5 Minute Epoxy?

[qquake]

Is there a 5 minute epoxy that really sets in 5 minutes? I've tried BSI, Loctite, and JB Weld brands, and they all take a lot longer than 5 minutes. It can be a good 20-30 minutes to be workable. I know I'm impatient, but it's frustrating to me. When it's hot, and I can't work in the garage in the afternoons, I work on pens a lot in the mornings before work.

 

[Hippie3180]

Is there a 5 minute epoxy that really sets in 5 minutes? I've tried BSI, Loctite, and JB Weld brands, and they all take a lot longer than 5 minutes. It can be a good 20-30 minutes to be workable. I know I'm impatient, but it's frustrating to me. When it's hot, and I can't work in the garage in the afternoons, I work on pens a lot in the mornings before work.

I use JB Weld and let it set up an hour or so before handling/turning, and sometimes overnight. Could you prep your pen the day before?

 

[jttheclockman]

Is there a 5 minute epoxy that really sets in 5 minutes? I've tried BSI, Loctite, and JB Weld brands, and they all take a lot longer than 5 minutes. It can be a good 20-30 minutes to be workable. I know I'm impatient, but it's frustrating to me. When it's hot, and I can't work in the garage in the afternoons, I work on pens a lot in the mornings before work.

2 ways around that. Add more hardener or add heat.

 

[hokie]

Maybe 4 minute epoxy? https://www.totalboat.com/products/4-minute-epoxy-fast-setting-clear-adhesive

 

[Muddydogs]

This is why I just use CA glue. If it happens to be cool enough to do something in the shop or all a sudden I decide I need to turn a pen the set up time for epoxy just doesn't work. With CA by the time I set up the lathe, and get the needed supplies ready it's time to square the blank and turn it. So far in over 150 pens or other tubes kits I have only lost 2 blanks, one due to carelessness not watching were I put the cutter after a tool rest adjustment and the other was Black Palm where I knew I needed to stop and apply some CA to the blank but just one more pass with the tool got me.
I have not had issues with CA not securely attaching the tube to the wood. I guess if I ever do then I might have to prior plan and glue some blanks up ahead of time but I'm sure I won't want to turn them when the time comes.

 

[derekdd]

This is why I just use CA glue. If it happens to be cool enough to do something in the shop or all a sudden I decide I need to turn a pen the set up time for epoxy just doesn't work. With CA by the time I set up the lathe, and get the needed supplies ready it's time to square the blank and turn it. So far in over 150 pens or other tubes kits I have only lost 2 blanks, one due to carelessness not watching were I put the cutter after a tool rest adjustment and the other was Black Palm where I knew I needed to stop and apply some CA to the blank but just one more pass with the tool got me.
I have not had issues with CA not securely attaching the tube to the wood. I guess if I ever do then I might have to prior plan and glue some blanks up ahead of time but I'm sure I won't want to turn them when the time comes.

Yeah, I'm the same. I use Starbond medium thick for tubes and haven't had any trouble. I've turned at least 100 pens this year using Starbond.

The only time I run into issues is when a tool isn't sharp enough or I get too heavy handed. User error rather than product.

The times I've used 5 minute epoxy, I get the Harbor Freight stuff and let it set up for an hour or the next day before turning.

 

[calabrese55]

heat it up while you are mixing it it will set a lot quicker try it .
calabrese55

 

[egnald]

Being very impatient myself, I certainly understand where you are coming from. I have used 1 Minute Epoxy from Loctite before, but I didn't like how fast it started to gel up - just not enough stirring and working time to suit me. That and I could only find it in those dual syringe - single plunger type of containers. So, I went back to 5-Minute and I use whatever brand that our local Menards store carries. At the moment that would be Loctite. (I think it is more odiferous than some of the other brands I have used, especially if I add a drop of acrylic paint - very stinky). I usually consider turning mine after about 30-45 minutes.

Dave

 

[Curly]

I've always considered the "5 minutes" to be the working time after mixing before it begins to set, the point where it isn't soft and runny and can be moved. The full cure time is usually on the package and it is always a lot longer than 5 minutes. Get up earlier and glue your tubes. Go back into the house and have your shower, morning coffee, breakfast and then return to the shop to turn the barrels. It's just time management.

 

[Woodchipper]

Had a rod building kit that 5 minute epoxy. Mixed it up and almost didn't get the grip on the blank. Moved to Duco Two Ton Epoxy which has a work time of about 30 minutes. I only use 5 minute epoxy for a couple of inserts for aluminum arrows.

 

[Humongous]

Courtesy of Wessex Resins.

