Marking silicone molds

[opal1970]

Hi all,

has anyone heard of a way to make permanent markings on RTV Silicone molds? I would like to catalog my molds and also note the amount of resin needed for the cast on the mold itself. unfortunately, permanent markers are not permanent when it Comes to Silicone. I believe Silicone is heat resistant up to 600 degrees or so, so Branding numbers into the Surface will not be possible with any Equipment that i have handy.

In my Research, i did find a link from a paleontology Website (no not a sect, the guys that dig out dinosaur bones and cast them ) how to Label molds, but as fate would have it the link is down. I will write them and see if they can help me out, but in the meantime if anyone here has any experience or suggestions, I would love to hear it.

Thanks

 

[robn1]

Only thing I can think of: silicone will stick to itself. Mix up a small batch, add some black tint, and paint it onto the mold.

 

[TazMan2000]

Another way is to package the silicone in another container and to put a sticker on that. This way the mold will be protected further from contaminants. When the mold isn't useful anymore, you can throw it away and put a new mold in the same container with a new sticker.

TazMan2000

 

[mirdhim]

Hi!
The most bored but permanent method is:

You put a coat of plasticine and grab whit a sharped point the text simetrical (bufff hard to oxplain me in English).
So, the silicone, will reproduce the text in relief

 

[opal1970]

Thanks guys,

Robn, you are a genius, that is an excellent idea. I do not know why I did not think of it. I can carve a small area out of the mold. I can make a stamp with the Inventory number and amount of resin required. Then fill in the gap with fresh silicon (I always have a bit extra when I make a mold), put the stamp on and let it cure.

TazMan, your idea is also good (if I was not so sloppy with putting things back where they belong when I am finished with them.)

- - - Updated - - -

Hi!
The most bored but permanent method is:

You put a coat of plasticine and grab whit a sharped point the text simetrical (bufff hard to oxplain me in English).
So, the silicone, will reproduce the text in relief

Hi Mirdhim,
Thanks for your input too. Unfortunately, I do now know the exact amount of resin required until after the mold is made and I have done my first cast

 

[mirdhim]

Hi Mirdhim,
Thanks for your input too. Unfortunately, I do now know the exact amount of resin required until after the mold is made and I have done my first cast

Arquimedes!

Put the piece into a gradued glass, And take note how much the water line increase!

 

[opal1970]

Arquimedes!

Put the piece into a gradued glass, And take note how much the water line increase!

LOL, yes. that works for larger pieces, but often I am working on pieces that only need 1cc or 2cc of resin.

 

[DizzyStrmtroopr]

I just pour water IN my molds, then pour it into a mixing cup, then that's how much resin I need

 

[opal1970]

I just pour water IN my molds, then pour it into a mixing cup, then that's how much resin I need

Hi DizzyStormtrooper,

Thanks for the tip. Yes, water works well for this. I have also heard of people using sand. My question was not so much how to measure the amount of resin needed for a mold but rather how to get a note of that measurement (permanently) onto the silicon mold so that I do not have to measure it each time I want to cast it or have to look it up in a list

Mirdhim's method mentioned above of putting the piece to be molded into a glass of water and measuring the difference is useful to determine the amount of resin needed before a mold is made.

 

[mslz22]

I would just use an exacto knife and cut a small inscription, not deep enough to effect the mold, but clear enough to see. It seems a bit easier than cutting a chunk out and having to replace it. As long as there is enough thickness to the mold it should not effect or deform a casting.

 

[opal1970]

I would just use an exacto knife and cut a small inscription, not deep enough to effect the mold, but clear enough to see. It seems a bit easier than cutting a chunk out and having to replace it. As long as there is enough thickness to the mold it should not effect or deform a casting.

Yes, that crossed my mind as well. It would be the easiest way, but it is not always easy to cut out small numbers and letters and have them readable in the end. Some of the molds are quite small so I would not always have the luxury of enough space to comfortably work with an exacto.

I will be adding data like the date the mold was created, the amount of resin needed and perhaps a catalog number for referencing the parts. At best they would be simply readable. Secondly, currently I am the only one using them, but I cannot foretell if it will always be that way... so it is best if everything is as clean and neat as possible.



I can use a DIY stamp (costs about 6 EUR on Ebay) to either stamp into fresh silicone on an old mold or create a thin square of silicone with information on it and then "glue" it to the mold with more silicone. Yes, It sounds like a lot of silicone making just to have a couple numbers on a mold, but when ever I make a mold I always have a bit left over that I do not know what to do with. So I can use that to bit by bit upgrade all the old molds.