What are Soft Spots

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
Ohio Chris
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Joined: Thu Feb 27, 2020 4:14 am

What are Soft Spots

Postby Ohio Chris » Mon Apr 20, 2020 9:27 pm

I keep reading about “soft spots” in the bottom of a boat.

What does "soft spot" mean exactly?

Where do I look for soft spots on a 14-year-old boat with bottom paint?

jimh
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Location: Michigan, Lower Peninsula
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Re: What are Soft Spots

Postby jimh » Mon Apr 20, 2020 11:52 pm

Soft spots are not spotted by eye unless there is a marked depression in an otherwise uniform and flat surface.

Soft spots are detected by applying pressure to the hull and judging the resistance of the hull to be moved inward. Soft spots can occur anywhere in a Boston Whaler Unibond hull. See

http://continuouswave.com/whaler/reference/buying.html

for more advice on assessing a hull.

biggiefl
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Location: south Tampa Bay area
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Re: What are Soft Spots

Postby biggiefl » Tue Apr 21, 2020 11:41 am

Usually soft spots are on the deck. They are usually where the wood underneath was compromised and is soft from rot. Voids usually occur on the sides or bottom and are usually due to the foam shrinking and making a void between the outer hull and foam. This usually happens due to a fault in the pouring process of the foam and usually fixed or replaced under warranty if detected within the 10yr warranty. There is also another type of problem, mainly found on early 18' outrage models where the foam shrank and instead of causing a void it made the hull(usually sides) wavy. Many were replaced but some are still around as I saw one a few years ago. It was owned by a Whaler dealer so my guess is they got it cheap or free from Whaler and was used as a shop boat.
On my 24th Whaler. Currently in the stable: 86 18' Outrage, 81 13' Sport(original owner), 87 11' Sport, 69 Squall(for sale cheap).

dtmackey
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Joined: Thu Sep 28, 2017 9:29 pm

Re: What are Soft Spots

Postby dtmackey » Wed Apr 22, 2020 10:04 am

biggiefl wrote:Usually soft spots are on the deck. They are usually where the wood underneath was compromised and is soft from rot. Voids usually occur on the sides or bottom and are usually due to the foam shrinking and making a void between the outer hull and foam.


I'm sure waterlogged foam does not hold up well to the freeze/thaw cycles in colder climates. The most common spot I have seen soft spots on Whalers is the area on the smaller hulls 13 - 17' in the stern area. The bronze drain tube is a very common fail item allowing the foam to absorb water. And yes, the closed cell foam Whaler uses can absorb water.

Heavy water soaked foam from an Outrage Whaler.
Image

Gutted deck of a 13" to remove all the water saturated foam.
Image

D-