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I've scratched my head for a while about how to deal with the edges of the plywood on the outer baffle. I really don't want the plies telegraphing through the shiny black paint. Gloss black is the absolute worst when it comes to highlighting imperfections. I didn't have a lot of confidence in the old diluted glue trick. Even so, I mixed up some Titebond 3 and water 1:1 and painted it on a test piece. I let it dry thoroughly and gave it a bit of a sanding. It was smooth, but I just didn't have confidence that it soaked in enough to really seal the edge. That method does work nicely for MDF, by the way, where the runny liquid can soak in a lot more. I wanted to completely conceal the edge. Veneer edge banding didn't seem like a good option since I'd then have to seal the veneer for painting, and again, you'd still have edges all the way around. Adding solid edge banding with something like a 1/4" piece would only make the problem worse. Enter my old fiend glazing putty.
I figured I'd cover all the edges of the 1/2" outer baffle with a thin-ish layer of glazing putty. So I cut the baffles about 1mm undersized all the way around, cutting the long vertical edges at the slight angle required to match the curvature of the side panels. I'm so glad I added those alignment pins. They make for easy and quick alignment when removing and re-installing the outer baffle. Then I added masking tape all the way around to protect the bits I didn't want to get covered with putty.
Using the two colors of tape is helpful when sanding as they provide a good contrast to indicate when I'm getting in the danger zone when sanding (blue is the warning zone, green is the danger zone). It would be tragic to sand through the veneer at this stage of the game. Plus the green automotive masking tape is quite a bit superior to the blue stuff from the big box stores. My glazing putty is getting a little old, so it's much more viscous than it should be. This makes it difficult to spread it out smoothly and thinly. I thought about buying a new container of Evercoat Metal Glaze Ultra, but YIKES! When I looked at the prices I decided just to deal with my old stuff. The price of that stuff has more than doubled in the last two years. I made due with extra thick putty. At least I feel like I'm using up the old stuff instead of throwing it away. It still sets up fine and feathers out to a perfectly smooth edge; it just takes more sanding since you have to put it on a little thicker. You can see in the picture below it looks like it was put on a little ham-fisted.
But it is still just as easy to sand and comes out nice and smooth. You can see how the layers of tape help indicate when you've have sanded down to the right level. I'm just getting through the blue tape in the picture.
Next I removed all the tape. At that point the putty was proud of the surface by the thickness of the tape. I could then easily sand that tiny amount flush without worrying about sanding through the veneer. It turned out better than I thought it would.
The outer baffles were cut from a 1/2" sheet of Appleply that was a bit of a banana. When the outer baffle was clamped down to the inner baffle it was perfectly flat. I was concerned when I removed the clamps and the outer baffle returned to its slightly curved shape that the putty would crack. But fortunately it didn't. I guess that makes some sense. In its intended application of autobody work, it has to be able to move slightly as the metal of the car panel expands and contracts slightly with heat and cold. You can see the curve in the picture below. It shouldn't matter too much. When glued on to the inner baffle after painting it will be nice and flat.
I figured I'd cover all the edges of the 1/2" outer baffle with a thin-ish layer of glazing putty. So I cut the baffles about 1mm undersized all the way around, cutting the long vertical edges at the slight angle required to match the curvature of the side panels. I'm so glad I added those alignment pins. They make for easy and quick alignment when removing and re-installing the outer baffle. Then I added masking tape all the way around to protect the bits I didn't want to get covered with putty.
Using the two colors of tape is helpful when sanding as they provide a good contrast to indicate when I'm getting in the danger zone when sanding (blue is the warning zone, green is the danger zone). It would be tragic to sand through the veneer at this stage of the game. Plus the green automotive masking tape is quite a bit superior to the blue stuff from the big box stores. My glazing putty is getting a little old, so it's much more viscous than it should be. This makes it difficult to spread it out smoothly and thinly. I thought about buying a new container of Evercoat Metal Glaze Ultra, but YIKES! When I looked at the prices I decided just to deal with my old stuff. The price of that stuff has more than doubled in the last two years. I made due with extra thick putty. At least I feel like I'm using up the old stuff instead of throwing it away. It still sets up fine and feathers out to a perfectly smooth edge; it just takes more sanding since you have to put it on a little thicker. You can see in the picture below it looks like it was put on a little ham-fisted.
But it is still just as easy to sand and comes out nice and smooth. You can see how the layers of tape help indicate when you've have sanded down to the right level. I'm just getting through the blue tape in the picture.
Next I removed all the tape. At that point the putty was proud of the surface by the thickness of the tape. I could then easily sand that tiny amount flush without worrying about sanding through the veneer. It turned out better than I thought it would.
The outer baffles were cut from a 1/2" sheet of Appleply that was a bit of a banana. When the outer baffle was clamped down to the inner baffle it was perfectly flat. I was concerned when I removed the clamps and the outer baffle returned to its slightly curved shape that the putty would crack. But fortunately it didn't. I guess that makes some sense. In its intended application of autobody work, it has to be able to move slightly as the metal of the car panel expands and contracts slightly with heat and cold. You can see the curve in the picture below. It shouldn't matter too much. When glued on to the inner baffle after painting it will be nice and flat.
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