Sawyer Kevlar Repair
Posted by: Clive on Sep-19-13 12:57 AM (EST) Category: Canoes
After years of waiting for a kevlar boat that I could afford, I now am the proud owner of a 18.5 foot Sawyer canoe. It's old (probably 1975 if the last two digits of the serial no. stamped on the boat means anything). I can't tell what model it is but it's 34" wide at the middle (not tumblehome) and depths from bow to stern are: 16",11.5", and 13.5". I'm curious as to what model it is, but my main question is how to deal with abrasion in the lower bow area. Seems most the solutions involve a grunch pad which I don't want to consider given the nice look of the boat. And I'm pretty careful with my boats, so I won't be running it up onto the beach. Is it possible to repair it by resin only or do I have to use cloth too. It doesn't leak but it is frayed and worn to the cloth for about a 3" run. Any suggestions would be appreciated.
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- Sawyer Kevlar Repair - Clive - Sep-19-13 12:57 AM
If it was me, I would use...|
Posted by: JackL on Sep-19-13 6:00 AM (EST)
West Systems epoxy.
Give it a coat, and then immediately before it hardens, take some clear plastic film like overhead projector film or loose leaf notebook page protectors, and tape it down as tight as you can get it.
The next day take it off, (it will come right off) and you will have very little sanding.
If it needs another coat, sand it lightly and do it again.
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Posted by: CEWilson on Sep-19-13 6:50 AM (EST)
Sawyer made USCA Cruisers and Pro boats at 18.5. An image of the boat and/or a sketch/ description of the cross sectional shape will help identify. AT that width, if it has a flared center section, it's probably a Super, an early Pro Boa and one of my all time favs.
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I don't doubt it was a racer|
Posted by: Clive on Sep-19-13 10:32 PM (EST)
Fiberglassed into the inward bow is a note stating: 'This is a special lightweight competition canoe and is not covered by the traditional Sawyer warranty.' It also had the number 8 in red taped to both sides of the bow hull. Apparently someone raced it. The guy I bought it from said he got it from someone in the San Francisco Bay area who had a whole canoe trailer of similar boats. It also came with spray skirts which the guy I bought it from never used.
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If the damage is really only 3", perhaps|
Posted by: g2d on Sep-19-13 10:32 PM (EST)
you can fix it with resin only. But try to count the number of layers that have been worn through.
A two or three layer fiberglass patch, brought off smooth with food wrap as described above, will not stick up or be visible in the way that a Kevlar felt grunch pad repair would. Unlike Kevlar, glass patches can be easily sanded and smoothed to get a nice contour.
C.E. Wilson will differ, but I use concentric glass patches, the largest first and so on down to one just extending a bit past the outline of the damage. At least the first patch should be bias cut, that is, cut with the scissors at 45 degrees to the line of the fibers. A bias cut patch is wonderfully willing to conform easily to the contour of the bow. Later, smaller patches can perhaps be straight cut. Patches should be ovaled, not rectilinear.
Using West 105/205 (fast cure) or 105/207, the largest, bias cut patch is placed and wet out first. Then the next smallest, which will soak up much of the resin it needs from the first patch, and then, if needed, the third, smallest patch, adding resin conservatively. Using cloth, you can lay on the food wrap film and tighten it using bits of stretchy vinyl electrical tape. Don't worry if some resin creeps out the edge, but if you see air in the cloth patches, try to gently work it out toward the margins. As I said before, any roughness, and the edges of the patches, can be sanded later when the resin is hard.
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I have Kevlar and Fiberglass cloth|
Posted by: Clive on Sep-19-13 10:44 PM (EST)
already. If I understand you, the fiberglass would be preferred because of it's sanding properties. What about the color. According to the above post, I'll have to paint or cover-up the repair. Are their no solutions where I can keep the original color showing through. I thought just filling it in with a clear fiberglass resin would do the trick. If I have to cover it up I'm sure I can come up with something creative. Thank you all for the advice so far.
