Introduction: Reinforcing Epoxy - Outdoor Lamp
This inscrutable is to show the use of metal mesh to reinforce epoxy repairs on almost any project; in this case on an outside light.
The entire weight of the light is hanging from where the repair is to be made but since the light is made from cast aluminum, the only choice I have is to use epoxy glue. However, epoxy is probably not strong enough to support the weight without some reinforcing. Wire mesh is a good medium to reinforce epoxy because the epoxy will flow over and around the mesh making it very strong.
The 3rd photo shows the hole in the inside top of the light and the 4th photo shows the mesh I used cut to size. You will notice that the area to be covered by the mesh has been outlined in the 3rd photo.
The 5th is the "Cold Weld" epoxy that I used because It is reasonable fast-curing and sets hard.
Step 1: Epoxy Reinforcing - Outside Light
Before making the actual repair, I needed to address the corroded studs that attach the two halves of the light fixture. It was easier to grind down the broken stubs of the bolts and drill 2 new holes at 90 degrees around the fixture. These holes were tapped 6-32 and stainless screws would be used to assemble the 2 halves together when the repair was completed. (photos 1,2 &3)
In this repair, it was necessary to force the mesh into the concave shape inside the light fixture and mark the perimeter of the mesh onto the fixture (photo 4). Once this was done, the area where the mesh and epoxy will go was scored and sanded to provide a good bond to the cast aluminum (photo 5).
I then mixed a very small amount of epoxy to secure the corners of the mesh to the housing. This allowed me to hold the mesh in contact with the housing while the epoxy sets without getting epoxy on my fingers (photo 6)
Once the epoxy had set, I turned the fixture over and glued the broken pieces on the top. When that had set, I cut the residual off the top and placed a piece of masking tape over the center hole to stop epoxy flowing out when I filled the inside.
Turning the fixture over, I mixed enough epoxy cover the mesh and to fill the inside of the mounting area.
Once the epoxy had cured, (about 1 hour), I cleaned off any residual epoxy using files and fine sandpaper. I also use fine sandpaper to clean off some corrosion around the top of the fixture. I then sprayed the bare metal with self-etching primer and then spray painter the entire fixture.
I re-drilled the center hole through the epoxy where the threaded tube went to assemble the fixture to the mounting bracket and fed the wiring through the tube for connection to the wall mounting box.
The new bulb is a 13 watt LED producing the same amount of light as a 100 watt incandescent bulb.