Monday, March 2, 2009

demolding the top part

I probably should have let the thing cure a bit longer in the mold but it looked solid enough and I just couldn't wait. I'm that way with scabs, too. And like a scab unready for the picking, it took plenty of encouragement to bust the mold loose. First some prying between the flanges, then a bit of drumming on the hull to pop free along the surface, more prying, more pounding, you get the idea. These things stick together quite a bit because of the PVA. It's weird stuff: a thin membrane that starts off applied to the mold but when you take everything apart, it ends up on as a coating on the final part that you just rinse off with water.

This is how it looked immediately out of the mold, so a lot of boogers and some flash to clean up, but the part seems pretty sound!

I ran it out to the garage to confirm fitment with the bottom, and after roughing out the edges a bit they look to be mating pretty well.

Next step will be to double up a few more layers on the top part from the inside where it looks a little thin, then it's on to fitting up the petcocks and gas cap.


  1. This is stunning! I'm impressed by the smoothness of the surface, with the piece coming right out of the mold.

  2. Hey thanks for the comment, Alexander - Believe me, every imperfection in your plug will be transferred over as an exact duplicate in your final part! There are a lot of little imperfections taht I'll have to sand out but overall it came out a lot better than I had expected it would.

    Also, I should mention in the post above, but it takes a bit of coercion to demold the part. First I had to rap on the outside of the mold with a large wooden spoon to help "pop" the surfaces away from eachother. Then It's a lot of careful prying before things start to release.

  3. I think the Opinel 8 is on several top 100 lists for elegant design. I would have to agree.