My Official build thread. 27 1/2’ GA

[Todd j]

So. I think there are a couple ways to go about this.
What is the simplest way to accomplish this?

 It seems raising the temp framing that the stringers sit on is the simplest way.  That means your not committed to bulkhead locations if you desire different deck elevations in different parts of the boat.

  I’m seeing a longer bow stem and less flare since the shelves and chines stay the same. Which will require a slight rework of the transom. 

I’m thinking 4 inches btw.  I’d like to keep the wheelhouse at the prescribe height, without change in elevation from cockpit to wheelhouse. Anyone do just this?

[Cannon]

I did both, raised the deck 3 1/2 inches (nominal 2x4)  and raised the sides the same. All you need to do is raise the stringer support 3 1/2 inches.
Because you raise the deck, you either want to raise or drop the splash rail. The reason for that is because depending upon loading; fuel, people, gear Etc. you might want to add fwd scuppers (which I wish I had). I didn’t do that one simple step so in order to add fwd scuppers I have to go right through the center of the splash rail on the fwd scuppers...😢
My wheelhouse is about six inches taller than the callout. I’m 6’4” and not in favor of banging my head. The proportions look normal, and I would do it the same again!

[Todd j]

Ya, good point.  I think I will slope the deck toward the transom.  Maybe 4” on the framing, but actually add a wedge that is 5” aft the wheelhouse  bulkhead. With a 1 1/2” taper.  Then 4” inside the wheelhouse.  I’m sure the 1” difference over the bulkhead will not be noticed.
  I’m hoping it won’t look silly if I don’t add to the height of the wheelhouse. 

[Todd j]

I know it’s not much, but I cut the 4 bottom panel molds today.  Set them aside for now.  My plywood order won’t be in until Friday, so maybe I will get the lvl framing on Wednesday for the jig and stringers.  I bought a new 7 1/4” mag skillsaw.  It sure is nice, it’s much lighter than my 25 year old stand by.  The old saw sounds better, still. 

[Rbob]

Todd,

Raising the floor?  I made the stringers 4" taller, left the supports as is. More than one way to skin a cat! 

[Todd j]

I thought about that too.  The hang up for me was the amount of deck to roof clearance that would be gained in the cuddy by not raising the sole inside it.  It would be super cool if there was a way to measure off of the stringer offsets to locate bulkheads ahead of time.

[Todd j]

Lofted and cut the stringers today.  That starboard stringer was a rascal compared to the port side.   They are 25’ long so there’s some room to play there. I have decided to build to 27 feet, maybe 27 1/2’ tops.   I just will not allow myself to build so long I cannot walk freely around one end or the other.  I can already see shop space dwindling. 

[Brian.Dixon]

Ya, good point.  I think I will slope the deck toward the transom.  Maybe 4” on the framing, but actually add a wedge that is 5” aft the wheelhouse  bulkhead. With a 1 1/2” taper.  Then 4” inside the wheelhouse.  I’m sure the 1” difference over the bulkhead will not be noticed.
  I’m hoping it won’t look silly if I don’t add to the height of the wheelhouse.

Personally, I like the look of higher sides and a more hidden wheelhouse... very classic.  Definitely better than looking top-heavy.

Brian

[Todd j]

I finished fairing the stringers last night. It was easy and enjoyable.  I really like my new 7 1/4” mag skillsaw.  I tucked the stringers away port and starboard against the walls and buried them with more boat parts!

[Todd j]

I built the jig today while I was bored waiting to go pick up my plywood.  I got to within 1/16” measuring across the diagonals.  I bought lvl long enough to build to 28’ and 4 of them.  That way I could choose the best ones for the stringers. Glad I did.  The lvl on jig were a freakin pita!   I had a gnarly bow in one of them that was a real bastard to work out.  I used a 10’ 2x4 with about 3/4” crown and lagged it to the side of the jig to straighten it out.  Then I put a plywood brace to a transverse mounted 2x6.  Screwed the crap out of it!   It’s now strait  +- the laser line.  Gotta be good enough.  Hoping all the extra crap I added won’t be in the way and can just stay put for the rest if the build. Pic taken before the jig was straightened

[Todd j]

Question? 
Let’s say I add 4” to the framing that supports The stringers.  I want to loft and cut the transom now.  Do I simply add 4” to the 43 15/16” number and connect the dots?   
Here the edge of the level represents the flare if lofted to plans dimensions.  My pencil is the flare that I ended up with by raising the sole and keeping the same sole to shear as designed.

