no bits of polythene bag left sticking
to the molding, apply another coat of resin spreading it as evenly
as you can.
The molding may well separate from the pattern at this point.
If it is a large part that is being molded it will be a bit ‘floppy’
in which case shove the pattern back to give it some rigidity until
you have applied further coats of resin. With small, rigid
moldings like this however, it doesn’t really matter providing you
handle it reasonable carefully.
Applying Further Coats of Resin
It is surprising how far the stuff goes and this is a very small
molding - experience will quickly tell you how much you need to mix
(Important - see also the note in ‘End Stuff’ below on volume
mixed). What we are trying to achieve at this stage is to
completely fill the weave by adding further coats of resin until we
end up with sufficient thickness to rub down without cutting through
to the carbon cloth.
Keep on applying thin coats until you
have a layer of resin built up - you will probably need about 3 +
coats to do it. When satisfied, give it a gentle rub down with
380 wet & dry paper used wet. We are trying to take the top
off any lumps and bumps in the resin only. Again, be very
careful not to cut through the resin and abrade the carbon cloth.
Don’t worry about the finish on the overlap as this will be trimmed,
however, do make sure that it has been wetted out with at least one
coat of resin.
After applying about 3 coats of resin, the overlap will need to
be trimmed. There are several ways to go about this and you
will have to choose the one best for you. Depending on the
method you use, make sure you wear a dust mask - as stated earlier,
carbon fiber dust is not good for you.
Trimming the Mold Edges and Removing the Pattern
 The goal is to leave about 2-3 mm of overlap to enable the edge
to be sanded flat and even. If the pattern has come away from
the molding (either at this or at any previous stage), that is fine.
All we do is to fit the molding back onto the pattern and mark round
the edges with a very soft thick pencil so we know where the edge
is.
You can trim the edges using:
- a ‘Dremel’ tool and a very thin cut-off wheel, however you
have to take great care not to slip or allow the wheel to jump
out of the cut and damage the molding. Causes a fair bit
of dust doing it this way.
- a very fine bladed razor saw to cut off the excess.
Tool stores or model shops will be able to supply them and they
are a useful tool to have in your box. If you use a blade
with large teeth or try to rush it, you will splinter the edges
for sure. This is steady-away stuff and you need to be
careful to cut at an angle so as not to tear any of the carbon
fiber, break off chunks of resin or splinter the edge of the
molding. This is not a bad way to do it - less dust and
more controllable.
- a scalpel. It can be a bit tedious as it needs a fair
bit of care and patience but provides good results with no dust.
If you are a bit ham-fisted, make sure your local A & E (e.g.,
hospital!) has someone on standby who is good at stitching.
- If you are very careful, you can trim it using a pair of
sharp tin snips or wire cutters. This is my personal
preference but may not suit everybody.
Releasing the Molding From the Pattern and Trimming the Edge
Whatever method you use, take your time, use the Mk.1 eyeball
often and cut gently. Don’t try to rush it – you have lashings
of time. Trim the overlap then gently twist the molding
backwards and forwards a few times and you will hear clicks and
creaks as the molding separates from the pattern.
Work your way
around the molding easing the edges away from the pattern with your
fingers. The molding should release from the pattern without
too much effort. (This could be the point at which you find
out whether or not you applied sufficient release agent)
Worst case scenario is if the molding is well and truly stuck to
the pattern. If it is, and there is nothing you can do to
shift it, no problem (at least not with a side panel) - just use it
as-is in which case you have a carbon fiber molding with a bit of
plastic reinforcement inside it.
Once the molding is separated from the pattern, give it another
couple of coats of resin making sure the remaining overlap gets a
good coat.
I initially use a file to remove most of the lumps
and bumps from the edge and then place a full sheet of coarse wet
and dry (something like 120 grit) on a flat surface, place the
molding on it and rub the edge down by moving the molding back and
forth until you are happy that the edge is nice and flat and that
the overlap has been removed; don’t worry if it’s not absolutely
perfect as we aren’t watch-making here.
Rubbing Down & Applying Logos
If the ambient temperature is at a reasonable level, you will not
have to wait too long for each coat of resin to harden to the stage
where you can rub it down. If you are working in a cold, damp
and draughty shed then it will take much longer to harden.
Build up the finish by brushing on more coats of resin. Rub
down in between coats with 380 wet & dry paper used wet. This
way you get rid of many imperfections as they happen and they are
not carried over to the next coat. Just be careful you don’t
cut through the resin and into the carbon fiber.
As you add
subsequent coats the finish will improves. Use a dollop of
washing-up liquid in the water (you don’t need much to do the job)
which will give better wetting properties and prevent any sticking.
Once again, and I can't stress this enough, when rubbing down, be
very careful not to cut through the resin and abrade the carbon
cloth (or the logo / transfer if you have applied one).
