With the right stamp, you can stamp cured soap

[glendam]

Caveat: I still do not know how to achieve it myself and I doubt it would work with really small letters.

but.... I just learned that I can stamp my already cured soap, with a 3d printed stamp that was originally designed to be a cookie cutter.
It seems the key is having tapered edges on the print design (what first makes contact with the soap). I modified a puzzle cookie cutter file I found online, to make a puzzle stamp instead.

After some failed attempts, I printed something that could work, but I only have cured bars to test it. I am usually unable to stamp already cured soap, but I tried it and it worked (without using a mallet)!
It seems the way to achieve this tapering is beyond my current software and abilities, but perhaps it is something you could inquire from vendors. I will be looking more into it.

 

[KimW]

I call first dibs if you figure it out with your setup!

 

[glendam]

I call first dibs if you figure it out with your setup!

Cool! I am redesigning my stamp and have downloaded a free software that might work, going into a rabbit hole I fear!

 

[ResolvableOwl]

I fear with you. You remind me that I have one or another silicone mould project in the make… my concept is a 3D-printed positive, cast with silicone rubber to make a (or multiple) flexible moulds. Reproduction quality of silicone is no less than mind-blowing, and its elasticity even allows for “impossible” shapes (that aren't tapered, have overhang etc.).

 

[DeeAnna]

@glendam -- the taper you talk about is called "draft" by engineer types who do this kind of work for a living. Maybe knowing that word will help you figure out how to convince your software to give you what you're looking for.

The computer aided drafting program I use has a setting where you can extrude a flat shape to form a 3D shape. Normally a circle, for example, would extrude into a cylinder. But if you set a value for the "draft" angle, you can extrude a circle into a cone. Hope this helps.....

 

[glendam]

I fear with you. You remind me that I have one or another silicone mould project in the make… my concept is a 3D-printed positive, cast with silicone rubber to make a (or multiple) flexible moulds. Reproduction quality of silicone is no less than mind-blowing, and its elasticity even allows for “impossible” shapes (that aren't tapered, have overhang etc.).

That sounds very interesting! I have some silicone I neee to use but can’t figure out what to make. Do share it when you have made it!

@glendam -- the taper you talk about is called "draft" by engineer types who do this kind of work for a living. Maybe knowing that word will help you figure out how to convince your software to give you what you're looking for.

The computer aided drafting program I use has a setting where you can extrude a flat shape to form a 3D shape. Normally a circle, for example, would extrude into a cylinder. But if you set a value for the "draft" angle, you can extrude a circle into a cone. Hope this helps.....

That’s very interesting! I wouldn’t have known, thank you!

 

[glendam]

Well, most of my day yesterday was spent learning what DOES NOT work to achieve the draft/tapering. Installed several programs only to learn that they did not work for my purposes. It seems achieving this an easy option in paid software though, like fusion 360 but at a cost above $400 a year, I will pass for now. However, this morning J. gave me the idea of trying photoshop, which I already pay for anyway. And it seems to have worked! I will print an attempt and see what happens, it seems I may be doing too steep a taper so far, but we shall see.

 

[luluzapcat]

Have you tried OnShape? It's is a free online CAD software that's pretty powerful. I'm sure it has a draft feature, although I haven't used it yet.
If you get stuck I can try figuring it out and share what I learn--I actually used to design plastic parts for a living, which all require draft to come out of the mold!

 

[glendam]

Thank you! I will check it out. Funny you mention the mold/parts needing drafting, I read that elsewhere while researching this and it has informed my future mold making projects!

Have you tried OnShape? It's is a free online CAD software that's pretty powerful. I'm sure it has a draft feature, although I haven't used it yet.
If you get stuck I can try figuring it out and share what I learn--I actually used to design plastic parts for a living, which all require draft to come out of the mold!

 

[glendam]

So here are my findings.
1. while the draft / tapering improves the stamping in a 4-6 weeks old soap, it does little for a soap that has cured for 3 months or longer.
2. thin lines seem to work better than thick sections. I may make two stamps, one for when I stamp on time, and another for when I forget and need to stamp after two weeks.

The first soap is how my stamp looks when I stamp 2-3 days after cutting. The one to its right is when I stamp after 2 weeks. The initials work but the feather detail is gone.
The last picture is with the new stamp that has the draft, stamped after 4 weeks of cutting. More detail on the feather but not quite an indentation.
Lesson learned is that it is better to stamp on time, but with a redesign of the logo I may have a stamp that works in after 3-4 weeks, but would not venture beyond that.

 

[Todd Ziegler]

Caveat: I still do not know how to achieve it myself and I doubt it would work with really small letters.

but.... I just learned that I can stamp my already cured soap, with a 3d printed stamp that was originally designed to be a cookie cutter.
It seems the key is having tapered edges on the print design (what first makes contact with the soap). I modified a puzzle cookie cutter file I found online, to make a puzzle stamp instead.

After some failed attempts, I printed something that could work, but I only have cured bars to test it. I am usually unable to stamp already cured soap, but I tried it and it worked (without using a mallet)!
It seems the way to achieve this tapering is beyond my current software and abilities, but perhaps it is something you could inquire from vendors. I will be looking more into it.

I have experienced the same thing that you have. I took a very small jewelry file to one of my stamps and tapered the edges to a finer point and it works great on 1-2 month old soap but I had difficulty with older soaps like you did.

However I found a way around the older soap by heating it up in the microwave just a little. It works but it is very easy to get the soap to soft.

 

[ResolvableOwl]

Great looks, you're definitely on to something! I'm very curious about your progress.

Next time when you have a dark coloured soap in the making, you might take a bit of the batter, smear it onto the stamp, and scrape off the excess with a squeegee or a soft spatula.

 

[glendam]

I have experienced the same thing that you have. I took a very small jewelry file to one of my stamps and tapered the edges to a finer point and it works great on 1-2 month old soap but I had difficulty with older soaps like you did.

However I found a way around the older soap by heating it up in the microwave just a little. It works but it is very easy to get the soap to soft.

Warming it up is a good idea, I had not thought of that. Thank you!
It did occur to me to make a stencil, if I really want a logo on the older soap, with soap dough

Great looks, you're definitely on to something! I'm very curious about your progress.

Next time when you have a dark coloured soap in the making, you might take a bit of the batter, smear it onto the stamp, and scrape off the excess with a squeegee or a soft spatula.

How timely! That is the process I was thinking of, except with a stencil. However now that you mention it, it would look nice on a stamp impression, for contrast. I tried adding mica to the stamp before as well, and it was good too. Thank you!

 

[luluzapcat]

@glendam, just want to say your stamp is beautiful!

 

[glendam]

@glendam, just want to say your stamp is beautiful!

Thank you!!

 

[msunnerstood]

I bought a 3d printed soap stamp and have really good luck with stamping soap up to several weeks after cutting. I have not tried 3 months though

 

[glendam]

I bought a 3d printed soap stamp and have really good luck with stamping soap up to several weeks after cutting. I have not tried 3 months though

Nice! I wish I could do that. My soaps harden really fast, normally I do a 40% lye to water concentration and my recipe has over 60% of hard fats.

 

[LidiaG]

Warming it up is a good idea, I had not thought of that. Thank you!
It did occur to me to make a stencil, if I really want a logo on the older soap, with soap dough

I know this is an old post! Thank you for this info! It was the only thing I found when I was trying to stamp a super hard 3 week old ZNSC batch that I had.
In case someone ends up here with the same problem that I had. I was able to use a blow dryer to warm up the surface to be stamped and gently stamp it with a rubber mallet.
I did not stamp as deep as I usually would but it was better than leaving it without the stamp.