Jack S sent me this link to share with you-
If you don't feel like making your own DIY solar filter you can buy one ready made for $10!! AND if you follow their shipping deadlines you will have your filter in time for the venus transit.
They have several sizes available to fit scopes, finders, and binoculars and at $10 each I plan to pick up enough for my 25x100 binos, finders, my little apo refractor, and one or two more for the larger scopes.
They apparently do not yet have the mylar film type in stock but for $10 I'm not going to be fussy and besides, I suspect the polycarbonate filters are more resistant to damage.