Homemade Bulkhead?

This may be a dumb idea but here goes… I just bought a 13 foot poly recreational kayak with a rear hatch but no internal bulkheads. I was wondering if it would be feasible to add my own behind the seat? Things that come to mind incude what material to use (must be flexible I would think), what adhesive to use (does anything stick to poly boats?), how to get the right shape considering the kayak is fully assembled and I don’t have the blueprints. If anyone has any thoughts please let me know. If you think this is a crazy idea please tell me that too, with some explanation. Thanks.

I just added a front bulkhead to my Perception America 13.5. It already had a rear bulkhead.

Figure out where exactly you want your bulkheads, then get some cardboard, make a rough shape. Try to fit inside and trim a little off where it doesn’t fit. Keep trimming away until the carboard fits perfectly. If you trim too much, start with another piece, tracing the good parts, leaving excess in the bad areas.

Once the cardboard fits perfect, trace the outline on to a piece of 3" or 4" (I used 4") and cut it out with a bread knife. Shove the bulkhead in place. It should fit tight since the kayak will be tapered where bulkheads are located. Seal around the bulkhead with silicon sealer.

The foam I used is 4’ thick open cell white foam that is flexible. I think Chesapeak Light Craft sells bulkhead foam, as on online source.

ditto above plus
you can use a piece of solder to take off the shape of the inside of the boat to facilitate making the cardboard template. you only need to do one side, press the solder against the inside of the hullhull till it conforms to the hull on one side. flip it over for the other side, cut and try as above. seems to me 3" foam would be plenty thick

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Thanks! That is a great suggestion for getting the internal shape! Regarding the foam, would closed cell be better? I must admit I don’t think I have seen 3-4" thick closed cell foam but it strikes me as a tougher and more waterproof solution than open cell. Thoughts?

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i read about it right here on pnet : )

You can purchase 2" thick eathafoam from NRS 12" wide sold by the foot up to 4 foot in length. NRSs eathafoam is very dense but will compress to give you a good seal. Use Lexel (Ace Hardware) to glue it in place. Lexel sticks to plastic yaks great!



closed cell foam
I would only use closed cell foam. Redfish kayaks sells 4" thick closed cell foam. Make sure the foam is secured well with glue. Here is the link. http://www.redfishkayak.com/foam.htm

closed cell foam
I would go with closed cell as well. You can order a 12" x 20" piece of closed cell from REI for $17.

I had a hard time getting solder to hold it’s shape when I removed it from the curve. I found that a 75 sq. ft box of tin foil works better. You can ball up the tin foil into long wads and then smush it into the curves of the boat. It makes a perfect form.


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H2 glue…
You can find this on the Northwest River Supply website. It sticks well to poly and closed cell foam.

When you get your foam cut to size, put a very generous bead (or three) on the inside of the hull at the point where the foam will make contact. If you put glue on the foam itself, you’ll just end up smearing it all over the place as you insert it into position. Once the bulkhead is in position, seal it around the edges with more H2 glue.

Do not expect a permanent watertight
seal. You can read Necky’s elaborate approach to putting bulkheads in their poly kayaks (one of which I own). They roughen and pretreat the inner surface of the hull, and of course they have an optimized template for the bulkhead. They use goopy stuff to seal the perimeter of the bulkhead. With all this done carefully at the factory, they have a good record for bulkheads staying watertight.

However, Necky will NOT install bulkheads on already purchased poly boats, and they will NOT support dealers who want to do so, because they believe that the job can be done only on new boats by trained people in the factory.

You want to put a bulkhead in a boat which has, I believe, a significantly larger cross section than my sea kayak. That will make secure installation even trickier.

You do not state WHY you want a bulkhead behind the seat. Are you then going to put in a hatch? That will raise more problems, unless your boat manufacturer offers a hatch kit.

Why not put in a longitudinal minicell wall instead?? This is an easier project, and the wall can be pinned in place with small wedges of foam contact-cemented to properly prepared inner hull surface. Possibly you can index the wall to the rear of the seat at the cockpit. You can drill holes in the 3" minicell wall and put in tie lines. THEN you can buy some Voyageur Stow-Float bags with slide closures and inflation tubes. Suddenly you have rear floatation, support for the rear deck, possibly support for your back (against the front end of the wall) and lots of secure dry storage. You will not have to thread your storage bags out through small hatches in the stern or the bulkhead, but can deflate them a bit and slide them easily out on either side of the wall.

Thanks for the suggestion but my Kayak already has a rear hatch, just no bulkhead. My thinking for adding one is the same for having one in the first place. Having a dry (dryer?) area inside the boat and providing some extra floatation. Also, it seemed like a bit of a challenge so why not! Based on the previous helpful posts in this thread I think I will try it, and I will be under no illusions about its absolute water tight nature. Of course, from what I’ve read, commercial bulkheads can leak too.


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Sounds like a really expensive solution and I don’t think that was the point.

Use silkaflex , not silicone to seal the bulkhead…otherwise good summation

I watched a lot of videos and did a lot of research
on installing bulkheads and learned that there’s no difference between regular 100% silicone and “Marine” silicone. Lots of videos on this. I recommend watching a lot of them because some of them are very clever and some of them are almost ridiculous.