"Tunnel Mite" Building Question?

Outboard designs up to 14'

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"Tunnel Mite" Building Question?

Postby weasel » Sat Apr 30, 2016 7:37 pm

I am finishing up the bottom of the tunnel mite. I am on the spray rail now, and have a question. The plans call for #8 - 1" screws to fasten on the spray rail from the inside/out. If you cut the spray rail exactly like the plans show, the screws will come through the spray rail when the screws are put in from the inside. You only have 1/8 in plywood and the middle thickness of the spray rail doesn't even make 3/4". Even the 3/4" - #8 screws barely come through the rail too. Do you drill a pilot hole all the way through (so the rail doesn't split), then I assume then that you put the #8 - 1" screws in and through the spray rail then grind the excess off on the outside when finished. That just doesn't seem right for some reason. So if there are any experienced Tunnel Mite builders out there that tackled this problem, it would be great to hear what you did, Thanks!

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Re: "Tunnel Mite" Building Question?

Postby BarnacleMike » Sun May 01, 2016 11:13 am

I haven't built a Tunnel Mite. However, what you're describing doesn't sound much different than attaching planking to chines. You're just driving screws from the inside out, rather than from the outside in.

From what you're describing, I'd say at the very least, use 3/4" screws if you know for sure that the 1" screws will go all the way through. If any of the 3/4" screws come through the spray rail, then it would be fairly easy to sand or grind the tips away.

Here's another idea: Can you attach the spray rails with epoxy only? If you have a way to clamp them into position so that you could do the job using only thickened epoxy, then that might be the simplest option.

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