Eighth Doctor Cravat Pin Project Update
i am continually amazed at the degree of interest in my little project here, so i thought that an update might be in order.
for those interested, current details can be found under the cut...
when last i posted on this, my first attempts at shrinking my master form button resulted in castings that were ultimately too thin. to correct this, a sanded down casting of the button was flipped around and glued to the back of the button, as seen here:
to smooth the seam, it was then puttied and sanded multiple times (3 times, if i remember correctly). with that finished, a new mold was poured.
as the original button is 1" in diameter and the proper finished size of the cravat pin is 11/16", i have engaged the services of a casting material called Hydro-Shrink. with the new mold in hand, a new casting of Hydro-Shrink was made to evaluate the new mold. well, the earlier problems i encountered with Hydro-Shrink shrinking beyond the target size only seemed to be more manifest with the new bulkier master form. the new Hydro-Shrink casting can be seen here:
given that my master form is too small to meet the minimum shrinkage of Hydro-Shrink and meet my target size, i chose to look into making a new larger master form using Hydro-Shrink's sister product Hydro-Span.
Hydro-Span was acquired and a casting poured - seen here:
after soaking in water for 14 days, the Hydro-Span casting of the button was fully enlarged at a diameter of 1-7/8", nearly doubling in size (and yes, the color change is a bit disconcerting). :
this was just a test casting to get a feel for this new material. future trials will focus on how to best pour bubble-free Hydro-Span castings. should this result in a viable enlarged new master form, Hydro-Shrink will then be applied to hopefully result in a properly sized form from which to cast final cravat pins.
this is unlikely to happen within the next month or so, as i am currently focusing on completing an Eighth Doctor costume for Dragon*Con at the end of the month, not to mention the fact that Hydro-Span takes 2 weeks to fully "cure"...
for what it's worth, here is the original master form next to both the Hydro-Shrink and Hydro-Span castings:
