Heljan diesel body fixing screws - problem

[chaz]

I have a Heljan O gauge BRCW type 2 ( later Class 26) which I would like to run on Dock Green as D5330. The holes in the body which receive the fixing screws have stripped threads so that the screws have nothing to "bite" on and the body remains loose. Obviously not a good feature on an exhibition layout. Is there a way of filling the holes and restoring the threads? What glue or filler would be likely to work? 

 

I would be grateful for any advice on how to fix this problem (especially from someone who has successfully done this repair!).

 

Chaz

[81A Oldoak]

I have a Heljan O gauge BRCW type 2 ( later Class 26) which I would like to run on Dock Green as D5330. The holes in the body which receive the fixing screws have stripped threads so that the screws have nothing to "bite" on and the body remains loose. Obviously not a good feature on an exhibition layout. Is there a way of filling the holes and restoring the threads? What glue or filler would be likely to work? 

 

I would be grateful for any advice on how to fix this problem (especially from someone who has successfully done this repair!).

 

Chaz

I have tried various two-part epoxies and car fillers in the past. However, an effective solution I have used is to make a polystyrene goo by mixing sprues with MEK or other suitable solvent and filling the hole. Let it set, drill a small pilot hole and then cut the thread with the screw. As easy as Robert is the brother of your mother.

[chaz]

I have tried various two-part epoxies and car fillers in the past. However, an effective solution I have used is to make a polystyrene goo by mixing sprues with MEK or other suitable solvent and filling the hole. Let it set, drill a small pilot hole and then cut the thread with the screw. As easy as Robert is the brother of your mother.

 

Thanks for that suggestion Chris - as you say sounds a Bob job. I presume the "goo" needs to be thick-ish, bearing in mind that if the loco is picked up it would be by the body, which puts the weight of the frames etc on the screws!

[JeffP]

Yes, the goo is made thick, then it sets hard, just like having liquid polystyrene.

 

I have used this method in the past to add pony-tails to the back of the heads of 4mm female figures, amongst other things.

[chaz]

Yes, the goo is made thick, then it sets hard, just like having liquid polystyrene.

 

I have used this method in the past to add pony-tails to the back of the heads of 4mm female figures, amongst other things.

 

Thanks for that. (I don't think my BRCW type 2 will need a pony tail  ).

[Pete Harvey]

Also sliding a length of brass tube over the outside of the fixing spigot before refitting the screws will reduce or eliminate the chance of the spigot bursting as you try to re thread the hole in the spigot.

 

Pete

[chaz]

Also sliding a length of brass tube over the outside of the fixing spigot before refitting the screws will reduce or eliminate the chance of the spigot bursting as you try to re thread the hole in the spigot.

 

Pete

 

Thanks Pete. If the spigot has clear space around it I will use this ploy.

[Simond]

Chaz

 

if you have adequate access where the screw head would be, you might want to epoxy short lengths of threaded rod into the holes in the body, and use nuts to secure the chassis.  This avoids the problem of threads in plastic - if a thread like this failed once, even with a good repair, it is likely to fail again, either due to overtightening or simply not being strong enough for the job.

 

best

Simon

[chaz]

Chaz

 

if you have adequate access where the screw head would be, you might want to epoxy short lengths of threaded rod into the holes in the body, and use nuts to secure the chassis.  This avoids the problem of threads in plastic - if a thread like this failed once, even with a good repair, it is likely to fail again, either due to overtightening or simply not being strong enough for the job.

 

best

Simon

 

Overtightening is almost certainly the cause of the problem Simon (not by me!) but I would not repeat the error. Your method is workable however it is likely to a bit more of a fiddle to get nuts (and washers) in place. I will look at the job and assess whether there is enough space to do it this way. I don't anticipate having to take the loco to bits very often - it already has DCC sound installed.

 

Chaz