Bad glue

[mick]

How do you tell when your 2 part epoxy isn't any good?
I'll tell you how. It's when you've got a dozen slimline blanks prepped to go and you blow out the first three you put on the lathe. Tubes were roughed up but none of the glue was stuck to them. Now I've got 9 more sitting here and I swear they're talking to me daring me try and turn one if them. I can hear them going,"me me me, pick me!" Is it just me or can you hear then taunting me?

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[Dieseldoc]

For those nine left. Plug the tube and apply thin CA around the end of blank on both ends. This will help keeping them together.
Good luck, hope this help save the blanks.

 

[WriteON]

I have had blanks where the tube broke loose and could finish them. Sharp tool, high speed, light passes.

 

[jttheclockman]

What type glue was it?? I find it hard to believe epoxy glue went bad. It goes bad if it hardens and usually the resin will harden. The hardner will thicken but a little heat can make that flow again. I have epoxy glue over 3 years old and use it. Store in cool dry place. Keep cap tightly on and store out of sunlight. 5 min epoxy is not that good of a glue and will degrade fastest.

Maybe some reading for you as this has come up before.

Does Epoxy go BAD?

Folks: I have always used a 5 min 2 part epoxy with no problems. Lately, I have had several blanks come loose from the tube. Epoxy I am using is six moths old (maybe 8). Does anyone here know if this glue has limited shelf life? I know poly glues certainly do. Thanks OSCAR

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[dogcatcher]

On another forum we had a glue expert, as he explained it, all glues have a certain shelf life, described as :best used before this date. Usually not marked in containers as such, but there is a code on some brands. Shelf life can also be shortened by exposure to heat and cold. This guy worked for a major glue manufacturer and was their troubleshooter. In his words, fresh glue or throw it out. Stores fail to rotate stock, so find a source that sells a lot of glue so you have a better chance of getting fresh not out dated glue.

 

[mick]

What type glue was it?? I find it hard to believe epoxy glue went bad. It goes bad if it hardens and usually the resin will harden. The hardner will thicken but a little heat can make that flow again. I have epoxy glue over 3 years old and use it. Store in cool dry place. Keep cap tightly on and store out of sunlight. 5 min epoxy is not that good of a glue and will degrade fastest.

Maybe some reading for you as this has come up before.

Does Epoxy go BAD?

Folks: I have always used a 5 min 2 part epoxy with no problems. Lately, I have had several blanks come loose from the tube. Epoxy I am using is six moths old (maybe 8). Does anyone here know if this glue has limited shelf life? I know poly glues certainly do. Thanks OSCAR

www.penturners.org

John, it's Bob Smith Industries 15 minute. It's probably 6-7 yrs but I had never opened it until 6 months ago when I glued these up.
It is extremely thick, both parts but mixed together well. Excess glue on the ends of the blank was very hard, nothing noticeably wrong with it yet all three times I had the slightest catch and it ripped the wood off. I've not given up on the last 9 I can still hear them whispering behind my back. [emoji2959]

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[wolf creek knives]

To Johns point, I use system 3 as I think John does too. I've had my part B for well over ten years, probably closer to 15, and never had a problem with it. I'm thinking it's probably the brand? You might want to switch.

Also, what species of wood were you turning? I know Mango is a big pain and I don't turn it anymore because of the same problem you refer to. Just tried some and had blow out after blow out. Big time blow outs too, not just a small piece, I'm talking 3/4 of the blank.

 

[jttheclockman]

John, it's Bob Smith Industries 15 minute. It's probably 6-7 yrs but I had never opened it until 6 months ago when I glued these up.
It is extremely thick, both parts but mixed together well. Excess glue on the ends of the blank was very hard, nothing noticeably wrong with it yet all three times I had the slightest catch and it ripped the wood off. I've not given up on the last 9 I can still hear them whispering behind my back. [emoji2959]

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Well I can not speak specifically about the glue because there are so many glues on the market and not all are made for what we do gluing wood to metal with a gap filling property and staying flexible. It may have become unstable. It maybe the tubes were not sanded to give some tooth. It maybe that not enough glue was left on the tube. This is why we walk a fine line when drilling for tubes. If using epoxy you do want some space because that is where epoxy glues shine. If tubes are so tight it just scraps the glue off and no adhesion. I stand behind the epoxy glue I use and that is system3 t88 glue. Never had any failures and as I said I have bottles that were opened and are over 3 years old. I have not found a material that they are not comparable to yet. Open grain woods to woods always use Titebond 2 or 3. If exotic or tight grain I go to epoxy. Metal to wood epoxy always, or metal to metal either epoxy or JB Weld. I will use PL9000 for high construction adhesive and or Liquid nails. Rarely use CA as an adhesive but to get a quick hold but not for strength. Tried and true methods over many years and I do not experiment because too many factors go into tests and lists. Why fix it if it is not broken. Same with applying CA as a finish. So many methods but found what works for me and will never ever deviate because it works and I can prove it.

