View Full Version : Gluelits casting procedure

03-24-2007, 09:46 AM
It took a little bit of experimenting, but here's where I landed.

I start by spraying the mold LIGHTLY with WD-40. The primary areas of interest are the cavity and both sides of the sprue plate. If you notice any excess of spray, dab it off with a Q-tip or the like. Excess lube will accumulate in the cavity and cause dimples in the cast. Like Brylcream, a little dab'll do ya'.
Close the sprue plate on the mold and stick the gun nozzle in the sprue plate hole. When you start pumping the glue into the cavity, get it in there fast. You can only push the gun so fast, but don't mess around and DON'T stop in the middle of an injection. If you do, just figure that one's a failed cast. Keep a tight grip on the mold handles and keep a light pressure on the sprue plate with the nozzle of the gun. When the cavity fills, you'll feel the glue trying to back the gun nozzle away from the mold. Let the gun nozzle back out with the hydraulic pressure and hit the gun AGAIN. You'll need a LARGE sprue on the sprue plate to avoid a suck-back cavity in the gluelit. I found that a sprue about 1/2" in diameter and about 1/4" high works well. Set the gun down and hold the mold level for a minute or so. You can actually see the excess glue being sucked into the cavity because of the cast cooling and shrinking. Whe the suck-back stops, the sprue is set up enough that it won't drip. Dip the mold in a coffee can half full of cool water and slosh it around. This reduces the temperature of the cast quickly and enables you to remove the gluelit almost immediately.
Swing the sprue plate open just as you would in casting a lead boolit. Pick the sprue off the plate with a tweezer or hemostat. This is easily done IF you lubed the sprue plate. Open the mold slowly. The gluelit is still soft at this point and I found that it helps to dunk the open mold in the water again at this point to remove the last of the remaining heat in the gluelit. Touch test the gluelit for hardness. After a few tries, you'll figure out just what it needs to feels like to pull the cast from the cavity without distorting or damaging the cast.
If you hold the gluelit up infront of a bright light, you can see through it just like looking at an X-ray. If there's a suck-back cavity in the back of the cast, you'll see it very clearly. It'll be shaped like a light bulb. If you're a purist, you'll decom that one and use more glue in the sprue. If this doesn't matter, lay it aside to cool and cure and go again.
You'll have to experiment with how often to lube the cavity. I'm finding that every other cast is about right, but this may vary from mold to mold and user to user.
Avoid handling the gluelits until they are CURED. This should be about an hour or so. They'll harden and turn milky like the base material is in stick form.

Next step for R&D is gluelit lubing. This ain't as simple as you might think. However, if anybody has any CONCRETE evidence to contribute, please do so. As for "what if you........", keep in mind the physics requirements here are beyond a window that nobody has ever looked through.

See y'all soon. I'm knockin' off an' goin' shootin' for awhile.


03-24-2007, 01:00 PM
Jim, While I don't have a glue gun...yet, I AM intrigued with this "gluelets" business. After reading your post, it occurred to me that you could try wire pulling lube on the gluelets as it's very cheap, can be easily applied and has other reloading uses (case forming lube, bullet "pre-lube" when using Lee sizer dies). The only problem I see is that it dries to the touch rather quickly on cases & normally-cast bullets, and assume it will do so on gluelets too. In that case, a dab of Crisco applied with your fingers may do the trick. What do you think?

03-24-2007, 01:22 PM

I hadn't had much luck trying to cast and cut with the sprue plate. I'll have to try your method.

I am using a six cavity lee mold. Leaving the sprue plate open I try to fill each cavity untill it is just slightly rounded at the top. The "pull down" that results when it cools makes a pretty neat hollow base in the gluelit. Some of the bases don't turn out perfect but my technique is getting better. I'm looking at making a "stop" on the trigger of my glue gun so that I can meter the amount with 2 pumps.

I will have to see if perfect base (via cut sprues) vs. not so perfect hollow bases like I make have any advantage.

Keep up the good work.


NAGS life member

03-24-2007, 04:04 PM
Quenching...why didnt I think of that.

