3M Instant Set Epoxy- NOT!

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Forum topic by gfadvm posted 05-18-2012 10:23 PM 2215 views 0 times favorited 16 replies Add to Favorites Watch
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14940 posts in 2690 days

05-18-2012 10:23 PM

Topic tags/keywords: instant set epoxy

I needed to stabilize/fill some knots in some hedge today. I went to town, saw the ‘instant’, and bought it. Then the problems started: the 2 syringes attached to each other didn’t dispense equal amounts of goo. The clear was thinner so more came out. I mixed it up, filled the knots quickly, and 5 hours later it was still a goo. Which tube is the hardener? (clear or yellowish). Anyone have any tips for using this stuff? Other suggestions for stabilizing/filling knots?

-- " I'll try to be nicer, if you'll try to be smarter" gfadvm

16 replies so far

View Monte Pittman's profile

Monte Pittman

29233 posts in 2338 days

#1 posted 05-18-2012 10:30 PM

I am far from an expert, but I think the clear is hardener.

-- Nature created it, I just assemble it.

View vonhagen's profile


534 posts in 2365 days

#2 posted 05-18-2012 10:31 PM

i use the 5 minute epoxy and warm it up to over 100 degrees, the warmer it is the faster it will go off. and use equal amounts. or you can get some west systems epoxy that has a pump on each can for equal amounts or for longer set times you have to measure it out. like bondo the more hardner and the warmer it is the faster it will go off. you will find that warming it up it will come out like water

-- no matter what size job big or small do a job right or don't do it at all.

View shipwright's profile


7980 posts in 2798 days

#3 posted 05-18-2012 10:59 PM

Andy it doesn’t matter which is the hardener. The ratio is the ratio. If it comes one to one then that’s it.

I wouldn’t ever mess with the ratio in mixing epoxy. Increasing the hardener may make it set faster but it messes seriously with the hardness and other physical properties of the finished material. It also may prevent it from setting at all. For a more complete description of the difference between “catalyst” reactions like bondo and “two part” reactions like epoxy see my blog on epoxy tips.

With all due respect, it is not in any way like bondo.

-- Paul M ..............If God wanted us to have fiberglass boats he would have given us fibreglass trees.

View vonhagen's profile


534 posts in 2365 days

#4 posted 05-18-2012 11:23 PM

west system has mixing ratios and cure times right on the can. i meant that bondo and epoxy do respond to heat in the same manner. conversion varnish is also temp sensitive and the ratios for mixing vary greatly

-- no matter what size job big or small do a job right or don't do it at all.

View vonhagen's profile


534 posts in 2365 days

#5 posted 05-18-2012 11:30 PM

go to this link andy and it will explain it all

-- no matter what size job big or small do a job right or don't do it at all.

View dhazelton's profile


2767 posts in 2296 days

#6 posted 05-18-2012 11:49 PM

Doesn’t one button dispense the two parts out of the syringe at the same time? How could it have given you more epoxy than hardener? Look for one with that type of dispenser next time.

View SisQMark's profile


384 posts in 2600 days

#7 posted 05-19-2012 12:00 AM

I have tried this with great success.

It only costs about $15 but it works great. 1 to 1 mixture and it sets up fast too. Try it out, it won’t disappoint you.

-- Don't waste today, it is yesterdays tomorrow!~SisQMark

View rance's profile


4258 posts in 3160 days

#8 posted 05-19-2012 12:15 AM

Yeah, don’t store it in the freezer. Also, I’d suggest chucking up a dowel in your cordless drill on High and use that to mix it. It is much faster and uses less energy(my energy, that is). But more importantly, it is more thorough. If you’re really concerned which one is the hardner, I always go by taste. The hardner is the one that tastes like glue.

Alternatively, you can get some of that resin from Michael’s, or the West System stuff. These can both be colored with a myriad of materials including glitter(not my favorite), coffee grounds, sawdust(different consistencies), dried cow patties, and many others. Experiment a little.

The epoxy(that I regularly use) is about 25 years old and still works well.

-- Backer boards, stop blocks, build oversized, and never buy a hand plane--

View grizzman's profile


7836 posts in 3303 days

#9 posted 05-19-2012 12:19 AM

i have used the devcon for small projects, i add coloring for the ones i want to be that way and i have never had any problems with it, it sets up just like it says, but i also buy larger bottles of epoxy as i do a lot of projects and find that when used as told, it works really well, i would read what Paul has in his blog, as you know he is very well trained in all of those things, and i consider him an expert on such topics…i hope you get things worked out andy…

-- GRIZZMAN ...[''''']

View shipwright's profile


7980 posts in 2798 days

#10 posted 05-19-2012 12:52 AM

I didn’t mean to step on any toes. It’s just a bit of a knee jerk reaction for me when someone says you can mess with epoxy ratios. There is a fundamental difference between catalyst reactions and two part (for lack of a better expression) reactions and many people confuse them.

