I filled some holes on a model with the baking soda and super glue technique several months ago. I then set it aside and forgot about it for a while. I picked it up yesterday and I noticed a substance oozing from the filled areas. I appeared to be some sort of acid type of substance from the smell of it (vinegar-like).
Is this acid from the superglue? How would that effect the model in time after it is painted.
It seems to be a possible concern regarding this technique.
I have never heard of this, super glue - yes, super glue and baking soda - no. I do no know what to tell you, but if I were you I would get that stuff out and a)use just super glue or b)use putty
I don’t recommend to use either baking soda or baby powder. They will both yellow over time and this yellowing can show through paint. They can also deteriorate over time. Just use thick, gap filling CA or putty.
Baking soda is great for super glue, since it’s a cheap powder form of accelerator. The bicarbonate acts as the base the cyanoacrylate reacts with, and it sets up instantly. Talc should also act as somewhat of an accelerator since it is a hydrated magnesium silicate, and does provide hydroxy ions necessary for the reaction to occur; however, talc is hydrophobic (repels moisture), and moisture is what super glue needs to set up properly. Actually, straight, old-fashioned water should probably work just as good, since both the methyl and ethyl fractions polymerize quickly in the presence of moisture.
My guess is that the liquid you describe is unreacted material. When you added the baking soda, it reacted with what it came into contact with and no more. It could be you started with way too much super glue and not enough reactant.
Bad guess, it’s the baking soda rotting over time. The best bet is to use any inert material, resin dust works well as do microballons. Personally I don’t bother with any of them, if that gap’s that big I use epoxy putty or polyester putty over shims.
Please enlighten me. How does baking soda “rot over time”? I’ve used the material for its accelerative properties and have never experienced the effect described in the originator’s post.
I think Gip might be right, I might have had too much superglue and when the baking soda came into contact with it it hardened on the outside but never made it within. I will do it in thin layers from now on. I have not had this problem in the past…
The possibility for yellowing is a concern. I guess I should use this technique selectively.
I might just go back to regular putty filler or try polyester putty. I keep hearing stories of strange reactions or growths over time in areas where this technique was used. I have also heard that the baking soda and super glue technique produces cyanide gas.
Darn, I was hoping I had found the perfect filler.
If I understand the reaction, cyanide will be released as part of the curing process regardless of whether or not you use an accelerant. But not to worry, not enough cyanide is being released to cause any concern.
The TRUE medical emergency exists if you get superglue in your eye(s). In this case, get to the emergency room pronto; do not pass “go”, do not collect $200.