Remove header from single posts?

Hi, I need to embed a Timely events calendar into another site in an iFrame (don’t ask, an emergency fix for something else). Since it’s embedded in another page, I’d like to be able to remove the heading and footer, and since we’re not blogging anything, I can just remove it for all is_single pages.

But I’m running into issues applying this properly – I looked at modifying the header.php file in an Enfold child theme like this (modifying line 73 of the header):

	if( !$blank || !is_single() )//blank templates dont display header nor footer, and we don't want them on single posts at the moment

But this simply whitepages any single post, so I obviously did something wrong, probably just making mistakes with basic syntax – it’s been a while since I touched template code, and I’ve definitely got rusty!