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Through bolting help

Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Boat Maintenance
Forum Discription: Discuss maintenance of your Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=48345
Printed Date: April-26-2024 at 12:40pm


Topic: Through bolting help
Posted By: dasboat
Subject: Through bolting help
Date Posted: January-20-2020 at 2:00pm
So I have an 83 SN 2001 which I am doing some work on and need some advice on re-bolting various attachments.

First off, when people say through bolting is superior I assume they aren't referring to through screwing and actually as the name suggests as through bolting with washers and nuts. Sorry I know dumb question but had to ask.

Question 1:

There is a Bimini with various cleats, of which each cleat used 1" long #10 oval head sheet metal screws. The 2 anti skid step attachments were also secured using the same screws. All of these attachments are on the top side and were screwed directly into the body of the boat itself which seems to be roughly 3/4 - 1" thick. When you reach under to feel or look you will see that some of these sheet metal screws did go all the way through and others didn't. Screws were all the same length, but the underside body isn't a consistent thickness near the side wall where it transitions from horizontal to vertical, if that makes sense.

The conditions of the holes themselves seem to be decent, and I was curious if I should just do nothing and replace the same screw (of course the screws will be new stainless), or should I drill them all the way through just slightly larger to where there is a flush ID bore / pilot hole and use the appropriate length and thickness oval head machine screws with fender washers, lock washer, and nut.

Question 2:

I am also replacing the original swim platform brackets to an updated version with a slot/pin design so I can quickly remove the platform itself without unbolting anything. They were secured using 1-1/2" long 3/8" lag bolts. I have also read the superior set up would be to through bolt here are well, but I don't want to remove the tank if I can help it. Plus I am weary because these bolts would be submerged below the water line at times if not all the time and I don't want the through bolt holes to be a potential leak point.

I plan on drilling and cleaning out the holes a bit and filling in with epoxy. After that's cured I will drill fresh 1/4" pilot holes and re-attach the same 3/8" lag bolts.

Anyone see issues with this plan?

Thanks.




Replies:
Posted By: Mille1sj
Date Posted: January-21-2020 at 2:43pm
I replaced the platform and used the same style brackets you are referring to on my '77 Ski Tique last summer. I through bolted with stainless and used a 3M sealant to prevent any leaks. I also fiberglassed a piece of 1/4" aluminum plate on the inside of the transom then drilled through it. my thought was to distribute the weight across the plate rather than the washers. I'm a big boy so I tend to go overboard on its like this.


Posted By: JoeinNY
Date Posted: January-21-2020 at 4:06pm
Originally posted by dasboat dasboat wrote:



The conditions of the holes themselves seem to be decent, and I was curious if I should just do nothing and replace the same screw (of course the screws will be new stainless), or should I drill them all the way through just slightly larger to where there is a flush ID bore / pilot hole and use the appropriate length and thickness oval head machine screws with fender washers, lock washer, and nut.


If they are in good shape I would use the same holes on those gunnel mounted accessories, you can bed them in some 4200 if you like as it may keep a bit of water out.   Many times when I have drilled and through bolted such things I have lived to regret it as the nuts loosen over time, can be difficult to re-tighten, and then lead to the holes enlarging and hardware to move around.

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http://www.correctcraftfan.com/diaries/details.asp?ID=1477 - 1983 Ski Nautique 2001
1967 Mustang 302 "Decoy"
http://www.youtube.com/watch?v=cO5MkcBXBBs - Holeshot Video


Posted By: dasboat
Date Posted: January-21-2020 at 6:56pm
Interesting... I'll keep that sealant in mind if I go all the way through.


Posted By: dasboat
Date Posted: January-21-2020 at 7:05pm
[/QUOTE]
If they are in good shape I would use the same holes on those gunnel mounted accessories, you can bed them in some 4200 if you like as it may keep a bit of water out.   Many times when I have drilled and through bolted such things I have lived to regret it as the nuts loosen over time, can be difficult to re-tighten, and then lead to the holes enlarging and hardware to move around. [/QUOTE]

Right... this gives me an idea since I want to avoid through bolting. I checked the oval head size of the next size up screw and it seems to fit the hole indent on the cleats and other accessories. So I think I'm just going to use those so it will have at least a fraction of new material to bite into on the existing (and slightly smaller) screw holes.

Thanks for the insight, your boat looks awesome by the way.



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