bombproofing bulkheads

the bulkheads in my Capella are plastic-welded in and keep the compartments 100% dry. what’s the next best thing to approximate something like that in other RM boats with glued-in bulkheads? anyone try Hippo Patch?

Hippo not waterproof and does not
effectively increase strength so what for ? If you want redundant security I would say a bead of 3M 5200 … Make it thicker if you want even. That said, careful what you wish for.

I’m not a fan of ‘bombproof’ bulkheads. Sealed YES and ability to absorb a major hit and still stay sealed, YES.

So strong you cannot kick them out in an emergency, NO !!!

Example scenario # 1, you hole the front or rear of your boat on open water …

I am having difficulties visualizing an emergency that would require one to kick out bulkheads. First, bulkheads in a SK create compartments accessible through hatches. Second, I would find it rather difficult to kick out bulkheads right behind me, since I can’t reach them unless my vertebrae are totally messed up, but then I wouldn’t be able to kick anything anyways. The front bulkhead is out of reach again.

So, does kicking out bulkheads is a process that is required for boats of your design?

Hippo Patch tape worked for me
It was water proof and it really stuck the foam in place. It is kind of expensive to go all around both bulkheads so I just used it on the rear one that was causing trouble.

Your results may vary, etc.

Sorry for not adding more detail
Using the tape it would not be possible to do the perimeter of a bulkhead with it and have it seal 100%

Thats what I meant …

Foam bulkheads can be kicked ( or punched ) out.

could you elaborate?
Hey Patrick,

Could you explain the scenario where you need to kick or punch out a bulkhead in an emergency? I’m having trouble picturing it.

In my mind, if the front compartment is holed, kicking out the front bulkhead won’t do anything to improve the problem. Bulkhead or no bulkhead you have to either stop the ingress of water with a temporary patch, or displace the water (airbag, drybags, etc).

I can’t imagine the need either

– Last Updated: Oct-27-11 5:06 PM EST –

(but maybe I am missing something)... anyway, a bulkhead can be breached with enough force, I am talking about improving the seal, over just using adhesive. inevitably the adhesive shrinks/cracks/lifts with hull flex in plastic boats and lets some water through, no matter how thick you apply it. the bulkheads in the Cappella RM are foam also but plastic-welded in somehow to be about as leakproof as you could ask for, and it would be nice on other mfrs' plastic boats to emulate that. I would imagine that a taped seam would allow for more flexing and still remain watertight. I'm thinking something like Hippo Patch might do the trick, it's sold by various outfitter and marine places as a temporary repair material.

For glued-in bulkheads

– Last Updated: Oct-27-11 5:40 PM EST –

The trick to obtaining a durable seal IS to to cut a generous chamfer on the bulkhead, then fill that space with sealant. This provides a much larger area of adhesion, and a longer throat of sealant that is much less likely to fail.

The usual way:


Where "G" is for goo (sealant) and "F" is foam

The right way:


I like it
I like this whole kicking out bulkheads business! Sometimes i just want to punch out someones bulkhead.

You know what i mean?!


Some Jerk: Hey check out my new awesome boat that’s awesomer than yours.

Me: Hmmm. Let me see that…Kick!

Now you have an adjustable bulkhead. You can thank me later.

Totally plausible and a good applicationm for hippo tape.

I’m not sure we are talking about
the same hippo patch two inch wide tape. But I did use it all the way around the perimeter of the bulkhead to hull joint and I don’t think you’d have an easy time removing it. Once the adhesive on the cloth backed tape get warm it really really sticks. You’d need a heat gun or hair dryer and some time to get it off.

Way offshore pick anything
Hole, blown out seam, hatch cover, shark, too rough, too cold, no patching material.

Boat slowly filling with water beyond where you can reach to pump it out.

the best way to ensure a durable seal is how a lot of manufacturers now put a router cut into minicell about 3/4" in from the perimeter. This way the minicell AND sealant can bend together instead of pulling apart.

I’m right there with you jesse59!