John

I would like to offer a few suggestions that might make your job easier.

1.) For the small area you are working in a 6" grinder might be to large. I use a 4" grinder to grind in the bevel around the hole after I have cut it and even that seems a bit large at times.

2.) To cut the hole I often times use a small trim router similar to the one at this link. It allows me to control with a high degree of precision the depth of cut.

http://www.google.com/products/catal...CAcQ8wIwADgA#p

3.) If there is any balsa core intact under the cutout remove it carefully. It was bonded pretty well to the bottom skin which is often times very thin and fragile. Don't try to rush it just get it up slow and easy.

4.) Epoxy resin by itself is very brittle. You need the glass reinforcing to make this area strong. So cut all of your glass fabric pieces before you start putting things back together again.

5.) To keep a lot of resin from running down through the two holes that the mast step bolts through and dripping on your cabin floor you can wet out the top of the bottom deck skin and on a piece of visqueen (plastic) wet out the bottom piece of glass you will be putting in the hole. Then put the glass in the hole and make sure there are no air bubbles under it. Then let that start to kick and set up before you proceed with the rest of the glass. In addition I would use a couple of pieces of tape on the bottom of the holes to make sure nothing drips on the cabin sole.

6.) This repair will really take a small amount of epoxy. So mix small batches of epoxy so you don't waste it and it does not set up on you before you can use it all.

I hope this helps and I wish you the best on your project.