A distressed looking man is walking towards the doors of the workshop, in his hands are two plastic shopping bags. We unpacked the bags and laid out the contents piece by piece on to the work bench. I started placing the jigsaw of a faring together, the shape it formed was that of a Honda CBR 600F side panel. On closer inspection it became more complicated, there were a number of pieces missing, some of these major.
I looked at him, he said “I was told it could not be done” I replied ” The only limiting factor is price” A smile crossed his face the first bit of good news in his quest to put his pride and joy back on the road. ” This is why we say bring it in let us see it in the flesh.” It was not a lost cause. After fixing the price, he left with a happier look, to return in a couple of weeks.
We had our work cut out, first thing to do was to fix all the bits together so the main part of the faring was in one piece, then we could start fabricating the missing parts, these would be cut from sheet plastic of the same material, if it is not the same type it will not weld together.
We are not like other repairers in that, we do not use two pack fillers to replace parts that are missing in thermoplastic products which a lot of faring’s are made from. Other repairers will do this were they can get away with it or say it cannot be done. If you have a vintage farings on your bike would you not want the best repair possible for this rare item? I know I would!
When you use the same material to repair a breakage it should act in the same way that it did before it was broken. If you introduce another part whether it’s filler or fiberglass it will change the way the panel acts and can cause the repair to fail in the future.
When the man returned he did not believe that it was the same panel until I showed him the back with it’s fine lines of weld. He was very pleased with the result.
Mister street fighter Alan (good friend) decides to put a Ducati 916 seat unit on his GSXR. I said “what’s that got to do with me?” “Well, I want you to turn the square back lights into round inset lights! Can you do it?” he said. “Of course, but you find the lights you want to fit!” “Deal.”
A few days later he turns up with the light housings. Now the work begins.
Turning the square holes into round ones was straight forward. Making the housing to mount the new lights on was not. It means weldingplastic mounts into the seat unit that would take a plate with the lights on and come out with ease once on the bike, not fouling on the frame.
It all went surprisingly well; Alan was over the moon when it was finished. The only reservations I had was the red paint work on a blue and white paint scheme. Turns out Alan had a problem too with the paint work because the next time I saw the bike it was black with polished metal work. Now it looked really sexy!
It is not that well-known among the wider biker community that we were the first to put a set of foxeyes ( head lights from a Honda fireblade) into a Suzuki GSXR 11oo nose cone. We were also the first to do it using sheet thermo plastic, molding it to fit an existing faring and welding these parts into place giving it durability and strength and above all that distinctive sexy look.
GSXR nose cone custom
Nose cone custom to except Honda fireblad headlights
I only discovered recently that the nose cone was still about, in good condition and in one piece. But sadly not on the bike it was made for. It turns out that it is sitting on a shelf in someones garage looking for a new GSXR home.
I am pleased to say it has stood the test of time. Just go’s to show plastic welding is number one for repairs and custom work.
When considering whether or not a panel is worth repairing you need to take a number of things into account: Paint, decals, age and in some cases the foam backing.
Some manufacturers stick foam to the back of their side panels to stop the engine/frame
work rubbing against the back of the faring. It also stops any knocking noises and vibration while the bike is being ridden. When a panel sustains damage resulting in a crack or breakage or both, it does not always transfer to the foam behind. Even if it has not, the foam needs to be removed to do a repair. Where plastic welding is used the heat from the machine will melt the foam giving of a noxious gas. In most cases we can separate the foam in one piece from the plastic panel. So it can be reattached after the repair is compete, there by saving the cost of new foam for the customer.
There are some situations where it can not be removed in one piece. Foam, like plastic, deteriorates with age but at a faster rate. There are two types of foam backing – open cell and sealed. The former gets impregnated with road dirt, oil etc, this helps to degrade the backing more quickly turning it to dust, making it impossible to remove in some cases. Because the later is sealed it repels most of the detritus thrown up from the road and stops oil soaking into it. This increases the life of the foam, therefore making it a better candidate for removal when a repair is needed. The sealing helps to keep it in one piece making it easier to remove.
The pictures show.
Thunder cat side panel. One with the foam mat partly removed.
Even though plastic welding has been around since the seventies it is still surprising when a faring from that era comes in, how much fibre glass has been used to patch up the damaged areas. We were asked if it was possible to repair the plastic panel on a GSX 750 Katana the one with the pop up head light.
From what I have already said you would have gathered that these panels were in a bit of a state. Of all the farings that turned up it was the left and right side nose panels
( the nose cone in this case is divided into three section two sides and a Bezel that fitted around the pop up head light) that presented the biggest challenge. The customer wisely turned up with two panels for each side. The problem was to work out how much of each panel was the original plastic and which pair had the least fibre glass holding it together.
Fortunately the headlight bezel only had a cross shape lug missing. In itself not a difficult repair
but time consuming to reproduce. All the side panels were heavily damaged where the side mirrors would be mounted. One of which had a big bit missing.
The first thing that needed to be done was to get rid of the large quantity of fibre glass from the damaged areas.
Once it had been ground off the outside of the panel. The stuff caked over the inside was gently persuaded to leave home, coming away in one piece. Almost leaving it clean enough to weld. It just go’s to show if it had not been fibre glass both sides it would have fallen out ages ago.
The one thing plastic welding does not like is contamination of any kind. Which meant we had to remove as much of the residue as possible to be sure it would repair properly.
Once that was done new plastic was cut into shapes to replace all the missing bits. Because alot of the damage was concentrated in one place we had to be careful about over heating. By phasing the repair it would keep the heat shrink to a minimum, making for a better repair over all. You also have to take into account when renovating old plastic it has a tendency to get very brittle. A way round it is to temper the area with some heat before you start welding it together. This also helps to drive out any water that the plastic has soaked up over the years. This leads to a stronger weld and a satisfied customer.
Not all the plastic that turns up at our door can be repaired by gas welding. Dare I say it that we have to resort to two pack bonding don’t get me wrong it is a good repair but 90 seconds to apply the adhesive is not on some occasions enough time to get the job done.
This weather has implications for automotive plastic ( farings, bumpers, etc,etc ). Plastic looses its elastic properties when the temperature drops making it hard and brittle but this does depend on the plastic material used.
There are two main categories of plastic hard and soft. Hard plastics like ABS used in motor bike farings, can become very brittle and break easily. Soft materials like Polyprop , being more flexible , will not crack so easily but will show signs of stress in the cold.
With the weather as cold as it is, it means that any damage your plastic receives will be twice as bad. So take a bit more care around that bike stored in the garage.