Thread inserts for fastening points

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OnkaBob
Posts: 389
Joined: Fri Jul 18, 2008 10:12 am
Type of boat I like: <-- Please read instructions to the left and delete this text. Then, tell us what type boat you like! :-)
Location: Seaford, South Oz

Thread inserts for fastening points

Post by OnkaBob » Wed Jan 06, 2010 10:38 pm

This is useful for where you want to screw various attachments to the boat for different purposes. In my case the laker needed to have deck lines so it could be registered for use with my kids' scout group but I don't want them there all the time. By putting steel threaded mounting locations on the hull the lines can be removed/replaced quickly and I could even use the points for mounting rod holders, outriggers etc.

My general process was to make some bolt on loops (laminated ply), glue some hardwood backing plates under the deck then insert steel threads and bolt on the loops.


These are the loops:
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I used a dense hardwood for the backing plates after trying a few pieces to see which could be tapped and hold a bolt without the steel inserts. Interlocked grain would give more strength but is not essential.
The backplates were drilled undersize using the loops as a template then these were used to drill the hull after carefully marking the locations using masking tape and pencil. Wire was used to hold the plates in place while the epoxy cured.
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This is the thread replacement kit I used. Brand is Recoil but there are others.
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When the backing plates were set I drilled out the holes to the correct size for tapping and coated them with epoxy and let it set. The holes were then tapped out to take the thread coils and the coils inserted in place after a light application of epoxy. I then inserted a screw several times into each thread, cleaning with metho after each time to remove any epoxy that found its way to the inside of the coil.
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After allowing the pox to set the deck lines could be bolted on.
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I realize many people would not bother with this method as a nut and bolt is usually quicker and easier but it does have its uses.
Cheers, Bob

Laker 13 - christened and slimed (just).
Laker accessories underway.

Bemm 52
Posts: 309
Joined: Wed Feb 13, 2008 3:57 pm
Type of boat I like: <-- Please read instructions to the left and delete this text. Then, tell us what type boat you like! :-)
Location: Sydney Aust

Re: Thread inserts for fastening points

Post by Bemm 52 » Thu Jan 07, 2010 2:31 am

Top idea Bob :idea: 8)

I've toyed with the idea of using nut certs or captive nuts on some of my projects but your idea is better and a neater finish i think

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