Hardware Store Epoxy?

[Sweetfancymoses]

The skin coat of my Wenonah shows all the signs of having had good times in the wilderness. A few of the scratches are deep enough to expose the Kevlar. I checked out West Systems and it appears all their products come in relatively large size containers. I would need about 1 fl oz to take care of the project. I was thinking of the double syringe type hardware store epoxies. I'm not to fussy about the looks because I'm not planning on working on the superficial scratches anyway. I just want to stop further damage. Any recommendations?

 

[frozentripper]

If all you\re going to use it for is to fill in scratches, cheap epoxy should work, as long as the interior of the scratch is clean enough and rough enough for the epoxy to bond to. Washing with detergent and rinsing well may be necessary if there's any oil on the hull or if there's dirt in the scratches. Maybe sand as well in the larger ones, if they're not rough enough to give the epoxy some tooth to bond to.

Here in Canada, Canadian Tire has those small two part double tubes of marine epoxy that should work, cures in two hours, $10. OTOH, I have tried cheap five-minute epoxy and it didn't cure to the same hardness as slow-curing epoxy did... a harder surfaced epoxy should be easier to sand smooth without it smearing.

I tried some cheap CT epoxy on a small fiberglass reinforcement and it held up well... it was slow-curing not five-minute.

If ten dollars is all it is, maybe try a bit on a section of scratch and see how well it bonds (can it be pried out with the point of a knife) and how well it sands smooth once it's fully cured.

It might be better to just buy some good-quality epoxy and keep it available for any other repairs, West should keep for several years IIRC (I went with East, still good and cures hard after five years at least).. If the hardener crystallizes, warm it up in some hot water. Small quantities can be weighed out on a small weigh scale and then mixed. Anyway, try a little before you try a lot... good luck.

 

[Sweetfancymoses]

Thanks, frozentripper. I'll try the slow curing epoxy. I know West Systems is good stuff and I don't mind the expense, but good product spoiling on my shelf really gets my goat.

 

[Guest]

With a variety of hardware store epoxy or 2-part syringe mixer things it could be a crapshoot.

I’d just buy the smallest bottles of G/flex I could find, 4oz bottles of parts A and B, and use that.

https://www.walmart.com/ip/West-Syst...dSellerId=1148

And a 30-pack of nylon bristle craft brushes to paint beads of G/flex in the voids.

https://www.walmart.com/ip/Craft-Pai...iece/109107203

G/flex is tough, it sticks to dang near everything, it has a 50/50 mixing ratio, with room for error. If I ever needed to recoat the bottom or parts of the bottom with epoxy I know G/flex is compatible.

You’ll have G/flex and tiny craft brushes leftover. And be glad you did. I mix a teeny pea-sized batch of G/flex a couple times a month to fix something around the house.

Might as well pick up a bag of popsicle-sized craft sticks for mixing small batch epoxy while you are in that aisle. 150 count for $3 will last you a while.

https://www.walmart.com/ip/Go-Create...50-ct/19525318

While you are at Wallyworld, 2oz disposable shot glass mini cups are wonderful for mixing small amounts of epoxy. In the aisle with the picnic supplies.

https://www.walmart.com/ip/60X-Mini-...lors/988186007


Yeah, that is $35 in materials vs $8 for some questionably epoxy or loaded syringe. I guaran-freaking-tee you will find uses for G/flex (and shot glasses, stir sticks and teeny disposable paint brushes) for years to come.

I know West Systems is good stuff and I don't mind the expense, but good product spoiling on my shelf really gets my goat.

G/flex won’t spoil once opened. The hardener might get darker with age, but it will still work. I’ve used 90% gone bottles of G/flex, hardener black from being left in a friend’s summer sun baked and winter frozen barn for 5 years. Still worked fine

 

[Canotrouge]

Thanks, frozentripper. I'll try the slow curing epoxy. I know West Systems is good stuff and I don't mind the expense, but good product spoiling on my shelf really gets my goat.

Epoxy doesn’t go bad! No shelf life or rather lifetime shelf life!!

 

[PaddlingPitt]

When I first started canoeing in Vancouver in 1987, the standard epoxy used by my canoeing companions was Cold Cure. I still use it, as I have enjoyed a lot of success. People on this site are obviously big proponents of G-flex, which I had never heard of before. Has time passed me by? What are the relative strengths and weaknesses of these two epoxys?

 

[Guest]

The small two-part epoxy syringe style, usually more paste-like in mixed consistency, will harden over time once opened, at least firm enough that you can no longer depress the syringe.

