@willowleaf said:
I’ve been wondering about those yoga blocks and bolsters I often see (very cheap) in the off-price stores as raw material for kayak mods. They seem to be made of a pretty dense closed-cell foam.
Great idea. They’re about ten bucks at the local box store. Might pick one up for practice before working with the good stuff as I have some odd protrusions to cover. Also wondering if modeling clay might work as a mold over those protrusions for dimensional purposes.
Amazing the neat stuff you can learn just by having fun kayaking! Kind of an arts and crafts class for wet work.
Dragonskin is no longer available as the sole manufacturer discontinued it.
For cutting thick minicell planks, a band saw works best but if you don’t have one I have used a coping saw to good effect, especially if you want to cut along an arc at a tight radius that a wider blade cannot follow. Lacking that any long cutting tool like a fillet knife or bread knife will work. I favor surface forming tools (surform) for rougher shaping and sandpaper for finer shaping. This little tool is useful for forming curved surfaces:
Don’t use the little bottles of DAP Weldwood with the brush in cap. You will need to use a bunch of them because minicell is thirsty. Go to Walmart and buy at least a pint can or more. I like to apply it using a cheap, metal handle brush (often called an “acid brush”) that you can find at any hardware store.
For a mold, I’ve heard of ww folks using damp newspaper stuffed into whatever space you’re looking to fill, then pulling it out and voila you have a mold.
I’ve used yoga blocks successfully as seat backs and foot blocks. You can get a pretty nice “face” on it using some rough sandpaper.
Don’t use the little bottles of DAP Weldwood with the brush in cap. You will need to use a bunch of them because minicell is thirsty. Go to Walmart and buy at least a pint can or more. I like to apply it using a cheap, metal handle brush (often called an “acid brush”) that you can find at any hardware store.
Thanks for the advice. Do have a coping saw. Purchased the small bottle of contact cement to attach a strip of neoprene padding to a section of the seat pan. Rethinking that now as the Gorilla tape is working well, even though it got pretty wet yesterday. Would a pint of contact cement be needed for a block that would be 7" x 7" at the most? This video leaves the impression one very thin application is all that’s needed:
You can also glue pieces together with Barge Cement. Follow their instructions to lightly coat both sides to be joined, let tack up slightly, and then carefully stick together. Strap or otherwise fasten the pieces together for the first day of curing.
I have used it for adding thigh brace padding and other kayaking-related applications. It holds up well even in a wet environment.
No, you won’t need a pint. But if you go to Walmart dot com you will find that a 1 ounce bottle of DAP Weldwood costs $5.39, a 3 ounce bottle costs $6.96, and a 16 once can costs $5.47, so you are paying a lot for the convenience of having a little bottle with a brush in the cap.
I do not agree with the video. I have glued together a lot of minicell over quite a few years in all types of environmental conditions. I think the video is making too much about getting an extremely uniform coat. The time you need to let it dry will vary a lot with the particular foam, ambient temperature, and humidity so there is no point in using a timer. You will get a feel for how long you need to let it dry with experience. And I would never, ever apply just one coat of glue to each piece of foam on anything that is going to see regular water exposure.
I have found working in warmer conditions that after applying a coat of glue to two pieces of foam about 6" square in size, that by the time the second piece is coated, the first is nearly dry to touch and ready for a second coat.
Agree with pblanc. DAP Weldwood is not fussy to use. If it was I would have found something else because I can’t make myself care about fussy for kayak work. Just make sure it is on both surfaces and makes it to the edges so a section of an edge is not annoying sticking out when you paddle. I just let it get almost tacky and put the pad in. I have no idea what humidity it has been.
The small bottles are good if you are only doing a little bit and you hate wasting any from it going dry on you over time. But the larger sizes are a better deal in price.
I made myself a kneeling pad around a minicell core. The pad is three by four feet. I covered it with neoprene jersey and on the bottom used carpet grip. I did use a LOT of DAP Weldwood and a uniform coat just did not happen… Yet all adhered well and some twenty years later the neoprene is firmly bound still ( which is a miracle as neoprene is stretchier than minicell and the pad spends a lot of time rolled up)
For carving shapes to fit into curved cavities (and getting the shape of those protrusions), I find a shape gauge invaluable (and cheap). Bought one many moons ago to use for cutting floor tiles and wood in restoring the interior of a vintage motor home (talk about odd shaped areas!) and have used it for all kinds of stuff since then.
