They used staples, which are fairly easy to remove after the glue has set. To make it easier to get the staples out, put something underneath them. The old guys used to use thin wire, but now we have the perfect material - the polypropylene tape that's used to band parcels/pallets. This works really, really well and pulling out all the staples in one go becomes fun!
The tape is strong/stiff enough that you can also use nails with a resonably large head - the tape spreads the load enough that you don't get a dimple where the nail head was.
I have found the easiest way to get this tape is to ask factories that receive it on deliveries - in Britain, this can be achieved with the traditional industrial bribe, a packet of Jaffa Cakes to be shared around at tea break, but I guess you'll have to work out the US equivalent:
Andrew
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