WEST SYSTEM G/Flex Epoxy Adhesive | Two-Part Structural Epoxy for Fiberglass, Marine Repairs, and Durable Bonding in Demanding Conditions | Made in the USA (2 4.5 fl. oz. Tubes)

Great and super tough epoxy that saved our rotomolded hot tub spa from 2 hairline cracks that began leaking considerably. Was relatively easy to apply. Steps followed: - drill a 1/16th or 1/8th bit hole straight through the end of each crack. - dig out an 1/8th inch deep and wide U or V shaped trench between the holes with a dremel tool, be very careful to not punch all the way through here or weaken it too much if possible. Very high speeds/friction may start to melt the material, this is fine but slow down if this happens. - sand down the edges of the trench so that they aren’t too sharp. You ideally need a gradual edge groove to adhere better - heat treat both trenches. Basically just blast them for a few seconds with quick passes with a blowtorch, strong butane lighter, or a brûlée torch. Do not overdo this - apply the resin on relatively thickly, don’t go too crazy with it. Enough to fill the trench throughly and then a little over the edges to form a solid seal - optionally you can sand this down after for a cleaner finish or if your application was a little sloppy. My one complaint, which is enough to bring this down to a 4, but I’ve decided not to simply due to the unique value and quality of this product. The title listing says white, but the cured end result is a tree-sap translucent gold-yellow (as seen in one of the images). This is notable if you’re concerned about the visual end result in a high visibility area.

Arrived on time and in good order. West system products are the best epoxy in my opinion after having done several fiberglass repairs on boat. This G flex 655 is great for overhead and vertical surfaces because it's the thickened version. Used on a polyethylene RV holding tank along with fiberglass mat. Very easy to mix and use the 655. the key to any successful repair is surface preparation. Drill end of all cracks, 60 grit sand, quick acetone wipe, flame treat the plastic then epoxy. West system has awesome tech support if needed. The tubes went farther than expected after repairing a 1/2" x 2" hole with multiple cracks still have some left.

I bought a trailer and found there was a crack in the black tank, desperate to not replace the black tank I spent hours researching. I stumbled upon this product, after seeing a guy use this who put a jack through his black tank and patched much more severe damage than mine, I decided to pull the trigger. The difficult thing about my tank is it is polyethylene, which many products don't adhere to. This will work on both abs and polyurethane. MAKE SURE YOU READ THE INSTRUCTIONS. I cleaned the outside of the tank with you isopropyl alcohol multiple times using paper towels as recommended (rags may have softener which will affect its ability to stick), flushed the black tank multiple times, sanded with 80 grit sand paper everywhere I was going to apply, I then cleaned with more alcohol. Then the important step for polyethylene, flame treat the plastic, which is just running fire quickly over the surface, not melting the surface but chemically changing the surface. I then applied a thick layer in the crack, getting as much in as possible. I spread it wider placed some fiberglass mesh in it. Here is where I "messed up", after the first layer I thought it was a good idea to wait a day to apply the second layer. That night after googling and going to their website, they recommended thick layers, which generate heat and help it to cure. They also recommend waiting 3 to 4 hours only before applying the second layer (push your thumb into it, if it is still soft, but doesn't stick to you, you're good to apply the second layer. So after waiting two days, I had to 80 grit sand the epoxy , clean with alcohol again, flame treat and then apply the second layer. After letting it cure for a few days I put 30 gallons in to test the patch. Not a drop. Time will tell how it will hold up with movement and flex, but I'm pretty confident I'm good for quite a while.

This stuff works great, is awesome, and easy to use. Will buy again if I ever need to fix my hull again on jetblaster.

love the squeeze tube. makes mixing so much easier then the cans . if you have not used this. and you want a thick epoxy that does not slump and run. then this is it. the write up says it white in one part.. it is not, thank goodness, its standard amber colored epoxy and of course it can be colored. I don't know why they said it was white - a typo so to speak. further on in the spec's they say its amber - Some of the BEST instructions in the business which by the way builds brand loyalty

400 miles into a 2500 mile trip I noticed I had a leak in my black water tank and found a crack at the outlet that connects to the drain pipe. I tried other products and methods to repair with no success. I found the Gflex on Amazon and it worked amazing. I first let the tank drain - a slow, smelly drip into a bucket for a few days. Then followed the recommendation to try and get the adhesive into the crack to do an initial seal. I was able to flex the tank enough and used a meat injector to apply to both sides of the crack the best I could. I let that set up and then used Gflex and fiberglass cloth from a bondo repair kit (following the directions that came with the kit) to create multiple layers. The Gflex has the perfect consistency to achieve excellent results. Filled the tank with water - no leak. Drove a couple hundred miles - no leak. Took care of business - no leak. Due to the flexibility of the adhesive, and fixing the original problem that caused the crack (the factory forgot to install the bracket to support the drain pipe), I am sure this is a permanent and way less expensive fix than replacing the tank.

pricy but plenty of material to work with, I've spent as much money to get 1/2 as much, pretty large tubes. It"s not as thick as I expected. It's will stick on a vertical mend better then most everything else, but mine did sag and so you have to work with it, slow set and plenty of work time and when your working on holding tanks (mine) its usually a contorted position. No leaks on the first road trip so I'm happy but if it doesn't leak in the next 2 years I'd call it permanent and give it 5.5 stars.

I do alot of custom fabrication, mostly on custom cars. This is one of my favorite tools for bonding, sculpting, and finishing. It holds a decent shape before curing, and cures so great - strong - and shapable (is that a word?) I don't write reviews, but G/Flex deserves a bit of my time to give it a big thumbs-up