Other than that can not give a reason for failure then. But good luck. By the way when they say 5 min or 15 minutes you better believe it and prepare the work before hand.

 

[KenB259]

I have used BSI in the past, still have some. I switched to system 3, just because of the rave reviews of it here. I don't have any complaints about either of them.


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[TonyL]

I use Mercury and BSI epoxy (and Sys 3 etc..), but mostly BSI. I would mix a small batch of whatever you are using (maybe the size of a dime of A and B) on a any surface similar to a pen blank), mix well and see if it cures (becomes rock-solid) after the time indicated in epoxy instructions.
I just experienced a failure..but it was probably my fault. I glued a painted tube into a painted acrylic barrel. I didn't wait 24 hours for the paint to cure. I turned the blank, but the tube had shifted. I also suspect that the shear strength of the volume of glue (it's just a thin layer) was not enough to overcome the force of the chisel on the rotating (2500 rpms) blank. Despite sharp chisels and light cuts, my centers are holding the ends of the brass tube very tightly while the chisel is applying force against the blank. I didn't have a blow out, but I think (and I am no scientist), that had the glue paint been fully cured, the epoxy would have had a more "solid" surface to bond to. Every 50 to 100 blanks, I may experience this for one reason or another. I would simply check that the test sample of epoxy cures so that you can at least eliminate the possibility of the glue going bad. The folks above know a lot more about these things than I do. I am just relating my hunches and experiences.

 

[JimB]

John, it's Bob Smith Industries 15 minute. It's probably 6-7 yrs but I had never opened it until 6 months ago when I glued these up.
It is extremely thick, both parts but mixed together well. Excess glue on the ends of the blank was very hard, nothing noticeably wrong with it yet all three times I had the slightest catch and it ripped the wood off. I've not given up on the last 9 I can still hear them whispering behind my back. [emoji2959]

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you say three blanks and three catches? That sounds more like a turning technique problem than a glue problem to me. If you don't have good glue coverage a small catch will sepárate the blank from the tube. Considering a catch will chip a piece of wood off a larger piece of wood it isn't surprising a catch will break the blank off the tube.

 

[Dehn0045]

One time I glued up a blank after mixing a dab of Part 1 with another dab of Part 1. Needless to say 2-part epoxy really does require both parts... Luckily for me it was so obvious that I didn't even try turning it and I was able to re-glue without blowing it up.

 

[Gary Beasley]

From the way you describe it the epoxy didnt bond to the wood. Sometimes if I think the glue will have trouble sticking to the wood I will soak the inside of the hole with thin CA then after that cures run the drill back through to clear it. This give a harder less permeable surface the glue wont wick into and disappear, and seems to bond better.

 

[mick]

you say three blanks and three catches? That sounds more like a turning technique problem than a glue problem to me. If you don't have good glue coverage a small catch will sepárate the blank from the tube. Considering a catch will chip a piece of wood off a larger piece of wood it isn't surprising a catch will break the blank off the tube.

Oh I agree with the poor technique, I'm trying to get back in the groove after too long away from the lathe.

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[mick]

One time I glued up a blank after mixing a dab of Part 1 with another dab of Part 1. Needless to say 2-part epoxy really does require both parts... Luckily for me it was so obvious that I didn't even try turning it and I was able to re-glue without blowing it up.

I've never done that! Said no one ever.

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[mick]

From the way you describe it the epoxy didnt bond to the wood. Sometimes if I think the glue will have trouble sticking to the wood I will soak the inside of the hole with thin CA then after that cures run the drill back through to clear it. This give a harder less permeable surface the glue wont wick into and disappear, and seems to bond better.

I've done that and never had any problems with those blanks. If it wasn't so time consuming I'd do it more often but like you if the material is suspect I'll use this method.

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