Small puncture in hull... how would you

-- Last Updated: Jan-23-07 2:15 PM EST --

go about repairing. Would you do a fiberglass , gel coat job. Or what? It is a fiberglass hull and the small 1/8" puncture is directly under the seat , which I can remove (wilderness systems tempest). Thought about just epoxy.Hope the photo helps. Thanks.

check out…

can’t see pic…
Have to register first…

Try putting it on webshots…

how small?
most big repairs are done with the same kind of resin but epoxy would work. If the hull is vinylester you can’t use polyester over it but vice versa is ok,epoxy will work over both,someone correct me if I’m wrong. Not sure if you can apply gel coat over an epoxy repair. So if the exterior requires a few square inches of repair i’m not sure you could put gel coat over epoxy.

If it’s a 1/4" hole theres probably some adjacent cracks in the glass. On the inside I’d grind down over the hole and radiating cracks a fraction of a millimeter and out beyond any cracks about an inch then cover with layers of glass from one beyond the cracks to many over the hole. The repair on the outside is function of the size of the hole.

Is the source of the hole from the inside or outside?

Repair kit
McMaster-Carr has a number of fiberglass repair kits on page 3290 of their online catalog - - one of these would probably do the job.

Match original resin
I would call the manufacturer and find out what kind of resin was originally used when the boat was laid up.

There are a lot of chemicals you’ll need. The resin (vinylester or polyester) plus it’s hardener (MEKP, methyl-ethyl-ketone peroxide, nasty stuff). Then the gel-coat and it’s hardener (also MEKP). Then you need to seal the catalyzed gel coat from the oxygen/air using mylar film or polyvinyl alcohol (I prefer PVA, it washes off easily).

Unfortunately, the amount of work to fix a small hole is about the same as to fix a substantially bigger one. So follow LeeG’s advice and make sure you grind away the visible damage and an inch or two around it.

Use a lightweight mat fiberglass patch instead of the woven stuff you get at the hardware store as that will significantly reduce your sanding time and give you a much better finish.

Feel free to email with any more questions. I’m not proud of all the tight mark roundings I’ve done coming in on port tack, but it’s taught me a lot of glass repair as a consequence.

denso tape
and fohget about it

if you can’t see the photo , when I click on the yurl, it shows up. The puncture is about 1/8" diameter.


Take the seat out, sand maybe 1.5 inches
away from the hole, but don’t bother sanding deep for an inside patch. Clean out the hole. Tape the outside of the hole.

The prefered cloths for an inside patch are Kevlar or polyester. However, you can use glass cloth if you want. I would not use glass mat because of its inferior strength. But then, I only repair whitewater boats. You should cut one piece of cloth to cover the entire sanded area, and another smaller concentric patch to fit OVER the first.

The preferred resin is epoxy, and West epoxy is easier to get, and keeps indefinitely, than vinylester (which I have also used). West Epoxy works as well as, or better than, any other commonly available resin on any layup using any other resin. You can buy polyester resin cheap. It will work, then it will harden in the can, and in a year you may find it unusable. Epoxy resin keeps.

Lay the bigger patch over the sanded area, mix your epoxy resin, and wet it out. Use gloves. Epoxy hardener can be sensitizing. Place the smaller patch over the larger one. It may wet out even without more resin.

For a smoother result, once the concentric patches are wet out, you can put a piece of Glad clear food wrap over the patch and lay a sandbag or similar thing over it.

Now, you recall we taped the outside of the hole. When the epoxy is hard, you can take off the tape, and the hole will be plugged with epoxy. I would just leave it that way. Trying to sand it out and get a gelcoat color match is just really not worth it.

If you suspect that the cause of the hole also strained the composite layup around the hole, then you consider a 3 layer interior patch.

Us whitewater types often have to do concentric patches to the outside of the hull because we can’t get to the inside. But when we CAN patch the inside, that is the place to do it, using Kevlar or polyester (or even Nylon) because these cloths excel at resistance to stretch and tearing when used on the inside of the boat.

