How do I paint hot glue so that it's slightly translucent?

Question

I'm going to try to replicate the fire effect that you can see in the picture below using hot glue, to produce a ring of flames around a 3" model.

What kind of paints and/or techniques should I use so that it retains some of the translucency of the hot glue?

Should I, for example, color it by hand using alcohol marker pens, or use a certain kind of paint with an airbrush?

Plan to extrude the glue from the gun and to paint the colors, as this is what I know already.

Have you looked at coloured/tinted hot glue? It's EVA which doesn't take paint very well, and alcohol markers fade pretty quickly in sunlight — Chris H, Aug 08 '22 at 10:35
No, if you were dying it you'd have to work from a melt pot, or use something like a heavy duty piping bag (normally used for decorating cakes or making sausages) and thick gloves instead of the gun. I'm not sure whether or not a gun would be easier than working from a melted pot for this shape anyway — Chris H, Aug 09 '22 at 19:12
Is your plan to draw these freehand with the glue gun, or use (or make) a mold of the design and cast the hot glue in it? Using a mold opens up some options. Painting gives you a lot of control on placement and blending of the color. I'm not familiar with transparent colors that would work well on hot glue (maybe the stuff used for faux stained glass?). If the color doesn't bond well applied to the cooled glue, with a mold you could paint the mold surface, then add the glue. The hot glue would probably bond better with the dried color. (cont'd) — fixer1234, Aug 09 '22 at 19:29
You can color your glue sticks (say a red and a yellow), then apply and crudely blend them. That would be tough to do well on freehand artwork while maintaining the shape of the design. Easier in a mold. Or you could apply and blend the colored glue on oven parchment, then cut out the shape with a scissors,and even add some clear on top for depth/surface texture, and to enhance the translucency. Adding a small amount of fine glitter (red, yellow, or gold), to the glue sticks when you color them might enhance the fire effect. — fixer1234, Aug 09 '22 at 19:29
re: discussion with Chris H, yes, you can color the glue and then mold it back into glue sticks to use in your gun (some simple methods). — fixer1234, Aug 09 '22 at 19:30
I'd look to form the broad shape out of molten material in a few layers (gun or spooning from a pot and spreading with tools), then draw the flame tips up from the melt. The tricky bit would be getting it so it sets quickly enough to not slump too much, while still being liquid enough to be able to pull up strands — Chris H, Aug 10 '22 at 08:45

score 7 · Answer 1 · edited Aug 10 '22 at 14:59

The best material that comes to my mind is Window Color, an acrylic based liquid paint used to create faux stained glass ornaments. Alternatively, acrylic paints designed to paint directly on glass work as well. It's important that the paint is formulated to stick to glass and stay flexible after drying.

The advantages of Window Color and glass paints are:

It stays very flexible after drying. Whereas hot melt glue is rather flexible, most other paints will chip off.
Colors that are vibrant and translucent are readily available.
Paints mix easily.
It's relatively cheap.

It should stick to hot melt glue, but I have no first-hand experience and my old Window Color paints are a rubbery, dried mess. You might have to cover the entire glue flame with a thick coat of Window Color to make sure it doesn't separate from the glue.

I did a test comparing acrylic glass paints with regular acrylic paints:

Left (foreground): Hot melt glue painted with acrylic glass paint. The paint drew back from the glue in small places. It's translucent and vibrant. I only had yellow and orange paints, it would look better with red in the mix.
Left (background): One bit of unpainted hot melt glue to demonstrate the opacity of the base material. My glue isn't very transparent.
Right: Hot melt glue painted with normal acrylic hobby paint. The paint drew back from the glue instantly and only stuck to it in rough patches. The paint itself is also opaque. I stopped this test after applying yellow paint because anything more would have been a waste.

All other ideas I had for paints (common acrylic paints, alcohol markers) have the disadvantage that they don't stick well to hot melt glue. Something in the formula for glass paints makes them stick to hot melt glue as well.

Oh, and let me tell you how utterly horrible my "flames" look... If you really want to create something like in your question, you'll need a glue gun with adjustable temperature or work in a very cold environment. I barely managed to make 3 spikes stick up, not to mention add any flame-like details.

I think let it cool a bit, then pull the flames up with a toothpick or similar. — Chris H, Aug 11 '22 at 15:42
@ChrisH The biggest problem is that the glue doesn't separate from the gun or the toothpick. You end up with countless wispy glue "hairs" that get in the way or stick to the still liquid glue and ruin the look. What I produced looked more like tentacles and I had to cut the tops off. — Elmy, Aug 12 '22 at 05:29
My thinking is that partially cooled glue doesn't give those fine hairs, and will draw into a thicker section. The hairs are also likely to be worse with a gun providing a source of more glue (it keeps flowing slightly even with the trigger released, due to thermal expansion as the glue heats up). It's also a source of heat and I reckon you need to pull up to the right height, let it cool more, then snap it off. That's me guessing though, based on using it when I don't want it visible — Chris H, Aug 12 '22 at 05:37
To make the hot glue thin, you can squeeze or roll it between sheets of oven paper — user3025, Sep 08 '22 at 07:49

How do I paint hot glue so that it's slightly translucent?

1 Answers1