Total madness with an 18,000 piece jigsaw puzzle

A month ago, I bought this https://www.playthek.com/ravensburger-rav-puz-magisches-buecherregal-xxl-18000-17825-18000-teile-ravensburger-toys-spielzeug-pZZa1-2097727285.html?language=en&currency=EUR&utm_source=froogle_nl&utm_campaign=froogle_nl&gclid=Cj0KCQjwjPaCBhDkARIsAISZN7R8P1dGoYk2w1a4O5C7NTZQdBchyMUEGXuXJ7KmZTiHhO4ilF8wJEwaAgBFEALw_wcB . I was working on a 4000 piece puzzle at the time, and I have been wanting to do something completely crazy like this for a while. I can do it while I live somewhere rented without a cat - that may change in 2023.

The 4000 piece puzzle took three months - the objective is to finish the 18,000 piece puzzle by Christmas. It has been tipped into one box, and I won't look at the box again until I dismantle it on New Year's Day. Here's the full box with the picture - I've tipped the four plastic bags of 4500 pieces each into the box:

The first thing which struck me was the relative size of the box bottom and the box top. There is no way that I can go through and take the edge pieces out, putting the rest of the pieces into the lid - there simply isn't the space. But it doesn't really make sense, in any case. In a 500 piece puzzle, let's say 25x20, there are 88 edge pieces. That's 18% of the puzzle. However, the 18,000 piece puzzle is something like 180x100 - 478 edge pieces, or 2.65%. Put another way, having sorted the edge (and doubtless having missed a few pieces) I would have 17,522 pieces to go. I need a different plan.

There are two facts you need to know which are input to the plan. Firstly, here's where the puzzle will go:

 

There is just about enough space. The table in the corner may need to move until next year, but we'll see. 

Secondly, I have a new bookcase arriving, allegedly next week. I want the floor space to be clear when the bookcase arrives, so no pieces can go on the floor until then. So how do I approach things?

Well, I kept the plastic bags which each contained 4500 pieces. I have some Ravensburger sorting trays and some microwave reheating dishes. I started out like this:

This is sorting by colour and edge - from the plastic bags clockwise, white, black, yellow and green, edges, red and pink, blue. If it's a mixture, it goes with the colour with fewer pieces. When a tray becomes full, it will be tipped into a microwave reheating dish. When a reheating dish becomes full, it will be tipped into a plastic bag. The thing I really want to avoid is having 9000 "miscellaneous" pieces in the box lid, so new sorting categories may be needed.

Why the bulk approach rather than sorting into smaller groups from the start? Two reasons. One is that I don't want tens of containers all over the place for nine months. The other is that I think I can tip 4000 fairly similar pieces on to the floor and work that way when I need to, keeping the rest fairly out of the way. I tipped the last 2000 pieces out from the 4000, and went much faster once I did.

So, given the floor is out of bounds for a while, how will I approach putting pieces together? Well, I have a puzzle mat I can use on my kitchen table, so I could put sections together there, roll it up, and move it. I won't start with the edge for obvious reasons, but I found that it doesn't give the huge advantage it does with smaller puzzles for the reason stated above. 

I aim to update the blog about three times a week with progress. Please feel free to comment.