[Brian.Dixon]

Question? 
Let’s say I add 4” to the framing that supports The stringers.  I want to loft and cut the transom now.  Do I simply add 4” to the 43 15/16” number and connect the dots?

Yup ... loft it the same way, but look at the drawing and imagine the bottom panels/chine flats moving 4" further from the top of the transom.  Connect the dots between the junction of the chine flat and side and the top outside corner of the transom.  NOTE: The motor cut-out will be deeper versus the top of the transom so that the shaft length of 25" (XL Shaft) will still work ... the cut-out is measured from the bottom of the transom, not the top. I'm sure you spotted that, but who knows who else is reading this?    Also NOTE that the outer ends of the motor boards and the outer edge of the upper transom doublers (either side of the cut-out) will change since raising the bottom panels (upside down boat) without making the boat wider will slightly reduce the side flare.  It's a tiny change though and you can just use the outer edges/sides of the transom as a template on the pieces to draw a cut line.  It'll all be buried in a strong epoxy/glass seam regardless, so don't sweat it too much - just make sure the slot for the shelves are cut in the right spot.  You'll add your 4" to the 17-13/16" measurement shown on the doublers (drawing 008a) to locate these slots ... cut'm a little loose and the devil be damned.  It'll go together just fine.

Brian

[Todd j]

I am building to 27.5’.  I will be building the 4" taller transom similar to what is in the plans at this point.  I guess I can always cut it off if I decide to go with the bracket look like Rbob is doing.  I have seen some pretty sexy splash wells on tolman skiffs.  Will worry about swim platform later. 
  Brian, let's say for instance I max out the transom weight rating with horsepower.  I construct/install some variation of a swim platform.  If I go diving and crawl back into the boat over the transom using the swim platform.  Will the transom rip off the boat motors and all.  Consider I weigh between 220 and 240 depending on what time it is.  My soaking wet dive gear likely adds another 100 pounds.  Now the transom is overloaded by 340 pounds plus the weight of the swim deck.

[Brian.Dixon]

I am building to 27.5’.  I will be building the 4" taller transom similar to what is in the plans at this point.  I guess I can always cut it off if I decide to go with the bracket look like Rbob is doing.  I have seen some pretty sexy splash wells on tolman skiffs.  Will worry about swim platform later. 
  Brian, let's say for instance I max out the transom weight rating with horsepower.  I construct/install some variation of a swim platform.  If I go diving and crawl back into the boat over the transom using the swim platform.  Will the transom rip off the boat motors and all.  Consider I weigh between 220 and 240 depending on what time it is.  My soaking wet dive gear likely adds another 100 pounds.  Now the transom is overloaded by 340 pounds plus the weight of the swim deck.

Haha ... you weigh less than me!

First, no, you will not rip off the transom.  Impact loads on the transom during normal operation exceed that by a long shot - no worries.

That said, my suggested build style for divers is to extend the stringers past the transom far enough to provide a swim platform, and extend the bottom panels and chine flats as well.  This effectively lengthens the boat and puts the motor 'on a bracket' (of sorts).  The way to lengthen the boat is to space out the lofting stations (equally) from the amidships point aft - check the manuals and study how the loftings change between the base 26' model versus those that are longer (noting that the same thing is done in reverse for shorter than 26 feet).  In a nutshell, you divide the extra length by the number of gaps between equally spaced stations, then increase each station separation by that amount.  The manuals will illustrate this better than this post.

The reason I like the method above is because it naturally provides flotation for motor and/or weight (you) climbing onto the swim platform.  Since the boat is becoming effectively longer as well, this also mediates the aft movement of the CG due to the motors (and you) being behind the transom.  This method has already been used on a few Great Alaskans and it works very well.

In your case, you'd effectively lengthen the boat from 27.5 ft to say ... 29 or 29.5 ft long on the water.  K. Cannon in Oregon has a 29' 4" GA that already proves this length works well.

Brian

[Todd j]

I need to decide which way to I guess. Fortunately I have a long way to go before I make a decision. I made about 20 gallons of sawdust today.  Scarfed all the bottom panels minus the last 2 3/8” scarfs.  I can’t image doing that job with a hand plane.  I used my power planer and it was still a job. 
   Back to the salt mine for a week!