Glass cloth is better for most outside patches, because it has better resistance to the types of compressive loading that occur when an object impinges on the hull. I have used Kevlar for exterior patches, and it works, but it fuzzes when abraded. Glass wears smooth.

…and get a poly boat! melt a spot that doesn’t show (Edge of the seat)…use a popsicle stick to smear the melted plastic into any holes…trim with a razor blade…

(COME ON! that’s FUNNY I don’t care who ya are!)

Good long explanation
for a small 1/8" hole, the repair should be quick and quite easy. I would sand out a small area and apply no more than two layers of glass. We talking silver dollar size pieces of fiberglass on the inside of the hull. However, there are cracks emanating from the hole, these have to be opened up and filled with epoxy and glass, making it a bigger job. Still the same idea.

On the outside, I would maybe put a dap of epoxy and just the level and fill out the indent. 1/8" can hardly be noticed on the outside of the hull.


stop channeling p140

A puncture wound in your boat?
To get all this free advice, it seems a small price to share with the community - just how you got small a puncture hole amidships in your boat.

Were you using it as a workbench and you drilled through your work into the boat? Did you shoot at a sqirrel that was sitting on your boat? Was your boat impaled on a hidden 6-penny spike while you were running a class 5 rapid?

Inquiring minds …

After taking my seat out

– Last Updated: Jan-23-07 5:37 PM EST –

I have found out what caused my hole. This will be cause for a new topic. Seems my seat pan has rubbed into the glass creating a groove and now a hole. Futher more it is creating a rub and wear area in a couple more places. I am not happy, the boat is only a year and a half old.

Once you have the damage fixed,
you can put a sheet of minicell foam under the seat to prevent further damage.

Probably the designer/builder should have forseen this and have changed the design.

Quick fix with a rivet -
If there are no cracks around the 1/8" hole, you might try a rivet fix. Put it in from the outside, using both metal and rubber washers on the inside, with gasket sealer smeared on everything. Fill in and build up the inside groove wear with cloth and epoxy. No rivet gasket on the outside to minimize protrusion, as the rivet head should be almost smooth to the outside surface. Just an idea, as I have not tried it, but it should be easy and quick, and should work. Happy paddling!

hmm - composite Tempest kayak
a year and a half old. That’s your boat, right?

I saw the earlier thread.

Why was there no minicell underneath the mfgr installed seat to prevent abrasion on an expensive composite kayak?

Even my 10 year old North Shore Fuego has that.

On the WS site it states that if you are the original owner you have lifetime warranty rights.

I salute your willingness and ingenuity in attempting a repair, but, if you are the original owner, why should you have to? I mean, this is a hole apparently caused by nothing more than sitting in the seat, not in any way abuse.

What if this is just the first indication of a general weakness in that area of the hull? It’s your kayak and your call of course.

I’m sure you are justifiably proud of your new Tempest & hope it all works out.

Call WS…

I will be calling WS.


Because you say you have a groove
with the hole (presumably) at the deepest point, the interior repair I described may require sanding to create a very shallow ellipse, with the groove connecting the axis of the ellipse. One can use a sanding disk on an electric drill, but a mask and goggles should be worn. Usually one can see where the successive cloth layers are as one dishes out the area.

This also means, in my opinion, at least a three layer patch, maybe four. And to restate the rule, the LARGEST patch goes in FIRST, followed by the next largest, and so on down to the smallest, centered over the groove. (With aggressive sanding, there should be no groove, only the hole, backed by outside tape.)

The more serious an interior patch, the more I tend to recommens Kevlar or polyester (CAP) rather than glass. Kevlar is hard to cut, and it is somewhat harder to judge whether Kevlar is wetted out properly by the resin.

Now, I must admit that a sea or touring kayak, treated respectfully, may not get the kind of abuse that whitewater boats receive during seal launches off docks and rocks, or when the current drags the entire boats over a ledge. So for a sea or touring kayak, it is certainly possible to get away with a less serious patching technique than what I have described. However, the patching technique I have outlined will result in no weak spot whatsoever.