I wonder – just a musing thought here and it might not work, but I wonder if you could shove a light gauge trash bag inside the hull of a kayak, then gather the opening around a toilet paper tube and fasten it with elastic and then shoot the bag (through the tube) full of that expansion spray foam used to fill insulation gaps. I imagine if done right it would expand and then harden to fill the entire space, then you could pull it out and have a mold of the inside to use as a template. First drawback I can think of offhand is that spray foam is rather fragile once it congeals and the mass might disintegrate when you pulled it out.
I have also used 8 or 10 gauge bare copper wire to make curve templates. It is flexible but holds its shape well.
I wonder – just a musing thought here and it might not work, but I wonder if you could shove a light gauge trash bag inside the hull of a kayak, then gather the opening around a toilet paper tube and fasten it with elastic and then shoot the bag (through the tube) full of that expansion spray foam used to fill insulation gaps. I imagine if done right it would expand and then harden to fill the entire space, then you could pull it out and have a mold of the inside to use as a template. First drawback I can think of offhand is that spray foam is rather fragile once it congeals and the mass might disintegrate when you pulled it out.
I like to saunter through Lowes, Home Depot and good hardware stores. Always a fun trip. I stopped at the expansion spray foam display at Home Depot, then remembered I never know when take my finger off the button, so my project looks like Jabba the Hutt. Went to Hobby Lobby and picked up a package of Crayola Model Magic for two bucks. More forgiving, it’s not supposed to crumble and can be air dried. Will try that first for a template.
The protrusions are two rounded sections of the seat pan where the hinged backrest pillar attached (via a pin). When I removed the backrest and pillar, that left them exposed. They stick out about an inch above the seat. They now have strips of an old seat pad taped to them as I goofed on a dock entry practice and landed on the hard plastic instead of the seat. That was painful.
I like the idea of using bare cooper wire for the curves. Thanks for that suggestion.
I know you’re supposed to test cockpit modifications before making them permanent - but permanency is a question because in my case, I’m removing standard equipment and stashing it in a gear drawer. What happens if I decide to sell the kayak in some future year and the buyer wants that standard equipment reinstalled? That would be easy to do since I have the parts. But how easy is it to remove minicell that’s been glued in?
@pblanc said:… I do not agree with the video. I have glued together a lot of minicell over quite a few years in all types of environmental conditions. I think the video is making too much about getting an extremely uniform coat…
The video where the guy made it a point to say that you needed a respirator with a specific filter…then never put it on. The video that said you needed good ventilation like a fan…and never turned it on. It was an ok video for someone that hasn’t don’t any of that before.
Personally I’ve laminated way more cabinet tops than minicell foam blocks, but the process is basically the same. Well, except for the rollers and router… I usually use a chip brush (throwaway) not a squeege. The foam is easier. The amount you need , oz, pint, quart, depends upon the surface area to be covered.
@willowleaf said:
I wonder – just a musing thought here and it might not work, but I wonder if you could shove a light gauge trash bag inside the hull of a kayak…
I like the idea of using a bag. I was going to mention the spray foam for temporary work but thought it might be too messy. The bag would nicely take care of that.
Another idea spurred on by this is to wait until winter and carefully make an ice mold. You’d need to make sure expansion didn’t damage anything though.
I would be inclined to spray the outside of the bag with Pam to aid extraction. And check to make sure the solvent in the foam did not dissolve or degrade the plastic film. Be interested to hear if anybody tried this.
Applied the Crayola Model Magic after paddling today. Placed a sheet of deli wrap over what I wanted to cover to avoid getting the stuff into nooks and crannies. It was kind of like applying fondant to a weirdly shaped cake. Leaving it in place to dry, which will take 72 hours. Glad I have another kayak to paddle.
Thanks, Sparky. My outfitter (Marshall) helped me out and I was able to get a large block from him at a very good price.
My yellow Crayola template dried and I’ve been staring at it for a couple of days, trying to figure out where to start so I can cover those wretched protrusions. Plan to do a carboard mockup first so that might help. I do know it will have to be done in two sections which will be glued together.
Also been doing lots of reading and collected a couple of photos so I know what it’s supposed to look like.
I did read that some cover their minicell with neoprene fabric for the slide factor. That was something new.
Might be paddling Lake Michigan tomorrow so I reinstalled the backband just for purposes of derrière protection, as I’ll be entering my boat from a dock. Sure hope I land in the kayak and not in the lake.
