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How to make your own
Cyanoacrylate (Krazy/Instant/ZAP) Glue tips

By Darren Scannell
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If you’re looking for the best way to control cyanoacrylate glue application, try this technique for making your own extra fine glue tip applicators!

First, you need some tube. I won’t try and spell the chemical names, as I don’t know them all, so I’ll stick to a basic description. It’s a white teflon like material that can’t be too soft or hard/brittle. I’ve tried several types and have found that the guide wire tube made by Dubro for RC airplanes is about the best.  Most Hobby shops can order it in easily enough and it’s only about a buck for a 3 foot tube. The key is, not too big, not too little, about 3/16" round is perfect with a wall thickness a little under 1/16". If you have some tube like this, try it, if it doesn't work, just keep looking for something that will.


Second, you need a heat source. A lighter can be used, but I find a Weller Pyropen JR with a heat gun tip to work better. ( it blows a small stream of hot air on the tube to soften it, without leaving any black carbon behind)


Third, you need something sharp. I use an Exacto knife with a No.11 blade, but you can use a small pair of side cutters, scalpel, razor blade or anything you find that will cut through the tube easily. (it’s not very hard, but it should have a smooth edge and after stretching it is a little delicate, that’s why a sharp No.11 blade works well.

Cut your tube into manageable lengths of about 4-6 inches (10-15cm). Take one piece and ensure the end is cut square. Holding the tube in one hand, place it over the heat source so that there is about ¼ inch (6-7mm) from the tube end to the point that will get hot. Rotate in your fingers over the heat source until it goes clear. Just after it starts to go clear, it will start to sag. At this moment, take it away from the heat source.


Before it cools, carefully grab the end that is sagging (without touching the hot clear part!) and pull apart slowly (not too slowly! practice!!) and gently about 2-4 inches (5-10cm). Hold steady a minute or so to allow it to cool slightly, keep a slight tension between the ends. Set down on a flat surface and let cool a few minutes.


After the tube is white again, carefully cut the center of the stretched piece roughly in the middle of the two tube pieces.

cut in half

 Now cut the stretched piece off the longer tube about ¼ inch (6-7mm) from the bubble. You now have two glue tips. Keeping the tube barrel short will prevent the tip from getting too stuck in the glue bottle and making it hard to remove. I cut it to be about 3/16” long. The stretched part will probably need to be trimmed as well, generally I keep them an inch long and cut off small bits as I glue, or need more flow. When it is only 1/16” long it is time to put a new one in.

 cutting tip offtip

The small glue bottles I use can have the opening cut off and the inside diameter fits the tube nicely. Simply press it in and make sure it is a tight fit. If it is too loose, it may fall out, spilling glue all over your parts! If it is too tight and won't go in, drill it out to the correct diameter.

 bottleinsert tip

This tip will allow a tiny drop to flow out the end, sometimes so small it's impossible to see!! Cutting it closer to the bottle will allow more glue, enough to flow along a joint and create an invisible fillet of glue to hold your part in place. If I don't use the glue for a few minutes, the end will dry over, I simply cut off a tiny piece and glue flows again. When the hole gets too big and too much glue comes out, I pop it off and put a new tip on in seconds. Sometimes I need more glue for larger parts, I will keep a second bottle on the work bench with a shorter tube for those jobs!

glueing railing

I make tips for about 10-15 mins and will have a bag with enough in it for 3 - 4 models.




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