After clamping the edges, and ensuring the corner was square, it was time to apply the cement. I found that the easiest way was to start at the BOTTOM INSIDE of the corner, and slowly apply the cement to the joint. Being water thin, it wicks into the seam by capillary action, and as it does so it makes the seam CRYSTAL CLEAR. I tried to take a picture of this, and this is the best I could do. Move the needle tip slowly upward letting gravity help, and ensure it goes all the way across the joint. You can see it easily beacause areas not cemented are not clear. Now, I must tell you you will get areas that DO NOT completely fill. To address these move to the outside of the seam, and apply some cement. If you are lucky it will then completely fill. I did get areas of microbubbles, but as you will see, this did not effect the water tightness as long as most of the seam is cemented at that area (you have to ensure that a bubble DOES NOT completely cross the seam..more on this later).
Now is the time to go over the fact that even with a good glass shop cutting the edges, I still had some saw marks and a few irregularities on some of the edges. I am not upset by this, it is to be expected. Someone on wetwebmedia mentioned using a wood chisel to square the edges, so this is what I did.
I just slowly drew the chisel across the edge several times. These are good wood chisels, and are razor sharp. Contrary to popular belief, and probably common use, it is VERY rare to need to hit the back of a properly sharpened chisel. The chisel easily smothed the edges and got rid of the saw marks. Here is a picture of the full chisel...once again they need to be SHARP!
After dressing the edges of my next piece with the chisel, I added the second side to the sump. I used the crossbraces I had already had cut in the initial diagram to make sure the sides stayed square.
