discussion Sprue Goo, do people actually use this?

[pjgtech]

Watching yet more YT vids, (yes, I know, not always a good idea!)
I have seen a couple, where people make "Sprue Goo" and keep it in a jar.
A sort of melted plastic, made from left over sprues, melted down using plastic cement. The idea being that you can use it to fill gaps, etc.
Is this actually a thing? and if so is it a good idea?
Does anyone actually use it, or would you just rather use a dedicated filler?

 

[Steven000]

I prefer a filler but sprue-goo can definitely be used,
the trick is to get the right amount of plastic cement in the jar so it behaves like it should...
Cheers

 

[pjgtech]

So once you have made it, does it set hard, or does it stay "gooey"?
and how long does it last? eg: does it go off after a while or any other things to watch out for?
Cheers

 

[Tim Marlow]

It’s a very old idea from back when most of the things we use now were not available. Personally I think it’s more trouble than it’s worth. Unless you have a low price supply of solvent, filler is cheaper, more convenient, and more reliable.

 

[Stefee]

I find the sprue good easier to rescribe panel lines in than filler as it doesn't chip away at the edges, just make sure to make a small line with a toothpick before it dries. Also it tends to melt both sides of the joint to make the bond stronger.

 

[PaulTRose]

Old fashioned way of doing things

Has the advatage that its the same material as whats around the gap your filling

But these days theres so many other ways of doing same job thats easier or neater or safer

 

[Tim Marlow]

I find the sprue good easier to rescribe panel lines in than filler as it doesn't chip away at the edges, just make sure to make a small line with a toothpick before it dries. Also it tends to melt both sides of the joint to make the bond stronger.

Tamiya and Mr white putty (I think that’s its name, it’s part of the Mr range anyway) bond excellently to plastic and don’t have this problem. They sand to a glass smooth finish and a true feather edge. Tamiya putty is the best on the market IMHO but can be hard to source. Other cellulose fillers are also good, though the Mig range has rather a too high thinner to filler ratio, but these two are the best I’ve tried.

Acrylic putties simply don’t work like this as they bind poorly to the subject. They are, however, very good at filling cracks because they can be cleaned up with a damp cotton bud so leave very little sanding necessary afterwards.

Another way to treat things like poorly fitting wing joints is to glue stretched sprue or plastic card into the gaps, let it dry, then sand it back. This gives proper strength to the joint as well.

 

[Nicko]

I use it all the time, especially on sink marks and to strengthen joints on the reverse side and it never goes off in a closed jar, just keep topping up with the dregs of a glue jar and a few more bits of old sprue.

Nick

 

[PaulTRose]

If the gap isnt too big ive always prefered thick ca with talc as a binder.........dries very quickly and sands very easily

 

[Geoffers]

I have tried sprue glue in the past but found it was more trouble than it was worth.
I always struggled to get the right consistency and it seemed more messy to apply so gave it up.

So now I tend to use a variety of solutions including super glue mixed with talc or squadron putty for gaps, sink marks etc, I also use acrylic Perfect Plastic Putty for faint gaps.
For larger gaps such as at wing roots I glue plastic card into the space and trim/sand it flush.

Geoff.