You can make your own glue tip using a Bic mechanical pencil. You want the "cheap" pencils that are typically sold in multiples. I have NOT done this myself, but found the following instructions for anyone brave enough to try them:
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You need: Bottle of Elmer's washable School Glue; Bic mechanical pencil (0.5).
Directions:
Remove the point part from the pencil. Use it to score a line on the orange cap of the glue.Pop the orange cap off the glue bottle after "unscrewing" it all the way out.Cut the top part of the glue bottle off below the first ridge after it stops tapering down.Cut the top off the orange top part of the bottle along the scored line you made.Insert the pencil point in the orange cap so the point is out through the enlarged opening you just cut. Push itfirmly into place.Replace the orange cap on the bottle.
Use a knitting needle point protector (Clover makes one) as a sealing cap on the bottle.
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I am currently using a plastic bottle with a metal tip that I purchased at our local hobby store. I found the bottle in the section where they sell models.