Re: Q1 Fuselage comes up


Rob de Bie
 

Working from memory, the heat-up rates that I saw recommended for postcuring epoxy were way lower, like 3°C/h. Probably this was for free-standing products; in mold postcuring can be done more aggressively. Check your epoxy data sheet. For the rest it looks really good.

Rob

On 07 Apr 2021 20:58, Eugen Pilarski wrote:
Dear Q-Community,
thanks for your hints and comments. Again, great to get that feedback from you guys!
To post cure the Resin that I use for the Q1 Project (MGS LR385/LH386) it’s already a oven available that is used for the ASSO X-RAY Project (MGS LR285/LH285), please find below some Picture. It´s a full control heating process with some thermocouples and a customizing software solution (DIY).
It’s a easy construction of XPS elements, some cheap fans (Ebay 8$), two control cabinet heater from EBM Pabst (Ebay 20$), some bulbs (5 * 200W) and in the end a customizing fermentation controller (BrewiPI), please find below the link. https://www.brewpiremix.com <https://www.brewpiremix.com>  After all my aircrafts are in the air, maybe I will start to made my own beer :-)
To fit all parts of the Q1 in that oven it will be needed an extended version, if my buddy isn’t ready to go with his paint booth. So we will see……
The temperature will not rise more than 65°C, based on the Foam used in wing and canard area, for min. 15h but heat up 10°C/h (5h) and cool down with 10°C/h (5h).
So far all bulkheads are ready to go, just the seat bulkhead need to heat up (bending area) and fixed with resin/glass combo. The next step will be to contouring/cut out the bottom for fuselage. So far the temperature here in Germany will rise up a bit more, the glassing will start soon.
Best regards from Germany
Eugen

Am 07.04.2021 um 17:59 schrieb One Sky Dog via groups.io <http://groups.io> <Oneskydog@... <mailto:Oneskydog@...>>:

If your airplane gets above 150 F you will have other problems. 150 F cooks flesh. We post cure in aerospace because the designers cut the margins thin knowing we had proper process control.

No mold less construction airplane that I know of has had heat distortion problems post cure or not.

Much ado about a statistically non issue.

Time promotes cross linking and that is all post cures do is further cross linking.

Charlie






My you tube channel
https://www.youtube.com/channel/UCr3x6bkHUw1UUQ96ATcRFfg <https://www.youtube.com/channel/UCr3x6bkHUw1UUQ96ATcRFfg>

On Wednesday, April 7, 2021, 8:26 AM, Rob de Bie <robdebie@... <mailto:robdebie@...>> wrote:

> In any case, the way I see it, time is a partial substitute for temperature in the cure
reaction,
> and especially effective if you take a such a very long time to build like I did!  …..So
maybe I did
> post cure my wings after all.

I see your point, but as far as I know this does not apply to the glass-transition temperature.

Rob




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