# HDPE and Cooking Temperature



## flaco (Mar 5, 2015)

I have watch videos from some members cooking HDPE at 350ºF and having to manually mix or massage the plastic to fill voids and blend the colors, others cook it at 400ºF and take the plastic to a molten state and cooking it till the plastic begins to turn brown and then planning the burnt layers.

My question, have someone experimented with temperatures between 350ºF and 400ºF and gotten to a molten state without having the plastic turn brown even if the process is longer?

Main reason I want to avoid burnt areas is because I have no access to a planer.

I just don't want to re-invent the wheel if somebody has found the sweet spot or ideal temperature to melt without planning will be a time saver.

I'm all ears!


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## JTslinger (Jan 26, 2015)

I know BigDH2000 started making HDPE pretty successfully lately. Might be a good idea to shoot him a PM.


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## Susi (Mar 3, 2013)

Some so called HDPE has a lower melting point than other HDPEs. It 's not standardized. Many items made of HDPE are made of recycled HDPE and it's "toss a quarter to call heads/tails" if it's really all HDPE...maybe some LDPE in the mix. It happened to me. A HDPE chair..used it for the brown component in a woodland camo billet I cooked up. Black poly tube and green from a wash tub. The billet had a lot of holes, not voids, bubbles from one of the three HDPEs vaporizing at 165C or 329F. It was usable but I had to patch the holes...big pain. I recommend using new HDPE from buckets or other rrelatively cheap HDPE sources that are not made of recycled HDPE. Actuallly, HDPE thick sheet isn't expensive, you might just board cut it or fuse two sheets together and board cut the sandwich. Use a heat gun or carefully play a torch over both surfaces to be welded together, slap them together so liquid plastic oozes out of the seam to assure a good bond, clamp, let cool and work.

you'llshootyoureyeout has a lot of HDPE experience too...PM him as well.


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## Kerry Cornelius (Nov 11, 2014)

I tried 425 and that destroyed a whole batch. back to 395 for me.


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## you'llshootyereyeout (Apr 5, 2014)

There might be a significant difference in temperature effects between conventional and convection ovens. Meaning that at the same temp the HDPE will behave differently in each of the oven types.


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## flaco (Mar 5, 2015)

you'llshootyereyeout said:


> There might be a significant difference in temperature effects between conventional and convection ovens. Meaning that at the same temp the HDPE will behave differently in each of the oven types.


That is what I'm afraid since I only have access to a conventional oven (in the house) so avoiding the stink is a big factor however I prefer the molten method that higher temperatures achieve.


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