Sprue 'n Glue Filler??

The sprue'n'glue was in fairly widespread use in the 1960s, before the widespread avaiability of model fillers. Even the earliest solvent-based fillers worked better than sprue'n'glue, and that's saying something!

Generally, it seems to me that the best approach is to minimise the need for filler n the first place, by careful test-fitting and trimming to shape. If gaps remain, try to fill them as much as possible with plastic strip or scrap plastic, then fill the remaining gap with CA and acelerator, and sand to shape before the CA has hardened fully. For areas where you don't want to have to use abrasives, epoxy putties work well for large areas, typewriter correction fluid for small gaps.

Cheers,

Chris.

Triarius wrote:

Well, we've got plenty of corn starch in the pantry. I'll see how it reacts to CA.

 Sorry if I mislead you, the stuff I use is Baby Powder that has talc in it not corn starch.  The label indicates it is talc.  You might check your drug store for baby powder with talc.

Well, we've got plenty of corn starch in the pantry. I'll see how it reacts to CA. 

See there now. Just when you thought you had someone pegged, you learn something new! All this time I thought you were just an old pirate.

I used to roam the deserts of AZ in search of agates and geodes, shooting my .357 and generally having a high old time sleeping under the stars and all. 'Used to have to know a few things about the area geology in order to actually find anyting besides snakes! No specialist, for sure, but that you are/were is very cool.

Gypsum it is.

You're welcome, but no hard work or research was involved. I'm a retired geologist—got the rocks right here in me head, matey! Har!

No reason you couldn't use gypsum as a filler. Just don't use it as body powder! 

No, talc is not ground up gypsum!!!

Talc and gypsum are both minerals, but the similarity ends there. Talc is hydrous magnesium silicate, {UGLY WORDS! paste from Word doesn't work! I can't give you the proper formulae!)

and gypsum is calcium sulfate dihydrate. Talc crystals and fragments are thin plates, like mica but much smaller. Gypsum is tabular to acicular crystals. Put gypsum on  your skin and leave it there and all you'll get is a case of dermatitis. Talc, at STP (standard temperature and pressure: sea level and 68°F) is chemically inert.

The reason not to use talc in talcum powder is that many natural deposits of the mineral are associated with (WARNING: BUZZ WORD! FOOLS, IDIOTS AND MEDIA CRETINS ARE TO HAVE HYSTERICS!) asbestos minerals. Pure talc (last I checked) is harmless.

I havent tried the talcum podwer thing, but I will. Baking soda/CA has been a trusty standby and I haven't had the 'fuzzies' develop as Ross suggest. But, that doesnt mean they wont, nor do want them to! DO tell us your talc brand.

QUESTION: Isn't talcum just powdered gypsum? I have a ton of drywall I could sand down for talc!

I tried exactly what you described to make a seam filler, what a disaster.  Once the plastic is dissoulved and you apply it, the mixture will casue the surrounding plastic to melt and take over a month to harden.  Even after a month the area will shrink due to the evaporation of the solvent. 

The shrinkage happens with any type of solvent based filler.  I quit using the solvent type filler and started using  CA and talcum powder.  It sets up faster and won't shrink.

dahut wrote:

Super glue and baking soda - little mentioned, works good

Yes, it works—until the bicarb starts migrating to the surface, and your model gets a case of the fuzzies—Had a T-rex do that, looked like he had the creeping awfuls! 

The old sprue-in-glue trick is as old as many of us here. I cant say I ever tried it, but I've heard about it for a long time. I did mix some sprue with liquid cement once, but it made such a noxious, frightening mess that I tossed it without trying it. I gotta agree with Ross and Gerald (a pretty good idea, most all the time) - there are so many other options for filler that it hardly seems worth the effort. I use:

Regular model fillers - Tamiya and Testors

Epoxy putty - rarely

Super glue and baking soda - little mentioned, works good

Auto glazing putty - dries out before you can use it!

MOST IMPORTANT: Steady filing and fitting in order to minimize the need for fillers.

Well Mark.......their ignoring or not sharing with you is about the stupidest and silliest......ugh!

Shame on the pompous idiots! 

oleander13 wrote:

HawkeyeHobbies wrote: Which would you prefer...a classic car restored with metal or one filled with tons of bondo? Metal for metal...plastic for plastic...anything else just isn't as strong or as long lasting.  Good point.  I was just more curious as to the process as I'd never heard of it before.  The guys in the IPMS group here tend not to speak with or let me in on things.  I'm not sure if they look down on my because I'm so much younger than them (I'm 25, average age is probably 45+).  Most of them just comment that I'm really young and then they kind of ignore me.  Either way....thanks for the response, but the link you provided isn't working.   Thanks again Gerald!

We were all young once...then we grew out of it. Some of our younger modelers at both clubs I'm a member of do fantastic stuff...better than me without a doubt. I think you should knock some heads and get them into sharing the wealth of knowledge...they might actually learn something too! It is all a mindset on their part...if membership doesn't benefit the entire organization...maybe its time to start another chapter. One that is more open minded towards younger folks. Our group here ranges from individuals who are in their 80's down to those in their 20's, an occassional teen too...of course they grow older in a blink of an eye...hell I was 18 just yesterday...errr well a whole lot of yesterdays! 

HawkeyeHobbies wrote:

Which would you prefer...a classic car restored with metal or one filled with tons of bondo? Metal for metal...plastic for plastic...anything else just isn't as strong or as long lasting.

 Good point.  I was just more curious as to the process as I'd never heard of it before.  The guys in the IPMS group here tend not to speak with or let me in on things.  I'm not sure if they look down on my because I'm so much younger than them (I'm 25, average age is probably 45+).  Most of them just comment that I'm really young and then they kind of ignore me.  Either way....thanks for the response, but the link you provided isn't working.

Thanks again Gerald!

I've heard of guys making plastic filler goo using a pint of MEK and a ton of sprue. Can't say I would recommend it. You might want to read my article on how I fill with sprue here.

Which would you prefer...a classic car restored with metal or one filled with tons of bondo? Metal for metal...plastic for plastic...anything else just isn't as strong or as long lasting.