Not Scarfed, Not Butted, but Puzzled | SouthernPaddler.com

Not Scarfed, Not Butted, but Puzzled

JEM

Well-Known Member
I tried this, although not quite as elaborate. It's a pain to get to fit correctly. It does seem to be a little stronger but is it worth the trouble?

Keep in mind that in orer for the finger to interlock, you loose some of the length of panel. So the panels must be designed to fit that way. You can't just "retrofit" existing panels with that joint.
 

Kayak Jack

Well-Known Member
Aug 26, 2003
13,976
171
86
Okemos / East Lansing Michigan
JEM said:
... Keep in mind that in order for the finger to interlock, you loose some of the length of panel. So the panels must be designed to fit that way. You can't just "retrofit" existing panels with that joint.
this point has to be emphasized. It's a "before" step, not an after. Individual panels have to be joined into a composite BEFORE it is cut into a finished panel for a boat.

Also, why would the tongues have to be rounded? They could be simple triangles with straight sides. These could then be easily marked and cut with a common saw, coping saw (my choice), or a very careful jig saw.

I still, however, will use the simple butt joint. If I'm not really worried about strength, a couple of layers of fiber glass on each side will suffice. If strength is a concern, I'll use glass on the outside, and a scab patch (reinforcing block) on the inside of the boat - thank you very much. I misuse my boats too much to be skimpy.
 

BEARS BUDDY

Well-Known Member
Aug 27, 2003
1,492
6
76
BAY CITY MI
The joints are rounded because he used a router template. You could do an even stronger joint with a keyed dovetail joint, but the joints would take forever manually. I think it would be great for joining panels if you had a template that was wide enough to do the full sheet before doing the layout and cutting of the panels.
 

hairymick

Well-Known Member
Dec 8, 2005
2,107
2
Queensland, Australia
Hi Guys,

I reckon this could work very well. Boats with an assymetrical hull come to mind. You could laminate two or more complete sheets of ply together and then mark and cut the entire hull panel in one piece.

Even a little stronger is much better for me. Like you Jack, i am pretty hard on my boats. Just think how flash a boat would look with puzzle joints instead of a butt. Gonna have a play with this method at work and see if I can work out a quick and efficient system.
 

Kayak Jack

Well-Known Member
Aug 26, 2003
13,976
171
86
Okemos / East Lansing Michigan
The first two panels I joined would have to go together with a gaggle of other joined panels to build a larger workshop.

With proper offsets measured from a string to the edge of the joint, it would be fairly easy to do a composite plank from a 16' long piece of wood. I wonder how they joined the ends of plywood to make the PT boats? Or the British Mosquito aircraft?
 

JEM

Well-Known Member
BEARS BUDDY said:
The joints are rounded because he used a router template. You could do an even stronger joint with a keyed dovetail joint, but the joints would take forever manually. I think it would be great for joining panels if you had a template that was wide enough to do the full sheet before doing the layout and cutting of the panels.

Oops. Looks like I gleened right over what BB said. :oops:

A dovetail type joint would be nice, but as stated, a royal pain to do manually.

Seems we have yet another boat building trade off. :roll:
 

BEARS BUDDY

Well-Known Member
Aug 27, 2003
1,492
6
76
BAY CITY MI
Another possibility would be to make the joint, then connect the panels without gluing to do the layout; pop the panels apart and cut; and then glue the individual sections. That way you would not be attempting to handlle a 4x16 sheet (and Jack would not need to build a bigger garage).


Henry Ford said to hire a lazy man to do the job--he will find the easy way to do it.
 

hairymick

Well-Known Member
Dec 8, 2005
2,107
2
Queensland, Australia
Hi guys,

I just can't resist this one. :D

Jack, re the Mosquitoes, I was allways taught that the mosquito fighter was Designed and build in Australia by Australians for the Royal Australian Air Force. they were built with timber frames and canvass covered and were designed specifically to outmanouver and outfight the Japanese zero. They did this very well in the skys over New Guinea.

I believe your PT boats were glued and screwed to frames.

A bigger shed is allways a good thing :D

Matt,

I bloody hate dovetail joints. :D

B.B.

Henry Ford was a genious - and so are you mate. I love the way you think. I tossed and turned all night trying to figure an easy way the handle a 16 X 4 sheet of ply.

A bigger shed is allways an option. I reckon sheds are like boats. They are never big enough and you allways end up filling them up with crap.
 

Kayak Jack

Well-Known Member
Aug 26, 2003
13,976
171
86
Okemos / East Lansing Michigan
hairymick said:
... Jack, re the Mosquitoes, I was allways taught that the mosquito fighter was Designed and build in Australia by Australians for the Royal Australian Air Force. they were built with timber frames and canvass covered and were designed specifically to outmaneuver and outfight the Japanese zero. They did this very well in the skies over New Guinea.

I believe your PT boats were glued and screwed to frames.

I tossed and turned all night trying to figure an easy way the handle a 16 X 4 sheet of ply.
Best way to handle a 4' X 16' piece of plywood is with about 3-5 other guys helping. When you figure in the cost of beer, the idea loses some of it's constructional appeal.

Thanks for the info on Mosquitoes. One helluva bird! I knew they were a multi-mission aircraft, but didn't know they'd operated in the Pacific Theater at all, let alone against the Zero. The Zero was a very good aircraft, but would not withstand much battle damage.

A close friend of mine was a PT boat fixer in WWII (the big one). I'll ask him for some more info.
 

john the pom

Well-Known Member
Jul 30, 2007
345
1
Queensland
Just found this bit bout mossies, which has to be the prettiest warplane ever to fly. Sorry Mick but while Australia Canada and a few other countries built mosquitos the first few thousand were designed and built in the UK. The site listed below has comprehensive lists of UK and non UK builds of the aircraft, and is in itself a really good read.

http://www.flexi.net.au/~bfillery/mossie01.htm .

(Hey we had to beat the Aussies at something!)
 

Wannabe

Well-Known Member
Apr 5, 2007
2,645
2
on the bank of Trinity Bay
Bears B,
If the foint fits as tight as they claim then dry fitting would be out of the question. Once you pound them togeather they would probally splinter the edges of taken apart. Never hurts to look at the other side of the coin so get some scraps and try putting it togeather and taking it apart. Sometimes you just need to see for yourself. :D
Bob[/quote]
 

BEARS BUDDY

Well-Known Member
Aug 27, 2003
1,492
6
76
BAY CITY MI
Wannabe said:
Bears B,
If the foint fits as tight as they claim then dry fitting would be out of the question. Once you pound them togeather they would probally splinter the edges of taken apart. Never hurts to look at the other side of the coin so get some scraps and try putting it togeather and taking it apart. Sometimes you just need to see for yourself. :D
Bob
[/quote]

A little 50 grit applied to the edges would loosen the fit but not to the point epoxy and filler powder would not fill the gaps.
 

dangermouse01

Well-Known Member
Sep 8, 2006
312
1
Palm Bay, FL (East coast)
hairymick said:
Just think how flash a boat would look with puzzle joints instead of a butt.

Would look like this.
shearwater7.jpg


Chesapeake Light Craft has had them on their last few designs. At least with the kits, but those are cut with a CNC router. Would be a royal pain to do by hand if working from plans, unless they send a full size template. Maybe the plans call for scarf joints. Or maybe they just want to sell more kits.

I am still not sure if I like the look or not. Probably because I am used to the scarf or butt joint look.

DM
 

Ozark

Well-Known Member
Oct 23, 2007
627
0
Ozark Mo.
I wonder how your router blades would react to the epoxy and fiberglass as I use a templet and router to cut many things.