Sprues, sprues... oh look! MORE SPRUES.

[Junkman]

Harry, for body work, sure it's not the best choice, but for places where it won't be seen, it's a great way to bond parts . . .

Yep, that's where I use it. To reinforce the sections of chopped tops from underneath. If it has the right consistency you can even shape it to resemble a headliner. Also good for bonding custom front and rear ends to a body, but always use it on the inside.

For the visible areas I agree - better use modern materials.

Edited January 7, 2012 by Junkman

[Scale-Master]

If you are happy with the results you are getting, great, by all means continue.

But from my experience, the solvents can bleed through from the inside to the outside and do all sorts of things, like ghost in emblems or trim that has been sanded off the outside, make the areas where styrene meets fillers swell and/or shrink and create other damage that in many cases is near impossible to fix.

It may take a few years for the damage to become visible, it may happen the week you finish the model. And it may never manifest itself.

But with all the superior, easier and more economical to use products/materials that are exceedingly more stable, I have to wonder why this technique is still being promoted?

It is at best a wild card, at worse a death knell to an otherwise fine model down the road.

I know I am repeating myself, but I do not think this technique is good advice to be dispensing despite the intent.

My suggestion is if you have not used this technique, don’t start now. Just toss the sprues and save the solvent for better uses.

As far as using it for general bonding of parts, why dilute the strength of the solvent/adhesive strength of the chemical with another plastic? Better to use the liquid cement as it is for maximum bonding strength.

Edited January 7, 2012 by Scale-Master

[Junkman]

If you are happy with the results you are getting, great, by all means continue.

But from my experience, the solvents can bleed through from the inside to the outside and do all sorts of things, like ghost in emblems or trim that has been sanded off the outside, make the areas where styrene meets fillers swell and/or shrink and create other damage that in many cases is near impossible to fix.

It may take a few years for the damage to become visible, it may happen the week you finish the model. And it may never manifest itself.

But with all the superior, easier and more economical to use products/materials that are exceedingly more stable, I have to wonder why this technique is still being promoted?

It is at best a wild card, at worse a death knell to an otherwise fine model down the road.

I know I am repeating myself, but I do not think this technique is good advice to be dispensing despite the intent.

My suggestion is if you have not used this technique, don’t start now. Just toss the sprues and save the solvent for better uses.

As far as using it for general bonding of parts, why dilute the strength of the solvent/adhesive strength of the chemical with another plastic? Better to use the liquid cement as it is for maximum bonding strength.

It has worked well for me over the past 30 years without causing even the slightest of problems. To the contrary, it doesn't cause problems I encounter with other materials and it is dead easy to make and use. Hence I will continue advocating it.

[Ramfins59]

This has probably been mentioned a thousand times before but one of the sprue sections from the Lindberg 64 Dodge kits makes a perfectly symetrical dual axle trailer, with fenders. The framework for it, anyways.

One thing that I do save is the red and amber sprues from any taillights/marker lights sections. You can use them to create custom lenses.

Yeah, I do the same thing. I save the red, amber and some clear sprues just in case I need to make an odd shaped or custom lense. I've also made taillight lenses from a red toothbrush handle, but it was a lot of work, even though worth it in the end.

[Scale-Master]

It has worked well for me over the past 30 years without causing even the slightest of problems. To the contrary, it doesn't cause problems I encounter with other materials and it is dead easy to make and use. Hence I will continue advocating it.

For those in the U.S., be aware the chemicals are not the same here as in the U.K. Heck, from California to the rest of the U.S. chemicals are different. What may work with chemicals deemed to be the same or be referred to by the same terms doesn't mean they will work the same with comparable but actually different chemicals.

Some people have had acceptable results, fine, as I said , if it works for you... But I have experience to the contray of this being such a wonderful technique. Use it if you want, it won't affect my models... I just thought it should be made clear it can create major problems and as a prolific long term builder, I have seen it happen many times and to many builders. You can make up your own mind.

Maybe it just boils down to what one builder compared to another is willing to accept as satifactory results?

[Gluhead]

I used to do the spru-glu thing. Now, after all my builds finished and otherwise have been sitting for several years, I'm looking for an alternative. I've gotten to where I can cut and fit things close enough to where I have very little in the way of blemishes that need to remedied, but there's often that last little sliver or hairline that needs attention. Where I've used spru-glu on this in the past, I get ghosts.

If you've solved the mystery like many others, fantastic! But myself, I'm interested in the latest job-specific product now that I'm back into building.

But as far as the sprues go, I do keep certain ones. After you've used it for whatever comes to mind for a while, you start to pick up on what types cooperate well for you (specific type of plastic, etc). Like many have said, I pretty much always keep clears and reds.

[Abell82]

I keep a few pieces of the old Revell and Monogram sprue. But not AMT or MPC, as it always seemed weaker.

When a wheel spindle breaks off a kit, I simply drill out the old piece, and glue in a new one.

[Guest Johnny]

I clip off the longer straight sections of various sizes for future use.

Also any odd curved or odd shaped pieces you find from time to time! You just never know! .

