Hi,
I have a few cars, mostly Athearn, that have the female screw threads stripped out of the body and the screws will not tighten all the way down. Evidently someone tried the tighten these down without removing the collar from the bolster and stripped out the threads. Is there a trick or an oversize screw (without having to tap the car body) that will let me tighten the screw all the way until it is tight?
Thanks, Hansel
If you are talking about the box or reefers, remove the body from the floor, use a slightly longe screw and use a nut on the inside of the car. You can then put a drop of epoxy glue on the inside between the nut and floor. When dry, you can remove/replace the screw without taking the car apart again. My [2c]
Here’s a couple of tricks I’ve used. Wrap some masking tape around the screw then screw it into the car body. Put a piece of masking tape over one end of the hole then put some white glue in the hole and let it dry. Then drill a hole through the glue and install the screw.
If it’s not too badly stripped, a wrap of plumbers teflon tape can sometimes be enough to let you snug the screw down. If not. Get some JB weld and fill the screw hole. Let it dry 24 hours and then you can drill and tap the hole again.
Ivanhen’s suggestion to use a longer screw and a nut inside the car is a good one. The traditional fix for overlarge or unwanted holes in styrene plastic (Athearn underbodies are styrene) is to fill the hole completely with a bit of plastic sprue. Glue the sprue in place with your favorite plastic welding cement. Give it plenty of time to dry. Then file the surface down flat. Center punch for the new hole and drill it with the proper size (the tap drill size). Machine screws will cut their own threads into plastic, no need to tap the hole. 2-56 machine screws want a #50 drill.
Or, go up one size in screws. A 4-40 pan head machine screw is not too large.
Unfortunately, it is a hopper car.
that in mind, your best bet would be the “fill in the hole with a bit of sprue” method… or maybe mixing sprue bits with some slower-drying styrene cement and making a runny-ish plastic filler. in my experience, the best glue for this was the black bottle of Testors’ Model Master…
Pretty much you mix sprue bits and the cement until you get a goopy plastic/glue mix and then fill in the hole… works wonders as a gap-filler too. [tup]
Then, if you value the car, and can stand to spend a total hands-on time (over three sessions or so) to fix it, you must disassemble it, and fix the female receptacle. I favour using sprue carved and sanded down to the thickness of the drill bit you will use to creat a larger, smooth-bored hole, wiping the sprue in MEK glue, and inserting it to let it dry. Once fully dry (10 hours?), sand to flush with the frame. Then re-bore and tap the new hole.
I’ve actually taken care of similar problems by usnin a little glue in the hole, letting it dry a bit, then re-inserting the screw. It worked alright for me, not recommending it as a great method and everyone else’s suggestions are probably better. Sometimes you just need something to cause enough friction to hold it in place.
Having done this before I offer two solutions:
use a bolt and a nut and then put some kind of load in the bottom ot the hopper and that will instantaneosly solve the problem; or
since epoxy has very little torsion–maybe the word should be tension; whatever it is resistance to horizontal motion such as you get when you turn a screw–strength epoxy the screw in place and when the epoxy has dried simply back the screw out ot the hole. This, by the way, was one of the first tricks I learned when I got into the hobby in the '60s.
A couple times I drilled out the offending hole to the closest styrene tube size. I then pressed in the tube and used plastic glue if in styrene or two part epoxy with metal. I then drilled and tapped for 2-56. Done this with 0-80 and 00-90 screws also. Quite easy using a pin vise. Patience required.
Rich
If you need a quick fix, get a styrene lid from a butter container or something similar and cut a very thin slither of it and place two of them in your hole. Your screw with the slither ( or even 2 if yours is thin enough and your hole is stripped enough) should then act like a rawl plug and pressure the side and hold your truck.
Alternatively drop a small dab of PVA into the hole and place the screw not fully in in and allow to dry. The PVA should form around the thread allowing you to remove the screw, replace your truck and drive it home.
Hope this helps
Regards from Down Under
Trevor www.xdford.digitalzones.com FYI
Thanks for all of the suggestions!
This trick has worked for me in the past as well. I have fixed about 7 cars this way. Remember, you don’t want the wheels tight, should have around 1/8 inch of slop.
For unseen screws inside a car, I just glue a 1/8" piece of styrene or other plastic over the old hole, then drill and tap when its dry. For visible ones, I bore out the hole to 1/8" and insert a piece of styrene tubing and glue it in place. I sand it flush and paint it to match. It is just too small to thread so you have to bore it out with a #50 drill and tap it.
I insert a length of .010"x.020" styrene strip into the hole, snip it off flush at the top, then install the truck as usual. The strip styrene usually provides just enough interference for the screw threads to grab - if not, use two strips of styrene.
Wayne