true acrylic cement is [methylene chloride] Perhaps weld on (which is good stuff) contains this as well. I had a hard time finding the weld on stuff even on line for a good price and a small quantity. Had a friend that works in a lab that uses the stuff and he got me a bottle of the mehtylene chloride, it will evaproate right in the bottle but is really good stuff, no leaks. Water thin, use a syringe and it will take care of that crack. Weldon use the lower number and a syringe, I think the IPS16 is to thick for what you want to do.
Thomas