Howdy all,

I have a bit of a wierd thing happening to one of my models. I was wondering if any of you have had a similar experience.
I have used gap-filling CA glue for many things, including strengthening joins and filling seams. It has always worked like a charm. But this time I've had a rather strange thing happening. I applied the CA glue to the inside of an approx. 90 degree angle join. I then proceeded to sand and file down the outside of that seam (an 'onery' seam) to get it to line up. During this process I sanded down the styrene itself until I literally sanded a hole in the plastic. But because there was the gap-filling CA glue already there behind the join ( I knew I was going to have to sand thru the plastic BTW) the outer surface was still intact.
Now, here's where it get's a little weird.
For weeks now the CA glue that I originally placed on the inside of the join is 'growing' from inside the hull and very slowly expanding throught the new hole and creating a small 'pimple' of dry, hard as a rock, CA glue. I sand the pimple down so it's flat once again, but after letting the hull just sit for a day, voila!, there it is again!!

Any idea what the heck is happening? Any chemist's out there?

Trread.

Hey Tread

I'm not sure whats going on but I've heard of CA glue doing some strange stuff. Let me ask you this is the kit in a glass case by chance. An old cop trick is to put an open tube of crazy/super glue in a closed glass fish tank i.e [ glass display case] to bring out finger prints. I'm not sure how but somthing about the fumes from the glue sticking to the oils from the skin. Like I said I'm not sure if this is whats causing the glue to "grow" or not its just a theory. If you do find out the cause let us know good luck.

Wolfsix

Howdy wolfsix,

Many thx for the input, I really didn't expect much response to this one since it is so weird! Unfortunately the answer is NO, it's not in a glass case (interesting intel there tho ). The kit's been sitting on the piano, the desk, the kitchen table, etc, etc.
Weirdest thing........
I just checked it right now and it's grown a wee bit since i first typed this question this morning!


Tread.

Tread

Sorry to hear that . I have no idea what could be causeing this. Maybe some of folks on the site can figure this one out.

Good luck
Wolfsix

Hi Tread

That's a new one on me!

The only way I think of CA expanding is when it "bubbles up" with accelerator - did you use any on the inside of the join?

It does sound weird, because the fact it's expanding suggests it can't be fully cured... which is the opposite of what you'd expect if it was "accelerated".

All the best

Rowan

Howdy Merlin,

Unfortunately NO, didn't use any accel. (don't really care for the stuff, I move too slow)
It's a weird mystery..............


Tread.

OOOOOOOO!! Spooooky!! Perhaps you should involve agents Mulder and Scully to investigate this one #:-)

I'm sorry, couldn't help myself.

NP Marty.....it does sound like a job for the X-files!..........got their number?

Tread.

Apparently they have found the answer somewhere in these woods, or at least thats what Fox told me. He has yet to call me back!

Hey, if you want me to, I can ask my Chem teacher why. I am kind of interested myself.

~Chip #:-)

Hi
weird!
It might be that the particular tube or whatever of CA was a rogue. Maybe the mix of ingredients in that batch, at the manufacturers, was a little off...???
Have you used the same glue on anything else?
You could do a test with the same glue on different bits of scrap styrene?
At least you might get to know if its a "one-off" or not.
Or change the brand for future models.
Weird...weird...weird.
Sorry can'y help more.
Peter

I have had an old bottle of Zap go like that and blow out the bottom of the bottle and grow all over the bottom of a drawer....when I tried to take it out i almost dislocated my shoulder....was it an older bottle you were using for this project? maybe it just goes off after a while.

TH -

All I gac think is that when you sanded thru the plastic you let uncured superglue come in contact with air and that caused the reaction - how lang have you had the glue?

Jeff #:-)

Howdy all,

Many thx for taking the time to do some 'head-scratching' for me. But it wasn't in vain. I believe that both dioman and Ranger have put it together! The bottle of CA was an older bottle, so that might be a reason, plus, Ranger made a very good point regarding the uncured portion of the glue coming in contact with the air (I had applied the glue on the inside seam in a couple of layers, i.e., thick)
So, I think we've GOT IT!!
(unless it really is a case for Scully and Muldaur)

So, the lesson for today my fine lads is; Never reawaken the sleeping Gods of CA glue!! Because the bloody thing won't stop growing.

Thanks again fellas for putting this mystery to rest.

Tread.

We use CA at the foundry in the pattern shop a lot. We buy Loctite buy the case. I do know this, the stuff gets flakey when the humidity is high. I have seen it grow too, just like you described. Usually only does it in high humidity.

Shaun

why dont you let it keep growing and see what happens?

Moisture is the Reason CA hardens........ So using a Accelerator in this case may help stop the "growing pains" #:-) #:-) #:-)

using CA for getting stronger bonds i use also the gap filling sand that comes in a seperate bottle with the brand i use . in some cases using this sand if i had thrown much glue and formed a bold drop the filling sand came strong only on surface and experienced some incidents like whats described in the post , but not so spooky , much less scale. I believe that has to do with glue aging and related to the air chemical procedure for drying .Or maybe it was a cheap plastic and the glue decided that will cooperate only with Tamiya and Afv models ...lol

Tsk, tsk, tsk. You could have avoided all this "gap-filling & accelerator "heartace, if you'd only used "Supafilla." Once you've tried it, you'll throw all "other" fillers in the trash! (this is an unpaid testamonial for Supafilla, a roughly 50/50 mix of medium viscosity CA and talcum powder. It's sandable in "one-five mikes" to a feather edge, bridges huge gaps without backing, and won't soften (& distort) even the thinnest plastic (also works on resin). For full details, contact the undersigned. Regards, Rob

Can you see the back of the joint at all and is it growing on the other side as well? Or is it maybe just warping out into the hole? I have neve seen this.

Rob