Water in Hull of 1981 13-footer

[David Montgomery]

I have found a generally good 1981 13-foot hull here in the Pacific northwest. Given the hull has no apparent soft spots top or [bottom--please not use abbreviations for common words of a few letters--jimh] I think the hull is good. Even the original gel coat is great.

Something was mounted toward the stern of the boat leaving two trails of 1/4-inch empy screw holes, several inches apart, about two feet long. The empty holes actually looks like two parallel cribbage boards The holes were plugged with silicone, which did help but water still got into the hull.

I want to plug the holes with epoxy and make the floor look like new. Water appears to only be in the aft one-third of the boat. It’s damp in there but not something that would pour out.

Can the water that is in there be left in place so I can move on with the epoxy work?

I’m confident there are hundreds of these boats out there like this.

Or, am I lying to myself about the importance of the water?

New forum member and Whaler owner--Dave

[biggiefl]

There are many ways of drying out [water in the hull] if just on the surface. You want to get the [empty fastener holes] as dry as possible before repairs.

If the boat is upside down do the holes weep water?

How heavy is the hull?

[David Montgomery]

Getting it weighed sounds like a great idea.

How would I find the weight of a “dry” 13-footer?

Would that weight be with or without seats and other gear installed?

Thanks--DaveM

[jimh]

DAVEM--As you are new to the forum and the website, you may not realize that the FORUM represents only a portion of the information content archived here on CONTINUOUSWAVE. I suggest you explore the entire Boston Whaler portion, beginning at

http://continuouswave.com/whaler/

The REFERENCE section is located at

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

The articles on the 13-footer begin from

http://continuouswave.com/whaler/reference/13/

In the main article on the 13-footer you can find specifications for the hull, including weight of particular models. The listed weights are for a particular model with its standard components such as seats, rails, and other fittings included in the base model of the boat.

[jimh]

Questions about removal of water in a hull are frequently asked, and in the FREQUENTLY ASKED QUESTIONS or FAQ for the Boston Whaler portion of the website an answer has been prepared. It is listed in the INDEX for the REFERENCE Section. See:

Q3: Is There Water in a Hull?
http://continuouswave.com/whaler/reference/FAQ/#Q3

Your (original topic asked a) question regarding quantification of the volume of water contained inside a Boston Whaler Unibond hull which would reach the level of being "too much" water; this question will be impossible to answer for several reasons. First of all, establishing the volume of water contained in a Unibond hull will be difficult. There is no particularly precise method to establish a volume of water present in a hull, other than by weight comparison to a published weight for a newly manufactured hull. For older boats in particular, the manufacturing process may not have been closely controlled and completely uniform, so some variation in weight among hulls is believed to be very typical. Generally weighing a hull will only be able to detect rather excessive weight gains, which may be attributable to water ingress.

Another problem is to know the precise interior volume of a Unibond hull in order to use that data to compare to the volume of entrapped water (if such a datum were available). I have never seen any published data from Boston Whaler about the amount of interior volume contained in a Unibond hull.

Even if the volume of water in a hull and the volume of space in the Unibond double bottom were known, a method of establishing what percentage of water content would be excessive has never been explained or demonstrated.

The chemical reaction of creating the foam from a liquid most likely also generates some water. The use of sprue holes and vents allows the water to be pushed out during the expansion process. However, it is generally thought that ALL Unibond hulls may have some water which may remain in the double bottom sealed space. Evidence of this water is often seen as a brown liquid that oozes out of screw fastener holes unexpectedly; the liquid is likely a product of water mixing with some uncured reagents of the foam process over time.

[jimh]

Are the many empty fastener holes located in the cockpit deck?

Are the many empty fastener holes located in an area that has embedded wood reinforcement?

Compare the wood locating diagrams. See the REFERENCE article on the 13-footer under the subheading EMBEDED WOOD.

[jimh]

There are many ways of drying out [water in the hull] if just on the surface.

[Methods to remove water are generally:

• suction
• evaporation
• draining by gravity

]

A simple test may be to just use a hair-dryer or heat-gun (on low) and blow warm air into an empty fastener hole for five minutes or until it appears to be dry. Come back a day later and assess the moisture in that hole.

[David Montgomery]

[Combined a second thread started on this topic with the original thread started on this topic.--jimh]

I cleaned out the holes and shoved strips of ShamWow in each.

B4C6F45A-1065-4488-853F-C6FAC5C7F0AD.jpeg (17.22 KiB) Viewed 6541 times

I made a tee-pee of cardboard over the top, and placed a hairdryer on low heat at one end. Water is sucked out and evaporated via the strips. Totally nuts.

21100A46-E0DE-426A-B999-68CC6249DC18.jpeg (30.94 KiB) Viewed 6541 times

[Phil T]

Weigh the hull to see if you even have a problem.

Getting water out is not easy and may not be worth effort.

Report back weight of boat.

[David Montgomery]

PHIL--yes, my method is possibly a waste of time due to the “Sham Wow” approach not working and also because there might not be that much water in there.

Weighing makes complete sense and I’m trying to find a crane scale to hang from my backhoe bucket which the boat will then hang from the scale. I suspect there are drive-on scales somewhere near me.

[David Montgomery]

Thanks for the realization that getting all the water out of one of these hulls after some has gotten in (for what ever reason) is virtually impossible. To get [this 1981 13-footer] totally dry without ripping out the floor seems impossible.

The Sham Wow methodology did really seem to work. The amount of water soaking into the strips has been greatly reduced from wet to now damp and some holes are dry.

I have not been able to get a weight on the hull yet. I suspect [the 1981 13-footer] condition is mild "water logged". Or so the prayers go.

Now it is time to plug the holes permanently and on to painting.

DaveM

[jimh]

DAVE--thank you for the follow up that your water removal method using absorbent strips and a forced flow of warm air was successful in drying up the empty fastener holes in the deck of your 1981 13-foot hull.

As I said in my earlier reply, it is generally thought that ALL Unibond hulls may have some water which may remain in the double bottom sealed space. At some point in a restoration, there is a realization that whatever water might be inside the Unibond hull will just have to remain there.