1978 13-footer Hull Soft Spot

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
jeopardy954
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1978 13-footer Hull Soft Spot

Postby jeopardy954 » Fri Sep 25, 2020 7:23 am

I've just discovered my 1978 SUPER SPORT 13 foredeck forward of the locker hatch is soft. I've notice a single crack about 1-cm [0.39-inch] long. When I step on [the soft spot] there is some hissing as if something—air or water—is escaping. [The soft spot] depresses maybe 1/4-inch [0.64-cm] when I stand on it, so [the deck at the soft spot is] far from being flimsy soft, but I can definitely tell [the depression of the deck at the soft spot] is there.

I may do the repair with the West System injection method.

Or, I may repair by pulling up a triangle-shaped section of [laminate and] assessing the foam underneath; then remove and replace as needed; then bond and tie the skin back in with fiberglass—a much more involved process.

Clearly [the hull of the 1978 SUPER SPORT 13 has] some delamination, and possibly water intrusion.

Could [the water intrusion into the hull interior be] from up at the area of the bow eye lifting ring from improper sealing?

Recommend a method of repair.

Thanks in advance for the help.

[Moderator’s note: replaced “it” is several places with possible antecedent noun. Please do not use “it” repeatedly when the antecedent noun is not clear. Also, please don’t mix units between inch and centimeter. Use of inch dimensions is strongly preferred over use of centimeters.]

jimh
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Re: 1978 13-footer Hull Soft Spot

Postby jimh » Fri Sep 25, 2020 10:09 am

Before a repair can be made the wet area should be dried as much as possible.

When you mention “bow eye lifting ring”, do you mean the bow eye on the bow stem? Or the lifting eye in the foredeck compartment?

Water inside the Unibond hull would be expected to move by gravity. This suggests that the soft spot is probably no higher than the point of water intrusion.

jeopardy954
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Re: 1978 Super Sport 13 Hull Soft Spot

Postby jeopardy954 » Fri Sep 25, 2020 10:58 am

I guess [my intended meaning was to refer to] the bow eye on the bow stem, the bronze eye Inside the hull that connects through the hull to the Stainless triangular eye on the exterior of the hull.

I do not have any lifting eye inside the hatch, other than the hold-down for the hatch.

biggiefl
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Re: 1978 Super Sport 13 Hull Soft Spot

Postby biggiefl » Fri Sep 25, 2020 11:14 am

A couple clarifications:

Boston Whaler did not make a Super SPORT 13 model until 1984. I assume you have a SPORT 13.

There is a bow eye and a lifting eye that are connected by the same rod. The lifting eye is below the Norman Pin.

I highly doubt the delamination is due to water intrusion. Any water in that area is probably there from the small crack.

I personally would try injecting [resininto the soft spot]. Use a Spectrum gel coat patch paste to fill the holes when bonded. You have nothing to lose by trying.

The hissing is most likely air. Any moisture would leave a stain.
On my 24th Whaler. Currently in the stable: 86 18' Outrage, 81 13' Sport(original owner), 87 11' Sport, 69 Squall(for sale cheap).

jeopardy954
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Re: 1978 Super Sport 13 Hull Soft Spot

Postby jeopardy954 » Fri Sep 25, 2020 12:33 pm

I guess [the boat is] a SPORT 13; I am not sure.

To know about the water leaving stains is good information.

I'm not getting staining, so perhaps just air may beescaping through the crack.

If so I'm a lot more comfortable doing [a repair using] the injection method.

I didn't want to inject epoxy on top of wet foam.

biggiefl
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Re: 1978 Super Sport 13 Hull Soft Spot

Postby biggiefl » Fri Sep 25, 2020 1:20 pm

You will know when you drill the injection holes if the foam is wet. If so many will fan dry it or use small wicks.
On my 24th Whaler. Currently in the stable: 86 18' Outrage, 81 13' Sport(original owner), 87 11' Sport, 69 Squall(for sale cheap).

jimh
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Re: 1978 Super Sport 13 Hull Soft Spot

Postby jimh » Fri Sep 25, 2020 2:45 pm

jeopardy954 wrote:I guess [my intended meaning was to refer to] the bow eye on the bow stem. The bronze eye Inside the hull that connects through the hull to the Stainless triangular eye on the exterior of the hull.


