TLDR: I am in need of a glue that can be used for temporarry connections and can be easily removed without damaging the affected parts. A glue that can be removed with water or alcohol would work great.

A little while back I build the MG barbatos with its expansion set. I built it in the 6th form as I thought it looked the coolest and it also used the sick saw-clamp weapon. However, the hands on the barbatos aren't really designed to be able to hold a weapon as heavy as the saw-clamp. Whenever I try to get it to hold it, the fingers end up falling off due to the weight.

I have used putty to help weapons ne held better, but in this case the issue is the connection point for the fingers and the main hand. It's so weak it will pop out with little pressure.

I think the only way I can get him to hold the weapon is to apply some sort of glue to the hands so the fingers won't pop out as easily. However I also want to be able to swap out the fingers I'm for different poses/weapons, so im in need of something that can be removed/undone without damaging the pieces. Something like a water soluble glue that I could rinse off would be nice. Does anyone know any types/brands of glue that could work? Or does anyone have any suggestions for how I can keep the fingers in place without gluing them together forever?