I’ve been reading several past posts on annealing aluminum trim. Is there a primer for doing this on the site? If not, all of the information on annealing should be put into one set of instructions under the Important Information topic.
I’m going to look for some aluminum angle today or tomorrow (depending on Alberto’s mood), probably 3/4” or 1” x 1/2” as I need to screw the wide side down onto the roof and extending down the front and back corners, so that the narrow side of the angle covers the edges of the roof and front/back 1/4” plywood. (That also means a visit to HF for a metal punch.)
Here’s what I think I have learned about annealing. Please correct me if I am wrong and/or add any comments if I left anything out:
1. Use a candle to apply a light, even coating of soot to the aluminum (I presume that means to the inside of the angle by some of the photos I saw).
2. Use a propane torch to heat no more than a 6” section at a time until most, but not all, of the soot burns off, keeping the flame moving. Don’t overheat as aluminum trim will melt if too much heat is applied…when the flame appears to start turning orange, move on to the next section immediately. (Use a scrap piece to test to see how much heat will melt the aluminum, then stop short of that point when annealing for real.)
3. Allow the aluminum to cool slowly.
4. Install the aluminum trim by positioning one end, inserting a couple of screws, bending it down to follow the curve, and applying screws as you go to hold it flat. Flatten kinks or ripples in the other edge with a rubber or plastic head mallet. Using blocks of wood against the aluminum will prevent denting and allow use of a regular hammer. If the bend is too tight, you may need to cut some kerfs into the outer edge.
5. After annealing, bending the aluminum will cause it to re-harden. It can be annealed again if additional bending is required.
1. Screw holes. How much distance between them. I'd assume 4" on curves, maybe up to 6" on flat sections?
2. Screw holes in aluminum should be punched, not drilled? Before or after annealing? Or does it matter when?
3. What type of screw should be used with aluminum trim (steel, aluminum, etc.) Or does it matter?
4. Aluminum can be painted after proper priming, right? What type of primer is needed? Will the common "sandable primer" in spray cans work? I want mine painted white.
Did I learn my lessons? Thank you.