CA and Sodium bicarbonate vs CA and Calcium hydroxide

[Maximitsurugi]

Hey @Randy Holmes-Farley . Here to pick ye great chemistry brain again.

I read up on making Cyano Acrylate stronger for bonding rockwork before adding reef epoxy. I found two options, Sodium Bicarb and Calcium oxide/hydroxide.

Which would form a stronger bond with CA? Bicarb or kalkwasser?

If the bond is super strong then I might be able to forgo the epoxy putty as I cant get it easily here on the island.

Thanks bro.

 

[Randy Holmes-Farley Verified Community Expert]

You are talking about mixing powders of sodium bicarbonate or calcium hydroxide into uncured cyanoacrylate and then using it as an adhesive?

Both solids will form strong hydrogen bonds to the cyanoacrylate adhesive, but I suspect the interfacial bond strength between the glue and the fillers is not really what you care about or are asking about.

If you are asking about the tensile strength of the final cured product, I do not know which is better, or if either increases it compared to not having it there.

The glue may start to cure fast if the solids are mixed into it, even before you apply it to the rocks.

 

[Maximitsurugi]

Thanks for replying. Well there is a technique that reefers are using to make a very strong glue for repairing items or bonding rocks which is to put some baking soda in the crease of whatever needs to be glued and then squirting CA on to the bicarb. This apparently hardens almost immediately and is supposedly stronger than glue alone.

The case is though that I found online that calcium might form a more structurally secure bond when applied in the same way as bicarb so that's why I'm asking, chemically, which mix is stronger.

 

[Randy Holmes-Farley Verified Community Expert]

Thanks for replying. Well there is a technique that reefers are using to make a very strong glue for repairing items or bonding rocks which is to put some baking soda in the crease of whatever needs to be glued and then squirting CA on to the bicarb. This apparently hardens almost immediately and is supposedly stronger than glue alone.

The case is though that I found online that calcium might form a more structurally secure bond when applied in the same way as bicarb so that's why I'm asking, chemically, which mix is stronger.

The reaction above between baking soda and calcium hydroxide would form calcium carbonate. Not sure where the glue comes in or how sturdy it would be.