Repairing a machined hole in non-critical areas of the boat are relatively easy, at least from a structural point of view. The cosmetic finish can be a little labor intensive, but I'll come back to that. I categorize this repair as non-critical because if it fails while sailing there are no life threatening consequences involved. First, use an orbital sander to grind a bevel around the edge of the hole. Working carefully what you want is a consistent angled surface from the edge of the hole extending back a distance that is egual to 8 times the thickness of the bulkhead laminate. For example, if the laminate is 1/8" thick then the bevel should be 1" wide. Sometimes this is not possible because there is a corner or other obstacle. In this case, make the bevel as large as possible. By wetting the bevel you will be able to count the number of layers of glass used to build the laminate. Generally, bulkheads in this area are relatively thin (1/8" to 1/4" for most 30 - 35 footers) and often times built in the mold using chopped strand fibers, so chopped strand mat (csm) can be used for the repair. Personally, I prefer using a woven cloth because it's easier to work with. Either way, you want to cut a series of concentrically sized patches equal to the number of layers revealed by the bevel. The first patch is the largest and should fit slightly inside the outside circumference of the bevel. The remaining patches are concentrically smaller and spaced so that the last smallest patch is slightly larger than the inside circumference of the bevel (slightly bigger than the original hole). You will need a backer to laminate the patch against. You can make one easily by wetting out a single layer of fiberglass on a sheet of polyethylene plastic (heavy mil drop cloth)and allowing it to cure. Epoxy does not stick to the plastic so the cured glass just peels off it. Now you have a somewhat flexible epoxy/glass skin to use as a backer. Use sissors to trim the backer so it covers the hole with good overlap. sand the surface of the backer that will contact the repair laminate and sand the surfaces inside the boat on the bulkhead where this backer will make contact. A very quick and easy way to mount the backer is to use our G-5 5 min. epoxy. Mix a small quantity and spread it on the backer where it will make contact with the bulkhead, tape it in place, and wait 10 minutes. Pull the tape off and the backer is bonded in place. Now, using our 105 resin and either the fast 205 hardener or the slow 206 hardener and the 406 coloidal silica you're ready to laminate the patches in. Mix some resin and hardener thickened to a katsup consistency with the 406 and brush it onto the entire beveled surface and the backer. Then laminate in the patches with unthickened epoxy starting with the biggest patch until all the patches are wet out. Ideally, it's really helpful to squeegee a piece of release fabric over the repair and then let it cure. Using the release fabric allows you to apply more pressure with the squeegee to compact the laminate without disturbing the glass patches. It also keeps any blush from contacting the repair surface and once removed leaves a nice textured surface ready for finishing without sanding (although sanding may be needed around the repair when finishing). Which brings us to finishing. Using either the 410 Microlight or 407 Low density filler, mix some resin and hardener, add enough of either of these fillers to make a non-sag (peanutbutter consistency) fairing material. Apply it with a squeegee so the repair is filled a bit more than the level with the bulkhead surface, let it cure, and sand fair. It's a good idea to then coat the faired surface with a coat of unthickened epoxy to fill the porosity of the sanded filler. Once this cures, wet sand the surface a bit to dull the shine on the surface of the cured epoxy. At this point you're ready to either gelcoat or paint, which is the reason I mentioned the finishing could be labor intensive. Applying gelcoat in a secondary bonding situation like this will require LOTS of sanding - by that I mean LOTS AND LOTS of sanding - to get it to look like the rest of the boat. I would prefer priming and painting if at all possible. The specifics of finishing with either material can be the focus of a separate posting. Refer to the posting that addresses gelcoat over epoxy in this forum. You can find additional information regarding the fixing of machined holes on the WEST SYSTEM web site <www.westsystem.com> under the 'Epoxyworks Magazine' tab, back issues, issue #21.