Your clarification seems ambiguous.

Usually in the bow locker of a Boston Whaler boat there is an eye-nut that is threaded onto the threaded rod that passes through the hull and connects to the towing eye fitting on the bow stem. The bow stem is the edge of the hull where the hull sides come together to form the bow leading edge. There is usually a towing eye there. The towing eye is also used to hold the boat on a trailer. The towing eye is not used for lifting the boat. The lifting eye in the forward locker or anchor locker is usually used for lifting the boat.

biggiefl
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Re: 1978 13-footer Hull Soft Spot

Postby biggiefl » Fri Sep 25, 2020 2:56 pm

"Usually in the bow locker of a Boston Whaler boat there is an eye-nut"

Not on 9-17 classics. The Towing eye is connected to the lifting eye that is underneath the norman pin(like your 15') It is not in the anchor locker.

One can use the towing eye to lift the boat which is usually done with a strap as to not scratch the hull with a cable. I would most likely use that method on my 1986 18' Outrage rather than keeping my anchor locker open while the boat is in the air.
On my 24th Whaler. Currently in the stable: 86 18' Outrage, 81 13' Sport(original owner), 87 11' Sport, 69 Squall(for sale cheap).

jimh
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Re: 1978 13-footer Hull Soft Spot

Postby jimh » Fri Sep 25, 2020 3:00 pm

NICK--ROGER on the lifting eye nut being located on deck on the 13 and 15-footers.

jeopardy954
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Re: 1978 13-footer Hull Soft Spot

Postby jeopardy954 » Fri Sep 25, 2020 9:22 pm

Yes, my boat has a single lifting eye which attaches via a threaded rod through the hull to a towing eye on the exterior.

Could a bad seal at the installation of the towing eye contribute to the problem that I am confronted with, as described in my original post?

Does anyone else have advice as to the best way to fix the problem which I described in my original post?

Thank you.

jimh
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Re: 1978 13-footer Hull Soft Spot

Postby jimh » Sat Sep 26, 2020 10:18 am

If bow towing eye has allowed water to get into the interior of the Unibond hull, the water would be presumed to then move by gravity to other areas.

What is the vertical distance and direction to the soft spot from the bow towing eye? Is it uphill or downhill?

Don SSDD
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Re: 1978 Super Sport 13 Hull Soft Spot

Postby Don SSDD » Sun Sep 27, 2020 7:30 am

biggiefl wrote:You will know when you drill the injection holes if the foam is wet. If so many will fan dry it or use small wicks.

If you follow this advice to repair the crack, if there is wet foam, it could be coming through the crack you are fixing in the foam. If you are concerned the leak is around the bow towing eye, remove it and see if you detect wet foam. Seal both inside and outside of hull with 3M 4200 when replacing the bow towing eye.
Last edited by Don SSDD on Mon Sep 28, 2020 5:48 am, edited 1 time in total.
1986 Outrage 18 with 2001 Honda 130 HP
Former Owner 1991 Guardian 19 with 1994 Evinrude V4 140HP
Former owner 1987 Montauk with 1998 Mercury 90HP
Nova Scotia

jeopardy954
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Re: 1978 13-footer Hull Soft Spot

Postby jeopardy954 » Sun Sep 27, 2020 9:21 am

The lifting eye is about 8 inches in front of the soft spot, and yes the lifting eye is uphill of the soft spot, so water would flow down toward the soft spot from the lifting eye.

biggiefl
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Re: 1978 13-footer Hull Soft Spot

Postby biggiefl » Mon Sep 28, 2020 11:41 am

Remove the bow eye and put some life caulk in the hole to seal it, I doubt however that is where the problem occurred. Delamination happens, boat is old. Drill small holes, inject epoxy in holes, put something heavy on it and be done. This is a common repair and does not need an engineering degree to fix.
On my 24th Whaler. Currently in the stable: 86 18' Outrage, 81 13' Sport(original owner), 87 11' Sport, 69 Squall(for sale cheap).