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I'd probably use cloth too|
Posted by: pblanc on Sep-20-13 8:10 AM (EST)
You said that the area of damage was "frayed" which suggests that at least one layer of cloth was broached. It it was only a single layer over a 3 inch length, the loss of strength at the stem might not be that consequential.
I am assuming from your comments on "color" that the boat has a pigmented gel coat. It is true that epoxy would be somewhat less conspicuous than a repair with cloth, but it is still going to show.
I would do something along the lines of what g2d suggests. If there is any chipped gel coat debride it in the area of damage and thoroughly clean the area. You can often tell if the damage extends through multiple cloth layers. I might use only a single layer of 6 oz/yd glass if the damage is not too extensive.
Make a template out of cloth or packing paper in a pleasing shape that will look good on the stem as an abrasion plate and secure it to the boat with a few pieces of tape. Make sure it is properly centered and aligned and mark the edges with a Sharpie. You can lay that template on your glass along the bias and mark the cloth along the cut line.
I would sand off all the gel coat within the marked area until you see cloth fibers. Once you lay down the cloth, if you thoroughly feather the edges and fill the weave of the cloth it will be very smooth and stand barely proud of the adjacent hull.
Polyester gel coat adheres poorly to epoxy so I would either paint the abrasion plate or add graphite powder to the epoxy when you apply it. If you do the second the plate will be black and will also scratch black. I have found that if you carefully mask along the edge of your plate when applying the epoxy, the contrasting black color will look good on boats of any color.
You could of course paint the plate. You probably won't get an exact color match but you might come pretty close with automotive paint. Scratches on the plate will show white, however.
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Posted by: Clive on Sep-20-13 11:09 AM (EST)
I was referring to pilotwingz's comment about the West System product drying to a light blue color which would need to be covered up. The boat itself is the golden color from the underlying kevlar. Thank you for detailing the "cloth" process. It will be helpful if I choose to go that route. I'm still hoping to get by with applying some sort of clear product without cloth.
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I'll bet their hulls were all Kevlar. |
Posted by: g2d on Sep-20-13 1:50 PM (EST)
Back then, builders didn't know about the limited compression strength of Kevlar, and hadn't had enough experience with the fuzzing problem.
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sorry Clive, didn't proof the link ...|
Posted by: pilotwingz on Sep-25-13 9:51 AM (EST)
-- Last Updated: Sep-25-13 10:27 AM EST --
..... wasn't refering to West Systems .
I fixed the link now , was talking about 3M Premium Vinylester fairing filler ... I use and like the stuff alot for repairs both major and minor , but it won't be clear when faired out .
You see , your application sounds like surface cosmetic maintenance to me , not structural , so to get a decent contour to match the existing hull I automatically think a fairing process is involved . To me fairing requires filling (with something) and then sanding to desired shape (fairing) .
I don't see how one could just "fill" and cover with a release paper , w/o sanding , and end up with a very good hull contour match (like invisible to the naked eye) . So if sanding is going to be req. , any clear epoxy product will get dulled and not have that glass clear appearance .
I can't say for certain because I've not tried it myself , but ... if using a clear epoxy like West 207 catylist , you might be able to progressively sand to fair in steps all the way to 1200 wet paper which will polish some plastics to a clear glass like sheen , then extra fine rouge compound polish and wax ... but I'm doubting that because epoxy won't be able to take much sanding friction heat and stay clear , it's low heat stuff and really not a very "hard" product .
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Posted by: CEWilson on Sep-26-13 8:56 AM (EST)
Sawyer didn't use epoxy in production boats.
If your fabric isn't worn through, try re-gel coating the stem. That clear exterior is probably a clear Poly Urethane gel, the easiest of all to apply and sand to match.
Sources: Joe Moore at Placid boatworks uses clear poly gel nd has shipped small quantities. You'll need to get MEKP locally, ~$4.00 in your local hardware / automotive store.
Email me at firstname.lastname@example.org for the protocol.
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