u/Content_Resident_318

Since I know how much this subreddit loves López de Heredia, I thought I'd share a few photos of what I found at Costco here in Spain: Viña Tondonia Reserva 2013 and 2014 just casually sitting on the shelves.

Not exactly what I expected to find on Costco run, but I'm certainly not complaining.

There's something slightly dangerous about being able to buy a giant pack of toilet paper, a rotisserie chicken, and a bottle of Tondonia in the same place.

Anyway, I figured the LDH crowd here would appreciate the sight.

Posting this here because I originally considered posting it in a resin 3D-printing subreddit, but most of the discussion there seems to be about printing miniatures rather than abusing resin molds with molten metal, so I figured r/metallurgy might find this experiment more interesting.

I've been experimenting with casting small lead parts using molds printed directly on an SLA/MSLA resin printer.

The mold is made from regular UV-curing printing resin. No high-temperature or casting-specific resin was used. The idea was simply to see whether a directly printed mold could survive molten lead long enough to produce a few usable parts.

Lead melts at about 327 °C, so this is obviously far outside the normal operating temperature of this type of resin.

Surprisingly, it worked reasonably well.

The pictures show the mold, some of the resulting castings, and the thermal damage after several pours. The geometry was reproduced fairly well, although there is some flash along the parting line and some surface defects.

The resin mold gradually deteriorated rather than immediately failing. The surfaces directly exposed to the lead became rougher, cracked and locally degraded after repeated pours.

There were two different molds with different cavity volumes. The larger one suffered noticeably more damage.

This seems reasonable from a thermal point of view. With a larger casting there is more molten lead transferring heat into the mold, and the larger thermal mass also keeps the metal above its solidification temperature for longer. Therefore, the resin remains exposed to high temperatures for a longer period.

Another uncontrolled variable was pouring temperature.

The lead was melted with a torch and I wasn't measuring its temperature. Some pours were made shortly after the lead melted, while on others it remained molten under the torch for considerably longer before pouring.

Since molten lead looks essentially the same whether it is just above its 327 °C melting point or considerably hotter, I suspect this explains some of the differences in mold damage between pours.

For the next version I'm changing the gating system. The casting will connect to the pouring area through a short tapered neck so the sprue can be cut off more easily. I'm also planning to add a small open reservoir/riser above it. The intention is to keep some molten lead available to feed the casting during solidification and reduce shrinkage defects.

Thanks for reading, and sorry for the massive wall of text!