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Author Topic: Racing Sparrow 750  (Read 651 times)

rosso69

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Racing Sparrow 750
« on: November 07, 2020, 02:22:02 pm »

Hi Guys,


Just started my new lockdown project - a Racing Sparrow 750.  It's based on a free plan from Racing Sparrow.co.nz.  It will be my first plank on frame build, so I may need some tips and advice as I go along.  I've been building planes for 45 years and recently built a Fairey Huntsman 31 and a Wee Nip (Strathclyde 70) sailing yacht, so thought I'd step up a gear and go for plank on frame.  I'll upload some photos as I go, with today being the first day of the build, so mainly cutting out the bulkheads and setting them out.
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CGAux26

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Re: Racing Sparrow 750
« Reply #1 on: November 07, 2020, 05:40:28 pm »

Welcome to plank on frame building.  I have built 2  boats this way. I made a plank soaker from PVC pipe, cut to the length of the balsa strips.  Soak them for at least 30 minutes in Windex.  Longer soaking is OK, too.  Take one strip out and wipe it with a paper towel, leaving it wet.  Run thick CA along the frames and the edge of adjoining planks, and apply the plank.  Hold it in place with your fingers for about 30 seconds.  No pins or clamps needed.  Do a length of plank just long enough to control with your hands.  Keep doing this for the length of the plank, then trim off the excess. 


You will have CA on your fingers, but if you wipe it hard on a paper towel it will not stick fingers together.  Keep the CA debonder handy anyway.


And keep your working area well ventilated, with a fan perhaps.  CA is hard on the lungs.


And have fun!
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rosso69

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Re: Racing Sparrow 750
« Reply #2 on: November 07, 2020, 11:21:07 pm »

Thanks for the advice.  I'll certainly give it a try!
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rosso69

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Re: Racing Sparrow 750
« Reply #3 on: November 13, 2020, 08:18:48 pm »

Part way through planking now, so here are some photos of progress so far.  Cutting the 1/16" x 1/8" wide planks is not as easy as I thought, but with careful use of my scroll saw, cutting into both ends of the sheet and joining the two cuts with a scalpel actually gives a good, straight plank.
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Martin [Admin]

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Re: Racing Sparrow 750
« Reply #4 on: November 13, 2020, 09:40:26 pm »


Looks Great!   :-))
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dlancast

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Re: Racing Sparrow 750
« Reply #5 on: November 21, 2020, 07:52:34 am »

are your planks made from Balsa wood?  You are doing a nice job of keeping the planks fair, even with a long space between bulkheads.  Are you edge gluing your planks as you go?  I like to start my planking from the deck and work my way towards the keel, tapering each plank towards the bow and using "stealers" where needed towards the stern and bow.  You can check out my current project of the racing yacht Endeavor.  Keep up the good work.  Always find planking to be very satisfying.
Best to you,  Dennis
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spearfish99

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Re: Racing Sparrow 750
« Reply #6 on: January 02, 2021, 11:24:19 am »

Cutting the 1/16" x 1/8" wide planks is not as easy as I thought, but with careful use of my scroll saw, cutting into both ends of the sheet and joining the two cuts with a scalpel actually gives a good, straight plank.


  If you try balsa planking again, you might find it easier using a balsa stripper to cut them .   [size=78%]Balsa Stripper (slecuk.com)[/size]

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rosso69

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Re: Racing Sparrow 750
« Reply #7 on: January 02, 2021, 12:00:13 pm »

Planking is now finished and faired as best I can - remember this is my first plank on frame attempt!  The planks as mentioned were cut using a scroll saw and scalpel.  I now have a Minicraft table saw which is perfect for cutting planks and will be used on my next build.  They were then edge glued and pinned, starting in four places - approximate centre of the frames and from the bottom edge upwards, and four planks put in place at a time and then left to dry and set.  As I was using thin balsa there was no need to soak the wood before gluing.  Subsequently, after filling any unevenness, I have glassed the hull using Eze-Kote and lightweight glass cloth.  The deck base was laid with 1/8 balsa laid grain across the hull and then a full length 1/8 balsa deck laid lengthwise.  I'm now making the necessay hatches and trying to make up the lead keel from lead strips, which is not easy, but I don't like working with any form of metal and really don't want to cast lead for the keel.  I'll upload some photos soon of progress to date. Any ideas how to shape lead once it's glued up?
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rosso69

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Re: Racing Sparrow 750
« Reply #8 on: January 02, 2021, 12:03:50 pm »

P.S.  Tried using my balsa stripper, but then remembered why I stopped using it, as I didn't find it cut accurate enough strips!  Table saw is perfect.  I use a fence set to the correct size and away you go!.  I also built a simple device to ensure that cuts can be made at 90 degrees really accurately.  Pics to follow.
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