Melting sprue in liquid cement Q.

Tools, Techniques, and Reference Materials Techniques
1

I was watching a build vid YouTube which was not in English and the guy put chopped up sprue in a jar of liquid cement and used this to fill some gaps etc.

Is this a good practice.It looked very easy to file.If it is good,how do you know how much sprue to use for the correct thickness and would this keep in the sealed bottle or would it set in the bottle.

2

I’ve tried something similar, didn’t like the result. The liquid cement softens the sprue and the joint when you fill the seam. It takes forever for the solvent to evaporate and when it does it shrinks and you end up with a sunken place where the solvent was.

I use Cynoacrylate glue and talcum powder (Baby Powder). I usually put some powder on the seam and then a drop of glue and mix into the seam. The end result is a filled seam and the glue/talcum mix is the same hardness as the plastic. Easy to sand.

3

I would say no, the solvent evaporates too quickly and you’ll end up with a block of plastic in a jar.

Here is a good reference for you to read about filling seams with plastic.

4

I did recently use some stretched sprue to fill some gaps on a Messerschmitt 110 bomb rack, just put the sprue in the gap, cement, and push into the proper place.

5

Hi,

I have used the liquid glue/melted plastic “goo” a number of times. I have found that the plastic leftovers from vac-form kits work well for me. I wait until a Testors cement bottle (the kind with the brush in the lid) is about half full, then add the vac-form bits over a period of time, mixing well, until I get a goo that VERY slowly oozes off the brush when held vertically. The mixture saves indefinitely (years) in the Testors bottle. I’ve used it to fill gaps and also for purposes like building up the non-turret nose of a couple of post-war PBY’s. (Cansos to me)

I’ve also had reasonable success using the mixture in rubbertex molds to make small parts. You just have to make sure you poke it well into all the crevices of the mold. “Painting” the mold surface with liquid glue also helps this process. I’ve even used this to make corrugated wing panels for a Junkers 52 when converting from tri-motor to single engine. Had to fill the holes in the wings where the engines were.

Hope this is of some use.

Mike