Have been trying to splice an eye in 5/8" Samson Nylon double braid. Have had a very hard, read impossible, time getting the fid through the cover to push the core through. The cover is so tight that it's been near impossible to get it through the cover with the core still attached. Usually lose the core from the fid long before I can pull it through. The line is a cut off from a long length that's been dumped in the lazarette for ages. It's never been used but has suffered the abuse of stuff piled on top of it. Watched the videos and it looks so easy but not the case with this line i'm using. Have the right size fid and doing all the tricks to loosen the cover up without success. Am I doing something wrong or is it just an obstreperous piece of line.