Getting the angle for framing

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Jdholmes

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Having a crazy time trying to get it right on the bow of my semi V...it's so different than most of the construction/carpentry work I have done where emerging is generally square and level...:p

Any pointers?
 
Yeah I gotcha there...that part is done...crappy cause I am down on tools here but done good nuff.

The part I am concerned with is the framing - in other words the vertical slope is what I am dealing with...attaching angle bracket or wood framing to the sides puts it out of level because of the vertical slope of the boat...
 
Just keep working the angles, mesauring and doing the math to get it right.

Sohcahtoa and whatnot.

Since a boat has compound angles when dealing with the hull, there's lots if measuring and measuring and measuring. There's no short cuts, just gotta keep workin it until you get it.

Cardboard templates can help, but they're always off just enough to mess up the finished product.

That's also cheating the way I look at it.....8)

For example; when I cut just the plywood for the front deck on my 12 footer, I had measured in excess of 40-50 points, 2 or three times for each measurement to get the hull taper to the front.

But: it fits perfect and I have a great feeling of satisfaction when I look at the perfect curve on both sides to the bow. You have to decide how far you have to go to be satisfied with your work.

Also; what do you mean by "attaching to the sides of the boat"?

You don't have to attach to the hull at all if done right. Plywood panels will support themselves with a few properly placed braces. I can't tell you where, every hull is different....
 
The braces are what I am talking about attaching to the sides.

I got a little angle aluminum to use as braces but of course when you put it square to the hull and try to put a cross piece or something on it makes it point up at the sky instead of directly across the boat...thus the pain in the butt compound angles.
 
Jdholmes said:
The braces are what I am talking about attaching to the sides.

I got a little angle aluminum to use as braces but of course when you put it square to the hull and try to put a cross piece or something on it makes it point up at the sky instead of directly across the boat...thus the pain in the butt compound angles.

If I understand what you're saying, it sounds like you're using 90 degree angle brackets on the hull.

Won't work.

You probably need something around 100 or so degrees if you're hanging them to the gunwales or under 90 degrees if you're attaching them upside down to the sides of the hull....but I'd have to measure the hull to say so either way...
 
They are 90 degrees...it is just L channel that i cut a couple short pieces to use...If I do that I figured I would have to beat them down to a different angle...

I think I would prefer to use wood but sounds like that is going to be hard with the bare minimum tools I am stuck with right now.

Maybe spacers between the hull and the top of the bracket would work to push it down more level? My worry with that would be it may weaken the connection...
 
That's why I love my 10" delta with the eight foot roll around table:

16288335.jpg


I can rip a 3/4" 4x8 sheet single handed and nothing drops or flops anywhere.

Best thing I ever built....
 
Sup JD, here is how I figure angles. What we are going to do is simulate a right triangle, measure the sides, plug in the known dimensions to figure out the unknown dimensions.


The picture above is me standing on the starboard side facing towards bow. You are looking at where the bow comes together, just below the bow plate. If you read up on the properties of a triangle you should never have a problem with finding angles again, even without an angle finder. Something to know is all angles in a triangle, no matter the shape add up to 180 degrees. Using right triangles ensures you have one piece of the triangle figured out, one angle = 90 degrees.

Here i took a level and clamped a piece of aluminum to the top to form a triangle where one angle measures 90 degrees. It is important to level out the bottom of the boat (both ways) and to hold the level plumb during the measuring process. The clamped aluminum makes it so I can adjust the length for the top of the triangle when level, against the side of the boat...an adjustable tri-square would achieve the same thing with more accuracy.. Keep in mind that the level and clamped straight edge need to be 90 degrees. Once you have your custom square made you can measure the long sloping end of the triangle called the hypotenuse. i marked the side of the boat to accurately measure this distance.


Above shows the exact triangle from the measurement process, i measure in fractions and converted to decimals for the calculator. There are fraction to decimal charts available as well. We are going to take the known dimensions and using the properties of a triangle to figure the degrees. There are calculators out there if you don't understand trigonometry. https://www.cleavebooks.co.uk/scol/calrtri.htm I basically measure the level length from the bottom of the aluminum to where it touches the side of the boat (6.59"), this is the rise. I also measure aluminum piece from the inside of the level to where it touches the side of the boat, 4.3125 or 4 5/16", this is the run.The distance where these two points are on the boat (hypotenuse) came out to 7.875 or 7 7/8".

This is an image where I figured the degrees of the triangle. This should be all the information needed to form your support angles or to cut your miters for the supports.

So if a support came through at this point, it would have to be cut at 56.8 degrees. Lots of the time including Valcos, the side of the boat isnt a true flat line, I measure only the section needed at the location to figure the most accurate degree. Basically if a deck support is to be installed at the top of the boat I measure at the top of boat, in the general location of the support. If the support is to be at bottom, I measure at bottom.

If these were your measurements... you need to change the angle of your 90 degree brackets to 56.8 degrees. This would make one side of the angle against the boat and the other level for your deck supports.

Hopefully this helps you out, let me know if you need help.
 
I hated trig...never figured I would need it either. And I haven't...till I decided to mod a boat. ;)

I was an English and history guy.

Thanks for the help, that does make it easier on my mind. I may go pick up an adjustable tri-square.
 
Jdholmes said:
I hated trig...never figured I would need it either. And I haven't...till I decided to mod a boat. ;)

I was an English and history guy.

Thanks for the help, that does make it easier on my mind. I may go pick up an adjustable tri-square.
Well trig is to figure the angles using math, nowadays they have calculators where you plug in the numbers and they tell you the missing sides or angles. I know trig but I dont use it, just the rise-run calculators..much faster and less chance for error.
 
johnnyclack said:
A Point of Trivia

The only time levels are used on the constructing of ships is when they are on the launch ways, once the boats are launched there is no such thing as a level ship/boat......
Right, it's used in this situation to reference level from starboard to port. Not to fabricate just to figure the angles without the use of angle finders.
 
johnnyclack said:
A Point of Trivia

The only time levels are used on the constructing of ships is when they are on the launch ways, once the boats are launched there is no such thing as a level ship/boat......

Level?

Nope.

Square?

Yup.

8)
 
Thanks for the advice guys. Given my lack of Ideal tools right now I have decided to try something different. I picked up some thick vinyl spacers today. I can cut the angle on those easily and then put them between the bracing and the hull. It may effect the structural strength somewhat, but distributed well I don't think it should be an issue. Plus my wife and I are both lightweights. ;)
 

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