Keel Templates
- Thread starter Relentless
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If you have access to another you can take off the shape with a tick-stick.
The Tick or Joggle Stick.
I was fortunate that Mignonne’s structural bulkheads did not need replacing, just refastening.
However I did have to build all the ‘non structural ones.
At first I curt cardboard templates but these left me with a lot of trial and error fitting, scribing, shaving, re fitting, scribing again, shaving a bit more and wasted not only time but timber.
I then tried making up template from scraps of light timber glued together in situ with the hot glue gun. This worked reasonably well but I quickly ran out of scraps.
Then someone introduced me to the ‘Tick or Joggle Stick.’
This is without doubt the most accurate and practical method for making any odd shaped pattern.
The ‘stick’ can be any old scrap timber preferably a stiff piece the length will depend on the shape you want to trace, for a bulkhead perhaps about a third of the beam of the boat.
Cit a point at one end and a couple of notches along the length, these are to make it easy to relocate the cognise position of the stick later.
Next you need a scrap piece of reasonably stiff plywood.
This needs to be large enough to be tacked or clamped firmly vertically along side the proposed position of the new bulkhead, this will be you ‘pattern board’.
The board also needs to have a clean surface so you can draw on it with a pencil, a coat of white undercoat will give a perfect surface.
Now you have that set up, with the stick flat on the ‘pattern board’ place its point at a position on the hull that you want to record and then trace the outline of the stick onto the ‘pattern board’ with your pencil.
You will need to be able to put you stick on to the trace in exactly the same position and way up later, this is where the notches come it as reference points.
Repeat this for as many points as will be needed to create a complete profile of the hull shape including frames chain-plates etc.
Now take the ‘pattern board’ out and lay it on the panel that you wish to cut out.
Clamp it firmly to the panel.
Now take the same tick/joggle stick and place it onto those penciled outlines on the pattern, then mark the position of the point onto the panel.
Do the same for all the positions you have marked then join the points up with a spiling baton and straight edge.
Cut it out and hope it fits but don’t expect the other side of the hull to be a mirror image.
Better to slap some more white undercoat on your pattern and do another trace for the other side.
http://www.diy-wood-boat.com/Bulkhead.html#name2
The Tick or Joggle Stick.
I was fortunate that Mignonne’s structural bulkheads did not need replacing, just refastening.
However I did have to build all the ‘non structural ones.
At first I curt cardboard templates but these left me with a lot of trial and error fitting, scribing, shaving, re fitting, scribing again, shaving a bit more and wasted not only time but timber.
I then tried making up template from scraps of light timber glued together in situ with the hot glue gun. This worked reasonably well but I quickly ran out of scraps.
Then someone introduced me to the ‘Tick or Joggle Stick.’
This is without doubt the most accurate and practical method for making any odd shaped pattern.
Cit a point at one end and a couple of notches along the length, these are to make it easy to relocate the cognise position of the stick later.
Next you need a scrap piece of reasonably stiff plywood.
This needs to be large enough to be tacked or clamped firmly vertically along side the proposed position of the new bulkhead, this will be you ‘pattern board’.
The board also needs to have a clean surface so you can draw on it with a pencil, a coat of white undercoat will give a perfect surface.
Now you have that set up, with the stick flat on the ‘pattern board’ place its point at a position on the hull that you want to record and then trace the outline of the stick onto the ‘pattern board’ with your pencil.
You will need to be able to put you stick on to the trace in exactly the same position and way up later, this is where the notches come it as reference points.
Repeat this for as many points as will be needed to create a complete profile of the hull shape including frames chain-plates etc.
Now take the ‘pattern board’ out and lay it on the panel that you wish to cut out.
Clamp it firmly to the panel.
Now take the same tick/joggle stick and place it onto those penciled outlines on the pattern, then mark the position of the point onto the panel.
Do the same for all the positions you have marked then join the points up with a spiling baton and straight edge.
Cut it out and hope it fits but don’t expect the other side of the hull to be a mirror image.
Better to slap some more white undercoat on your pattern and do another trace for the other side.
http://www.diy-wood-boat.com/Bulkhead.html#name2
http://www.computerkeels.com/
In Edina MN are usually the best source for templates. They don't list the C36 (nor the H34!) but might be worth the call
In Edina MN are usually the best source for templates. They don't list the C36 (nor the H34!) but might be worth the call
You could make your own. Chances are good that the sections were supposed to be NACA 00xx or 63-0xx. The offsets are widely available and you an either print some up or loft them. The critical number is the nose radius which varies quadratically wrt the thickness ratio -- ie. thicker foils have relatively rounder noses. IME it is better to err on the side of too large a radius than too small. When fairing be very aware of twist and asymmetry. Make sure all your templates are parallel and aligned to the same centers. If the foils are 6 series then you can fair them w/out the aft hollows and make them "A" series. They work just about as well that way and are a lot easier to fair.
--Tom.
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