-- Paul M ..............If God wanted us to have fiberglass boats he would have given us fibreglass trees.

View gfadvm's profile


14940 posts in 2690 days

#11 posted 05-19-2012 12:55 AM

Thanks for the input guys. I read Paul’s blog again. I wasn’t trying to alter the recommended ratios. The double syringe thing put out a lot more of the clear goo than the yellow and that’s probably what caused the problem. Maybe I can separate the syringes to get accurate dispensing and salvage the rest of this?

-- " I'll try to be nicer, if you'll try to be smarter" gfadvm

View hhhopks's profile


651 posts in 2377 days

#12 posted 05-19-2012 03:18 AM

I am a bit intrigue on the mechancal side of the syringe dispensing. The side by side cylinders are identical. Right? The plunger is one piece. So it should be pretty tough to move one side and not the other but it is possible to have the plunger slightly cock to one side. What is left potentially, is how the dispense end tips are cut. I would think the dispense end needs to be cut in a way so that both dispensers opening are the same. The opening would need to be the same or about the same so the two parts flows out more equally. The pressure resistance should be the same and the plunger won’t cock to one side.

How equal is equal? It is just an approximation. Get it close.

-- I'll be a woodworker when I grow up. HHHOPKS

View vonhagen's profile


534 posts in 2365 days

#13 posted 05-19-2012 11:59 AM

Mixing the Epoxy
The heart of working with epoxy is the basic epoxy resin, combined with one of several hardeners. The clear amber resin cures to a high-strength plastic solid at room temperatures when mixed with specific proportions of the correct hardener. Hardeners are selected by the ambient temperature (which results in a reasonable “pot life”), or by a desired characteristic of the resulting mixture (like extra clarity for a clear finish in the case of WEST SYSTEM’s 207 Hardener.)

To make it easier to buy, the right amount of resin and hardeners are packaged in group sizes. For each container size of resin, there is a corresponding container size of hardener like WEST SYSTEM Group A or Group B.

Modifying the Epoxy Mixture
Because unmodified epoxy is both expensive and has low viscosity, you frequently add fillers or additives to create the right blend of properties for the job. Fillers are designed to thicken the epoxy mixture and are broadly grouped into two categories: High Density and Low Density.

High Density fillers are used to modify the structural properties of the epoxy by adding strength, bulk or both. Examples include WEST SYSTEM’s #404 and #406. High density filler mixtures cure to a strong, hard-to-sand plastic useful in structural applications like bonding, filleting and laminating.

Low Density fillers cure to a light, easily-sanded material which is often used for cosmetic or surface applications such as shaping or fairing. Examples include WEST SYSTEM’s #410 and #407.

Additives alter the physical properties when the epoxy mixture is used in coating applications. Barrier coat additive (#422) improves the effectiveness of the basic epoxy/hardener mixture at resisting moisture penetration. Adding graphite powder (#423) makes coated surfaces slick, which can be used on rudders, centerboards or centerboard trunks. Aluminum powder (#420) can be used to prevent UV deterioration. Unlike additives and fillers, reinforcing materials are not mixed with the epoxy, but are often used in conjunction with the epoxy mixture to provide additional physical properties.

-- no matter what size job big or small do a job right or don't do it at all.

View CharlieM1958's profile


16274 posts in 4218 days

#14 posted 05-19-2012 12:34 PM

I’ve used a couple different brands (can’t remember which) and never had a problem, but I’ve never used the stuff with the double syringe. Like hhhopks, I keep thinking about the mechanics of that. If the plungers are linked together, it seems like the amount of material exiting both nozzles would be limited by the slower of the two sides. In other words, even if one liquid was thicker than the other, or one nozzle cut larger than the other, as long as both plunger have to move together, the same amount of material should be exiting each nozzle (unless one liquid was so thin that it literally drips out on its own).

But all that is theoretical, and things don’t always work they way they are drawn up on paper.

-- Charlie M. "Woodworking - patience = firewood"

View sIKE's profile


1271 posts in 3754 days

#15 posted 05-19-2012 07:52 PM

The trick with the double syringe is that one of the two sides gets more viscous quicker than the other side in cooler weather. So one side is “harder” to push out than the other. Like John said, get you a Red Solo cup put some warm ~100 degree water in it and drop the syringe in it for a couple of minutes and you should then be able to dispense out equal portions.

-- //FC - Round Rock, TX - "Experience is what you get just after you need it"

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