POT LIFE

Pot life is the amount of time a given mass of mixed resin/hardener will remain in the liquid state at a specific temperature. It allows you to compare the relative rate of reaction or cure speed of various resin/hardener combinations.

To allow you to compare PRO-SET epoxies easily, we determine the pot life of each resin/hardener combination based on either a 100 or 500 g mixture stored in a standardized container, at a consistent temperature. Pot life is not intended to directly correlate to actual working life or assembly time. Rather it indicates the potential working time of the resin/hardener combination compared to other combinations. An epoxy mixture's mass and temperature during the manufacturing or assembly process contribute to its actual working life.

As you can see there are many variables to the actual working time, Temperature, Mix Ratio, etc. 5 Min is the pot life under an "ideal" or standard set of conditions for that supplier.

 

[jrista]

Is there a 5 minute epoxy that really sets in 5 minutes? I've tried BSI, Loctite, and JB Weld brands, and they all take a lot longer than 5 minutes. It can be a good 20-30 minutes to be workable. I know I'm impatient, but it's frustrating to me. When it's hot, and I can't work in the garage in the afternoons, I work on pens a lot in the mornings before work.

Just curious what you consider "set"?

Different manufacturers can describe this slightly differently, but, the set time is the time it takes for the epoxy parts to actually start reacting, which is when they start cross-linking and forming a solid bond. That said...the set time is NOT usually when the epoxy is actually, truly "hard" as I think most people think.

It really takes the full cure time, for the epoxy to become fully hardened, properly crosslinked, and actually bonded. Depending on the epoxy, it can be in a varyingly soft-ish state for a good while (good deal longer than the "working time", such as "5 minutes") before it really starts to harden. Then for most of the epoxies I use (which includes Gorilla, Loctite, JB Weld and T-88...the latter of which is my go-to unless I need something clear, in which case JB), the epoxy will be in an intermediate state, which can feel rubbery and flexible, for a good while before truly hardening.

For a good bond, you actually don't want the epoxy to go full hard too quickly. Epoxies are supposed to create these cross-linked polymers, which is where their strength comes from. If an epoxy actually hardened in just 5 minutes, it is doubtful it would have been able to fully cross-link. You would generally feel this, and it wouldn't feel truly hard, even if it wasn't particularly flexible. Good crosslinking requires some time (although not necessarily 24 hours) and the right amount of heat. Warming the parts being glued, then warming the assembly, can help speed up the curing process and improve cross-linking. You don't want to over-heat, as that can cause bubbling, but warming can help speed up the actual curing process to a full hardnes.

The T-88 I use at 70F (room temp) has a working time of 45 minutes, set time of 6-8 hours, and full cure time of 24 hours. Warmed to about 150F, though, it will take 30 minutes to set and reach full cure in 2 hours. (Can be a bit tricky, right around 150F it does start to bubble, so you need to keep it cooler than that, but close, for that fastest set and cure time.)

Anyway. There are, I guess, three key times for any epoxy:

Working Time - The time you have to use and work with the epoxy before it begins to set and continued "working" may weaken the eventual bond
Set Time - The time it takes before the chemical reaction really "sets in" and starts the process of hardening
Cure Time - The time it takes for the cross-linking process to complete and produce a fully hardened bond

 

[GaryMGg]

Jon
Could you please explain your warming process?

 

[qquake]

2 ways around that. Add more hardener or add heat.

It's 80 degrees in my house. How hot does it need to be?

 

[qquake]

Maybe 4 minute epoxy? https://www.totalboat.com/products/4-minute-epoxy-fast-setting-clear-adhesive

Not worth the price for one minute.

 

[qquake]

I use JB Weld and let it set up an hour or so before handling/turning, and sometimes overnight. Could you prep your pen the day before?

If by "prep" you mean cutting and drilling, then not really. It can be 105 or more in my garage the day before. I suppose I could prep it the morning before, but I'd prefer to do it all in the same morning. Maybe it's not possible, but it seems like the epoxy used to set faster.

 

[qquake]

This is why I just use CA glue. If it happens to be cool enough to do something in the shop or all a sudden I decide I need to turn a pen the set up time for epoxy just doesn't work. With CA by the time I set up the lathe, and get the needed supplies ready it's time to square the blank and turn it. So far in over 150 pens or other tubes kits I have only lost 2 blanks, one due to carelessness not watching were I put the cutter after a tool rest adjustment and the other was Black Palm where I knew I needed to stop and apply some CA to the blank but just one more pass with the tool got me.
I have not had issues with CA not securely attaching the tube to the wood. I guess if I ever do then I might have to prior plan and glue some blanks up ahead of time but I'm sure I won't want to turn them when the time comes.

