I did a quick search on this but couldn't find an answer so here is a new topic! Can a household oven be used for curing? Other than a vacuum bag port of some sort, what modifications absolutely need to be made for it to work? I have access to a cheap used one that i could put in my garage but wont bother if it wont work well for composites!

Of course, it would work fine. 

The problem with household ovens, aside from the hygiene issue if its still in the kitchen, is the temperature regulation.  Most domestic ovens the temperature can vary from what is set by as much as 20C as the oven heats and cools while it is running.  Depending on your cure cycle this might play havoc with the resin flowing stage of the cure and compromise surface finish. 

We know people regularly build ovens using domestic oven components and side from the obvious safety precautions, we always suggest using a good quality PID controller to ensure the temperature regulation is pretty accurate. Also many PID controllers are programmable so you can in theory program an entire cure cycle into the unit.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

Thanks for the replies! I do plan to bring the oven into my garage. I was wondering about the temperature control and you guys have verified it would be best to override the control. I have an arduino that i could maybe program to control the burner with PID and an SSR. 

If yours is a gas oven rather than electric, then I wouldn't want to suggest an ideal controller as gas ovens are not a familiar area of expertise and the potential to blow up your house is quite high if the gas burner is modified and not properly checked.   The PID controllers generally are switching, via a relay, an electric element which in most cases has a fan to ensure even heat distribution in the oven.  I would imagine a gas oven would not be that evenly heated.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

Luckily this is an electric oven! I may try to also use it for powdercoat curing on metal parts. Thanks again.

on second thought, with the price of those chinese PID controllers im finding, it would be silly to waste time with the arduino! Maybe another project later on

Just make sure the PID controller you get can directly switch a SSR. Many of the Chinese ones on ebay say they can use a SSR or even come with one, but then require you to do some minor rewiring inside the PID to make it work. 

You also need to think about how fast it would heat up.. You do need a controlled ramp rate if you only have a simple PID controller. Some may not agree but I have seen a massive difference in finish with a higher ramp rate than the 1 degree every 90 seconds I currently run. I have also seen issues with a temp difference as little as 5 degrees too..  So make sure you check the oven has even heat in multiple locations through the oven and no hot or cold spots. A higher rate of flow from the fan would help if the air flow is not great. My oven recirculates the air once every 12 seconds according to the claimed airflow on the fan. This creates enough turbulence to make the oven have a more even temp throughout.   

hmm. I wonder if the oven im looking at has a fan already. Is that a standard feature or is a circulation fan something i will need to install myself? Also, im wondering if one PID could handle controlling both the SSR for the element(s) and a relay for the fan.