I always do the ribs cutout after the deck rim and propshafts and rudders are installed. This makes sure you are at the final hull width and the ship floats right when you ballast it to mark the water line. Marking the water line is important because the bottom of the windows you cut out has to be at least 1 inch below the waterline by the rules, and you don't want to make the bottom of the windows excessively deep. The Scharnhorst (L) hull with ballast inside should be 29 lbs 4 oz when you float it to mark the waterline. With the decks on you can put a small round target type bubble level (harbor freight has one for a couple bucks) in the middle of the deck and adjust the ballast until you get everything to sit level in the water. then mark the water height at the bow and stern and a couple of places along each side.
This is where we should break out the movie projector and play the old black and white film "Learn Not to Bleed"..or reference to the McSuds incident...
Jackson, Best practices for cutting windows (IMHO): Mark waterline as stated previously. Glue in subdeck (this prevents hull from sagging or "hogging" when you cut away 85% of the hull structure) Use masking tape to mark off hard areas at bow & stern. Use masking tape to mark off top & bottom of windows (top=bottom of subdeck, bottom=1" below waterline or turn of bilge at stern) Determine if there is a allowed stringer. Looking at the drawings, it looks like a distinct armor belt "knuckle" runs the middle 1/3 of hull. Tape off stringer using 1/8" wide masking tape. Determine number of ribs allowed. SAS - Rib Calculator Note that you can use less than the full 2" at bow to adjust the number of ribs. If you drop bow hard area to 1.137", you get 20x 3/8" ribs Tape off vertical ribs to form "windows". Recommend you put one at the start & one at end of stringer, a few in middle of stringer, then work toward bow & stern. Some people favor crowding more ribs into bow area, but for a ship like Scharney, evenly spacing them will work well. Carefully drill corners of your now-defined windows using a medium-ish sized bit (1/8" or so) to radius the corners & make it easier to cut them out. Now using a cut-off wheel on your dremel, saw away on that once-pristine hull.
Never use a toothed saw blade on a dremel! They often grab whatever you are cutting and run away from you. Carbide cutting wheels work the best for cutting fiberglass and epoxy and last through several hulls. They are pricey (at about $20) but worth it. Dremel has two types: one that is smaller at about one and an eighth inch and has carbide all over it (Good if you need to shape something with the side of the wheel or cut a curve), and one that fits their quick change shaft that is about one and a half inches in diameter and only has carbide around the edge. (Great for cutting a straight line) Also you will generate a lot of objectionable airborne dust, so do it outside or in an area that is easy to clean and use a dust mask.
I used one once for about 30 seconds, then carefully left the blades in the back of a cabinet. Way too hard to keep under control.
I recommend using a respirator that uses cartridges and not one of those white dust masks whilst cutting the fibreglass hulls.
Keri contacted me yesterday and told me Stephen will email me soon. As soon as he emails me, I will order the decks!
Good to hear. You know, you can start laying out the ribs while you wait. That way once you get your decks installed, you can cut the windows right away.
You can also find enough weight to burden the hull down to target weight and figure out roughly where your waterline will be.
Just got a response from Stephen. He said that he is hoping that his CNC router will be pit back together in no more than a week, but the machine has beat him down numerous times over the course of the upgrade. The decks that I will receive after the machine is put back together will cost $75. I am very excited!!!
Start by reading THIS. It will answer most of your questions about how to lay out ribs properly. I try to space them no more than 3 inches apart, maximum. You really need to determine the floating waterline before you start cutting, so you can mark the bottom of the windows.
