North River Seahawk Drain Holes?

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deltafishing
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North River Seahawk Drain Holes?

#1

Post by deltafishing » Sun Dec 27, 2015 12:42 pm

Good morning everyone!

Pleasure to be a part of this site. I finally took delivery of my new North River Seahawk and couldn't be happier. Upon installing my transducer wiring yesterday afternoon I came across some small holes drilled in the bracket structure and lifting strake/chines of the boat and was wondering if anyone can shine some light on this for me. My concern is with water finding it's way into the structure and not draining completely leading to corrosion problems. However, if I understand correctly, as long as air is circulating within the structure, I shouldn't have much to worry about since it shouldn't lead to crevice corrosion. Am I on the right track? I look forward to posting many pics! Thanks!

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Chaps
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Re: North River Seahawk Drain Holes?

#2

Post by Chaps » Sun Dec 27, 2015 1:17 pm

Welcome, yes those holes are to drain small spaces when the boat is pulled out of the water. while the boat is in the water those spaces will flood.
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kmorin
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Re: North River Seahawk Drain Holes?

#3

Post by kmorin » Sun Dec 27, 2015 4:20 pm

D'fish'n
I notice that most of the welds are MIG, and the holes imply the builder chose not to air test the voids. MIG is somewhat porous welding process, compared to TIG you might see in comparable welds on other builders' boats. (Pacific is an example of a builder that TIG welding details on their skiffs.)

If a void is sealed, no limber hole, and welded tight (closed without testing after the seal weld) in the shop at 68-70some degrees F; that void will be under a vacuum as soon as you launch the boat, well maybe if you live in Florida it won't? but all cooler water temp. means a sealed void will be in vacuum compared to the outside ambient air- and certainly when compared to the shop temp air sealed in the void.

To avoid pulling water into voids by vacuum, (then) having the water stay, stagnate, and become acidic (natural process for water in voids) then promote either crevice or acidic cell corrosion... the builder chose to drill the holes to allow water out of those spaces. Other builders air test these voids, and usually those builders use TIG welds (less porous than MIG) on these sealed void welds.

The last reason for the drilled holes is when you're closing a weld on these voids of small volume -pipes, small plate formed areas, and some hollow brackets- the air inside is being heated by the weld- so the air is expanding and if you 'close' the weld to seal the void- not usually true of entire sub-deck areas in volume of many cubic feet- then the weld puddle is 'blown out' by the escaping gases inside the void. So by drilling small breathers- the weld can be closed (TIG or MIG) and there is no 'blow out' of weld seam.

If there is a concern the water inside your voids has become acidic and therefore represent potential damage, find some litmus paper strips and test the 'weep' out of these holes. http://www.amazon.com/Litmus-Strips-Uni ... B00S730YWG

If the drips that come out of the voids, one day or two days after the boat has been hauled show up acidic then inject a little baking soda/water or ammonia/water solution and let that neutralize the acid- otherwise the flush of water in and out of these holes should keep the voids from becoming acidic.

cheers,
Kevin Morin
Kenai, AK
kmorin

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goatram
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Re: North River Seahawk Drain Holes?

#4

Post by goatram » Thu Jan 14, 2016 1:08 am

Kevin got it right those holes are in short sections of pipe or tube on the Swim Step. The holes are installed to stop the welds from Blowing out. The Big hole in your first picture is of your Kicker Bracket for water drain. Good to go. No worry if it was mine. :thumbsup:

An welcome to the site and enjoy your boat. The Northriver is a well made boat. :beer:
John Risser aka goatram
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deltafishing
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Re: North River Seahawk Drain Holes?

#5

Post by deltafishing » Sun Feb 07, 2016 7:45 pm

Thank you all for your replies. I apologize for the late reply of thanks, I've been so busy the last month so hopefully now I can start posting. I'd also like to say how awsome it is to have a site with so much information. Hopefully I can follow Kevin's recommomendation of getting rid of the mill scale on my boat. I'd like to take it out to the salt/brackish water with minimal problems. Also goatram, in many of your posts you suggest rinsing the bildge with simple warm water and dish soap to neutralize the acid. Any brand in particular? Is it a good idea to rinse my boat wish dish soap as well?

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goatram
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Re: North River Seahawk Drain Holes?

#6

Post by goatram » Sun Feb 07, 2016 11:18 pm

Kevin is the one that has talked the most about adding soap to the bilge. He also has talked about using water test strips to test the water. Most of us have Lemon Joy dishwashing soap on the boat to wash our gear after fishing. The LJ soap does not upset the fish, they kinda like the smell. Congrats on the new boat and I can tell by your comment that you troll IFish. I have learned a lot from here, Ifish and BDoutdoors, Washi googan sub forum.
John Risser aka goatram
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2015 Ford F350 Dually
Master of R&D aka Ripoff and Duplicate

kmorin
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Re: North River Seahawk Drain Holes?

#7

Post by kmorin » Mon Feb 08, 2016 4:54 pm

delta, I've mentioned several times mixing SODA or baking soda or ammonia with water, I'm not sure dish soap is "base ph" ? I have said you could add a base (other end of the ph scale from acid) and that will work to neutralize the acids.

Soap, would work on the oil films, help reduce organics in the boat, but I'm not sure of dish soap's ph so I wanted to clear up this confusion- add a base to neutralize any acids, then rinse the dickens out of the entire bilge, too much base is little different from too much acid.

cheers,
Kevin Morin
Kenai, AK
kmorin

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goatram
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Re: North River Seahawk Drain Holes?

#8

Post by goatram » Tue Feb 09, 2016 11:59 am

Kevin I was sure you had said that. I just did a search but could not find any reference of that. You have always advocated either baking soda or ammonia to neutralize acid.

My take on the subject is soap is a mild base that will clean and neutralize mild acidic water in the bilge. If used on a regular basis it will keep the bilge clean and fresh, hense less of a corrosion issue developing.

Now to find where I got my thought process from.
John Risser aka goatram
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Re: North River Seahawk Drain Holes?

#9

Post by kmorin » Tue Feb 09, 2016 12:31 pm

john,

if soaps are mildly basic (didn't know that) then they'd work just as you say they could. And if done regularly there'd be no 'time' for trapped water, humidity or any other water source to stagnate or deareate and become acidic, as the periodic washes would #1 renew the stagnate water with fresh, #2 work to neutralize and beginning acids, & #3 continue to remove organics that contribute to acid cell formation.

Lots of bilges' corrosion issues seem to come from open bilges, this entire exploration of maintenance seems to further the arguments for boats with welded in decks, vents to allow air expansion and contraction and bilge drains at the centerline transom aft to allow the deck void to be left open in the trailer times and avoid allowing any moisture except ambient air content into that space.

I'd still say stripping mill scale in all voids, before or after building, was good practice. And trying to use as much 50 series in the enclosed spaces as possible and skip 60 series (tiny galvanic differential) was also good practice, but the main concern is to be able to keep the bilges free of the (standing) rain, spray and wind blown debris that seems to kick off lots of these corrosion problems.

Cheers,
Kevin Morin
Kenai, AK
kmorin

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