Best Practices: Gapping Code 55 Rails.

[robert3985]

Excellent tips and references on this thread! When I'm making my turnouts, I cut all the gaps with an ultra-fine blade in a jeweler's brace (saw), and since they're in between PCB ties, I don't fill 'em with anything since I'm not worried about them closing due to expansion/contraction. 

On my handlaid code 40, I cut my gaps in between a couple of PCB ties with an ultra-fine bladed rotary saw tool stuck in my cordless Dremel and (this is important) lubed with beeswax.  Gives me a .005" gap and the steel blade won't shatter like a Dremel cut-off disk if you move a little forwards or backwards while making the cut.  Trouble is, they're almost impossible to find nowadays (liability problems I'm sure) and they eventually wear out.  I'm on my last one and I'll be replacing it with DKS's recommended diamond coated cut-off disc when it finally goes.

Sometimes if I cut a gap that isn't between PCB ties, I'll slip in a piece of paper (usually from my drawing tablet) that's been trimmed into a little strip that's about the same width as the foot of the rail.  It usually extends below the foot, but that's okay since it won't be seen when the track is ballasted, then I carefully apply some runny CA, which saturates it and then spray it with accelerator which sticks it to both ends of the cut rails.  I then trim the strip even with the tops of the rails with a sharp scalpel and then more carefully trim it so it's even with the railhead all the way around.  Then, I take a stiff (but fine) wire rotary brush that's been placed into my Dremel, and hit the gap with that a couple of times, which takes the paper down even with the gap on both sides of the rail web and top of the foot.

Quick and dirty, and I don't have to worry about expansion forever.

[peteski]

I just prefer cutting down at a 90 degree angle so I know I have better control of the cut depth and such. Nothing like ruining a nicely laid piece of track and having to rip it out and start over.

That I don't understand. In order to isolate the rails electrically, you need to cut *ALL* the way through the rail.  If anything, a non-90 degree cut IMO allows even better control over the depth of the cut. (assuming you hold the Dremel tool in a way that allows for fine control).  Just *NEVER* cut without wearing safety glasses.

[pnolan48]

I use a thin razor saw from 30 years ago or a Dremel with a large diameter thin disc that I purchased some years ago and never managed to break. I have no idea of what the blade is, as everything has worn off. Just in case, I use a track gauge to hold the rails in place while cutting with either method. I never cut gaps directly across, and that means extremely short strokes with a saw. I'm used to working in small spaces with my ships. I use a piece of styrene or cardstock--whatever fits in the gap--and a bit of superglue. Prefer cardstock because it trims away more easily.

[nkalanaga]

Razor saw or circle saw blade in the Dremel.  I have one that's about the same diameter as a cutting disc, but it won't break.  Be careful, though, because it will take a finger off.  That may be why they're hard to find!  If possible, I'm one of those that simply leaves a gap when laying the rail.

As for vertical, I agree, why?  Many of my gaps are not only not vertical, as the Dremel itself gets in the way, but not at 90 degree angles either.  For gap filling I used a lot of magazine insert cards, soaking the joint in ACC, then filing and sanding to match the rail.  Not one has ever come loose, they're invisible after painting, and varying gap widths are no problem.  Just add more layers of paper.