Stripped screw in plastic shell

[tadowler]

Unfortunately I stripped the screw that attaches the shell of my Lionel F-3 to the frame. The shell is attached with two clips on the back and the screw on the front.

Does anyone have an easy way to repair this? I was thinking about filling the hole with Krazy Glue and retapping the screw. However, I am open to ideas.

Thanks!

- Todd

[Poppa_Zit]

Easy fix: put part of a wooden toothpick into the hole -- just enough to fit the depth inside -- and work your screw in.

You could also fill the hole with plastic cement. While still workable, put Vaseline on the threads of the screw and carefully screw it into the hole. When the cement dries, the Vaseline will allow you to back out the screw -- leaving perfect threads.

[darianj]

QUOTE: Originally posted by Poppa_Zit


You could also fill the hole with plastic cement. While still workable, put Vaseline on the threads of the screw and carefully screw it into the hole. When the cement dries, the Vaseline will allow you to back out the screw -- leaving perfect threads.

Good tip!

[Anonymous]

Variation on the toothpick trick is to use "sprue" and then plastic cement. Sprue is the scap plastic trees from model kits. You cut off a chunk and gently heat it over a candle flame and stretch it out to the desired thickness. You wind up with a "plastic" toothpick.

[Sturgeon-Phish]

I've filled striped screw holes with jb weld, then drilled and taped for the screw. For screw holes that are blown out I reshaped the area with epoxy putty then drill and tap. The toothpick trick works great in wood, but in plastic I'd think it would blow out the hole since the fill material needs to be softer than the hole it's filling.
Jim

[lionelsoni]

Just replace it by a 6-32 x 1/4" or 5/16" flathead machine screw, if you can stand not using the original screw.

[Poppa_Zit]

QUOTE: Originally posted by Poppa_Zit

Easy fix: put part of a wooden toothpick into the hole -- just enough to fit the depth inside -- and work your screw in.

You could also fill the hole with plastic cement. While still workable, put Vaseline on the threads of the screw and carefully screw it into the hole. When the cement dries, the Vaseline will allow you to back out the screw -- leaving perfect threads.

QUOTE: Good tip! -- darianj

Thanks for the kind words. I have been told I'm the Norm Abram of inventing ways to fix hopeless trains. LOL

Here's what I usually do, and you'll understand why I didn't list this methodology originally because it includes products that may not be easily available to everyone.

Let me also say I know nothing about Lionel products and how they're designed/constructed, but they can't be much different than my dear and grossly underrated A.C. Gilbert American Flyer... 'cept bigger.

I have a friend who is a dentist who orders for and sells me dental acrylic powder and liquid activator. It can be useful in many applications. For example, in some American Flyer plastic locomotive boilers, through a drop or otherwise rough handling, the entire screw hole post has split open -- which like stripped threads, also won't hold a screw. I have used part of a plastic soda straw as a form and recast the post in acrylic, then re-tapped it.

Or if all the pieces are present (and it didn't chip apart), rather than trying to CA (i.e. "Crazy") glue it and risk messing up the threads with squeezeout, I first clamp it in place. I next wet a tiny brush in activator and dip it in the acrylic powder to create a paste and slowly -- layer by layer -- build up the exterior of the post until it holds a tightened screw again.

If you are retapping a rebuilt post, it is best to use the chassis or "the part the screw holds in place" as a jig -- or drilling guide. Never use an electric drill or Dremel tool, use a finger drill. You may need to make a small pilot hole with a very small drill bit, then move upwards in bit size until you get where you want to be (hole diameter).

You can finish by painting the arcylic black -- or whatever color you desire.

NOTE: While very effective, if you can indeed find a way to get some, you'll also need to know the powdered acrylic AIN'T CHEAP.

I "Googled" the product I use and found this listing. If you buy some, make sure you get the liquid activator with the powder. You can also do a web search for the product and find smaller, "relatively" cheaper amounts -- in the $15 to $20 range:

http://cgi.ebay.com/JET-TOOTH-SHADE-POWDER-LANG-DENTAL_W0QQitemZ7586941447QQcategoryZ31471QQcmdZViewItem

[dwiemer]

one more idea,
put teflon plumber's tape around the screw and then just screw it in. While it is not as strong as the original, it should still hold plenty well and you have done nothing to harm the value of your train.
Dennis

[choochin3]

I'm with Sturgeon-Phish on the JB Weld idea, I have used it many times and works great.

Carl T.

[lionelsoni]

The original screw involved here is a #4x3/8" flathead thread-forming screw, not a machine screw; so tapping a reconditioned hole for the original screw is not appropriate. However, the original screw will have left a hole about right for a short #6 screw to form new threads without splitting the post. It will not look out of place, since the countersinking of the casting is actually oversized for a #4 and about right for a #6 screw.

[Anonymous]

Can you use a spring clip on the inside to hold the screw in place? This is a small rectangle of metal (quarter by half inch) with a hole in the middle and two metal flaps cut into it. They are the springs and they'll hold a screw in place and allow it to be removed. You'll probably have to tape or paste it to the inside of the shell behind the hole.

[FJ and G]

This is definitely one of the finer "how-to" posts. I'm copying this baby. Previously, I would have advised JB Weld & tap method, but now I see there are more ways to skin a cat (or screw a thread; well, you know what I mean).

[lionelsoni]

Grumpy, those are called "speed nuts". I'm pretty sure the hole in the F3 shell is blind. But, even if it weren't, I think you would have no way to hold the nut in place while you put the shell on.

[palallin]

No need to drill and tap JB Weld. Use epoxy and coat the screw as PZ suggested. You could even use JB Weld except that it might just hold the crew notwithstanding the coating.