| Author | Message | ||
     Anonymous |
I made the vaccum pump project and my dad and I tryed a bunch of kind of glue and they all leak... We were using stuff like sealent and nuts to hold it down but I think we need something harder but my dad says that epoxy isnt approved for food products (strawberrys that we are freez drying) We are using the brass fitting but solder doesnt stick to it and its not exactly heathy either. My dad said to ask you what you reccomend. | ||
| Simon Quellen Field (Sfield) |
The glue for the PVC parts of the pump should be standard PVC cement. It is a solvent that will weld the parts together. To solder something, the parts must be very clean. Use sandpaper or steel wool. Also, use a soldering flux, or solder that contains flux. Plumbing solder in the U.S. contains no lead, and is safe for pipes carrying drinking water. It is tin with a little bit of silver. Both are safe for foods. Likewise the PVC cement is safe for pipes carrying drinking water. PVC cement will not work on anything but PVC, so use solder for the brass and other metal parts. If you are having trouble with the first pump described in the book, try the second one, which is much simpler (but about $5 more expensive). The second pump uses two store-bought valves, instead of one store-bought and one homemade. |