You know, I tried CA back in 1999 when I started turning pens. I had a tube get stuck halfway in a blank. It wouldn't come loose no matter what I tried. I haven't used CA for gluing tubes since. Besides, I color the epoxy for translucent acrylic blanks. Can't do that with CA.

 

[qquake]

heat it up while you are mixing it it will set a lot quicker try it .
calabrese55

Heat it up how? It's 80 degrees in my house.

 

[qquake]

I've always considered the "5 minutes" to be the working time after mixing before it begins to set, the point where it isn't soft and runny and can be moved. The full cure time is usually on the package and it is always a lot longer than 5 minutes. Get up earlier and glue your tubes. Go back into the house and have your shower, morning coffee, breakfast and then return to the shop to turn the barrels. It's just time management.

Maybe I'm thinking about it wrong. I'm thinking about the 5 minutes as the cure time, but maybe it is the working time. I already get up at 3:30 and eat breakfast at work.

 

[qquake]

Being very impatient myself, I certainly understand where you are coming from. I have used 1 Minute Epoxy from Loctite before, but I didn't like how fast it started to gel up - just not enough stirring and working time to suit me. That and I could only find it in those dual syringe - single plunger type of containers. So, I went back to 5-Minute and I use whatever brand that our local Menards store carries. At the moment that would be Loctite. (I think it is more odiferous than some of the other brands I have used, especially if I add a drop of acrylic paint - very stinky). I usually consider turning mine after about 30-45 minutes.

Dave

Sometimes it's workable after 30 minutes, but not very often. I've worked it when it's still a little soft with no problems. But lately, it seems like it takes a lot longer. Maybe it's the way I'm mixing it, I don't know.

 

[calabrese55]

You might revisit you mixing process. I have used various brands of 5 minute epoxy for years building radio controlled airplanes. It is ready to go shortly after a 5 minute process especially when heated with an ordinary hair dryer.
calabrese55

 

[leehljp]

Generally it is the working time. I have tried numerous 5 minute epoxies on two continents and accept that I have about 5 minutes of working time, but it takes longer to cure - to be able to use effectively 20 minutes to an hour. That has never been a personal problem as I am constantly working on a 2nd or 3rd project while the epoxy is curing.

 

[jrista]

Jon
Could you please explain your warming process?

I just use a cheap toaster oven at the lower setting.

 

[jrista]

It's 80 degrees in my house. How hot does it need to be?

I don't know all the various optimal curing temps for every epoxy. You should be able to look up data sheets for that.

The T-88 is designed to set in 30 minutes and cure in 2 hours at ~150 degrees. I've tried JB Weld at that temp, and it didn't go well. The T-88 is also explicitly designed to work in a pretty wide range of temps. I think most epoxies work in a narrower range of temps, and usually below some cold temp they will just not cure. The T-88, though, has this yellowish opaque color, so if you need something clear or tinted, you may want another epoxy for that. I have had pretty good luck mixing just regular old painters pigments with JB Weld.

If you have 105 out in the garage, you could always work indoors, then when you are done getting all the tubes in place and whatever else, you could just transfer it out to the garage and let it cure out there. You wouldn't have to be out there, but 105 should be good enough to speed up the process and improve crosslinking.

 

[jttheclockman]

It's 80 degrees in my house. How hot does it need to be?

Alot hotter than that. Stick in a toaster oven. Why can't you prep the blanks that you work on the day before. I think you need to change your pen turning habits but who am I. I am retired and glad for it. No 3:30 AM for me. There is no epoxy that is going to cure in 5 min. 5minmeans work time and that depends on temp in work area and also how well it was mixed. Switch to med CA and use accelerator on the ends. the tube won't pull out at least. I am so glad I do not have a timetable to work under any more. Good luck.

 

[qquake]

Alot hotter than that. Stick in a toaster oven. Why can't you prep the blanks that you work on the day before. I think you need to change your pen turning habits but who am I. I am retired and glad for it. No 3:30 AM for me. There is no epoxy that is going to cure in 5 min. 5minmeans work time and that depends on temp in work area and also how well it was mixed. Switch to med CA and use accelerator on the ends. the tube won't pull out at least. I am so glad I do not have a timetable to work under any more. Good luck.

I don't have a toaster oven. I wonder how low my oven will go.

 

[jttheclockman]

I don't have a toaster oven. I wonder how low my oven will go.

can't help you sorry. I gave my opinions and that is all I have. Good luck.

 

[jrista]

I don't have a toaster oven. I wonder how low my oven will go.

