Do you post-cure a part inside the mold, or outside (once demolded) ?

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Do you post-cure a part inside the mold, or outside (once demolded) ?

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Jess8bit	Jess8bit posted 12 Years Ago HOT Topic Details
Group: Forum Members Posts: 133, Visits: 566	Yeah, again a silly n00b question of mine And how do you heat it ? simply by placing it in a domestic oven, @60° for some hours ? thanks guys !!
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carboncactus	carboncactus posted 12 Years Ago HOT Post Details
Group: Forum Members Posts: 243, Visits: 1K	Depends on the HDT of the resins in your mould and in the part. Not to mention the release agents used. Data sheets of the resins you used should mention post cure cycles. Due to shrinkage, I always post cure with the part inside as much as the part will take. Even with "zero shrinkage" resins, there is always shrinkage. Although your part fits in a domestic oven, so no significant shrinkage will occur. Another reason to post cure with the part inside is less chance of damaging the mould when you pull, as the mould will be much stronger. For example, I recently made a mould off a fibreglass wing. Lowest HDT of my resins used was 100C for the tooling resin. So I started at 45 and ramped to 65, left it for 4 hours. As the part inside was fibreglass of unknown resins, I didn't want to take it any higher. So at this point I took the part out and continued with the post cure. Ramped to 80 for 4 hours, ramped to 90 for 4 hours then ramped to 100 for 4 hours. Shut the oven off and let it cool down by itself. If this was a carbon part I was moulding off, I would have left it inside all the way up to 100. Ramps should be at 2 degrees per minute. In large ovens its not much to think about since the larger the oven, the slower it heats up. But in smaller ovens, it's something to keep track of. Also mind the fumes that are going to be released, is this your kitchen oven?
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