I have used several types of liquid cement (Tenax 7R, etc.) and tried with varying degrees of success the draftman's ruling pen, fine paint brushes, eyes of needles, and several others. I finally found something that delivers a small drop or a large line, never clogs, and is readily available. I used a small diameter brass tube and press-fitted it with a 2 inch long stainless steel tube (a hypodermic needle with the point cut off). Do not close off the upper end of the brass tube. I rounded off the cut edge of the hypo so it was not sharp and would not gouge my model. By dipping the stainless tube in the liquid cement, capillary action draws the cement up to the level of the dip allowing a measured amount to be dispenced. It gets into tight places, is long enough (I made the brass tube 8 inches) so as not to get lost on my workbench, and gives me complete control at most any angle. Even tipped upside down, the cement will not run out backwards. Hope this helps someone.