Installing / sealing kayak Minicell Foam bulkheads

Just bought a used tandem sea kayak. Need advice on sealing one bulkhead and installing a new one. One bulkhead needs to be re-sealed and I also want to divide a single compartment that has two hatches into two separate water tight compartments. Selecting the right foam and glue and how to accurately measure, cut and fit the bulkhead would help.

I’ve used lexel caulking to seal minicell foam bulkheads. You should be able to find it at most hardware stores in the same area as silicone caulking.
As for making a minicell foam bulkhead, you could make a template using heavy solder, such as you would find in the plumbing supply area of your local hardware store and bend it around the interior of the kayak where you want to install the bulkhead, or you can use some heavy paper stock, such as 3x5 index cards from the office supply area of your local dept store (such as Walmart) and cut into 1.5 inch strips, place the short side (1.5 inch) against boat and staple the pieces together to make a template of the interior of the kayak where you want the bulkhead. I would use 2 inch minicell foam for the bulkhead and seal it to the interior of the kayak using lexel caulking.

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I made a bulkhead once . It wasn’t pretty but it worked. It would be great if you could buy one.
They are best made from Minicell foam which is dense and stiff.
I got some cardboard and cut and mushed it for a template . Cut the Minicell a bit bigger than the template and squeezed it into place.
I used Goop to glue it but I know there are better adhesives .
Someone will let you know which ones shortly.

I have not done it, but I have read of some who have had success by wrapping stiff wire around the outside of the kayak and using that as a template. You might use a wire template to cut a concentrically smaller template out of stiff cardboard or Correx plastic, then shaping that internal template to get as close a fit as possible before marking out your foam.

I spoke to Current Designs on the phone once and asked them what they used to seal the factory bulkheads, but can’t remember what they told me. Give them a call, they are very responsive and helpful. I’m sure they’d be happy to tell you what they use for the bulkhead foam, too.

CD told me they use silicone on bulkheads

Avoid silicone. It is not an adhesive, nor does it have much strength. Use a polyurethane adhesive/sealant like Lexel (or other brands).

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Polyurethane is really hard to remove. If you bulkhead fits all you need is a sealant. Silicone still fine in my 20 year old CD kayaks. Silicone used in huge fish tanks and in construction as is polyurethane.

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Thanks for the help. I found this video on You Tube that I might follow and that may help others wanting to install a bulkhead in a kayak (

Bit rough in video also bulkhead needs taper as kayak is tapering towards the bow. Zero need for glue.

@PaddleDog52 said:
CD told me they use silicone on bulkheads

Interesting. This was a few months back and I’m sure they didn’t tell me silicone. It was a brand name IIRC but I can’t recall what it was.

I have four CD kayaks all use silicone.

@High Desert said:

Interesting. This was a few months back and I’m sure they didn’t tell me silicone. It was a brand name IIRC but I can’t recall what it was.


I have heard of quite a few people using Lexel. I have not used it myself.

So I called and talked to Allison at CD. She recommended either Kop-R-lastic or GE 1200 construction silicone.

I’m not impressed with CD’s expertise on adhesives. I have a CD kayak and the gaskets started coming off the hatches after six months. Also, there is mini cell padding under the thigh braces that is coming off. Whatever they use, use something else.

Silicone might work okay, but if you ever have to remove or repair it, that’s a problem. Lexcell is what you should use.

I installed mini cell bulkheads in fiberglass kayak. It took me a couple tries to before I was happy with the templates. Rough fit it, then tape on little pieces of index cards or yellow-stickies where there are gaps. Be patient, because the bulkhead will only fit as well as the template. After you cut the bulkheads, hand shaping may be needed to taper the edges to fit the tapered bow/stern of your boat. I smeared lexcell inside the hull where the template was to go and then stuffed in the bulkhead. Then ran a bead of Lexcell around the edge of the bulkhead. It worked well.

Here is a link with some pictures:


Nice work Chip, and great photography too.

Just need to seal the existing bulkheads, no space for an extra bulkhead. Now the glue question.
Lexel, $9 at Lowes, GE SCS1200 Silicone Construction Sealant, $15 at Amazon and Kop-R-Lastic Sealant, (no price / where to buy found) a one-part, highly elastic, high-performance thermoplastic sealant (a Henry product) were mentioned.

I have another Henry product, Crystal Clear Roof Patch 212, also a one-part, highly elastic, high-performance thermoplastic sealant. My guess is if Kop-R-Lastic works, Crystal Clear Roof Patch will work too. Plan to use that unless someone says they tried it and it didn’t work.

NRS sells H2 Glue, $27 including shipping, a bit pricey but I want to seal the bulkheads right the first time.

What are your thoughts and experience?

Beyond Lexcell and various silicone products, I have no experience. Perhaps, others can help. ~~Chip

You know, for $9 Lexel at Lowes is the way to go. It is highly recommended. Wanted to avoid adding yet another glue/sealant to the shop but sometimes that is what is needed.

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