I had a partially used 2-part epoxy syringe with the plunger frozen solid, so I cut it in half. The innards were a solid epoxy outer donut around a still slightly gooey inner core.

I wasn’t risking mixing that inner goo, so into the trash it went.

For small batch epoxy needs, filling scratches and gouges, G/flex.

 

[Canotrouge]

Well maybe I should have specified “real” epoxy lol like west system etc!!

 

[Guest]

Well maybe I should have specified “real” epoxy lol like west system etc!!

I’m just not a fan of those wee quantity double syringe stuff. I still carry one in my Spares and Repairs kit, did for years without ever using it and finally thought I should buy a new one to replace the old.

The old, never used one was frozen solid un-plungable. I haven’t tried the replacement, which is now a few years old, probably should.

I would need about 1 fl oz to take care of the project. I was thinking of the double syringe type hardware store epoxies.

I wouldn’t buy epoxy based solely on needing a single ounce.

 

[dramey]

West Systems has a kit called Plastic Boat Repair Kit that has 4 oz tubes of Resin and Hardener, 2 applicators, gloves and mixing pallets.

 

[PeteStaehling]

West Systems has a kit called Plastic Boat Repair Kit that has 4 oz tubes of Resin and Hardener, 2 applicators, gloves and mixing pallets.

They (West Systems) also sell the "Fiberglass Boat Repair Kit" that has eight little packets of the 105 Resin and the 205 Hardener as well as some fillers brushes and other stuff. There is also another repair kit.

They sell just the packets of resin and hardener as a refill for the kits. "Additional pre-measured packets of 105 Resin/205 Hardener (0.56 fl oz of mixed epoxy) are available in packs of six.

101-T Resin/Hardener Packets, pack of 6" They sound like just the ticket for times when you need just a little. On the other hand having a quart around for general repairs and construction is kind of nice since the shelf life is long.

 

[frozentripper]

Pitt... I\ve never tried G-flex either... I always had some extra regular epoxy left over from larger projects and never had a need for it since plain old epoxy worked fine. It's about $50 including tax in Toronto, the two small bottles about 125 ml each if I remember the ounce to ml conversion (how large is an ounce anyway, never could picture an ounce, metric made more sense).

The cheap hardware store epoxies in small tubes also worked on odd job occasions as long as they weren't five-minute epoxy.

 

[Guest]

When I first started canoeing in Vancouver in 1987, the standard epoxy used by my canoeing companions was Cold Cure. I still use it, as I have enjoyed a lot of success. People on this site are obviously big proponents of G-flex, which I had never heard of before. Has time passed me by? What are the relative strengths and weaknesses of these two epoxys?

From West Systems:

G/flex Thickened Epoxy Adhesive is a toughened, versatile, 2-part epoxy for permanent waterproof bonding of plastic, fiberglass, ceramics, metals, damp and difficult-to-bond woods. With a modulus of elasticity of 150,000 PSI, G/flex 650 is a bit more flexible than standard epoxies and polyester, but much stiffer than adhesive sealants. This gives G/flex 655 the ability to make structural bonds that can absorb the stress of expansion, contraction, shock, and vibration. It is ideal for bonding dissimilar materials. Mixed at a 1:1 ratio, G/flex 655 gives you 46 minutes of pot life and 60-75 minutes of working time at 72°F. It reaches an initial cure in 7 to 10 hours and full cure in 24 hours.

I don’t know about the relative strengths are weaknesses, but can list a few reasons I like G/flex.

G/flex can be mixed with regular West System epoxy in any proportion. I mix some G/flex in with top coats of West for skid plate installations.

G/flex uses a 50/50 mixing ratio, and that ratio seems forgiving if you are eyeballing tiny amounts and off by a bit.

With proper surface prep G/flex sticks to dang near everything. Scroll down this link to the Tensile Adhesion chart:

https://www.westsystem.com/specialty...adhesion-data/

That it adheres to various plastics is a help in various repairs, including stuff around the house.

Being able to make teeny pencil-eraser sized batches of G/flex is, for me, a huge boon. I mix tiny batches of G/flex with regularity, often for some household repair.

Perhaps the most impressive was repairing the ceramic lid to a humidifier pot that lives on the wood stove all winter. Dropped on the floor and broken into a half dozen pieces, repaired with G/flex, still going strong after 8 winters living atop a pot of boiling water and steam.

G/flex has a long shelf life. I don’t know how long, at least 5 years even with poor storage in a summer baking/winter freezing barn. Even there, while the hardener went dark, the G/flex still worked fine. In my shop, without such temperature extremes, much longer.

