Perc Sonoma 13.5 thigh pad advice

I love my old kayak, but I wish it had thigh pads. It was made with them, but that was many years ago and they’re long gone. I’m fine with making new ones, but I wanted to see what the originals looked like.
Researching them has been challenging, the kayak was only made for two years total and apparently wasn’t popular.

I’ve finally found a couple of images of them, after months of desultory searching. I thought it was going to be some custom sculpted thing, but it actually looks like self adhesive minicel foam, I think.

This is the best picture I could find. The plastic material is .21" right there, so does that look like 1/4" minicel? Does it look like there’s another piece of foam in there?

Here’s a different view, and zoomed in

In this zoomed in crop it clearly looks like self-adhesive foam I think?

Opinions? 1/4" minicel? 1/2"? Am I on the right track?

It is pretty easy to shape and replace that pad. When you sit in the kayak and have your knee against the plastic brace, note (or mark with pencil) how much coverage you need/want front and back as well as down to the side of your knee. Those will be your “outside” edges. The “inside” edges will conform to the shape of the thigh brace.

Thickness of minicell will be determine by how tight of a fit you want with the paddling. If you want just loose comfortable padding in the area around your knee, stick to the 1/4" thick minicell (less expensive). If you and tighter fit (as would want for a “performance oriented”) kayaks for edging/rolling, then you either have to go with thicker minicell and carve (or rasp) to shape, or you build up with thinner minicell (some shaping is still needed). With thicker minicell, you may to score line the outer bend to help you keep to the rounded shape of the inside hull.

Minicell sticks on very easily and is durable over time when using Dap contact cement. Before cementing on, you should just tape the minicell on just to get the feel of the location and size of the padding before sticking on.

These days, I find it convenient and less expensive just to pick up packs of 4 of these interlocking foam mats. These are the same, or perform the same, as minicell. These can be found in home improvement, toy or dollar stores.



Sonoma 13.5 was during Perceptions attempt at the thermoformed market. The kayak is quite fun and lightweight but you have to actually paddle it as opposed to just float about, with its hard chines and rocker.
Gad, I know too much about old boats.

You’re good to go with minicell foam. I carry the self adhesive stuff which makes the process much cleaner. Comes in 1/8,1/4 & 1/2 inch thicknesses. Let me know if you get stuck (early morning pun) for foam and I can ship you some.

See you on the water,
Marshall Seddon
The River Connection, Inc.
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Hyde Park, NY. 12538
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I’ve replaced several like that over the years with adhesive-backed 1/4" minicell. It looks like you have the original, so use it as a template to draw out the new ones. Cut with good scissors then trim as needed with a razor knife. Make sure the contact area is as clean as possible (wire brush and a flexible sanding block work well) then wipe down with rubbing alcohol or solvent. Preheat the area if you’re in a cold environment. Remove the adhesive covering a little bit at a time as you attach it to the boat and work the area with pressure from your fingers and hands. I find they are much easier to install with the boat resting on it’s side.

You can use a sanding block or this shaping tool to clean up the edges if you like:

I made these large pads for a Whisky 16 that uses the deck for thigh braces and had no padding:


Wow you guys are so helpful! And knowledgeable!

I don’t have the original thigh pads, that would have made this project vastly easier. I don’t even have the adhesive outlines on the hull for a guide. It literally took me months to find these images.

I’m looking for a tight fit. The seat already fits so snugly that I can’t fit my hand between my hip and the side, so that’s perfect. When my legs are in good position my knees and thighs are an inch or more from the hull and so I need to shift slightly to get firm contact for edging. The goal is to be able to heel the kayak over without shifting my legs. My Necky Eliza was like that and I really liked it.

Comparing your replies to the photos I now feel pretty confident that the original thigh pads were layered 1/4 Minicell. In the picture of the yellow kayak you can see what looks like part of a lower layer peeking out. I theorize that this layering was to compensate for the shape of the hull interior. These shots show the contours it has to stick to.

But just because Perception used 1/4" minicell on a mass produced kayak doesn’t mean that I have to. I really like the idea of using thicker minicell and sculpting it.

Thank you very much to everyone who gave such great advice. I feel fairly confident moving forward now. I think that my next step is to sit in the kayak and take a bunch of measurements of the distance between my body and the side of the kayak to figure out how thick I want the foam to be.

I’ll be honest, when I started this project I hoped for something like this

But I’ll be happy with anything that gives me that firm contact functionality and doesn’t fall apart rapidly.

Thanks again for all the great advice! When Sing mentioned EVA foam pads, I remembered that I had some 3/4" EVA foam in the garage. I did a test fitting and it was perfect. The tape is nano tape, it’s pink because it was a present. More tape was added after the tape photos. Nice thing about nano tape is that I don’t need to worry about temperature like with conventional tape. But I cleaned every surface 3 time with alcohol. I really liked the Necky Comfort Fit thigh braces, the way they allowed a large contact area between thigh and pad, so that’s the idea I was going after here.

I’m going to use these for a while to test them, but I may want to redo it with substantially larger pads, but I’ll have to hit Dick’s for some more stadium seat pads, this time in green obviously.

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I finally got a chance to try the thigh pads in action and they were GREAT! Superb fit, if you picked me up while in my kayak the kayak would come with. I really like the soft feel of the EVA foam.

Alas, nano tape just WILL NOT hold these in place. Not sure why, it’s been cold in the garage but the tape is not supposed to be affected by cold. I cleaned everything really well, I even scrubbed the EVA pads with detergent and water before cleaning them again with alcohol. Nano tape just doesn’t seem to live up to the hype.

I wanted to try them some more before gluing them in, but I guess it’s off to the store for contact cement for me.