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Author Topic: upside down plank on frame query  (Read 5004 times)

joppyuk1

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upside down plank on frame query
« on: May 25, 2012, 08:22:17 am »

When builders make plank on frame hulls upside down, with extensions from  the frames to a baseboard two things always puzzle me.
1) how do they work out how long to make the extensions
2) how do they remove the hull from the board afterwards
alright, three things,
3) how do they cut off the extensions without spoling the hull/sheerline

I haven't tried this method yet, but am thinking of it. I'm sure there are simple answers.
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rmaddock

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Re: upside down plank on frame query
« Reply #1 on: May 25, 2012, 09:02:40 am »

1) Assuming you're working from plans, the plans normally have the water line on the cross-sectional drawings. This is a level. You can make this parallel to your building board and, drawing a nominal line above the drawing, simply measure to that.
2) I fastened the formers to the board using screws from the underside of the board. So, to remove it you simply undo the screws.
3) I don't know. Carefully? The boat I built this way had a canoe hull and so the formers came out anyway.
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boatmadman

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Re: upside down plank on frame query
« Reply #2 on: May 25, 2012, 09:06:23 am »

3: One option is to screw extensions to the frames so that once the hull is built you just unscrew the extensions without risk of damage to the hull.

I usually use a dremel with a small circular saw fitting and go carefully to cut off extensions
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john44

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Re: upside down plank on frame query
« Reply #3 on: May 25, 2012, 12:08:39 pm »

All as above, but if some frames need to come out after building the hull. Make sure you put tape over them so that
the glue etc. on your planking will not stick to them and they will be easy to remove.

john
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joppyuk1

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Re: upside down plank on frame query
« Reply #4 on: May 25, 2012, 06:51:53 pm »

See. I knew the answers would be simple (note, I didn't say easy).  Thanks.
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CGAux26

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Re: upside down plank on frame query
« Reply #5 on: May 25, 2012, 11:39:55 pm »

Here is my Jim Wilder tug kit, just after I set up the frames on the building board.  If you look closely you can see that the T-shaped uprights attached to the frames are scored so they will snap off easily. 
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RAAArtyGunner

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Re: upside down plank on frame query
« Reply #6 on: May 26, 2012, 12:53:35 am »


Getting off subject,
does anyone know the link to the build on how to draw/transfer the half frames from the drawing to the 'ply/wood' framing material.

Can't seem to find it  {:-{ {:-{
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JerryTodd

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Re: upside down plank on frame query
« Reply #7 on: May 26, 2012, 05:39:04 am »

A little clarification:  the waterline is not necessarily your "level."  Many plans have the vessel flat on it's keel and the stations are drawn at 90° to the keel, which often places the waterline at an angle.

The forms are attached to a building board in some manner that they can be taken loose.  For instance, I use plywood forms with wood strips attached that are wider than the forms.  The strips, usually 3/4 inch square help hold the form at right angles to the base board, and are screwed down to it.  At any time, the screws can be removed and the hull lifted off.

I draw a line 90° to the stations and maybe an inch above the highest point of the hull at the bow or stern.  Flip the plan 180° and that's your building base line.  Match that line on the body plan and extend each of the stations up to that line.  It doesn't need to be a lot - more is a waste of wood.

What's nice is you have a steady point to measure from any where on the model.


HMS Macedonian framing completed, just before planking began - the waterline is not level to the keel or the building board.  Note also that ALL the forms were removed from the hull when planking was completed.


On getting the lines onto the forms.  I used to trace them with tracing paper - place the paper pencil side down on the board and redraw it from the back side - which has a carbon paper effect.  Now I make up each one in a drawing program (Paint Shop Pro v7) and print each one to paper and paste that to the wood.  I can explain that process in more depth if you require it.

john44

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Re: upside down plank on frame query
« Reply #8 on: May 26, 2012, 12:27:18 pm »

Getting off subject,
does anyone know the link to the build on how to draw/transfer the half frames from the drawing to the 'ply/wood' framing material.

Can't seem to find it  {:-{ {:-{
Hi raaarty,
what I do is fold the plan so that I can photostat the half frames.
e.g if there are 10 frames I make 10 copies, number the sheets 1 to 10 fold them back on the center line
and cut each of the frame shapes out. When unfolded you have a full frame. I then glue the frame shapes
onto my frame material with wallpaper adhesive and cut out when dry.

hope this helps

john
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John W E

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Re: upside down plank on frame query
« Reply #9 on: May 26, 2012, 12:37:35 pm »

When builders make plank on frame hulls upside down, with extensions from  the frames to a baseboard two things always puzzle me.
1) how do they work out how long to make the extensions
2) how do they remove the hull from the board afterwards
alright, three things,
3) how do they cut off the extensions without spoling the hull/sheerline

I haven't tried this method yet, but am thinking of it. I'm sure there are simple answers.

Hi this may just help you out

http://www.modelboatmayhem.co.uk/forum/index.php?topic=13888.0

http://www.modelboatmayhem.co.uk/forum/index.php?topic=9758.0

http://www.modelboatmayhem.co.uk/forum/index.php?topic=7947.0

http://www.modelboatmayhem.co.uk/forum/index.php?topic=1951.0

http://www.modelboatmayhem.co.uk/forum/index.php?topic=8904.0

http://www.modelboatmayhem.co.uk/forum/index.php?topic=9014.0


aye
john
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joppyuk1

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Re: upside down plank on frame query
« Reply #10 on: May 26, 2012, 06:33:45 pm »

Bluebird, thank you. Pictures worth more than many words. I've printed of one of your referrals so I can keep it handy.
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tassie48

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Re: upside down plank on frame query
« Reply #12 on: May 26, 2012, 10:46:52 pm »

I always build this way when cutting out my frames i allow extra 50 to 100 mm per frame length then come in 25 mm from both sides and screw this to your keeper (strip of timber that holds the frame to the base board) then screw the keeper to the base board this allows for planking to the deck line and fiberglassing as well every frame is 90 degree to the base board allows for a strong frame then fit the keel to the frames after the frames have the correct cut out for fitment by far the best way to build tassie48
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