Wavy epoxy...

In a previous thread it was discussed about the waves that you can get in epoxy, especially when laying it down on something like ACX ply. To demonstrate this, I took a piece of MDF and put some sandpaper on it and just lightly sanded the side to hit the high spots and really show what we were talking about. Plywood is run through a sander and isn't typically really flat due to the grain, not like a finished veneered ply, the grain in it will take on epoxy differently, leaving high and low spots till it's sealed off and filled.
This shows a couple of coats of epoxy laid down on top, the first one really soaks in, so I mix in some fairing filler in it (red colored) to minimize some of that...It isn't pretty as a lot of the time, I use all my left over epoxy from other steps and smear it on the ply, with a plastic spatula, hence the sag in it, lower right, the rest is in the ply...This portion hasn't been faired out as I had the fender temporarily mounted and couldn't work this area. It'll all be done up smooth.
Here's what I use to flatten it all down...mostly hard rubber blocks, get the ones that allow you to use a equal portion of paper so you don't waste any sand paper, the air file (straight line sander) can be bought from HF and will cut it really fast, but it's an air hog on the compressor...little compressors won't keep up with it... Doug

This shows a couple of coats of epoxy laid down on top, the first one really soaks in, so I mix in some fairing filler in it (red colored) to minimize some of that...It isn't pretty as a lot of the time, I use all my left over epoxy from other steps and smear it on the ply, with a plastic spatula, hence the sag in it, lower right, the rest is in the ply...This portion hasn't been faired out as I had the fender temporarily mounted and couldn't work this area. It'll all be done up smooth.
Here's what I use to flatten it all down...mostly hard rubber blocks, get the ones that allow you to use a equal portion of paper so you don't waste any sand paper, the air file (straight line sander) can be bought from HF and will cut it really fast, but it's an air hog on the compressor...little compressors won't keep up with it... Doug