West marine plastic repair kit

Has anyone here had any experience with the new plastic boat repair kit from West Marine (The Plastic Boat Repair Kit (655-K)). Specifically, I have a Necky Chatham 16 with a crack in the area where the coaming transitions to the rear deck right behind the seat. It’s about 6" long and runs right along that transition, as in it follows the curve of the coaming. Wondering if this stuff, at $29.00 or so is worth it.

West Systems G Flex epoxy kit
It really isn’t that new and this 655-K kit and the 650-K kit are sold by multiple vendors including West Marine. You can also buy just the epoxy and hardener without the extras that come with the kit (mixing palettes or cups, spatulas, disposable gloves and dental syringes) a little more cheaply.

The 655-K kit comes with G Flex prethickened with colloidal silica. The 650-K kit, which is somewhat misleadingly labelled an “aluminum boat repair kit” comes with unthickened G Flex epoxy and hardener and works on plenty of stuff other than aluminum boats.

Yes, G Flex epoxy will work on your super linear-polyethylene kayak and is about the only epoxy that will but you will need a few other items.

I prefer using the unthickened epoxy and adding silica powder to it to thicken it as needed. Thickened epoxy is better for bonding cracks and filleting but unthickened epoxy is better for wetting out cloth.

I have repaired a cracked cockpit coaming on a polyethylene C-1 using G Flex and fiberglass cloth on a boat where the cockpit coaming was cracked off over at least 1/3 the circumference of the cockpit and it has held up well.

Here is what I did in some detail. First, you want to “gutter out” the crack from both sides enlarging it by scraping a V-shaped channel through half the thickness of the polyethylene from both sides. West Systems suggests that you then round off the edges of the crack by running some sandpaper through it. This will maximize the surface area for epoxy bonding.

After doing this you need to clean the surface well with alcohol or acetone and when dry, pretreat it with flame oxidation by passing the flame of a propane torch over the surface of the hull. You need to have the inner blue cone of the flame contact the hull surface to which you want the epoxy to stick, and if you don’t do this you might as well forget about the repair because the epoxy won’t bond. You don’t want to melt or even much heat the plastic so keep the flame tip moving.

Back up the crack on one side with clear plastic tape to confine the epoxy and arrange the boat so the epoxy settles into the crack with the assistance of gravity. Use thickened epoxy to fill the crack from one side. After it cures, reposition the boat, flame oxidize the other side of the crack, and fill the crack with thickened epoxy from the other side. You may need a couple of applications of epoxy to completely fill the crack.

After bonding the crack, I would apply a smooth fillet of thickened epoxy to the outside of the cockpit coaming but not so thick as to interfere with seating your skirt. On the inside, I would reinforce your repair with a strip of fiberglass tape (8 oz/sq yd thickness) which overlaps the ends of the crack by an inch an a half or so. The fiberglass is best wet out with unthickened epoxy and it may take one or two additional applications of epoxy to fully fill the weave of the cloth.

Sand smooth on both sides and cover the repair with a spray paint that approximates the hull color to protect the epoxy from UV degradation.

Thanks so much for the detailed instruction, I really appreciate the help!

I will attempt the repair in the next week or so.


What he says.

Thread hijack
Let me jump in with a related (but I think simpler) question.

I need to fill a small hole in my poly boat. Short story: had to replace the recessed skeg slider control box, but the new box’s entry point for the skeg tube is slightly higher than the original. I’ve drilled out the hole for the new, but I want to fill the old. (I haven’t glued in the new box yet because I want to wait until I patch this hole. I’ve rough-fitted everything and know that it all works.)

Excellent description by pblanc! West Systems provides excellent resources for DIYers. Here’s an article on plastic repair - http://www.epoxyworks.com/26/pdf/Gluing_plastic_Gflex.pdf

When we were looking for an adhesive for attaching D-rings to plastic boats we worked with Tom Pawlek at WS lab and they wrote this paper on the research - http://www.westsystem.com/ss/assets/gflex/D-ringPadsGflex.pdf

I’ve used the G/flex 655 for lots of repair jobs, boating and home repair alike, and have never had it fail me. Good stuff.

Yes, G Flex
Read & follow the articles referenced by H2OAddict & pblanc’s great directions. G Flex is excellent stuff. A tip of my hat to ezwater for turning me on to it a few years ago.

gluing small plastic repairs
Cracked a Walmart bucket bottom. Tried Wal’s Locktite Epoxy Plastic onto the crack backed with duct tape on opposite side. Yes, that does work, progress in gluing.

Locktite sells a general purpose adhesive sticking to nylon, probably not structural but use able as filler.

3M 5200/4200 marine adhesive fills holes, mounts fixtures but not a crack welder.

I was thinking of using 5200, and I also have a tube of JB Weld marine epoxy plastic weld.