Pops Knife Shop
- Thread starter Gliden07
- Start date
EdCaffreyMS
"The Montana Bladesmith"
Personally, I'm not a fan of any "quick set" epoxy (otherwise known as "15 min"). Most everything we do in knifemaking is a "give-n-take" type situation. In this case the con is that "quick set" epoxy is generally NOT waterproof, and in general, the quicker the "set time", the weaker the bond, and the less the "hold life". (the amount of time before the bond starts to physically break down).
Some might consider it "splitting hairs", but suffice to say that I learned the hard way not to use such adhesives.
Some might consider it "splitting hairs", but suffice to say that I learned the hard way not to use such adhesives.
Gliden07
Well-Known Member
Thanks Ed!! I know you like the Acura-Glass from Brownells. I am going to try that one of these times. I really was trying to fill out an order and decided to try it!
EdCaffreyMS
"The Montana Bladesmith"
I'm sure there are many out there who use this type of epoxy and love it...... my guess is that they've just not had the same experiences as I.
Smallshop
KNIFE MAKER
I consider someone who has been making knives 30 years or so an invaluable resource as to the lifespan of different epoxies. especially since some of them have a planned obsolescence. That and the fact that I have rifles that my dad Acra-glassed 50 yrs ago that have withstood many years of recoil.
Gliden07
Well-Known Member
It definitely is good stuff! I've done a couple of rifles with it. Since I started doing this I never considered using it for making knives until Ed suggested it.
EdCaffreyMS
"The Montana Bladesmith"
Based on my experiences and research, pretty much all of the commonly available 2-part epoxies have "planned obsolescence", it's just something that it's not advertised or talked about unless you dig deep, and get lucky enough to actually speak with the folks who develop/engineer it.
In my early career I was using Devcon 5 min, epoxy. About 5-6 years later I had a rash of knives that were returned due to "loose" handles. There were both full and hidden tang knives. When I was repairing them, I noticed that much of the epoxy had a fractured/crystallized look, and some spots in it was more or less powder. After a lot of research and a lot of phone calls, to a number of different companies' "tech support" sections, I finally got transferred to a Chemist at Dow chemical.
He was very helpful, and once I'd explained my story, he chuckled and told me..... "There's nothing out of the ordinary.... the epoxy has simply reached the end of it's hold life." He went on to tell me.... "My job depends on selling epoxy, I'm never going to engineer an adhesive that lasts forever." Of course I was shocked, because in my mind epoxy was suppose to last "forever". But I suppose if you looked at from the perspective of job security/epoxy sales, it's not so strange.
We spoke for an extended period on the phone, and during the conversation he told me..... The vast majority of 2-part epoxies that are commercially sold are chemically engineered to start breaking down at approx. the 5-7 year point after they've been mixed. The individual I spoke with was very forth coming, and explained that most people don't know/understand "Shelf Life" and "Hold Life", or simply ignore it all together. (at the time, I was one of those) Both of these are engineered into the given product. "Shelf Life" simply means the length of time each part remains compatible for successful mixing, and optimum bonding/hold life. "Hold Life" is the length of time AFTER curing, before the bond/product starts to chemically break down.
His advice to me was to use whatever product advertised the longest shelf life, and the longest hold life, that would work for my application. That's the reason I choose to use Acraglas. It is advertised as having a 10 year shelf life, and a guaranteed hold life of 50 years. Last time I checked, the next in line was West Systems Marine epoxy, with a 5 year shelf life, and a 30 year hold life. I suspect that the reason you haven't/don't find this information publicly available , is because it's more or less a "trade secret", at least that's the inclination I got from the conversation.
When you take the time to consider it, planned obsolescence isn't so hard to believe. Within the last few decades it's become pretty much standard throughout the manufacturing/production world. Everything from the car you drive to your washer and dryer, to the "best if used by dates" on the food items you purchase at the grocery store.
I certainly don't have any empirical data to verify/support all of that, beyond my own experiences, and the conversation itself, but I feel that it pointed me in the right direction when it comes to adhesives for knives. All I can say is that since changing the adhesives I use to those with the longest shelf and hold lives, I've had no issues.
In my early career I was using Devcon 5 min, epoxy. About 5-6 years later I had a rash of knives that were returned due to "loose" handles. There were both full and hidden tang knives. When I was repairing them, I noticed that much of the epoxy had a fractured/crystallized look, and some spots in it was more or less powder. After a lot of research and a lot of phone calls, to a number of different companies' "tech support" sections, I finally got transferred to a Chemist at Dow chemical.