I picked up a Black and Decker basic one, which does enough for my needs with woodworking, for $22 on sale. They are super cheap, and quite handy. I picked one up to help me warm my epoxy, as well as cure stabilized blanks, and probably eventually to help me dry small pieces of wood.

 

[calabrese55]

Let me start a fire here on this epoxy cure issue. Cure time is not a definitive measure for functionability. Like concrete the "cure " time is not the issue. The concrete in the Hoover dam took over 10 years to cure. Polyurethane cures in about 6 weeks . Like concrete and polyurethane epoxy cures when the chemical reaction is no longer active. Five minute epoxy is useable , functionable in a very short time and can be accelerated by even marginal warming.

How hot do you have to get it...not very a typical hair dryer on low or medium heat is more than enough. Test the addition of heat this way.
When the two parts are first mixed the viscosity is more like toothpaste than water. The mixing process adds heat and the onset of the chemical reaction adds heat and the mix gets a little bit thinner.
Adding heat say with a hair dryer will thin the mix dramatically and the air flow from the hair dryer will definitely cause it to flow away. When this happens IT IS PLENTY WARM and the set time will be happening soon and so will the functionable time but the cure time will take much longer.
I have used gallons of 5 minute epoxy two little tubes at a time. When thoroughly mixed and at the correct temperature it really is pretty much 5 minute epoxy like the commercial hype suggests.
calabrese55

 

[Roy Nielsen]

I don't have a toaster oven. I wonder how low my oven will go.

You can get often find used ones for a few bucks at a thrift store.

 

[jrista]

Let me start a fire here on this epoxy cure issue. Cure time is not a definitive measure for functionability. Like concrete the "cure " time is not the issue. The concrete in the Hoover dam took over 10 years to cure. Polyurethane cures in about 6 weeks . Like concrete and polyurethane epoxy cures when the chemical reaction is no longer active. Five minute epoxy is useable , functionable in a very short time and can be accelerated by even marginal warming.

How hot do you have to get it...not very a typical hair dryer on low or medium heat is more than enough. Test the addition of heat this way.
When the two parts are first mixed the viscosity is more like toothpaste than water. The mixing process adds heat and the onset of the chemical reaction adds heat and the mix gets a little bit thinner.
Adding heat say with a hair dryer will thin the mix dramatically and the air flow from the hair dryer will definitely cause it to flow away. When this happens IT IS PLENTY WARM and the set time will be happening soon and so will the functionable time but the cure time will take much longer.
I have used gallons of 5 minute epoxy two little tubes at a time. When thoroughly mixed and at the correct temperature it really is pretty much 5 minute epoxy like the commercial hype suggests.
calabrese55

The specified cure time in most epoxy's data sheets, is the time it takes to reach "functional strength" or the bond strength they actually document. Before you reach the cure time, the bond will not have reached that level of strength, to one degree or another. With T-88, they very clearly state that heat speeds up both set and cure times, so I don't believe that heat (however you apply it) SLOWS cure time...that would be at odds with their specifications in their own data sheet.

Whether the epoxy has reached its maximum possible hardness or not by the time you reach the cure time, I don't know. But usually, as I've learned, cure time IS the time to functional bond strength.

 

[calabrese55]

The specified cure time in most epoxy's data sheets, is the time it takes to reach "functional strength" or the bond strength they actually document. Before you reach the cure time, the bond will not have reached that level of strength, to one degree or another. With T-88, they very clearly state that heat speeds up both set and cure times, so I don't believe that heat (however you apply it) SLOWS cure time...that would be at odds with their specifications in their own data sheet.

Whether the epoxy has reached its maximum possible hardness or not by the time you reach the cure time, I don't know. But usually, as I've learned, cure time IS the time to functional bond strength.

I think I was not maybe completely clear I said Adding heat say with a hair dryer will thin the mix dramatically and the air flow from the hair dryer will definitely cause it to flow away. When this happens IT IS PLENTY WARM and the set time will be happening soon.
I literally have used gobs and gobs of 5 minute epoxy for better than 50 years. Heating it accelerates everything. When it gets watery thin from the heat of even a small hair blow dryer you will not have much time before it gets super rubbery and impossible to add to any joint. Shortly there after you will be mixing up another batch. The only thing that will slow cure time is an uneven mix when the hardener is the short supply component.
calabrese55

 

[jrista]

I think I was not maybe completely clear I said Adding heat say with a hair dryer will thin the mix dramatically and the air flow from the hair dryer will definitely cause it to flow away. When this happens IT IS PLENTY WARM and the set time will be happening soon.
I literally have used gobs and gobs of 5 minute epoxy for better than 50 years. Heating it accelerates everything. When it gets watery thin from the heat of even a small hair blow dryer you will not have much time before it gets super rubbery and impossible to add to any joint. Shortly there after you will be mixing up another batch. The only thing that will slow cure time is an uneven mix when the hardener is the short supply component.
calabrese55

Do you mean, heat the epoxy before applying to the joint?

