Скачать или смотреть Tape Mold Release Experiment (No Wedges, No Fight)

Conventional method for one-off packing-tape mold release is to cover the part with clear packing tape before laying fiberglass over it. This works great and separates a lot easier than parts made in a conventional mold with wax or polyvinyl alcohol as a release layer. It can be a mild struggle and wedges are helpful when separating the new fiberglass from whatever shape it was laid over.

Experiment one replaced the packing tape with blue painters tape. When the fiberglass had hardened, the parts separated easily with minor hand pressure. No wedges were needed and it wasn't a struggle. The glue part of the painters tape let go when the parts separated, leaving the blue tape stuck to the fiberglass that was laid over it. Although it was possible to peel the tape away from the fiberglass with a lot of scraping, it was easier to make another part. Although the parts separated so easily, the new fiberglass was glued to the outside of the tape and this is not a method to use again.

Experiment two intended to gain the advantage of the blue tape releasing easily from the glue side but avoid the problem of new fiberglass sticking to the outside of the blue tape. The plan is to use two layers of tape, the blue tape covers the part the fiberglass will be laid over, then clear tape goes over the blue, so fiberglass won't stick to the outside of the tape sandwich.

The result was surprising because the pieces separated at the interface between the two kinds of tape. I had assumed the glue on the blue tape would separate from the original and both tape layers would be stuck to the new fiberglass and peel off of that just like packing tape always did. No wedges were needed and the parts could be pulled apart by hand. Downside is the time spent putting on two layers of tape.