How large a blank can go out of casting resin?

[Valin6210]

Aside from the quantity of material needed, is there any reason not to cast blanks for pepper mills out of casting resin?

Would there be a strength issue with something that big and then cutting a large hole through the middle?

For reference the pepper mills need to start with at least a 2 1/2" square blank and then get about a 1" hole cut out of the center.

Cheers,
-Rich

 

[Fred Bruche]

Maybe do a cost analysis first if you are going to offer these for sale.
Heat could be an issue, depending on the resin you use.
You could have a mold with a 1" wood dowel in the center, that would save some resin.

 

[Stubach]

Could also make a custom blank mold using silicone and or PVC to leave the hole hollow. I've seen makers on YouTube create tubes of silicone they suspend in resin blanks to create a void for various reasons so no reason you couldn't do the same with yours. Again would save the resin and the stress of drilling that large of a hole.

im picturing in my head a PvC length with painters tape or a custom silicone stopper on one end with a Silicon rod in the center. May need to reinforce the silicone with a steal bar or something internally though?

Deep pour resin only to mitigate the heat issue but if walls are only half an inch or less thick I wouldn't thing it would be too big of an issue?

 

[JohnU]

Alumilite slow works just fine for pepper mill blanks. Because it cures slower, there's less heat to cause thermal cracking. I've made some of these casts for a good friend who likes to make them. I cast them round. PVC will work as a mold but it can sometimes present challenges during remolding. Look for a plastic container with a recycle code #5, the size you want for a mold like armor all wipes or a one liter pop container. The grocery store is full of potential molds, only most of them are a one time use.