u/SecureStyle2913

Hi everyone,

I'm having an issue when making food-grade platinum silicone molds from resin 3D printed masters, and I'm hoping someone here has dealt with something similar.

I'm using:

• Silgom Food 725 by Sagrista Products – food-grade platinum silicone
• Anycubic Standard Resin
• SLA/MSLA resin printed masters

The problem is very specific: the silicone cures perfectly everywhere else, but the surface that is in direct contact with the resin-printed parts remains sticky/uncured.

When I use the exact same silicone with FDM-printed parts, it cures perfectly.

I've already tried different approaches:

• Thorough washing of the resin prints
• UV post-curing
• Different primers/barrier coatings
• Acrylic spray coatings

But I haven't found a reliable and repeatable solution.

There is one strange detail that might be important:

I made one resin master where I applied approximately 3–4 coats of Montana Plastic Primer. The silicone cured perfectly on that master.

Even more interestingly, I've reused that same master around 5 times and the platinum silicone has cured correctly every single time.

However, when I've tried to repeat the same process with other resin-printed masters, I've experienced cure inhibition again.

So my questions are:

1. Has anyone found a resin that is reliably compatible with platinum-cure silicone?

2. Is there a specific washing/post-curing process that eliminates the inhibition?

3. Have you found a reliable barrier coating or primer for resin prints before casting platinum silicone?

4. Could switching from standard resin to ABS-like resin make any difference?

My final molds need to be food-grade, so I'm looking for a process that is consistent and suitable for this type of application.

Any experiences with specific resin brands/products would be extremely helpful.

Thanks!