We do from time to time get asked to repair plastic on bikes that are more than thirty years old. These panels present some unique challenges. Panels made of ABS, age, this leads to deterioration that shows it’s self in a couple of ways. The first are fishers appearing in the panel as you pass heat over the area to be repaired and secondly moisture leaching from these hair line cracks. It is well known that untreated ABS is hydroscopic.
Recently we had a gent in with two very old Triumph battery covers that had stress cracks. I say stress but to be honest these were signs of their age. The next indication was the way little rivers of water came running out of the plastic as heat was passed over the repair area, with numerous fishers opening as well. This complication turned a straight forward repair into a bit of a challenge.
It is difficult to know how far to to take repair’s like this. It was handy that the owner was in the workshop to experience what was happening. We agreed between us to only make good the cracks and some of the fishers that lead into those creaks. Otherwise the repair would have become very expensive.
What a single sided repair could look like before new method
Wherever possible we try to fulfill the wishes of our customers. The work we are asked to do can be complicated and delicate at the same time, which can lead to some compromise.
For a long time one area of repair that our customers keep asking about is single sided repair. It is one of the most difficult repairs to achieve. Why? Because the customer adds a complication by not wanting to spend out on an expensive repaint. Which is very understandable when it comes to those annoying small accidents that happen in garages and sheds across the country.
Inner side showing welding with new method.
The reason this type of repair is difficult to complete is the heat from the gun penetrates through the broken area and puckers the paint and in some circumstances causes heat shrink. This leaves an unsightly look to the outer finish.
We have over the years completed this type of repair without this happening but it can be unpredictable in its outcome. Because of this we have been looking for a way to stop and or reduce the damage to the outer paint, leading to a more acceptable finish. Very recently we have come up with a method that may give us more control when it comes to single sided repairs. We are still in the early days of it’s use but are encouraged so far with the materials we have used it on. I must point out that this type of repair is only any good for small none structural repairs because this repair does not address the
This repair was completed using the new method.
issue of strength and is more likely to fail in the future. How far in the future only time will tell. We will always maintain that the double sided repair is the best and strongest as it gets rid of the crack completely.
We have noted that there is a fly in the ointment, namely super glue – people will insist that they have a go; we do not have a problem with this attitude but we ask that you use something else because the message is: super glue does not work!! Not only that it makes repairing it properly much more difficult and dangerous where plastic welding is involved and increases the cost.