There was a discussion on this forum about Lionel F3s getting a hump from the plastic shell shrinking and warping, but no remedies. Has anyone tried anything to fix this? I recently received a set of F3s from a friend, and both have the hump; other than that, they are not in bad shape. I'm not looking at this from a collector point of view but rather just wanting them to look better, so am not concerned about affecting their value, which I think is minimal anyway.
Replies sorted oldest to newest
Hello Bruce:
If possible, can you post a few pictures of the "hump". It seems there a are/were different locations from runs and even manufactures. Lionel had the hump, MTH had the shrinkage etc.
Thanks. Looking forward to your shots.
Charlie
the only models I can remember this being a problem on was the very early Lionel ALCOs, from about 1950-51. When the motors ran hot because of lack of maintenance, the shell above the motor would get a hump. The later production altered the mold so there was about a dime-sized piece of extra material there that would not warp with heat. Never heard of the issue on an F3 though.
I've heard of it on F3s. I believe there was a small dimple placed on the mold, just behind the cabs around 53-54 or so, which helped correct this.
Here it is on a 2344. Nothing can be done about it on the early F3s. As Christopher said, the slight change made in later years helped.
If you look along the roof line, you can see the hump. It looks worst at this angle. Most of the time it isn't too noticeable on this particular engine. The dummy A isn't as bad.
Jim
Since the dummy doesn't have a motor to get hot, one wonders why it would get a hump at all. 
Warpage, especially involving early plastics, was not all caused by heat. Slight, but
constant, internal molecular stresses due to subtleties of shape and varying thickness
of materials can cause slow but inexorable shape-shifting.
External (storage) or internal (motor) heat can make this worse, even if the heat itself
is not high enough to affect other areas not prone to it.
Here's a picture , a profile view, of the powered unit, but the unpowered is the same. You can see the hump in the roof just ahead of the leftmost fan, which is actually tilted upward a little.
I seem to be hearing that there is no solution, but I haven't given up hope yet.
AMT/KMT/Kusan F7 Diesels had an even more pronounced bulge on their roofs. It has to do with the way the plastic cooled after being taken from the mold. Both the powered and dummy units were equally affected.
Trick-or-Treat. 
Access to this requires an OGR Forum Supporting Membership
