Ask Andrew: Sikflex 291 Kit review

Sika Kit

July 21, 2022 

Chatting at the club bar last week, the subject of current boat projects popped up. One boater described his window-replacement project, and the tone from the get-go was one of dismay. Days of research. Lists of products and supplies to purchase. Youtube videos. The project started but was interrupted by multiple trips to the chandlery. Product recommendations gone awry. Professional grade products, at professional grade pricing, but without the professional grade result.
The story stuck with me, and I recently came across a new product from Sika-flex that might have solved some of the issues.

At first glance: It’s a caulking kit. The kit features the versatile 291 fast-cure Sealant – a product that many boaters are familiar with. But diving a bit deeper I realized that the kit is a well thought-out all in one project package. It’s meant to do more than just offer a tube of sealant. Inside, you’ll find:

– 2 tubes of fast-cure Sealant

– A cleaning agent (to prep the surface before applying fresh sealant)

– An Activator to allow the primer to adhere correctly

– Primer, which in turn allows the sealant to adhere.

– A full set of instructions, including glossy-photo directions

Sika Kit ContentsAt this point, you may be wondering: what’s the big deal? It’s a kit for sealant. The big deal is this: other manufacturers of sealants (and other products like epoxy and paints) will provide directions, without packaging a kit together. This makes it so much easier to say “I’m not buying that added product!”, or “The alternative product will work just as well and its half the price”.  This helps to take out the guesswork, and prevents unnecessary return trips to the chandlery mid-project to get missing parts and components

Sikaflex has thought this through, and is prepackaging all that you need, in order to give you the best result possible.

Here’s my favourite part: the side of the box lists off everything that you need to complete a project using the sealant that’s included. There’s nothing worse that reading the set of directions and trying to create a shopping list out of the instructions. Sikaflex has taken out the guesswork and made it simple.

I have a confession to make to Sikaflex: I’ve never used the added products (cleaner, activator and primer) when using 291 sealant before. I’ve cleaned and prepped the area, taped it off and applied the sealant. What more needs to be done, right?

Applying SikaTesting

So, I did some testing at home: an area that was prepped according to Sikaflex’s directions, and an area that was prepped the same old way that I have for years. I chose two opposite corners of a window frame in direct sunlight. A month later, the sealant that was prepped according to Sikaflex’s directions appears to have adhered better. When translating this to a window replacement project on a boat, or the installation of new deck hardware, adherence and the prevention of water penetration is key. Not only is the adherence a concern immediately, its important for the longevity of the sealant, when exposed to moisture, freezing temperatures, UV rays (which break down many sealants), salt-water, etc. Quality prep work at the outset means that the sealant will last that much longer.
Am I sold? Yes. Do I love that the kit contains all that I need (and give me a list of what I need that isn’t included)? Yes. Are the directions easy to read and follow? Does the end result have the same look as the photos in the directions? Yes.

Am I recommending this kit, as a replacement or upgrade to simply buying a tube of sealant? Yes. Would buying the kit have prevented some of the frustration that my fellow member had when replacing his boat’s windows? Yes.

Found at marine stores, along with other sealant products, widely available – check out the Sikaflex 291 Kit.

Andrew McDonaldAndrew McDonald is the owner of Lakeside Marine Services – a boat repair/maintenance firm based in Toronto. Andrew has worked in the marine industry for 12 years and is a graduate of the Georgian College ‘Mechanical Techniques – Marine Engine Mechanic’ program.

Questions or comments for Andrew? Email him directly via:


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