Blocking large items

[Oubli]

I am helping my teenage sister in law yarn bomb her wheel chair for her upcoming surgery, since she is a beginner at crochet and I am experienced so I told her I would d all of the large intricate pieces.

 

In light of this I made a large granny square for covering the back rest but it is off kilter now since I make a 4 yarn spiral and do not want to redo since it is a very complicated square.

 

So at this point I need help blocking such a large square. How do I go about blocking a 20in granny square, I tried steaming and stretching it but since I have no where to pin it (it's so darn big!!!), it reverted to it'd previously wonky shape. I need another method, help, pointers, an off the wall idea etc

 

Suggestions anyone?

 

 

 

 

Ps - Sorry if the photo is too big/small, working with a new tablet and don't know it's quirks yet.

 

[Flia]

I would dampen a towel, lay it over the piece, and then turn it into a big roll

[Oubli]

Will try this tonight, thanks for the suggestion!

[Sarah Schmidt]

Try pining it to your bed. Pin it out in the morning and put a fan on it for speedy drying. That way your

 Piece (and your bed) should be dry by night time.

[Oubli]

I never thought of using my bed! Thanks!!!

[RoseRed]

Can you get a big pizza box or a tv box?  I love blocking on cardboard.  I put plastic wrap over it so it doesn't get soggy.  It holds the pins really well. 

[Oubli]

Another great idea that's throwaway and can be made into almost any size!

 

Thanks guys for so many off the wall ideas!!!