Model Railroading > What glue to use with KD coupler pockets?

Hello to All,

I am mounting some KD 713's (HOn3) on some brass coaches. Unfortunately the drilled and tapped mounting holes don't even come close to matching up with the screw holes on the KD coupler boxes. So....the best way to deal with this is to glue he KD coupler boxes in place.

What glue will bond with the KD Delrin plastic and the factory painted interior of the coupler box? Is it strong?

Thanks for the help!!!



Edited 1 time(s). Last edit at 01/26/15 10:19 by pilotblue.

pilotblue Wrote:
-------------------------------------------------------
> Hello to All,
>
> I am mounting some KD 713's (HOn3) on some brass
> coaches. Unfortunately the drilled and tapped
> mounting holes don't even come close to matching
> up with the screw holes on the KD coupler boxes.
> So....the best way to deal with this is to glue to
> KD coupler boxes in place.
>
> What glue will bond with the KD Delrin plastic and
> the factory painted interior of the coupler box?
> Is it strong?
>
> Thanks for the help!!!

On my ON3 brass cars I used JB Weld 5min stuff works great. I have used the same for many tasks model and in my trade I retired from as a heavy duty mechanic on busses and trucks. Bought a pickup used, once in a while it would show a little moisture in the oil. Finally pulled it down to overhaul found out it had froze and cracked in the valley and had been fixed with JB Weld. I had run it for about four years that way myself. I glued the two halves together with liquid plastic glue first and have also used CA glue for the same.

the best solution would be to drill and tap new mounting holes.

Ted Curphey
Ontario, OR

Latex caulk might stick to the Delrin and still allow you to remove them later. I think I would put a couple of nubs on the top of the box to line up with the screw holes so the box is less likely to pull off the mount on the car under load.

Drilling and tapping would be best but not always possible.

EDIT
Another thought if the tapped holes in the cars are narrower than the coupler box. You might drill new holes in the top of the coupler box to match the car holes. Then you can use flathead screws to keep the inside of the box flush and smooth for operations.

Posted from Windows Phone OS 7



Edited 2 time(s). Last edit at 01/26/15 17:37 by fbe.

funnelfan Wrote:
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> the best solution would be to drill and tap new
> mounting holes.


It would depend on the model as some of the old brass ON3 PSC cars do not have anything to mount the box on once you remove enough to get it at the correct height. That is why I went to JB weld the calk another fellow used I don't think would be too durable and as easy to work with. Also takes too long to dry also it is very messy IMHO. PSC older coaches used scale boxes cast into the body and in turn they will not allow enough coupler movement at least with 34 inch plus curves and number 6 switches. I know should use larger radius but it is what I have.

I'm with Ted on this one. If you can glue a box on, you can remove material to put in a slug of styrene or sheet brass and tap it for a screw.

It's only a matter of time that train weight, or an overzealous grandson, will break off that coupler. Epoxy will dry out and become useless in the future, or will have such a tremendous bond that you may damage your car (or your thumb) trying to get the box off.

One of the problems isn't the box, but the coupler head will bend with repeated hard contact (or travelling in boxes) and will snap off when you try to straighten it. (I wouldn't recommend straightening any coupler while in the coupler box either)

I have used a tiny wick of MEK to glue the box covers on the coupler box (cuz you can pry them off to get at the coupler and spring) but I never affix a complete box to a car with glue. It impedes your ability to quickly service the car.

Sean Steele
London, ON

Tap & Drill new holes. Glue is NOT a permanent fix.

I agree that the JB Weld is good stuff in the right places, but as for working with the Delrin® plastic, I think the results will be ineffective. Recently I had a coupler box on a LifeLike P2K E8 that had a piece broken from its side when I received it. I found the piece in the box, so I first used ACC (at the joint only) to set its position. I then mixed some JB Weld (epoxy) and coated well the outer surface of the box. After 24 hours I attempted to assemble the coupler and gently snap the cover in place, and then "POP GOES THE WEASEL", and all the attempt is shot. I tend to agree with the drill/tap operation as the best option.

jburek Wrote:
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> Tap & Drill new holes. Glue is NOT a permanent
> fix.

Ok so how do you put things together? Not everyone is able to drill and tap holes and there is not one to start with on some anyway. JB Weld doesn't go snap either by the way and if its not roughed up just a bit and clean it will not stick by the way. Every one has there own way to do things by the way just stated one way to do it for those who are not very good with small drills or taps. I have by the way only broken or bent couplers when a car fell onto the floor as don't let kids play with my trains so they don't normally get bent either.

BAB, you may be right about the JB Weld and properly preparing the Delrin® plastic. I failed to rough the surface as you said before I applied the JB. I ended up drilling out the coupler pin on the cover and then drilled and tapped the hole in the box where this pin originally mated. I used a 2-56 screw and the cover and coupler are now well retained.

If you do glue the box on vs screws, I would recommend Walters GOO. I have used it. More sure thing if you scuff up the Delrin just a little.
Roger Beckett