In simple terms the journal is like a diary so contains things you have done to or with your car. When seeking advice, opinions or help etc then the thread should go in the appropriate section be it technical, trip reports or off-topic for example.
If you want to natter in your own journal so be it but just be aware that others will probably lose interest if your "build" journal is clogged up with non-build "natter" ;-)
Anything that is not about cars in general should go into the off-topic section.
As per some of the forum rules:
2. Post new threads in the correct forum category; each category on the main forum index page includes a brief description of what belongs there. Threads posted in the wrong forum will be moved to facilitate searching/retrieval of that information.
3. Whenever possible, post a reply to an existing thread vs. starting a new one. Like threads may be merged without notice.
5. Assign a meaningful title when posting a new thread so that the subject is obvious. No language-filtered profanity or special characters in thread titles, please.
7. Please stay on topic and do not “hijack” threads. The subject of a thread is determined by the original poster. Interrupting/derailing a discussion with off-topic remarks is rude and makes it difficult to find posts that are pertinent to the thread topic. Hijack posts may be removed.