Bricks, about 10 bricks!

Make sure the're nice smooth ones with 90 deg edges.

I use them on the building board to hold fuselage sides upright & square
when I pull the front & rear in to the required spacing for formers.

Sort of a poor man's building jig.

Come in handy for weighing things down too.

Did I mention they are as reliable as .... well, a brick?

- John.