exclude list of entries from craft.entries tag

Question

I am attempting to list out all jobs that the current author has created but which are not already to other entries they've created.

I have both an array and a string containing the entry ids to exclude which I can see with these tags:

{# delete later, only here to visually show entry ids while coding #}
<p><strong>array:</strong> {{ excludeRelatedJobs|join(', ') }}</p>

{# convert array to string #}
{% set excludedJobs = excludeRelatedJobs|join(', ') %}

<p><strong>string:</strong> {{ excludedJobs }}</p>

However when I try to exclude the ids from the list they are not excluded.

current code that should exclude ids:

{% set careers = craft.entries.section('careers').authorId(user.id).id('not' ~ excludedJobs) %}
<ul>
    {% for job in careers %}
    <li><a href="/careers/edit/{{ job.id }}">{{ job.title }}</a></li>
    {% endfor %}
</ul>

If I manually exclude the id like this it works correctly:

{% set careers = craft.entries.section('careers').authorId(user.id).id('not 581') %}

Answer 1

As @Youniteus stated in a comment to this post the answer was related to this question

I had to tweak the join statements a bit but it's working now.

complete code here:

{# convert array to string  so we can remove these ids #}
{% set excludedJobs = excludeRelatedJobs|join(', not ') %}

{# set careers to all jobs created by author#}
{% if not excludedJobs|length%} 
    {% set careers = craft.entries.section('careers').authorId(user.id) %}

{# filter out jobs already added to store#}
{% else %}
    {% set careers = craft.entries.section('careers').authorId(user.id).id('and, not ' ~ excludedJobs) %}
{% endif %}

<ul>
    {% for job in careers %}
    <li><a href="/careers/edit/{{ job.id }}">{{ job.title }}</a></li>
    {% endfor %}
</ul>