Explorer hull repair

A friend recently bought a fiberglass '89 MR Explorer (for $300). It is mostly in good condition. Part of the rails have started to come off and pulled through the screws, fixing that is the easy part.

The hard part will be to repair a 6-8" chunk taken out of the stern. Pictures are here:


My thought is to grind out a bit of the area, then fill it in with epoxy with microbaloon filler. Then cover the area with some leftover kevlar felt from skid plates.

Does that sound like the best option or should we cover it with s-glass? If so where can I get a small piece of it without having to buy a whole roll?

You can buy S-glass by the yard from
johnrsweet.com, but unless you are going to run a lot of ledges, you might as well use E-glass obtained locally. The microballoon plan is good if you have a lot of volume to be filled, but you could just tack in some FG and wet it to close the gap before continuing. Anything that is light and keeps the epoxy from running out of the final patch is OK. Remember that you have to remove amine blush after one layer of epoxy is set, or the next layer may not stick.

I recommend against using Kevlar for most exterior patches, especially for a break like yours that was caused by compression. Kevlar has only about half the compression strength of E-glass, is harder to wet out, and will fuzz when dragged.

Remember that the LARGEST piece of glass should go on first, and so on down to the smallest. You might need five layers of 6 oz glass, and don’t go under four. All layers can be put on at the same time if you are quick about wetting them out, and then you can tape some poly food wrap over the whole mess to squeeze out extra resin and smooth the surface.

That’s it??
That’s the damage that needs to be fixed?? It looks like its just down to the glass. Not particularly structural.

Easy repair. Sand the area, taper out the edges a bit. Thicken some epoxy, fill the area. Sand that down, cut a piece of glass 3" wide or so and longer than the repair area. Tape out the area…wet out the glass and lay it over the repair, brush it flat and smooth. Remove the tape before the epoxy sets.

Do that on boat ends. It’s a standard thing to do to canoes.

You are adding “tips and tails” to the bow stern for beaching. Think of them as sacrificial strips.

thanks for the responses
Now to find a place to get fiberglass locally. There is a 'vette shop nearby that I might try first.

The other thing was that with glass I should do a bias cut so it lays properly.

I couldn’t see the damage as clearly
in the photo, but since you mentioned microballoons, I assumed you had gone through the glass.

Bias cutting can be a pain, but is worth it when you go to getting the patch to lay on complex curves.

To get glass, also check boat shops in your area, those supplying the powerboat/sailboat market. They often will have glassing supplies.

John Sweet says that glass that has been lying around a humid basement for several years may no longer bond as well to resin, because the special coating on the fibers has degraded. It’s good you’re starting with new glass. Use it up before it is, say, five years old. Hit some rocks.

not through
there is a small part where the glass has broken, but most of it is just to the glass. I was thinking microballons as a thickener to get something close to the original hull shape.

Nice thing about a multi-layer glass
patch is that you can grind some off to achieve the desired form, without significantly weakening the patch.

repairing MR Explorer
Follow c2g good advice, he has learned it through the school of hard rocks. I second avoiding kevlar on outside surface.

My suggestion also is to use glass with epoxy. Then spray paint the repair to the finish color to protect the epoxy from UV. As the spray paint wears off re-spray. Much easier than trying to deal with epoxy/gel coat (polyester resin) compatibly. Cheaper too.

If you are planning to also repair the gel coat realize that it is hard to get gel coat to stick to epoxy-some say you can-my few attempts didn’t work. Vinylester resin works best for varied repairs on polyester resin hulls with gel coat outer surface. However, it has a very short shelf life and is not sold in the small amounts that would be useful for home repair. Use glass, epoxy and paint.


Good advice G2

No, it’s me, g2d, not that c2g !

sorry about d2g vs c2g mix up
I didn’t have my new glasses on. Near vision has suddenly gotten much worse while far vision has improved noticably. Just another adjustment in moving towards my mid 60’s (63 next week). Athletes are told that the knees go first. I’ve experienced many things “going” from my mid 50s to the present.

The thought that I’m able to paddle and expect to continue doing so for many more years still brings a smile to my face.


I’m just as old, and it surprises me how
my vision can change. My left eye has a mild cataract condition, but otherwise needs very little correction. I had a pair of glasses custom set for my computer screen, and they worked about a year, but now my right eye needs LESS correction, and I have to use weaker glasses.

Ten years ago my left eye was very farsighted, and my right eye nearly normal. Now it’s just the opposite. Damned if I would ever get laser correction… it wouldn’t last !

if UV is your concern
consider West System epoxy 105 resin with 207 hardener.

The 207 Hardener is a UV stabilized formula that will be more then sufficient for kayak applications which sees so little sun (unless stored outside)


It’s worth thinking about, but patches
I have done with West 205 or 206 have not shown UV degradation. Patches can be spray painted, or occasional application of 303 will help also.

Thing is, for patching a high stress area, the epoxy will be somewhat stronger with 205 or 206. The 207 hardener is best when glassing a stripper or a stitcher. It looks better, and one doesn’t have so much of an issue with amine blush when doing multiple coats.

Too much, dang

Just throw a pair of kevlar felt skid plates on it.That’ll seal it up and stiffen it just fine.

You might read through what others
have posted before jumping in. Kevlar skid plates are a junk solution to most problems. They are popular because they are easy to apply, but they hurt boat performance on flatwater, and are inferior to a properly done S-glass patch on whitewater.

The MRC Explorer
is a great tripping boat. The idea that skid plates are going to slow you down is a little over the top, the drag on this boat is negligible, just sand the skids down smooth.

If you are looking for straight up speed, the Explorer probably isn’t the boat you want to be using.

If you want to do a full repair, go ahead with resins, gelcoat and some wetsanding, oh yeah and a bit more of your time.

Sorry, many of us on this board do not
share your view that the effect of typical skid plates is negligible. The market for skid plates shows that you are in the majority, but some of us know better.

I do not even like the way a boat with Kevlar skid plates feels when it runs up on a rock, or has to be dragged over a log. S-glass skid plates sit low, run easy through the water, and run more smoothly over rocks and gravel.

Kevlar felt skid plates are the dominant solution only because Kevlar felt is much easier to apply. Otherwise, they don’t stand comparison with glass cloth.

Sanding Kevlar felt.
I’m curios about this approach. Have you tried sanding K-felt? Can you really get it ‘smooth’? If you’re going to the trouble of applying skid plates and sanding smooth, what’s the disadvantage of using glass?

I inherited Kevlar skid plates on one
boat I bought as a demo. They are the thin, low-profile kind sometimes applied to lake boats rented in BWCA and similar areas. They do not have the raised edge of conventional Kevlar felt plates, and so are quieter. They have worn fairly smooth where they have contacted the beach, so I assume that sanding with really fresh Adalox paper might smooth the surface.

Trying to cut down the raised edge on normal, thicker Kevlar felt plates is a rather thankless task, but can be done.

I certainly agree with your point, but then, I am a very experienced boat patcher, and putting on a 3 to 5 layer, bias cut, concentric glass patch is second nature for me. For a canoe owner who has done absolutely no such work, applying a Kevlar felt skid plate is much easier. That the result is heavier, noisier, stickier, and less able to protect the boat from sharp blows is something that the average boat owner just is not in a position to discover.

There’s a reason that light boats are built with S-glass on the outside and Kevlar on the inside. It’s because that’s where those cloths work best. Felt? Well, there’s a felt need for felt, and probably always will be. Certainly Kevlar felt IS better than sponsons.