Procedure for cutting into any composite panel....

Nick,

Perhaps I am misunderstanding in which case forget the following.

It appears that you want to cut a hatch in an already existing front area and you want to be able to have a door that opens and closes and seals on a flange (that fits it) you also want a drip rail for moisture (which of course you want to drain somewhere.

If I am correct, the way that I have done it was:

Before cutting the panel out:

1. draw the outline of the purposed hatch
2. Place one layer of duct tape over this line extending about 1" OUTside the line and approximately 1" inside of the line (this will be adjusted later
3. Make a 3 layer or so BID layup over this duct tape. (creates the flange which will be foxed inside of the fuselage)
4. Peel ply the layup.
5 When cured, separate it from the duct tape and totally cut out the shape. (I don't have to add the word carefully.
6. Neaten up the outside of the layup produced in step4.

7. If you want a drip rail put a round shape of foam on the layup (on the side that was touching the tape) at the inside edge sand and make a layup over this with enough overlap to secure it. if you do the drip rail, you will have to first trim the inside of this layup and let cure
8. Remove the foam and refine

9. sand the inside of the fuselage approximately 1.5" from the cutout hole around the entire hole left after the cutout (for bonding.)
10. make a few layups of BID around this hole the thickness that you want to use for your gasket material
11 Using a relatively thin flox (but still thixatrophic) butter the inside of this fuselage layup
12. fit the new piece that you created in step 9 and or 4 with or without the rail through the hole orientated in the same way in which it was made.
13. Press it into place (upward) (from the inside) and using multiple clamps hold it to the periphery of the hole allow cure and get rid of the goobers
14. When cured create a flox corner in the outside skin, a flox fillet at the junction of the inside skin and the now affixed flange and use some light bid to seal the foam and create a stronger joint.
15. clean the layup and slightly radius the outer skin flox joint
16. Reduce the size of the cutout panel to fit its new flanged hole (remember you will have to address the raw foam edges which will, of course take up some space)

Hinge and lock.