Drilled 4 holes in the top of my U-shaped pontoon

fatlaz

Cadet
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Aug 11, 2014
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27
While mounting a ladder onto my deck, I mistakenly drilled holes all the way through the top of my U-shaped pontoons. I can't get to the holes without removing my deck. The top of the pontoons are about 1 1/2" below the bottom of the deck.. The holes in the pontoon are about a foot from the edge of the deck and about 8 inches from the edge of the pontoon. Any advice as what to do? This was the last step of a total rebuild and I mistakenly used the same drill bit I was using to drill through my 1 1/2 fencing + 3/8 spacers. I'm hoping I can ignore the problem and just drain the pontoons each fall as I have drain plugs in the pontoons.
 

GA_Boater

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May 24, 2011
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Get 4 short bolts like these and slightly larger than the holes. Coat the threads and flange with marine sealant and seat it in the holes.

Click image for larger version  Name:	bolt.png Views:	1 Size:	20.6 KB ID:	10839442
 

HotTommy

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Mar 15, 2013
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Assuming your logs are aluminum, it suggest you use stainless steel bolts.
 

GA_Boater

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Tommy - You couldn't tell the pic is a stainless bolt. :smile:

I thought I said that. Meant to say stainless. Thanks.
 

fatlaz

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Aug 11, 2014
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27
Thanks. Great idea. I can just do that by opening the holes I drilled through the deck without taking the deck off too.
 

The Force power

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Even with stainless steel screws/bolts corrosion will occur!
The only difference between steel & stainless in contact with aluminum is that stainless wins over steel,
but with stainless-steel the aluminum will corrode away.
If anything; I would suggest aluminum fillers such as rivets/mono bolts and/or seal with silicone
 

Grub54891

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I was thinking silicone also. Something like 3m 4200. Or that " magic " tape they have on the infomercials.
 

Scott Danforth

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I'm hoping I can ignore the problem and just drain the pontoons each fall as I have drain plugs in the pontoons.

you cant ignore it. if you spring a leak and there is a "vent" hole in the top, the logs will fill up......

as stated above, you can screw in a bolt with sealant, then slather over the top with 4200 UV to prevent galvanic corrosion
 

fatlaz

Cadet
Joined
Aug 11, 2014
Messages
27
Thanks for all the advise. So actually I ended up gooping silicone adhesive/sealent and putting a 1/2" diameter aluminum sheet metal disc over it. I know the galvanic charts show 316SS and 6061 aluminum will have galvanic corrosion, but my experience with thousands and millions of lighting fixtures in the north sea show that in reality the corrosion is slow enough not to matter,
 

Silvertip

Supreme Mariner
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Sep 22, 2003
Messages
28,758
Ace hardware carries a good selection of plastic bolts. Cut threads in the tube the appropriate size, apply sealant to the bolt, screw it in and forget about slathering anything and worrying about co
 
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