[Jordan White]

Too bad the model companies don't just have you send back the sprues so they can reuse them, and maybe give you a coupon towards your next kit.

[Harry P.]

Too bad the model companies don't just have you send back the sprues so they can reuse them, and maybe give you a coupon towards your next kit.

Hey... that's not a bad idea! Recycle those sprues.

[SuperStockAndy]

Hey... that's not a bad idea! Recycle those sprues.

Indeed..I'm not into the whole recycling thing but it COULD definitely make kits a bit cheaper.

[Foxer]

I'm cheap so I tend to keep sprues and always seem to "need" one somewhere down the line.

First, I cut long sections off with a corner hook at the end ... like a J ... and tape or glue an alligator clip or toothpick on the end for holding parts to spray paint.

I've tried the glue/sprue body filler and for little things it's ok, but I do worry about the shrinkage.

Filling holes does work well with a piece of sprue stuffed into it. It's also useful filling a larger cavity without using half your putty supply.

I have used it to make small parts, especially cylindrical ones. Once inserted into the Dremel it carves nicely with this cheap lathe and is solid, which is the problem using perfectly round tube like this.

Clear red sprue is useful to make custom tail lights once carved and polished.

As mentioned, they make great paint stirrers.

Many times I'll super glue lengths of sprue to a part as a handle. Usually in an area that won't show. They easily break off when no longer needed.

I'm sure this list isn't complete as I keep coming up with new uses for sprue!

[Dr. Cranky]

That IS a wonderful idea.

I remember the very first model building tip I learned was the sprue-over-the-candle-flame-stretch and I still use it to this day.

[Guest Johnny]

I agree with Mark... homemade filler (melted sprue) is a terrible filler. It will still be drying (and shrinking and cracking and causing all sorts of problems under your beautifully painted model) long after you thought it was "dry."

If you don't like nasty surprises weeks or months down the road, don't use it! Use a stable, chemically set (two-part) filler instead.

Same could be said for any other type of filler if used incorrectly!

I've used it many many times to fill seams using a thin layer and have NEVER had an issue with it on down the road!

[Mark]

The sprues in newer kits are in many cases straight, and are round in cross-section. I save those. The odd-shaped ones usually get tossed unless there are duplicates in the same shape. If I see possibilities with the shape, I'll keep them, at least for a while. If I don't get around to doing anything with them in a reasonable amount of time, I'll toss those next time I re-organize the scrap plastic box. Besides sprues, the box contains small scraps cut from styrene sheets, and other items made of styrene like broken CD jewel cases, a couple of cores from Scotch tape rolls, things like that.

I've used sprue to scratch distributor caps. Cut one end of the sprue at a 90 degree angle, and drill the holes for your plug wires. Sometimes the holes aren't spaced to my satisfaction (they'll end up looking like three rows of three holes). In that case, cut the offending area off and start again. Leave the other end of the sprue alone, to make handling easier. Once you are happy with the hole spacing, you can file the diameter of the cap closer to that of the circle of holes just drilled. You want the diameter to stay slightly larger (taper outwards) towards the base of the cap. Vertical grooves can be sliced/filed in between each hole. Once you have the shape, cut the end off of the sprue at the desired height of the cap. I'll use these caps on engines that have the distributor at the rear; for engines with more prominent distributors I'll stick with the molded pieces.

As for sprue glue as a filler, the shrinking problems happen when it is applied too thickly in a single application. Shrinking is more likely to take place when cement is used to dissolve the styrene. Something added to the cement slows its drying time, and in large quantities contributes to the shrinkage. I have used MEK, and have heard of others using "hot" lacquer thinner without the shrinking problems. "And now, I'd like to take a moment to talk about shop safety". Whenever using these or any chemicals, paints, cleaners, solvents, or other similar products, be sure to wear protective gear and work outdoors or in a very well-ventilated area. Generally, the better something works, the bigger the skull-and-crossbones on the container needs to be...

[martinfan5]

I keep some on hand , I do find that come in handy a lot of times

[buskid]

I will throw most if it away but keep the longer straight pieces for emergency situations. I will sometimes clip a piece that resembles an "L" shape for stirring paint that has settled over time. I just twist it back and forth with my fingers for controlled mixing.

[Junkman]

Generally, the better something works, the bigger the skull-and-crossbones on the container needs to be...

The argumentum e contrario works equally well: If there isn't a big skull and crossbones on the container, it doesn't work.

[kitbash1]

I keep a good supply of sprues on hand, the rest I put in the Blue Box for recyling.

[Bartster]

I use very small diameter clear sprue cut approximately 3/16" long, then heat small guitar string & insert in each end. Paint the strings & just the flat ends of the sprue silver & you have a nice in-line glass fuel filter

[ZombieHunter26]

I use very small diameter clear sprue cut approximately 3/16" long, then heat small guitar string & insert in each end. Paint the strings & just the flat ends of the sprue silver & you have a nice in-line glass fuel filter

Now THAT'S something I would have never thought of! Very nice!

[scalenut]

look at some of the round join plugs at intersections they make nice tachometers,, I opened a kit yesterday and it had some shaped just like a k&N filter,,in chrome

Edited January 10, 2012 by scalenut