My new scratch built tunnel

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talonxracer

Well-Known Member
Joined
Sep 10, 2005
Messages
252
I decided I needed a tunnel for the UL1 motor I finally nabbed for a P-spec boat, and since there are no more kit's available I decided to scratch build one. I used a conglomeration of ideas for the build borrowed from my Nemesis, Villian S1, and my Drifter L cat. It has 29.5" sponsons and 6.75" wide tunnel. I will call it The Barracuda...

I drew out the sponson formers and keelsons directly on the wood and then went to town cutting and sanding. I used a 1/16" carbon plate for the last 8" of the sponson ride surface in a similar fashion to my Nemesis.

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Here are the sponsons laid out to get an idea of the center section, with the 1/8" liteply airfoil end formers.

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And here is the center section almost all cut out and pre-fitted, 1/16" bottom sheet, 2x 1/4" aircraft ply transom, 1/8" liteply doublers, 1/8"sq spruce airfoil spars(ladder looking pieces), 1/16" ply radio/battery box sides and 1/8" ply radiobox front former and 3/8" sq hardwood nose, she will have 1/32" top sheeting.

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spoonefcrx laid up the cowl for it this week.

and here is a pic with the Sponsons laid out with the center section.

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I have the center section glued up and the stringers sanded down to fit the top decking, The sponsons are have two ultra thin coats of 105/207 applied to to the ride surfaces to seal them. The top of the sponsns will get a second coat today and Keelson sides will be coated after final glueing to the center section. I apply the 105/207 with a very fine foam rubber roller so that it is ultra thin and very uniform. The first coat is almost completely absorbed by the wood and the second coat makes it glas smooth.

A overhead view

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from the bow,

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And the stern,

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***update***

Here is the cowl I got from spoonefcrx, fitted to the airfoil along with a coat of primer. Also included is the prototype outboard cowling plug I made yesterday to get an idea of how it would look...

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Looking good ! [ Man, I run out of patience just adapting radio boxes to RTR nitro tunnels. ] Keep the photos coming.

BTW, if you don't mind me asking, where do you get your CF sheet from; I need a piece to reinforce the transom on a P-Sport hydro I'm rigging ?

Tony
 
nice build! but i hope it runs better than that ebay dolphin lol
 
Will you need to fillet the joint betwen the CF surface and the riser on outside of the sponson to ensure the hull does not hook in turns? or is the 1/16 edge to small to be of concern?

Dave
 
Will you need to fillet the joint betwen the CF surface and the riser on outside of the sponson to ensure the hull does not hook in turns? or is the 1/16 edge to small to be of concern?

Dave
I need to post pics of the completed sponson(minus sealing), yes I did use a peanut butter thickness mixture of 105/205 + 404 high density filler from West Systems to make a fillet, but it still produces an edge. I used the same procedure on the Nemesis and I have no issues with hooking at all.

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and here is a pic with the Sponsons laid out with the center section.

IMG_1005.jpg
 
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***update***

I have the center section glued up and the stringers sanded down to fit the top decking, The sponsons are have two ultra thin coats of 105/207 applied to to the ride surfaces to seal them. The top of the sponsns will get a second coat today and Keelson sides will be coated after final glueing to the center section. I apply the 105/207 with a very fine foam rubber roller so that it is ultra thin and very uniform. The first coat is almost completely absorbed by the wood and the second coat makes it glas smooth.

A overhead view

IMG_1010.jpg


from the bow,

IMG_1011.jpg


And the stern,

IMG_1012.jpg
 
The build is coming along great! I cannot wait to get mine started :p I did get another project boat in the mail today tho, a 34" Hornet..So it may get done before I build this boat. Your cowl is going out today..In fact, let me get off of here, and bill it up, lol. Talk soon, Mike
 
How about uploading that cowling pic, LOL. It looks great man! Mike
***update***

Here you go Mike,,,

Here is the cowl I got from Mike (spoonefcrx), fitted to the airfoil along with a coat of primer, it looks awesome on the Barracuda. Also included is the prototype outboard cowling plug I made yesterday to get an idea of how it would look...The engine cowl is 3/8" wider than it will end up being as the parting trim portion is built into the plug already.

IMG_1018.jpg
 
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Wow man! That is one sexy looking cowling! Who made that! Just kidding. Dude, the boat looks great, the cowl looks to fit great, and that engine plug..Yeah, I want to be first on the list when you get it ready! That is gonna be one NASTY boat when its finished!
 
I plan on white DuraCoat S/L on the bottom surfaces, the top of the sponsons will get just a clear, the airfoil portion of the center section will be yellow and the cowl will be yellow/white and red, with a black cockpit windscreen.
 
Here is the cowl with some yellow on it, it was very humid this morning so the paint blushed and of course a bug landed on it,,,,at least it is where the canopy windscreen will be going. She will have to be wet sanded the windscreen added along with some additional stripes and maybe a few decals applied and then the clear.

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