Thanks for the info-would I put the foil on the back of the plate and if so would that stop the ghost image or do you mean put the foil on the front of the plate in contact with the film instead of 120 black paper?I've ben a dedicated infrared user(sometimes near infrared ,konica750,maco cube 400 plus and ilford sfx)for over a year now and usually i just focus first then screw in the filter.I tried a "pro-grain" filter(inside the camera)and discovered that no matter how clean I thought things were,they were not.
Is dust attraction an issue with those filters?

jim