DaveH6
Establishing the center line.
Using this string depicted keel centerline. I made sure that the port and starboard topside sheer lines were equally distant from the keel line. Having rigid garage walls were a big help in keeping things braced until the bulkheads were installed.
Using a hand plane, I fussed with the major bulkheads to get a good but not perfect fit with the hull side. Then I read submissions to boat building forums which claim that in an epoxied non-cosmetic wood joint, wood should not touch wood, instead leave an air gap between panels I presume so the fllets are locked together. I have read of drilling a 1/2" hole through a bulkhead so a thin stip of fiberglass can run between the filets/fiberglass on each side of a panel. I have also read of tapering the edge of a plywood bulkhead so the fiberglass on a seam is in contact with multiple laminations not just the top lamination.
If I were building a bluewater or high speed boat I would search for empirical evidence to substantiate the above opinions, and do some destructive joint testing. Since this is my first serious boat building experience, I have no qualifications to dispute recommended methodologies and instead rely on a gut feel.
Today I continue my practice of striving for a reasonably good bulkhead fit (there is usually some fillet squeeze out that travels to the other side of the bulkhead seam), installing a properly radiused filet and using a layer of 17 oz 45 degree bias bi-axial fiberglassed tape on each side of a major bulkhead.
My recollection from stitch and glue books from authors such as Devlin is a comment that stitch and glue is forgiving in regards to gaps between panels. I don't recall a specific recommendation to leave an air gap in the panel joints so more epoxy can be used. It seems counter-intuitive to substitute more glue for less wood.
I do seal the plywood edges with epoxy before I do the final fitting of the bulkheads. Before installing and with the bulkhead lying flat, I coat each bulkhead with epoxy but tape off the area where the fiberglass tape will land to avoid a "secondary bond" situation. Coating the bulkheads before installing should expedite the process of later painting these panels. I also rough up with 60 grit sand paper the wood areas that will be in contact with the fiberglass tape.
I believe that by carefully filtering advice and using common sense, I expect to have a successful and very enjoyable Bluejacket build. I have given up worrying what is the "right" way to execute a particular task since for most issues there is no strong concensus among boat builders and we tend to get rabid in a debate....just like politics and religion. Want to have some fun, go onto a boat building forum and ask, "Is it ok to use fiberglass mat with epoxy".
The Bluejacket has a modest top speed thus I suspect that there is no single builder mistake that can cause catastrophic structural failure or injury other than a mistake in installing the Bluejacket's fuel, AC electrical system or steering systems. These are three areas that we must ensure we are doing it the "right" way. USCG regulations on fuel systems meets my definition of the "right' way". ABYC standards provide guidance on electrical issues.
Establishing the center line.
Using this string depicted keel centerline. I made sure that the port and starboard topside sheer lines were equally distant from the keel line. Having rigid garage walls were a big help in keeping things braced until the bulkheads were installed.
Using a hand plane, I fussed with the major bulkheads to get a good but not perfect fit with the hull side. Then I read submissions to boat building forums which claim that in an epoxied non-cosmetic wood joint, wood should not touch wood, instead leave an air gap between panels I presume so the fllets are locked together. I have read of drilling a 1/2" hole through a bulkhead so a thin stip of fiberglass can run between the filets/fiberglass on each side of a panel. I have also read of tapering the edge of a plywood bulkhead so the fiberglass on a seam is in contact with multiple laminations not just the top lamination.
If I were building a bluewater or high speed boat I would search for empirical evidence to substantiate the above opinions, and do some destructive joint testing. Since this is my first serious boat building experience, I have no qualifications to dispute recommended methodologies and instead rely on a gut feel.
Today I continue my practice of striving for a reasonably good bulkhead fit (there is usually some fillet squeeze out that travels to the other side of the bulkhead seam), installing a properly radiused filet and using a layer of 17 oz 45 degree bias bi-axial fiberglassed tape on each side of a major bulkhead.
My recollection from stitch and glue books from authors such as Devlin is a comment that stitch and glue is forgiving in regards to gaps between panels. I don't recall a specific recommendation to leave an air gap in the panel joints so more epoxy can be used. It seems counter-intuitive to substitute more glue for less wood.
I do seal the plywood edges with epoxy before I do the final fitting of the bulkheads. Before installing and with the bulkhead lying flat, I coat each bulkhead with epoxy but tape off the area where the fiberglass tape will land to avoid a "secondary bond" situation. Coating the bulkheads before installing should expedite the process of later painting these panels. I also rough up with 60 grit sand paper the wood areas that will be in contact with the fiberglass tape.
I believe that by carefully filtering advice and using common sense, I expect to have a successful and very enjoyable Bluejacket build. I have given up worrying what is the "right" way to execute a particular task since for most issues there is no strong concensus among boat builders and we tend to get rabid in a debate....just like politics and religion. Want to have some fun, go onto a boat building forum and ask, "Is it ok to use fiberglass mat with epoxy".
The Bluejacket has a modest top speed thus I suspect that there is no single builder mistake that can cause catastrophic structural failure or injury other than a mistake in installing the Bluejacket's fuel, AC electrical system or steering systems. These are three areas that we must ensure we are doing it the "right" way. USCG regulations on fuel systems meets my definition of the "right' way". ABYC standards provide guidance on electrical issues.