Compatability of Epoxy, Lexel, Foam

I’ve progressed on my project to install bulkheads into the Kanoe Latvija. The bulkheads are cut out and I have mounted small “hatches” in the bulkheads. I’m about ready for final assembly and have a couple questions.

My intent is to epoxy glue the bulkheads into place as recommended by Sweet Composites, where I got the M-200. After the epoxy cures, I will use Lexel for a sealant around the perimeter of the bulkheads. Should I be concerned about amine blush interfering with Lexel?

I’d like to reinsert the foam pillar in the stern, since there is a lot of unsupported deck, and the bulkhead foam (m-200 minicell) isn’t rigid. The kayak originally had a pillar made of rigid pink foam, about 2" thick, that looks like something used in buildings for insulation. My guess is the pink stuff is extruded polystyrene. Lexel says on the label that it can be used as an adhesive and lists off a dozen materials that it sticks to, but specifies NOT polystyrene foam. What can I use to glue in the pillar? Will epoxy work? Maybe Gorilla glue?


Epoxy is OK for polystyrene foam
and for all other foams I know. Thicken it so it stays on the foam edge. You might even want to induce a bit of longitudinal groove on the foam edge to encourage the epoxy to stay in place. Oh, and Gorilla Glue won’t bother the foam either.

On the amine blush, it’s worthwhile to make an effort to remove it. It washes off with detergent. Otherwise it may sligthly weaken the bond you want.

Questions and comments
Are the bulkheads Minicel foam or a rigid material (wood, glass, etc.)? If the bulkheads are foam, I don’t see any point in using epoxy to install them. It’s not likely to bond to the foam or boat better than Lexel, it’s more complex to use and it may be a real pain to remove if you need to replace the bulkhead(s) at some point in the future.

Most boats that have pillars use Ethafoam (polyethylene foam) or something similar, which comes in various colors and densities - some of which are quite hard - so you may be confusing it with Styrofoam (polystyrene foam) insulation board. Polystyrene foam is not suitable for pillars, as it’s not elastic; once it compresses, it stays compressed. One good hit on the hull and you’ll have a damaged pillar.

What material is the boat made from? If it’s molded polyethylene, use Lexel for bonding everything. If it’s another plastic or glass/Kevlar/carbon, you have more choices in what you can use and epoxy will work.

There are no compatibility issues with the materials you’re using, but I agree that it’s wise to remove any amine blush from epoxy before applying a sealant over it.

The pillars are M-200 Minicell, from and as described here:

That source is run by the Hearns, and they recommended epoxy to glue in the foam. I think one of the reasons for that recommendation is because you end up sliding and squeezing the bulkhead into place, so you end up wiping off thicker material and you can’t effectively use tacking adhesives like contact cement.

The Kanoe Latvija is fiberglass. It came to me cheaply and from a lady in Shanksville, Pa, who acquired an inventory of them in a building she bought. She didn’t know much about them. Brad at Staark Moon Kayaks told me they were manufactured by some immigrants that didn’t know much about the boat business, and I think that is evident in the name. Who would try to market a sea kayak called “Kanoe”? I didn’t know at the time, but according to Brad, they ripped off the design from Prijon. All this to answer your question about the pillar. The pillar is 2" pink foam, with a partial set of specifications lettered in blue, like found on building materials. My guess is it is a piece off a 4x9 sheet of Owens-Corning pink foam, which, I believe, is extruded polystyrene. It is stiff and if crushed I think it would stay crushed. That it may not be the best material for kayak construction kind of fits in with Brad’s description of the KL operation.

Given that the minicell compresses, isn’t the stiff foam preferrable for the pillar? I climb up on that back deck when practicing rescues, so it seems like some stiffening in there is a good idea.

Thanks for the advice on the glue compatability.


BNystrom’s right about vulnerability of
Styrofoam or similar rigid foams to damage. Sometimes rigid styrene foam is used to shave weight in slalom racing kayaks, but they put an edge of flexible minicell foam all around the wall to absorb distorting forces.

With Minicel bulkheads…

– Last Updated: Sep-17-09 11:00 AM EST –

... if they fit as tight as they should, any adhesive is going to get wiped off the bonding surface to a large extent, regardless of its viscosity, so I don't know that there's any real advantage to using epoxy. I already mentioned downsides of using it above. In either case, you'll need to apply it to the bulkhead and the boat, then push it into place. If you can manage to inject extra around the edge after installing it, so much the better. One advantage of using just Lexel is that the bead that forms on the far side when you install the bulkhead helps to seal it and you don't need to or want to remove it. With epoxy, it's going to run unless you thicken it and you'll need to remove the excess. You will invariably get some of the adhesive on areas of the hull and deck where it's not wanted. Lexel is easier to clean up, especially if you miss a spot and have to remove it after it cures.

I absolutely would not use styrene foam for your pillar(s). While a degree of rigidity is useful, flex is not your enemy in most cases and can be beneficial to the life of your boat, as it prevents hard spots on the hull that can lead to cracks if you run over a hard object. A foam that cannot flex without failing is a poor choice. If you feel you need something more rigid than your M200 (you probably don't), track down some 6# Ethafoam (Ethafoam is categorized by density, with 2#, 4#, 6# and 9# per cubic ft being the most common types). It's plenty stiff enough, but still provides a degree of flex. You might find that 4# is rigid enough.

Thanks for the advice, fellas
I’ll ditch the pink foam and use Lexel for both adhesive and sealant. It makes sense that what gets squeezed off when I push the bulkhead into places ends up as a bead on the other side. My task is getting easier, and now I don’t have to worry about amine blush, either. Could be paddling the KL by the weekend!


Chip, Get the bulkheads in place
first … THEN put a bead around them …

Call me if you want.

Kanoe latvija
Ok, here’s the mystique about the Kanoe Latvija boats.

Depending on who you are able to talk to.

(I bought a couple of them from the owner of Kanoe Latvija as he was getting out of the boat building business.)

Allegedly— the kayak is the design that won the downriver Olympics in (I think he said) 1995. And it was his design.

The boats were manufactured in Peach Bottom Pa. The company also made canoes and a double kayak.

The kayak design is the same as the Prijon Eski. Again, depending on who you talk to— either Prijon got the design from Kanoe Latvija, or it was the other way around. Anyway, lawsuits were filed and as a result, Kanoe Latvija went out of business.

It’s a wonderful boat. I still have one. I use air bags, but have often thought of making bulkheads.

@BoozTalkin said:
Thanks for the advice, fellas
I’ll ditch the pink foam and use Lexel for both adhesive and sealant. It makes sense that what gets squeezed off when I push the bulkhead into places ends up as a bead on the other side. My task is getting easier, and now I don’t have to worry about amine blush, either. Could be paddling the KL by the weekend!


Chip, I just bought a 16 feet Kanoe Lavija, and thinking about adding bulkheads and hatches on the bow and stern. Can you give me ideas on materials, tools, please, thanks.