Flow Battery Research Collective

Hi, Timothy from the US. Casual interest in the project. Would like to build a battery for house backup at some point, but give the additional cost of inverters and solar for charging, permits, etc., it's likely more of a pipe dream.

I'm no expert ether. We used quick setting plaster a lot in construction for repairs on a lot of things and now they have a "wood epoxy" which is an epoxy for wood repairs. You have a thing epoxy you brush on onto wood which provides a good bonding surface for dry rotted wood and then you mix an epoxy that works more like the quick setting plaster and creates a strong enough repair that you can nail it. These plasters and epoxies could be formed or poured to create a nice mold. For the quickset we could build up an area, then carve and shape it before it fully set. The surface is very smooth and with a spray sealer of some kind should be even better for molds.

A quick look into casting, it looks like the most common is using silicon for making the mold. Yes it lets you do detail, but it is also soft and flexible. Not good for making thin plates without warpage.

I saw the blog post which also mentioned the problems of 3d printing the panels of that size without warping. I did a quick google on injection molding and that could also get $$$ and a bit beyond some DIYers with the need for pressure.

But what about casting? Are there resin based or other low temp materials that could be cast? Because making the mold would be easy. A dummy part could be printed from any material and it could be made in, say forths that could be glued together. And for the mold there is a quick setting plaster like material we use in construction for repairs (one brand is "Quickfix) that dries to a porcelain like material, very hard, and very fast. It's sold with set times in minutes. Make your dummy part and put it on some wax paper or plastic wrap on a flat surface with a frame around the part. fill with plaster and when cured, spray with a sealer that wont react to the resin to seal the micro pores. Then with it flipped over and the dummy back in, and the frame around it, pour the other half. You have a simple and cheap to make mold for casting.

I was thinking of casting (posted in the other thread), but if you are printing enclosed complex channels, that would be a problem. I didn't think you could print horizontal channels without the material sagging into the channel.

I can see that unless the gasket was supper thin, it could squeeze into the channels in a layered design. But something applied in a thin liquid form such as an adhesive might work. I just googled the printer and cutter you're using to make the plates and gaskets. Some $1300 for both, ouch.

The other post I was referring to was in "Designing the large-format cell". I was wondering if there are option to cast using resins or other material instead of printing. Would solve the problem of trying to print large plates without warping.