Putting miliput aside for the moment, do you actually need to fill the gap? I have isolated sections without using any joiners where the track is held by a sleeper close to the end so not likely to move. Confession, this was years ago when I was skint with the option of retrofitting a joiner if it became necessary. The layout in question survived over 20 years and I cannot recall any issues.

Link here: https://forum.mrhmag.com/post/mrh-202608-august-2026-13877155

Jon

I gave up using milliput for most things the moment my stepdaughter introduced me to good quality polymer modelling clay. With that I can make much better things and I've done stuff like a OO gauge model of our cat with it just fine, no way milliput would have worked.

My preferred multi purpose glue. / filler is glue'n'glaze   Will stay flexible in your application

Have to say, I've never even considered using filler to fill in a rail gap.
On the occasions where I haven't used IRJs, if I've been concerned about rails moving (through expansion, running or track cleaning) and making contact, I've just glued a sliver of plasticard in the gap.

Shouldn't be necessary to handle it.  When I've used it (and similar repair putty stuff from Lidl which is much better value)  I simply slice a tiny amount off with a scalpel and manipulate it into place using the blade. 

To be honest though, I'd persevere with the isolating joiners which will maintain proper rail alignment.  I've never had a problem with them.

First line of advice these days is generally "don't buy Milliput" - there are dozens of much cheaper alternative brands of epoxy putty... (Sorry...)
I've used the Hobbycraft own brand stuff which was about 1/3 the price...

Quote from: Bealman on August 15, 2026, 01:13:42 PMIt sets rock hard, and I can't see it being suitable for the job you intend, where an amount of flexibility would surely be required.

agreed...
I don't think it's the right material for the job. For the task, we used a flexible mould making resin (it was a games workshop product IIRC) - equally nasty to handle but remains flexible when cured.

A Hornby Minitrix signal cabin on my layout, with a carved Milliput lower half. Seriously, it's like concrete now!

Yes. I've used it to model dry stone walling on my layout. It sets rock hard, and I can't see it being suitable for the job you intend, where an amount of flexibility would surely be required.

Just sayiin

Mick.

I tend to have a box of disposable plastic gloves as epoxy resin causes irritation and an old knife for modelling purposes that you never use with food . There are some harsh curing agents in the epoxy that cause irritation to skin

Hope helps you out