I've been fixing engine covers in this manner for about ten years so you're really on to it here. I use a black powercoated steel bar in the same spot and use either fiberglass resin or urethane to hold it on. Either work well and have never failed but I guess epoxy should work too.
The black steel bar is stronger than aluminum, cheaper, won't rust and nearly impossible to see when installed.
It also seems like a lot less work than your method as it's cut to size, sealed, and ready to go for less money than aluminum stock or as Chris Nicholson would say "Aluminnium"!!!! At 18.99 (#106364G) out the door why bother with a strip of aluminum which has gotten very pricey?
This # is my own assignment so don't look for in the parts manual or DMCH website unless they decide to copy my part design & # some day
So many of my original parts designs have been copied by others that it gets a bit frustrating but that's life! The people who do this copying know who they are so I don't need to point fingers! I'm not referring to you either Rob so don't get selfconscious here.
Rob

Quote Originally Posted by rdarlington View Post
Materials:
High temperature marine epoxy. I bought LOCTITE brand rated for 300 degrees Fahrenheit.
Lots of clamps. Spring, squeeze, C, or other. Get as many as you can.
Mixing container. I used an empty soda can with the top half cut off.
Strip of aluminum from the local hardware store. It's about 1.25" wide.
File to bevel the edge and remove burrs
Saw to cut it. Bandsaws make short work of this stuff.
Empty frozen pizza box
Some type of matt or sheet of cardboard to protect your work surface.

Step 1, measure and cut the aluminum to length. Don't throw out the scrap. Make it a little long so that you can bevel the corner for a nice tight fit. Sand this or sandblast it. You want a nice rough surface for the epoxy, and later the paint to adhere to.

Step 2, remove the cover and move it to some place with a large flat work space where it's comfortable to work. I used the floor. Before bringing it in, I hit it with the sandblaster where the epoxy will be going. Hold your breath unless your cabinet is big enough for the whole thing. Silicosis is not fun.

Step 3, grind down or chisel away that small rib. You want a flat surface between the hinge mounts. The goals is to have no large pockets to fill with epoxy. It should be a near perfect fit between the aluminum and the fiberglass:
20130929_151502.jpg

Step 4, vacuum up any bits of fiberglass. Again, silicosis is bad, m'kay.
20130929_152007.jpg

Step 5, check your bevel. Test fit the aluminum.
20130929_152415.jpg

Step 6, clean the aluminum surfaces with acetone. Get fingerprints and grease off. It should be pretty clean if you sandblasted it. I also did a very quick wipe of the fiberglass to remove dust and get rid of oils. Don't go nuts here. You don't want the fiberglass absorbing solvent.
20130929_153114.jpg

Step 7, get your mixing container ready. Ever keep around old paintbrushes for modeling, long after they are hard with paint? Now's your chance to use one. Use the handle to mix up the epoxy. Use the whole tube, don't cheap out. Mix for a solid minute to 90 seconds to make sure it's thoroughly mixed.
20130929_153715.jpg

Step 8, use another small brush, or the same one if you wiped the handle, to brush epoxy onto both surfaces. Get a pretty even coating, and get it into all the crevices. Try not to get it on areas you don't want it on. It wipes up easy enough though.
20130929_154506.jpg

Step 9, carefully center up the aluminum strip, beveled side down (you did put the epoxy on the beveled side, right)? and press it in tightly. Start clamping from the middle and work your way toward the ends. My engine cover had little raised areas on the edge toward me that held the strip of aluminum down. Figure out how to lay down your strip before you put the epoxy on everything. Remember that pizza box and the piece of scrap aluminum? Wrap the box around the scrap aluminum and use that to clamp against. Don't use C-clamps directly on the fiberglass!
20130929_155456.jpg

Step 10, clamp. Make sure clamps are tight! Again, start from the middle, work your way toward the ends.
20130929_155506.jpg

Note the pizza box under the fiberglass.
20130929_155513.jpg

Another shot of the pizza box wrapped around the scrap aluminum strip. There are many ways to do this, but this worked for me. I considered using a shop towel but this cardboard just felt right.
20130929_155527.jpg

Give this at least 24 hours before painting. I plan to mask off most of the cover before painting with SEM trim paint. I hear that stuff works well and matches the rest of the trim and engine covers. I don't have this yet but will update this post with additional photos once I completely finish this.

Use your finger to smooth the excess epoxy that squeezes out for a nice clean finish.

Remember, before painting, use a little acetone, sandpaper, or both.

Original post I based this on: http://autos.dir.groups.yahoo.com/ne...s/topics/63402

-Bob, 1982 DMC-12 10904, sitting at 3706 miles as of 9/29/2013