Removing Water from Hull by Drilling Holes

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
GatorWhaler
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Removing Water from Hull by Drilling Holes

Postby GatorWhaler » Wed Apr 22, 2020 1:41 pm

I have an older c.1968 13 footer that I bought for $200 as a project. The seller said the boat satlow in the water. Given its age I suspect the foam is water;ogged.

As boat projects often go, the boat been sitting upside down for two years.

Q1; where should holes be drilled to drain water in this situation?

Q2: should a hole be drilled into the top of the transom?

Q3: should holes be drilled into several bilateral points along the hull?

jimh
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Re: Removing Water from Hull by Drilling Holes

Postby jimh » Wed Apr 22, 2020 3:55 pm

If you want water to drain from a hull by gravity by a newly-drilled hole for that purpose, the newly-drilled hole must be located so water flows downhill to it.

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Phil T
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Re: Removing Water from Hull by Drilling Holes

Postby Phil T » Wed Apr 22, 2020 4:20 pm

You need to weigh the hull before you do anything.

Going off vague information from a former owner is not a reason to embark in a major undertaking.
Member since 2003
1992 Outrage 17, 1992 Evinrude 115

dtmackey
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Re: Removing Water from Hull by Drilling Holes

Postby dtmackey » Wed Apr 22, 2020 5:57 pm

[Strongly endorsed] Phil's advice:
Phil T wrote:You need to weigh the hull before you do anything.


The hull may have minimal water or be very staturated. By weighing it, you will get a better idea [of the weight gain that may be due to water ingress into the hull].

My guess: the brass drain tubes failed and water was soaked up in the transom area foam, but now that the boat has been upside down, it's probably down into the gunwales due to gravity.

The drip method--drill holes and let it dry--could take years. There's a company out there that's dried several saturated Whaler hulls with success. http://www.dryboat.com/media/

Presentation at: https://youtu.be/mRvTQTqGDL8?t=167

D-

jimh
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Re: Removing Water from Hull by Drilling Holes

Postby jimh » Wed Apr 22, 2020 6:17 pm

If a boat hull has been in its normal orientation for 52-years (i.e. a c.1968 boat), any water in the hull that could migrate would then, due to gravity, have migrated to the lowest parts of the hull. If the hull is recently inverted for purposes of letting water drip out, then any water that was at the lowest part of the hull would now have to migrate through the foam to the new lowest point in the hull in order to flow out via a new drain hole. On that basis, the notion of inverting the hull in order to assist water draining from the interior seems like a bad idea.

jimh
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Re: Removing Water from Hull by Drilling Holes

Postby jimh » Wed Apr 22, 2020 6:19 pm

A frequently asked question: is there water in a Boston Whaler Unibond boat hull? See the answer to this frequently-asked-question at

Q3: Is There Water in a Hull?
http://continuouswave.com/forum/viewtopic.php?f=7&t=41