He was very helpful, and once I'd explained my story, he chuckled and told me..... "There's nothing out of the ordinary.... the epoxy has simply reached the end of it's hold life." He went on to tell me.... "My job depends on selling epoxy, I'm never going to engineer an adhesive that lasts forever." Of course I was shocked, because in my mind epoxy was suppose to last "forever". But I suppose if you looked at from the perspective of job security/epoxy sales, it's not so strange.
We spoke for an extended period on the phone, and during the conversation he told me..... The vast majority of 2-part epoxies that are commercially sold are chemically engineered to start breaking down at approx. the 5-7 year point after they've been mixed. The individual I spoke with was very forth coming, and explained that most people don't know/understand "Shelf Life" and "Hold Life", or simply ignore it all together. (at the time, I was one of those) Both of these are engineered into the given product. "Shelf Life" simply means the length of time each part remains compatible for successful mixing, and optimum bonding/hold life. "Hold Life" is the length of time AFTER curing, before the bond/product starts to chemically break down.
His advice to me was to use whatever product advertised the longest shelf life, and the longest hold life, that would work for my application. That's the reason I choose to use Acraglas. It is advertised as having a 10 year shelf life, and a guaranteed hold life of 50 years. Last time I checked, the next in line was West Systems Marine epoxy, with a 5 year shelf life, and a 30 year hold life. I suspect that the reason you haven't/don't find this information publicly available , is because it's more or less a "trade secret", at least that's the inclination I got from the conversation.
When you take the time to consider it, planned obsolescence isn't so hard to believe. Within the last few decades it's become pretty much standard throughout the manufacturing/production world. Everything from the car you drive to your washer and dryer, to the "best if used by dates" on the food items you purchase at the grocery store.
I certainly don't have any empirical data to verify/support all of that, beyond my own experiences, and the conversation itself, but I feel that it pointed me in the right direction when it comes to adhesives for knives. All I can say is that since changing the adhesives I use to those with the longest shelf and hold lives, I've had no issues.
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Gliden07
Well-Known Member
Quick version! Everyone that makes knives has their favorite products. One of the "HOT" Items is how to attach the scales. Many including myself use various epoxies some others use other products one of which is Acra-Glass by Brownells, it's bedding material for Rifles. Ed doesn't like epoxy and has his reasons why (good ones at that). Ed is very experienced and is very respected on thus forum. So the debate continues!
Ooops, Ed posted his response while I was writing this up and I didn't see his thread until after I'd posted. As I said before, Ed is one of the nicest guys around and I've learned MUCH from Ed. Met and talked with Ed a couple of times at Blade and a nicer guy couldn't be found. We just happen to disagree on the topic of epoxy bond life. Ed, I hope we can still be friends.
Here is a good thread discussing epoxy life and read thru the total thread for good discussion of "bond life" from an actual epoxy company. There are also comments from 3 different epoxy companies that NO real 2 part epoxies will have any "component of epxoy are designed to slowly, chemically break down at approx. the 5-7 year point."
https://knifedogs.com/threads/bladebond-epoxy-in-stock-and-ready-to-ship.41296/
Here's the thread where I posted responses from two more epoxy companies, West Systems and Raka about "bond life" is almost forever.
https://knifedogs.com/threads/which-epoxy-do-you-use-and-why.40604/
Ken H>
Here is a good thread discussing epoxy life and read thru the total thread for good discussion of "bond life" from an actual epoxy company. There are also comments from 3 different epoxy companies that NO real 2 part epoxies will have any "component of epxoy are designed to slowly, chemically break down at approx. the 5-7 year point."
https://knifedogs.com/threads/bladebond-epoxy-in-stock-and-ready-to-ship.41296/
Here's the thread where I posted responses from two more epoxy companies, West Systems and Raka about "bond life" is almost forever.
https://knifedogs.com/threads/which-epoxy-do-you-use-and-why.40604/
Ken H>
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Smallshop
KNIFE MAKER
I may have been overstating a perspective I read from a more experienced maker. So, without having done a bunch of personal research and the possibility that I am not completely understanding the nuances of what I have read on other posts, please accept my apology for speaking without reading up on this. I'll do a bit more study before weighing in on this....
Darrin Sanders
Moderator
I'm sure most of you are already aware of it but Matt is a good guy and a talented maker. He always seeks the truth in this sea of mis-information we call knifemaking and I'm sure that was his only reason for asking.
Glad to see ya here Matt and I hope to see you here more often.
Glad to see ya here Matt and I hope to see you here more often.
Smallshop
KNIFE MAKER
Not at all Matt!
I just realized that I was making a bold statement that maybe wasn't in the spirit of what had been shared with me. And I had done no studying to "own" my opinion. I usually do...I do know my ol' man thought Accraglass was the cats meow...lol.