Sharp stemmed vee bottomed skid plates made easy

[Guest]

Most of our boats have skid plates. The UL kevlar Malecite does not, and I find myself using that light on the shoulders canoe more frequently. It is a dedicated lake boat, usually wet-footed entry/exit, but I know that delicate practice won’t last, and it was dragged up on more than a few sandy beaches before being repaired and painted.

The stems are so sharp, and carried back so far into the vee bottom, that I don’t need a bulbous downriver canoe skid plate, just a narrow strip along the vee stems. I had thought about using 2” E-glass tape, but E-glass does not hold up well to abrasion.

Time for some 1 ¾” wide Dynel sleeve, peel ply covered and roller compressed.

P9070002 by Mike McCrea, on Flickr

30” long strips of 1 ¾” Dynel sleeve, longer strips of 4” peel ply. Having a roll of pre-cut 4” peel ply tape made that Dynel sleeve cover sooooo much easier. I am already loving that rolled, release treated peel ply. Enough that I ordered a 6” wide roll, some will surely be shared.

So much easier snip-snip cutting rolls of material to needed length, with no ugly strays and sloppy scissor cut frays along the edges.

https://www.aircraftspruce.com/catalog/cmpages/peelply.php

Dynel sleeve dry fitted on the hull for length/width and perimeter edge taped, then papered to catch my heavy hand drips.

P9070004 by Mike McCrea, on Flickr

P9070008 by Mike McCrea, on Flickr

The Dynel sleeve is from Sweet Composites, here in the catalog under Dynel sleeve and cord.

https://sweetcomposites.com/Polyester.html

What Sweets calls “light weight” sleeve is 1 ½” wide, the “standard” sleeve is 1 ¾” wide; the fabric weights and weave seem identical.

This time I remembered to apply a bottom epoxy coat with just 105/205 and black pigment, no graphite powder on that bottom coat. No reason for it on the bottom, and I don’t think the graphite powder penetrates the tight woven Dynel sleeve very far.

Dynel sleeve laid on, checked/shifted a bit so that it was even between the tape lines, heavy coat of 105/206/black pigment and graphite powder painted atop. Heavy because that is a 2-layer sleeve for the top coat to penetrate & saturate, and the sharp, near vertical vee stems don’t hold on to epoxy well.

The usually Sharipe marking of the necessarily heavy handed drips.

P9070009 by Mike McCrea, on Flickr

Once the marked drips stop running the paper and tape comes off, the peel ply goes, on and it is time for roller compression, especially along the edges and ends of the sleeve.

P9070013 by Mike McCrea, on Flickr

Even after some hard roller babysitting the cut ends of the Dynel sleeve, as always, want to rise up in rebellion, especially the sleeve end at the sharp stem curve. No amount to hard roller babysitting would prevent that, and in the past I just filed off or Dremeled down the offending protrusions once the epoxy cured.

This time I tried a DougD/DaveO trick. I laid a square of Stretch-Tite food wrap atop the peel ply and taped it down taut.

P9080017 by Mike McCrea, on Flickr

There may be no one clumsier handling that cling-wrap type plastic that me, but it can’t hurt, and I can always file/Dremel/sand down any remaining rebellious end rises or wrinkles.

The hardest part is waiting for the peel ply pull reveal. Release treated peel ply; I’m not pulling it ‘til tomorrow. It’s like a kid waiting for Christmas morning.

 

[LanceR]

Good post, Mike

I wonder if taping down one edge of the stretch wrap before pulling it taut to lay it over the stem and taping down the other edge would help. I'd probably have to practice the stretch wrap bit 2-3 times before attempting it for real.

Best regards to all,


Lance

 

[Guest]

I wonder if taping down one edge of the stretch wrap before pulling it taut to lay it over the stem and taping down the other edge would help.

I did just that, a little piece of tape pulling each corner taut. And then I thought covering the entire stretched piece of plastic with tape couldn’t hurt (it didn’t).

Peel ply pull reveal.

Nice! The edges of the Dynel sleeve are tight and nearly flush, and the once rebellious ends set up flat under the taped plastic wrap. Another useful shop trick for the books.

Note that, while the Dynel is Vanta black, even using black pigmented and graphite powder the resin rests thin, smeary fugly on the tape perimeter edges of the white hull.

In for a penny, in for a pound, or at least another ounce of epoxy. No need for sanding first (bless the peel ply and the plastic wrap trick), this epoxy top coat is going on less than 12 hours after the other, so I have some chemical adhesion.

