2-Part Epoxy Failing?

[StevenGuthmiller]

40 minutes ago, Ferbz said:

So much info to sift through here! Thank you guys 🙏 Mixing surfaces...different quality brands...different hardening times......🤪 I should mention that for the most part, my completed builds always sit in a display cabinet and hardly never get moved. I rarely take them out except for when I need to take pics and I've not packed them to transport them to a show in many, MANY years until recently. Also, I've recently moved out of state so naturally they had to get packed and transported. This may have caused the suspension parts I have on the two builds I mentioned to come loose. My builds span about 30+yrs and I'm grateful they've pretty much survived all the travelling they've had to do lately.

Well, if you’re models have been jostled around considerably as of late, that’s a lot more likely to be the cause of parts coming off than anything that was done incorrectly with the gluing process or the materials themselves.

I seem to recall you saying that the failures were mainly suspension failures, which makes absolute sense considering that not only has the weight of the model been putting stress on a few spindly plastic parts for decades, but add on top of that a lot of bouncing around, and yeah, there are very likely going to be some failures regardless of the materials or processes used.

That’s just common sense.

 

 

 

Steve

[Pierre Rivard]

If a part ever falls off one of my models 5 or 20 years from now, I'll glue it back on... and keep it quiet. Less stress that way... 🤫

[Ace-Garageguy]

2 minutes ago, Pierre Rivard said:

If a part ever falls off one of my models 5 or 20 years from now, I'll glue it back on... and keep it quiet. Less stress that way... 🤫

Odds are I won't be around to know...and if I am, I'll do the adult thing and throw it against the wall.

[peteski]

3 hours ago, Ferbz said:

So much info to sift through here! Thank you guys 🙏 Mixing surfaces...different quality brands...different hardening times.....

This is typical when certain type of questions or requests for assistance are posted in an online forum.

[StevenGuthmiller]

3 hours ago, peteski said:

This is typical when certain type of questions or requests for assistance are posted in an online forum.

Ha! 
Try asking a question on one of the Facebook modeling groups!

You might get a little disagreement here, but at least the information you do get won’t be a mixture of a couple dozen useful nuggets wrapped up among 150 completely idiotic fantasies! 😁

Here, we don’t all agree on everything, but we’re not morons! 😉

 

 

Steve

[Ferbz]

7 hours ago, StevenGuthmiller said:

Well, if you’re models have been jostled around considerably as of late, that’s a lot more likely to be the cause of parts coming off than anything that was done incorrectly with the gluing process or the materials themselves.

I seem to recall you saying that the failures were mainly suspension failures, which makes absolute sense considering that not only has the weight of the model been putting stress on a few spindly plastic parts for decades, but add on top of that a lot of bouncing around, and yeah, there are very likely going to be some failures regardless of the materials or processes used.

That’s just common sense.

 

 

 

Steve

Indeed. Still, I've packed them and moved/transported them in the past without anything coming loose. Maybe it was just a matter of time? Move and pack them enough times and something is bound to happen! 🤪

[StevenGuthmiller]

12 hours ago, Ferbz said:

Indeed. Still, I've packed them and moved/transported them in the past without anything coming loose. Maybe it was just a matter of time? Move and pack them enough times and something is bound to happen! 🤪

Certainly.

The more you bang something around, the more likely it is to come apart on you.

That’s just natural.

In all honesty, that would be my first suspicion of the culprit in your situation rather than an actual problem with glue.

 

 

 

Steve

[Ace-Garageguy]

 

[Ace-Garageguy]

 

[Skip]

I just watched the first JB Weld video Bill recommend about a month ago. I’ve used and been around epoxies in Engineering and prototyping (at Boeing’s Model Shop), where most of the time we used Devcon metalized to epoxy; but when they ran out we used JB Weld  for tooling and prototyping, the tool rooms carried it for that reason.

Biggest takeaway from that video (already knew it) is to roughen up the surfaces to be “glued” together to give the epoxy a tooth to bight into. This video includes recommended grits of sandpaper to give tooth to the surfaces, it’s worth the watch.

[Bugatti Fan]

The video about epoxy adhesives relative strengths was very interesting viewing.

However, for the sort of applications that most of us would be making on mainly static scale models I would guess that the strength of all the different epoxy adhesives shown would be far more than adequate for our needs.

The bond really just comes down to the preparation.  Making sure surfaces to be joined are clean, unpainted and the surface keyed to take the adhesive. An exception to the unpainted rule would be for the placement of small photo etched badges and logos etc. I have used many different brands of epoxy adhesives on my models going back many years including both big name brands and store name brands and never had any problems with either.     Like I said before, 'It's all in the preparation'.

 

Edited February 12 by Bugatti Fan

[Ferbz]

I just thought of a somewhat related question: If/when you have a build that was assembled with epoxy and you want to disassemble it, what's the best way to do that? I've never disassembled an old glue bomb or torn apart a previous build (once I build something, I'll leave it as is, problems and all! 🤪) I have heard of various techniques of soaking builds in water, then freezing it. Does that work on epoxied parts?

[Ace-Garageguy]

22 minutes ago, Ferbz said:

I just thought of a somewhat related question: If/when you have a build that was assembled with epoxy and you want to disassemble it, what's the best way to do that? I've never disassembled an old glue bomb or torn apart a previous build (once I build something, I'll leave it as is, problems and all! 🤪) I have heard of various techniques of soaking builds in water, then freezing it. Does that work on epoxied parts?

Plain and simple...it's going to depend on the specific epoxy used, where and how it's used, and the prep.

There's no one-size-fits-all answer.

[Brian Austin]

A year or two ago I dug out my metal-filled epoxy tubes dating from the early 1990s or so, IIRC.  The epoxy seemed to work OK despite its age.  I made some simple castings.