10 Days in the salt

General boating discussion
Browndog15
Posts: 2
Joined: Mon Jan 20, 2020 6:56 pm

10 Days in the salt

#1

Post by Browndog15 »

Hello,
I have a 17 foot plate boat, made with 5052 aluminum. I used Tef Gel on stainless fasteners (and nylon washers), i am awaiting aluminum fasteners,which I will use instead of stainless. I have a teardrop zinc anode on a fishfinder transom plate. There is no bottom paint on the boat. I am trying to find something other than the rubber plug with brass insert for the bilge. Should I be ok for 10 days of South Florida salt water? The 17 is a lot easier to tow than my 26 glass boat. I planned on pulling it out of the water every few days to rinse it off, and I would soak it in a fresh water canal before I towed it home. Thx.
Chaps
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Re: 10 Days in the salt

#2

Post by Chaps »

Not much can go wrong in 10 days! That boat is tough, don't worry about it. Stainless fasteners are fine, tef-gel is good stuff. The expanding rubber transom plugs are available with SS hardware which will do better than the brass. Would recommend swapping the zinc anode for an aluminum anode.
1987 24' LaConner pilothouse workboat, 225 Suzuki
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kmorin
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Location: Kenai, Alaska

Re: 10 Days in the salt

#3

Post by kmorin »

Browndog15 wrote: Wed Dec 16, 2020 7:29 pm Hello..... i am awaiting aluminum fasteners,which I will use instead of stainless.
Browndog, I'd caution you on that decision to use aluminum threaded fasteners. Aluminum threads are notorious for galling, and ruining the bolt and nut- and then having to be cut off (out) to replace. Insulated SS, or better galvanized (hot dipped zinc) works fine if installed well. A good bedding to the device or equipment being attached allows a glued or ribbed plastic bed and if SS fasteners are passivated, then sleeved with PEx or equivalent tubing the galvanic cell between the nickle alloy steel and marine alloy aluminum can be reduced to a very controllable level.

But aluminum fasteners haven't the tensile strength for many applications- certainly not in an equal exchange with SS/Galv. in dia. Between the thread sensitivity to galling and the weaker faster strength I'd say it was advisable to stay with well handled SS or move to galvanized bolts (hot dipped only) in order to reduce galvanic corrosion sites.

re bilge drain plug https://www.homedepot.com/p/Attwood-Dra ... /301397602 this is what is more often used in the bilge of welded aluminum boats- or the screw compression version- still in SS. Passivating the SS parts is pretty easy if you look up the acid treatments you'll find dozens or references and plenty of vendors willing to sell the acid gel/liquid.

5052 has no problems in salt water, some of the longest in-service boats in the country were built of '52 as the other 50series alloys weren't available back then!!

you might consider posting some views of the skiff? Everyone here enjoys pictures of welded boats, and a 17'er would be nice to see. Hope you have a good and problem free trip to the warmer latitudes, salt water has no reaction to 5052, but in some cases it can act as a catalyst for various combined corrosive actions on aluminum. Don't bother to rinse the boat till you're ready to head home, little can happen in 10 days, especially with a Skipper as attentive to detail as you!

Cheers,
Kevin Morin
Kenai, AK
kmorin
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gandrfab
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Joined: Fri Mar 28, 2008 12:33 pm
Location: Edgewater Fl

Re: 10 Days in the salt

#4

Post by gandrfab »

kmorin
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Re: 10 Days in the salt

#5

Post by kmorin »

G & R, don't need the weld passivation kit to dip and rinse the SS bolts!! Just the acid gel and someplace to let them dry.

Welds have a separate level of iron in the surface oxides so.... the acid gets a little 'jump start'.

Cheers,
Kevin Morin
Kenai, AK
kmorin
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gandrfab
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Joined: Fri Mar 28, 2008 12:33 pm
Location: Edgewater Fl

Re: 10 Days in the salt

#6

Post by gandrfab »

Thanks
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