Redback Motorcycle Smash Repairs - 1/ 9 Collie St, Fyshwick. Ph: 6280 5433
Race Glass Repair
Originally posted by @chubb
Race Glass Repair How To:
So I had a spill a couple of weeks ago at Wakefield Park clipping the ripple strip on turn 5, thus, resulting in my bike low siding across the tarmac. There was some damage to the bike of course. A nice hole in the belly pan, lots of damage to the upper cowl and some damage to the tail section.
All stripped down
When we do the repairs, we are essentially creating asecondary bond to the original structure of the fibreglass. There are two types of resins we can use. One is polyester and the other is epoxy. Polyester can shrink anywhere from 5% to 8%, creating stress after a certain period of time on the repaired sections. Epoxy type resins are more durable, hence stronger,and also more effective as a moisture barrier. It also forms a superior mechanical bond to other materials including cured polyester.
Firstly you want to examine the extent of the damage caused. Clean the surface down free of mud, sand or any other contaminants. If there is a crack, you would want to drill a small hole where the crack ends to prevent further cracks from happening.
Sand the area behind it to give the resin a better chance of bonding to the original piece. Mix up the resin according to the instructions. What works best I found is to actually dab the area being repaired first with the resin, then lay a sheet of glass on it, then DAB not BRUSH the resin onto the mat until completely saturated. Repeat for second and third layers and allow a working time of 24 hours. Extend each coat slightly beyond the previous to feather the edge. Should look like this when you are finished.
Finishing on the exterior:
Most fibreglass fairings uses a gelcoat of some sort to finish the fairing. Gelcoats are mainly made of polyester. I don’t exactly know how or where to get something like that so I used automotive body filler instead. I got mine from supercheap auto.
You need one of these
Again follow the instructions to for mixing of the bodyfiller. This time around, the body filler has a curing time of 20 minutes andonly 5 to 7 minutes of “workable” time before it starts to dry up.
What I used to sand was 80grit, then 100grit then 160grit to finish off. You may have to sand it all flat after the first filler application, spot any holes/uneven surfaces, reapply the body filler and re-sand everything again.
After all is done, it will look something like this ready for the final sanding then hitting it with paint.
Having a helping hand (@kelly) always help too.