Question about annealing an engraving

I’m looking to smooth out an acrylic engraving as much as possible. I’ve already defocused and flooding it with weldon improved things, but not as much as I’d like. Before I run out to get a toaster oven, will annealing work or would the raised clear areas slump as well?

This is after flooding with weldon


Annealing is a process of slowly heating then cooling to remove internal stresses. If you mean just melting the whole thing to remove detail, I’m sure that will happen but I can’t imagine how reliable it would be. I’d think hitting the areas you are concerned about with a flame would be more predictable.

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I can’t wait to see the results of your experiments, because I’ve felt the need for that in some pieces as well.

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Eflyguy is referring to flame polishing, which has been discussed previously:

I’m not sure if there was ever a thread that reached a conclusion about flame polishing but it’s worth a look. I’ve never tried it myself.

You might be able to get good results chemically, very carefully applied weld on might smooth it out kind of like your* clear resin 3d printed deer?

This might be a good use case for extruded acrylic, it already engraves with less contrast in the first place.

If all else fails this might be a good candidate for resin casting. Use the gf to make a positive, cast a negative with silicone, then cast it in clear resin. If you only need one you could just make it with the elegoo clear method?

In any case I’ll be curious about how it turns out.

* at least I think that was your project?

Edit: doh you already weld-on’ed. Reading is hard.


In Jr High Shop we made acrylic Swans. At around 300 degrees the acrylic becomes like soft leather You drop it in a pre-designed support till it cools, but you can handle it wearing gloves for a bit.

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Have you tried doing everything you’re doing, but using a higher lpi on your engrave? I’ve done that in combination with defocusing, and geta very clean engraving with no lines at all.

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I’d love to see examples and settings of this on PG acrylic. I’ve tested to the highest LPI and there is always an “artificial” banding (much lower than the actual LPI setting) introduced by what appears to be regular “modulation” of the beam.

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Hmmm… maybe it was just such an improvement that I remember it as no banding by comparison. I thank I have a piece of it around here, I’ll take another look at it.

Most of the improvement is probably from defocusing.

Here’s a focused/defocused example from @takitus of being almost .2” out of focus at 340LPI.

Obviously, the subject matter also matters - graphic image vs photo image, etc.


How about floating a very thin coat of UV-cure resin into the engraved recesses? If the refractive indices of the two materials are very close, the interface could virtually disappear. I’ve got some, might try it.


Okay, here’s the result of my test:

I dug out an old test chip from 2 years ago. UV resin added to the right hand side of each engraving.

It looks like some smoothing has occurred but you also lose contrast.

Here’s a photo of the backside:


Thanks for all the suggestions all. I was thinking of annealing becasue I know flame polishing the edges will smooth things out, but didn’t know if annealing would have the same effect to the body itself. (I actually used a flame to hit the one on the left and it didn’t do much to the body. You can see a little melted edge on the neck.) The contrast doesn’t matter becasue I’m just going to use them to make silicone molds from. Thanks for the idea and pics @cynd11 and @Jules! The resin looks the most promising and I’m going to have to look into it. For now I’m doing the last test with a different defocus height and I’ll see how smooth I can get it. The second try on the right is acceptable and I’ve decided to live with a little texture if need be. :slight_smile: I did learn a bit about flooding with weldon though and it does a nice job clearing the engraving. Not sure when I’d use it, but good to know nonetheless.

After and before weldon.


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