Downsides of G/flex? It is more viscous than regular epoxy resins, making it harder to wet out fabric using 100% G/flex. Of course that greater viscosity makes it less runny/drippy for small repairs.

Is it worth $25 or $30 USD for an 8oz kit? It is for me; I bought an initial 8oz kit, used it with surprising frequency, bought another, used it up, bought the 32oz G/flex bottles and eventually bought another 32ozs. I have about half of that one left and will buy another when they get near empty.

 

[Jim Dodd]

I have several left over jugs of epoxy that have definitely gone bad !

Old epoxy, still in liquid state, say 5 yrs old. Has a much shorter pot life. Yes West System epoxy !

Really old epoxy solidifies. No longer usable.

Yeah, Epoxy does have a shelf life.

Properly storing it extends it's life.

Jim

 

[scoutergriz]

I just use the repair kits, I even have one in my oh shi* bag.
https://www.westsystem.com/handy-repair-pack/

 

[Black_Fly]

I bought some marine epoxy at Lowes that is very good. It's white, however. There may be a clear version out there. I tried some G-flex and it is good too. The thicker stuff is best.

 

[dramey]

West System G-Flex is the only epoxy I have found that works really well on polyethylene canoes. I am not saying there are not other epoxies that work on polyethylene canoes, I just haven't found them. The trick is to slightly warm the polyethylene with a propane torch before applying the G-Flex epoxy.

 

[Chip]

Earlier this year, I repaired a boat with 15-year old West System epoxy. Other than the epoxy being coffee colored, it worked fine. So epoxy may have a shelf life, but it is beyond 15 years. Perhaps storage conditions make a difference—mine was indoors in a basement shop, so no temperature extremes.

Also have used the double syringe epoxy. Had some, unopened, in the glue drawer, for multiple years. I went to use that in March and found it had hardened in the syringes and was unusable.

I’ve also used g-flex, mostly in small batches. Parts A & B have different viscosity, so when pouring out a half teaspoon onto a mixing surface (usually a plastic coffee can lid), one pool sits up and the other spreads out. It’s hard to eye ball the puddles of Part A and B so that they have equal volumes. If I get equal volumes, it’s just luck. Yet it always has produced good results. So, I agree G-Flex works even with variations from the 50/50 mix.

yes, G-Flex is pricey. And you might get good results with the syringe kit. But I think your probability of successful repair will be greatest if you use the G-Flex.

 

[Guest]

I’ve also used g-flex, mostly in small batches. Parts A & B have different viscosity, so when pouring out a half teaspoon onto a mixing surface (usually a plastic coffee can lid), one pool sits up and the other spreads out. It’s hard to eye ball the puddles of Part A and B so that they have equal volumes

Chip, yeah, the amber colored hardener is more viscous. The handiest thing I’ve found for mixing small batches of G/flex is 2oz disposable plastic shot glasses, 30 pack for $2.65

https://www.walmart.com/ip/Hefty-Red...ll&athena=true

Actually the handiest thing was a sleeve of 1oz medicine cups. Hmmmm. . . . .

Well dang, I hadn’t bothered to look. 100 count for $4.75. Half the cost, and they are graduated. Just ordered me some.

https://www.amazon.com/Dynarex-4252-...s%2C162&sr=8-4

100 of those will last me a good long time, and, graduated, no more guess work at a 50/50 G/flex mix.

Thanks, I love how discussion on Canoe Tripping get me thinking, even if it is sometimes a DUH realization.

 

[frozentripper]

Small weigh scales can also be used to measure out the right amounts of epoxy and hardener if they are runny and difficult to estimate volumes with... with the caveat that the mix-by-weight proportion may be slightly different than the mix-by-volume. East epoxy has a technical PDF sheet showing the correct weight proportions for mixing epoxy and hardener, slightly different from the 5:1 ratio mix by volume. I've marked that on the cans and no longer mix by volume for small amounts.

It's pretty quick to measure out by weight... a small amount of epoxy is poured out onto something like a plastic yogurt lid, the weight noted and the roughly 20% hardener contribution (actually it's something like 18.58% but I'm not going to spend time searching for the exact number)... is calculated, X grams of epoxy multiplied by 0.2 gives the right amount of hardener to add into the epoxy. The total weight is added up on paper and the hardener added dropwise until the needed total weight shows up on the scale. Then mix, secure in the knowledge that you won't need to stay up all night worried that you've mixed in the wrong proportion... no mistakes.

Now, if you're tired of reading this blurb on accurate mixing;;, wellsir, I'm tired of describing it too. The actual mixing with weigh scales takes less time than writing about it.