Have you tried letting the bullet sit in the bottom of the water can until you are done casting?.....might help harden em up

03-24-2007, 06:00 PM

after reading one of dk's posts i started casting with a lee 200 grain swc tumble lube mold, i just spray it with mold release, close the sprue fill it up with hot glue and let it rest on a bag full of ice water, grab another mold and fill it, flip the first mold, set down the new one, grab the first mold again give the plate a wack with my stick and pop the gluelits out.

if you get it cool enough it will cut right though the sprue, if your to quick it will deform the gluelit and you will have to scrap it.

weights with high temp glue

.38 originally 158 grain swc is 13.5 grains on average
.44 originally 240 grain swc is 21 grains on average
.45 originally 200 grain swc is 18 grains on average

i use winchester 45 acp cases with the large flash hole so i don't need to drill anything no setback when using large rifle primers. slight flare then i just run it though my crimp die with very very minimal crimp just enough to take out the flare.

i have been using the frankford arsenal drop out lube and nothing else no thing has stuck in the barrel and accuracy is decent.

i have been popping pesky deer in the rear at around 35 yards to keep them away from the bird feeders, scares them but does no harm at that distance. at 7 yards they shoot about an inch low in my 1911, loading them is tricky i use the mag to push the round under the extractor as they wont feed from a mag.

my results with my .38 gb's was dismal in my ruger to much barrel for them to work maybe something around 4 inches would work

03-24-2007, 06:14 PM
After hearing you guys talk about this, I got an idea. People in humid areas or wanting to store their steel mould for awhile and need a way to keep them from rusting. Wouldn't this be a good method by filling them with glue and putting away?

03-24-2007, 10:29 PM
Because I don't use steel molds, I'm not qualified to answer that question. The guys on the cast boolits board might can help you with that.

When R&D comes up with a successful lubing procedure, rest assured it will be posted. Gluelits are made of a soft, high friction material which means they WILL smear going down the tube without lube.

You're gonna need more than the amount to fill the cavity to "top off" the sprue. The suck-back is substantial, so don't cut yourself short there by limiting the gun discharge amount/rate.

It is an honor, Sir, to have you join us here at NAGS! The knowledge and experience that you bring as an "old hat" caster is most certainly welcome. Actually, I have some Ideal Yellow 77 and am considering it's usefulness in this project. I'm also looking at the possiblity of incorporating graphite with it. At this stage, however, R&D doesn't have a clue as to what's going to work, let alone what's going to work best.

Mr. President, Sir,
Once the gluelit is cool enough to pull from the mold, it can be set aside for curing. I don't think that leaving it in water would actually hurt it, though. If a loader were planning to load the gluelits within minutes after pulling them from the mold, then leaving them in cold water would certainly accelerate the curing time. However, I would be a bit hessitant to do so. I'd rather leave them out at least overnight to completely air dry.

I've taken time to answer or address the points and questions submitted by each of you because all the staff at R&D appreciate your input. As Vice President of NAGS and Chief of Research & Development, I'd like to extend a warm welcome to our new members. We look forward to your being part of this exciting and growing society.

Shoot safely!


03-26-2007, 09:40 AM
This process of "shooting glue" into the mold - isnīt that called "injection molding", rather than casting where the lead fills the mold by itīs own weight?

03-26-2007, 10:40 AM
This process of "shooting glue" into the mold - isnīt that called "injection molding", rather than casting where the lead fills the mold by itīs own weight?

That would make holding a mold against the spout on a bottom pour pot full of lead injection molding, maybe so. DALE

01-29-2011, 11:04 PM
I will be getting a glue gun shortly, but want to know which is the best ''stick size'' one to buy?? There seems to be a varied size of sticks available just wondering which would be the most common? Dont wanna buy one to find you cant get the sticks for it, that would just annoy me! The sizes seem to range from 7mm to 12mm. Which is the one to buy? Looks like fun too!
Thanks, BB03

01-30-2011, 01:05 AM
The way I make my gluebits is to oil mold and leave spuce plate open and fill up past the top of the mould. As glue cools it may sink in some so i top it off to get a complete gluebit. Then I pop the mold in the frezzer. When it cools off some not fully I cut the extra glue off with a razor blade. If you load them and let them sit you need to store gluebit down so any oil dont get into the primer and foul it. Just how I do it dont think there is a right way or a wrong way just have fun.