The procedure you need to follow is the same as that he described for italian threaded fixed cups:You might worry about damaging the cup, but this is not likely to happen. The washer doesn't usually come into contact with the bearing surface. Even if it did, bearing cups are made of extraordinarily hard, heat-treated steel, much stronger than that used to make washers.
I cannot see the purpose of the second nut. It is only necessary to have one nut which can be held with a spanner to stop it rotating when the bolt is tightened against the washers.To remove a right-threaded fixed cup (French or Italian), tighten the bolt with the socket wrench from the inside of the bottom bracket, holding the nut with the box wrench. Once the bolt is as tight as can be, keep on tightening it, until the cup screws itself out. Once the cup starts to move, turn both wrenches together.
If your washers are warping significantly, then they will have less surface area in contact with the cup, and there may not be sufficient friction between them and the cup to stop them just rotating while the cup does not move. If that is happening, then I think you need a bigger bolt, nut and washers (ideally M16 if that size bolt will fit), and an appropriate sized deep socket which will fit inside the BB shell, ideally a socket which took the largest drive breaker bar you can lay your hands on.The size of the bolt is not particularly critical, as long as the bolt is strong enough not to break, but small enough to fit through the hole in the cup. I used to use an ordinary 1/2-inch, 13 TPI hex bolt (also called a "cap screw"), which served me well for quite a while. It finally met its match on friend's Schwinn that had an unusually tight fixed cup; the bolt snapped in two before I could remove the cup.
Now I use a 5/8-inch 18 TPI hex bolt 1 1/2inches long, with a nut, a flat washer, and four lockwashers. The 5/8-inch size is the largest standard size that will fit through the hole in the cup. This bolt and nut both take a 15/16-inch wrench. With my 1/2 inch drive Craftsman six-point socket set, the 15/16-inch socket is also the largest size that will fit into a normal bottom bracket shell.
If you have some other brand of socket, check the fit before you buy the bolt and nut-you might need the next size down (9/16-inch).
I don't know anything better than PlusGas Dismantling Lubricant.hoogerbooger wrote: ↑24 Jun 2021, 10:10am penetrating oil I used was a v old halfords graphite based one ...what's the best ?
I would have thought that washers would still be needed if two sockets were used, i.e. in between the nut and the socket at both ends.peetee wrote: ↑24 Jun 2021, 6:35pm I would forget washers, they will distort. Use a socket on both sides of the cup and roughen up and clean the end surface to increase purchase. The ends could even have notches filed into them without rendering them useless for their intended purpose in future. Find the largest dia threaded bar that will pass through and try turning clockwise initially (So the nuts are being tightened) to break the bond with the bracket shell.
Sheldon explained the use of those four washers as follows:531colin wrote: ↑25 Jun 2021, 10:01am Take your removed fixed cup to your chosen nuts and bolts shop....you need the biggest nut which will fit inside the cup, to substitute for Sheldon's stack of washers. (more bits = more chance of slippage). Then you need the biggest bolt which will pass through without engaging the thread, and a nut to fit. Also a socket to fit the new bolt....take your existing sockets with you.
Something else I would check is the maximum outside diameter of socket that would fit inside the BB shell, including allowing for any irregularities inside the shell. If there is a protuding bolt tip in the shell holding a cable guide under the bottom bracket that can simply be unscrewed, but any other irregularities might not be so simple to deal with.A large socket wrench will not fit into the cup, so you will need some small-diameter washers to space the head of the bolt out so that the socket wrench can reach it. This is what I use the four split lockwashers for. I didn't need lockwashers as such, but the readily available flat washers were too large in outside diameter to fit into the cup.