It won’t take much resin to topcoat those skinny skids, and I have become the fast master of taping and papering. Plus I can epoxy round off the square end of the Dynel sleeve for aesthetics.

Once more into the breach, with a top coat this time of 105/206 & G/flex mix, about 50/50, again with black pigment and graphite powder. I didn’t need to saturate the cloth, just provide a toughened, slippery outer surface. Worth another ½ ounce per end. I hear Glenn sputtering in consternation at that weight gain.

Taped and papered round two ready for a toughened epoxy topcoat.

P9090018 by Mike McCrea, on Flickr

That mix, with the addition of the more viscous G/flex and graphite powder, made the epoxy less drippy runny.

P9090024 by Mike McCrea, on Flickr

I don’t want to jinx myself, but dang I’m getting good at estimating the amount of epoxy I need to mix for a job. T’werent enough dregs in the pot or brush to bother smearing on anything.

P9090025 by Mike McCrea, on Flickr

I know the epoxy will take longer to set up with the G/flex in the mix, and the pigment, graphite powder and 3 layer epoxy coat on sleeve won’t hasten the cure. Without using any peel ply on the last epoxy topcoat it was a bit amine blush greasy the next morning. A little soapy water scrub made short work of that.

Shop spray bottles of soapy water and plain water made that amine blush clean up easy.

P9110029 by Mike McCrea, on Flickr

After a week’s wait cure I’ll lightly sand that, clean it, tape it again and top coat the skids with black paint; that will provide UV protection, hide the translucent fugly and provide sharper edge lines.

 

[ppine]

I use a similar technique for canoes with fine entry lines. I use several layers of fiberglass tape in different widths and epoxy. Then I paint the whole works. A little sanding and filling of the weave makes them barely noticeable. Most recently used on the 1987 OT Canadienne. I was doing some repair work anyway, so it was easy to add the protection on the stems. It is a great paddling boat and very easy to get from the trailer to the river at 49 pounds.

 

[Guest]

The Malecite’s Dynel sleeve skid plates have been finished for a week. I photographed the rest of the install, might as well write it up.

Edge taped and hand sanded to remove any little pimples from the un-peel-plied epoxy surface took only a few minutes. Taped because I didn’t want to chance oops scuffing the hull too far outside the epoxy perimeter. That was the third time taping the perimeter, made easier because the skid plate lines are but gently curved.
Taping and papering was a chore on the first boat or two, but practice makes perfect. The first few (eh, half dozen, I’m slow, and forgetful) hulls I taped and papered each took close to an hour apiece.

That was 3 ½ tape/paper jobs just on the Malecite skid plates, but I now know how to most easily run the tape, where to start and end with each piece, where to leave fold-over pull tabs and how to sequentially pull the outer tape and paper layer, then the initial tape.

The newsprint needed a gentle cut-out to fit half way up the perimeter tape along the stem curves. I’ve cut those newspaper curves so often I can just eyeball them and its close enough.

I’m down to maybe 20 minutes per boat; first run of tape, paper, second run of tape, done. Eh, always check the tape edges just before epoxy or paint to make sure nothing has lifted. Maybe 22 minutes.

The 105/206, G/flex and graphite powder surface is very hard and scuff resistant, shedding black graphite dust when sanded.

P9130003 by Mike McCrea, on Flickr

Pimples sanded smooth, de-dusted, taped and papered again, ready for a black EZ-Poxy paint topcoat. EZ-Poxy recommends two coats, and I have barely touched the can of black EZ-Poxy even after top coating a half dozen sets of wider graphite black skid plates. Lightly (carefully, not even taking the tape off) sanded the next day and a second paint coat laid.

P9150009 by Mike McCrea, on Flickr

P9150010 by Mike McCrea, on Flickr

Clean, crisp edge lines with the paint top coat. That’ll do.

I mentioned this in another thread, but the fiberglass vs Dynel results are worth repeating here.

I’m still searching for a source of rolls of 4” (or even 3” or 5”) Dynel “tape”. I did find another interesting Dynel vs fiberglass DIY test on the Glen-L site, someone who DIY abraded fiberglass and Dynel using a brick.


A 6 pound fire brick held on a 45 degree angle
The test with 6oz fiberglass cloth took 52 strokes to cut through to the wood
The 5.5oz Dynel has more than 250 strokes and is still not through to the wood