You
don’t want to ruin the finish at this stage. Y ou want to end up
with a smooth pinhole free surface that is ready for polishing.
I applied about 7 coats of resin, rubbed down between coats, to get
to this stage.
When you have a nice smooth surface, you can get very tricky
indeed. If you want to apply a decal / transfer / logo
whatever you want to call it, this may be a good point to do so.
Make a test piece to make sure the resin is compatible with the
transfer by applying a decal to a bit of aluminum or whatever, then
pour a bit of resin over it to make sure the resin doesn’t melt the
decal. Wet slide decals are generally ok (the same as those
you used on model aircraft when you were a kid?).
Apply the
decals and after they have dried, you can apply further coats of
resin to ‘cast’ them into the finish. This can give a lovely
‘depth’ to the final finish. I normally take an alternative
route and finish off the rubbing down before applying the transfers
then spraying the molding with several coats of Acrylic lacquer.
This may suit you if you want to use other types of transfer.
More anon.
Internal Reinforcement and Washers
I examined the molding after about 4 or 5 coats of resin and
because I had used a fairly light cloth, decided that it needed to
be a bit more rigid. I also decided that because I wanted to
mold in some aluminum alloy (Dural) to provide load spreading plates
at the fixing points, I would apply a layer of cloth over the whole
of the inside surface as the additional work was negligible, weight
was not a consideration and strengthening the molding was no bad
thing. You could if you wish, just apply reinforcement
locally. It is also possible at this stage to mold in other
types of reinforcing, stiffeners or fastenings.
Fit the molding to the pattern. Mark through onto the
molding the position of the fixing holes with a soft pencil.
Mark the hole centre, use a Mk.1 eyeball to get the position, and
drill through with a very small drill.
Don’t forget to wear a
dust mask for this operation. If you have a sharp ‘pyramid’
hole drill, you could now use this to open the hole up to accept the
fixing bolts. Check as you go using the pattern as a guide until the
holes are opened up to the correct size.
My preference is a
rotating burr fitted in the Dremel however In the past I have used
pyramid drills, rat-tail files etc. In all cases, take your
time and cut very gently or you will chip or splinter the resin if
you rush it and try and remove too much material at a time.
Once done cutting the holes, get the reinforcement sheet, clean
and degrease it and roughen the surface with a file, hacksaw blade
or whatever to give it a bit of grip and stick it on the inside of
the molding using a bit of ‘Araldite’
rapid or even a tiny bit of resin as an adhesive.
Make sure it
is stuck centrally over the hole in the molding. These plates
will add strength to the molding in the area of the bolt heads and
will spread the bolting loads, preventing cracking or splitting of
the covers.
Once the stuff sticking the sheet into place has gone off, cut a
piece of carbon cloth or chopped strand mat sufficiently large
enough to cover the inside of the molding. Lie the cloth or
mat inside the mold and mix up some resin.
Apply it to the
cloth/mat and make sure all is well covered with resin. Make
sure you remove any air bubbles. The objective is to get a
layer of cloth/mat inside the mold to provide additional strength
and to fully mold in the sheet. Allow to harden and apply
another layer of resin.
Definitely no watch making here – just
get the cloth/mat fully covered with resin and without any fibers
sticking up. If you feel like applying another coat of resin
just to make sure then go for it - any weight consideration is
irrelevant.
Allow the resin to fully harden and cut or file off any hairy
bits sticking out over the edge of the carbon fiber molding.
Finish the edge off with wet & dry used wet. The next bit is
to clean the cloth or mat from the bolt holes. Drill through
and clean out as before.
Finishing-off
When you are happy with the molding finish, and you want to have
a logo or decal on the panel, the time to apply it is after the
final rubbing-down. Then spray on several of coats of acrylic
lacquer. Allow it to dry for a few hours and finish off by
polishing with ‘T Cut’ till you are satisfied. Then apply some
of that lovely carnauba wax and buff to a mirror shine. And that’s
it.
If a matt finish is the one that blows your skirt up, then
instead of using wax you could try finishing off by gently rubbing
the surface with a bit of metal polish. You could also try
jewelers rouge to the same end.
Jewelers rouge by the way, is a very fine, red (hence ‘rouge’)
abrasive paste used by, yes you’ve guessed, jewelers.
You
should be able to get it at any good engineering equipment supplier
shop or if they don’t have it, and they are at all worth their salt,
they will know a man who has.
Finally, and this next bit really is mandatory, fit the molding
to your bike, stand back and admire it for ages. Tasty stuff and you
did it yourself.
Other Moldings
If you decide to make carbon fiber moldings using other panels or
bits on your bike as patterns, the main points to consider are:
- Will the shape of the part allow the molding to release
easily ?