To be clear, I heat AFTER gluing up the parts. So, tube glued into blank, or segments glued to each other. THEN I heat that glued up assembly...

I have never tried heating the epoxy before actually applying it. As you stated, I imagine that would generally result in a wasted batch. IIUC, the chemical reaction causes some flow in the epoxy naturally...and when the epoxy has a lower viscosity, that natural flow increases, improving the amount of cross-linking you get.

 

[leehljp]

Do you mean, heat the epoxy before applying to the joint?

To be clear, I heat AFTER gluing up the parts. So, tube glued into blank, or segments glued to each other. THEN I heat that glued up assembly...

I have never tried heating the epoxy before actually applying it. As you stated, I imagine that would generally result in a wasted batch. IIUC, the chemical reaction causes some flow in the epoxy naturally...and when the epoxy has a lower viscosity, that natural flow increases, improving the amount of cross-linking you get.

In winter or cool areas, heat or warm both parts before mixing, if one wants a quicker set. It is not uncommon to find heated adhesive and paint bins in cooler shops. An inexpensive setup can use an incandescent bulb under a shelf in the bin.

 

[jrista]

In winter or cool areas, heat or warm both parts before mixing, if one wants a quicker set. It is not uncommon to find heated adhesive and paint bins in cooler shops. An inexpensive setup can use an incandescent bulb under a shelf in the bin.

I actually do heat the parts, and then after glue-up and clamping, II'll stick em in the toaster oven for a little bit. I've never tried heating the glue itself before application before, though...

 

[Muddydogs]

Man you guys sure went down the rabbit hole with epoxy. Way more info then I ever wanted to know.

 

[jrista]

Man you guys sure went down the rabbit hole with epoxy. Way more info then I ever wanted to know.

CA can work great for some things. If you are just gluing tubes into holes, its fine.

For me, the switch to epoxy came with my foray into segmenting. The CA, particularly with certain materials, just did not hold up. Resin to metal, wood to metal, in particular, just didn't hold with CA (and I went through a lot of different kinds of CA glue!) Seems ok, resists breaking with hand force...but once you put a turning tool to it...usually the bond failed.

That's when I switched fully to epoxy. Then, at that, eventually entirely to T-88, which just has a much better bond between all materials when segmenting. I have had some bond failures with epoxy too, which...is what made me go down the rabbit hole.

 

[qquake]

I think I'm looking at this wrong. 5 minutes is the working time, not the cure time. Looks like I need heat to speed up the cure time.

 

[qquake]

Walmart has a toaster oven for $20. But if I decide to go that way, I'll probably look in a thrift store.

Robot or human?

 

[leehljp]

I think I'm looking at this wrong. 5 minutes is the working time, not the cure time. Looks like I need heat to speed up the cure time.

Jim, I am a little surprised at this. Just about every Epoxy type I have ever purchased going back 40 - 50 years states in the instructions that the CURE time is xxx, which is longer than the set time. I say that, because I have always check a new brand (new to me) as to the cure time. It should be on the instructions of each.

As to a toaster oven, every person will use it differently and every person's milage might vary; That said, don't get it too hot. The cheaper toasters might not have an actual temp that will be below 175°, which can destroy epoxy's strength. It could be just me, but I have ruined a few glue-ups by heating them a little too high.

I would like to see others experience in this area of overheating epoxy, and at what temp does that occur.

Jon Rista posted this: https://www.penturners.org/threads/t88-a-useful-paper.178952/#post-2197341

the paper has this in it:

Lap-Shear Strength vs. Temperature (Aluminum Tensile Shear)	67°F: 2,500 psi, 75°F: 2,000 psi, 150°F: 1,300 psi, 180°F: 1,000 psi
Heat Deflection Temperature	119°F (49°C)
Maximum Service Temperature	160°F (71°C)
Minimum Application Temperature	35°F (2°C)
Gel Time @ 77°F (25°C)	60 Minutes (100g mixture)

NOTICE the Temp variance in the Lap Shear Strength vx Temperature. Shear strength decreases with temp increase. Max service item is 160°. I mention this because an inexpensive toaster oven does not regulate the temp very well and the dial temp setting is an estimate at best.