Lag bolt for deck fitting?

Update: I have completed the repair. I removed the foam pillar and used a wrench taped to a stick to hold the nut inside. All done, thanks to everyone who helped!

I’m about to lose the bolt that holds the front carry handle deck fitting. The kayak is from 2004, on the other side of that screw was a washer with rubber washer bonded and then a nylock nut. The nut is gone, only the double washer thing holds it in place. There is no access to the inside. A long ways from the cockpit, very skinny bow and there’s a foam pillar blocking access anyway. The kayak is thermoformed ABS, t
he deck fittings had to have been done before they joined the two halves.

I’m familiar with lag bolts, moly bolts, etc. But I’m wondering if there’s a specific type that is best and/or recommended for kayaks?

Lag bolts are huge and here’s nothing in the bow of the boat to screw into, anyway. You need to install another Nylock-type nut and a steel washer if there isn’t one on the screw. You can attach one to a long stick with hot-melt glue or double-sided tape, and use it to reach into the bow. You’ll need a helper to turn the screw while you hold the nut in place. It may be easier to do if you remove the deckline, as it’s apparently causing the fitting and screw to sit at an angle, which would make it difficult to get a nut started.


You may have to remove foam pillar for access. Use a nylock nut super glue flat a washer to it.

I am super hesitant to do that. The kayak is 18 years old (it won’t tell me how it votes) and when I touched the end of the foam pillar it seemed to crumble to dust at the slightest touch. So I think removing the pillar would be permanent. The oversized float bags that I have installed could easily fill the empty space, my concern is if the pillar plays a structural role holding the deck up.

Then again, I could deal with all the loose nuts. Oh yes there are others, just not as critical or as recalcitrant.

(picture doesn’t show second bag installed after photo)

This is what the nuts look like, a locking nut similar to but not a nylock nut.

Put new foam pillar in if it’s that bad of shape. If it’s crumbling from touch it doubt it does much unless it’s just on the surface.


M5 Neoprene Well Nut M5 With 20mm Stainless Steel Pozi Screw (E) by H2o Kayaks

I think that may be beyond my skills and capabilities. Maybe a partial replacement. But maybe the full float bags are enough structural support?

Don’t think float bags have enough pressure to support things. What is the name of the kayak?

Putting in a new foam support would likely be easier than it will be to put a new nut on that bolt :slight_smile:

If I can put one in, I am sure you can. See my thread about bulkheads (or any of the many others for tips.)

Bulkhead Installation - Advice -

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Do you have a local kayak dealer?, they may have done it before and be good at fixing it, maybe also replace the pillar if needed too.

That doesn’t appear to be a bulkhead or a pillar. Just a square block of foam…kind of like a grey thing from the past…looking at the picture in the OP , looks like water flows all around it.

One of these would work, a toggle anchor bolt in stainless steel.

It’s a Perception Sonoma manufactured in 2003. I know that materials can be significantly degraded and still have a degree of structural integrity if there’s enough of the material. But the more I look at the picture and think about how soft the foam was the more I question if it played any structural role at all. Since the “tube” is so narrow around there it should have plenty of rigidity without foam right? Did they just put random blocks of foam in kayaks for “some floatation is better than none” back in the day?

Anyway you’ve really got me thinking about tearing out that foam. There is a screw that goes from the deck into the foam, presumably there’s some metal insert in there. I can fabricate a smaller support pillar there. With the foam out I can use the various tricks that people have thought up and get to every nut under the deck.

If I remove the foam pillar, I can get to all the nuts. In this view the screw that you see in the middle of the deck looking like it does nothing, that’s almost at the end of the foam pillar. The pillar extends from there to (apparently) the very end.

The nut for the fitting for the retracting carry handle is loose and inaccessible as well, but isn’t critical like the front fitting is.

The kayak usually sits upright in its cradles, it’s only sideways for this photo.

On Facebook someone suggested using a fish type tool to fish the bolt. So the bolt would be underneath and the nut on top. I could use two nuts and a lock washer since the bolt head under the deck would have minimal friction and just cut off any excess bolt. I have to admit that the ease and simplicity of this method appeals to me although it would obviously be less clean looking.

1/2" diameter hole in the deck line fittings would probably compromise it.

You need to hang the hull upside down just above your shoulders. Stick your head into the cockpit with a head lamp. Then you need a flat box end wrench on a stick with a nut. Someone has to slowly turn the bolt on the outside till you align it and feel it engage. With the hull upside down it’s easier to see. Upsidedown your not fighting gravity to hold the stick up to the bolt or really laying it on top. I may take a while and ten or fifteen minutes will seem like hours. Measure the stick from combing to bolt on the outside you be real close that way. Tape something on a wood dowel yo act like a stop on the combing. Make it go 1/2" longer to the nut for some play. Put the bolt through hole slide in wrench on dowel till you hit it. Mark the dowel then you know you have to go probably no more than 3/16" of an inch or really the sidewalk thickness of 5he small nut.

If some pushes the bolt up and your wrench is close you’ll feel the stick rise up. So hit bolt with wrench then you know it’s a smidge more and you’ll get it with time. You may have to walk away for 5 minutes and come back for another attempt. It does get frustrating.

Oh yeah, no way a 1/2" tool would work. The “bolt” is only 1/4"