- Will rigidity be a consideration? Depending on shape or
size, you may have to use a thicker cloth
- Will it need reinforcement for such things as bolts, Dzus
fasteners etc, as described earlier?
- Is it a complex shape with compound curves? Does it
need vacuum bagging to mold it effectively (and do they really
make sandwich bags that big)?
There may be other considerations but these are the main ones. If
you don’t have a part to replace and want to make from scratch, get
out the foam and bread knife. A word of warning though - once
you achieve success, and you will with only a bit of practice, it is
very difficult not to look at other bits without wondering “what
would that look like done in carbon fiber?”. Usually, the
answer is v. nice.
End Stuff
 How did my side cover moldings turn out? Well, there
were/are a couple of slight imperfections in the finish e.g.: I
didn’t notice the bit of cigarette ash that got stuck on the wet
resin. It is now immortalized (like a modern-day fly in
amber?) in my molding.
During a ham-fisted session, I dropped
a molding after one or two coats of resin had been applied - there
is a tiny star crack molded into the finish. There was a
little bit of de-lamination on the inside at one of the edges but I
ran resin into it and it turned out fine. Overall - not too
shabby.
The bolts that hold the cover in place really had to go.
Scrabbling around on the ground looking for a dropped bolt after
replacing a fuse is not my idea of fun (and the spectators didn’t
appreciate the bad language either).
Ducati fairings are held
on with a Dzus type fastener ( ¼ turn to release) that has a ‘D’
shaped ring that lifts up and you can undo them by hand
– they are the absolute business and are what I fitted.
Sources of supply are manifold; try Dzus fasteners.
Note on Volume
One REALLY important lesson I learned was that the volume of resin you mix
can be important. During the manufacture of the first side cover, I
decided after applying a couple of coats of resin to reduce the volume I
mixed up to try and avoid wastage, however to my horror, this coat of resin
did not fully harden in a couple of places and remained a bit sticky.
I originally thought it was traces of Meths on the brush that had caused the
problem however discussing it with a mate, I discovered that apparently some
resins need a certain volume before the chemical reaction of hardening is
fully effective – the ‘critical mass’ I suppose, and I failed to make the
connection at the time. However, I rubbed down the sticky bits and
after upping the volume of resin to that used originally, I slapped another
coat on and all was back to normal.
If you get stuck, I will help where I can. E-mail me at
vsheron@clara.co.uk. If you
do send an e-mail, please make sure you put a relevant and descriptive title
in the subject box – if I don’t recognize the sender or the subject of an
e-mail, I delete it at the server without reading due to the sheer number of
viruses flying around. Replies may take a while as I am pretty busy at
present (they’ve drained the swamp… etc)
Other Stuff
The following is all biased towards UK suppliers (makes sense when you live
there) however have a look at the Carbon fiber & Kevlar hybrid cloth on the
Fibertech GB website.
I recently saw and handled this stuff on their stand at a show and the photo
on the website really doesn’t do it justice.
I thought it looked
awesome, however at £23 per half metre length, so, it would seem, is the
cost of the stuff. When you consider however, what you can do with it,
and what a unique molding it would be, this tends puts the cost in context
as the cost of a plastic OE replacement side cover is around £25 (ish)
second-hand. I definitely intend to make something out of this hybrid
cloth as soon as time permits.
At present, I am fiddling around with the aim of replacing other parts on
the Guzzi such as the alternator cover, the fairings just at the front of
the tank next to the fork bushes (I don’t know the correct term) or even the
rot-prone thin steel mudguards. I am curious to find out if the raised
letters on the alternator cover come out all right - I reckon with a light
enough cloth it may be OK.
I have not yet decided what are, and what are not, viable options but
when I do, and if it turns out successfully, I will pass the info on.
Suppliers & Data Sources
Engineering suppliers as described earlier for the various bits of kit.
Car accessory shops for wet & dry, rubbing blocks, chopped strand mat,
possibly resin. Carbon fiber cloth suppliers via the web or off-cuts
if you know a local outfit that does commercial moldings. Model
aircraft suppliers or shops are a good source of further info on carbon
fiber cloth and resins.
Some websites I find very useful:
-
Permagrit
- (Permagrit sanding blocks. Some good info and links. Know this: once you
have used a perma-grit tool, you will never be without one in your workshop)
-
Materials - some good epoxy application info.
-
Resin - range of resin types with application data.
-
Composites and resins - some good info.
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Knowledge is Power: Have a look at the
University of Bristol site for COSHH data sheets. You can then be
fully confident about using the materials described above.
End Quote
Of some relevance when trawling the net: Arthur C. Clarke (he of science
fiction writing fame) is quoted as saying “getting information from the
internet is like taking a glass of water from Niagara Falls”. I reckon
he hit that one right on the head.
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