try again- cutting/measuring bevels

[Dale R. Hamilton]

Building a runabout. Plan calls for cutting bevels on the plywood stations/bulkheads to accomodate the planks landing on the frames. These bevels start off at 9 degrees at the sheer, then change to 6 degrees, 5, 4, 1 degree at the chine. So how do you measure 5 degrees bevel?- I know- a protractor- but what kind do you lay down on a board surface and read 5 degrees? And how to cut such a bevel- I mean 45 is easy, but how do these tiny increments? Would you any of you guys say to hell with it and just plane down the frames to fit the planks as you skin the boat?

[dmede]

My only experience with belveling frames or bulkheads (two canoes) has been to use a lining batten wrapped around the frames along the lines of each plank (one plank at a time) and to just plane the surface until the batten lands on the full face of the frame edge.

So in essence your testing the landing of the plank and adjusting the bevel as you go but your doing it all up front not as each plank is actually hung.

make any sense?

[paladin]

...now think about what i am about to say......

o.K.......i clamped a "plank" as a batten from stem to stern so that the plank was tight against the frames.....then..set the blade of a small skil saw to exactly the thickness of the plank plus the amount that the saw blade rides above the frame where the plank crosses it.....ride the shoe of the saw across the outside of the plank....and the "nicks" on the frame will be at the depth of the material to plane away...you must keep moving the plank up or down the frame to get the right angle....i dunno if this makes sense.....right now I'm a bit tired...and can sketch something if you like...

[John E Hardiman]

How do you measure a small bevel like that?...Simple.... you pick it up off the loft floor and put it on your bevel board!.....You did loft it full size, right?

[ 03-30-2005, 05:33 PM: Message edited by: John E Hardiman ]

[ssor]

You can also use a carpenters framing square and the trig function on your calculator.
Example 45Deg= 12 inches on each leg of the square when laid along the edge 5 deg=12inches on one leg and just a hair over 1 inch on the other leg. Or if you prefer 1 inch on one leg and 12 inches on the other leg.
But I like Paladins method better! ya don't gotta figure nothing. :D

[Stephen Hutchins]

There are alot of ways to do this. The one I liked best was to make a "witness cut" -new term for me, just learned it in the latest WB. Anyway, what I did was place a unbeveled frame temporarilly in place and record the bevels at the ribbands on a bevel board. And also record the ribband locations on the frame. Then take frame to bench and saw into frame the appropriate angle, checking with your bevel gage till it's right.Thene plane down to your saw marks. Once you do a few frames however, you find you don't even have make a "witness cut" This cut is probably more usefull in getting out planks as it is alot faster/easier than cutting the bevel with a jack knife as I've seen the old timers do. So now that I've told you all that I'll give you an even faster, more accurate way once your skills are up: With a unbeveled frame against the ribbands, eyeball the distance between the frame and ribband and record that distance on the other side of the frame. For example: if the corner of the outside face and aft face of the frame is 1/4" away from the ribband, then make a mark 1/4" in from the outside face on the foward face of the frame. Do this for each ribband and connect the dots and plane/spokeshave down to this line. In the above written instance nothing would be taken off the aft outside corner. You just shave right down to it. On the foward face, it doesn't matter if you use a fine pencil or a standard carpenters pencil -what matters is how you mark it- I use a carpenters pencil and use one edge of the drawn line as the mark. With most work, I mark it so I have to "take the line." No more, no less. Finally, use a strait edge to make sure your faying surface is perfectly flat. This might all sound a little annal but I think you'll find once your skills are up, These methods are not only very accurate but faster for one off construction as well.

[Ken Hutchins]

Mark on the piece of wood the angles you want at each particular spot, band saw the shape with an assistant adjusting the angle of the saw as you cut. With a good large protractor on the saw it is possible to cut accurately to 1/2 degree or closer increments.

[ssor]

Sears Craftsman is currently selling a tilting head band saw adjustable by way of a hand wheel. Not the best but not bad.

[Bob Perkins]

I picked up a little item at the woodenboat show called the bevel boss. It has markings in 1/2 deg increments. Put a bevel guage up next to it and then you know.

I've found that I use it to figure out an angle more than to set one.

When I cut the slots for the king plank on my runabout frames, I layed two long boards across the tops of the frames (so they behaved like fairing battens) Then I used my router with the table insert and a spiral bit and cut out the slots. I finished the sides with a chisel, but the depth and angle was perfect.

Not sure if this helps,
Bob

[paladin]

gee...izz that similar to what i did with the skil saw......i've never seen it dunn thataway....

[NormMessinger]

Five degrees? That's just a little off square. Eyeball it.

[Bob Perkins]

Hey Paladin,

I had never seen it done my way either. I just happended to think it up and it worked out. A key factor is the router table insert/plate is nice and big. The other one is that those spiral router bits cut across grain beautifully (no tearout)

I wish I had done the gazillion notches on the sides of the frames the same way. Those were beveled in a much more inefficent manner..

Take Care,
Bob

[pipefitter]

Fast way to guage a bevel is to take a speed sqare on it's pivot at whatever degree angle you need. Draw a line on a piece of wood along the speed square's edge.Then you can set an angle finder on this line and you now have a guage to check your bevels.
When I built my boat I had all my bevel angles on one piece of wood drawn in pencil with where it belonged written on the line. Transom angle,station angle etc. Makes for quick reference rather than going back to the print.

[ 03-31-2005, 12:33 AM: Message edited by: pipefitter ]

[Dale R. Hamilton]

Geez thanks guys- once again to the rescue. Will try several of these this weekend and will google- search for a bevel boss.

[Paul Morris]

Dale; Bevel Boss is a terriffic device and very well etched. They are made right here in Fairfield, Iowa by Mack Sutherland of Sutherland Tool co. I think it is by now available through good tool suppliers and marine chandleries(sp)- Veritas comes to mind. They are a bit pricy but in my boat shop, it is in the apron pocket all the time. The back side of the tool has a great inch scale all around its perimiter. I use that for measuring in tight spots all the time. www.sutherlandtool.com. (http://www.sutherlandtool.com.)
~~ Paul ~~
Cedar Tree Boat shop
Des Moines

[Paul Morris]

Dale; Bevel Boss is a terriffic device and very well etched. They are made right here in Fairfield, Iowa by Mack Sutherland of Sutherland Tool co. I think it is by now available through good tool suppliers and marine chandleries(sp)- Veritas comes to mind. They are a bit pricy but in my boat shop, it is in the apron pocket all the time. The back side of the tool has a great inch scale all around its perimiter. I use that for measuring in tight spots all the time. www.sutherlandtool.com. (http://www.sutherlandtool.com.)
~~ Paul ~~
Cedar Tree Boat shop
Des Moines

[pipefitter]

Hey,I just saw the bevel boss. Great idea but what I was saying about the speed square and the angle finder was the same principal I've been using for years in Marine welding apps. I had no idea they had a tool set up for this but is pretty close to my method. Only difference being I dont have all the in between increments on a speed square but i can pretty accurately eyeball half a degree with it.Just incase one already has a speed square and sliding bevel guage.