Cork and matte medium?

[TinyTurner]

I discovered Boomer Diorama's video on persuing track integrity, and would like to give it a try.
The ability to reposition hand built track would certainly help to reduce anxiety.
I can get a bucket of matte medium easier than I thought, and 2mm/5/64'' thick cork roll as the road bed, if that's correct.
Working with 2'' foam on what will be a small test layout.   
It's not clear weather the cork is rolled out flat as a sheet or cut into roadbed.  I presume the latter?
Has the matte method been tested on smaller scales/N?

[Bill H]

Hi;
I have used matte medium for over 20 years both to attach the cork to the sub-roadbed, which is either plywood or Masonite splines and then also used it to attach ME track to the cork roadbed or cork sheets. And i also use it for binding my ballast. Parts of my layout that were transported from Europe to the US built in that manner have survived now for twenty years with zero issues. I appreciate the flexibility this methodology enables to either make minor adjustments or to make major adjustments without losing the roadbed or track, but with the caveat that it is not the cheapest method. In most cases, I have found that at minimum it takes two coats, the first to absorb into the cork or plywood, and then a second coat to bind. And the latent flexibility of matte medium, IMHO, does a lot to diminish sound transfer.

Kind regards,
Bill

[chuck geiger]

Remember he doesn't use foam, but hardwood sub-roadbed. Interesting as well, he only uses CA to secure the track to the cork, a drop every few inches, and lets the bonding agents with the ballast hold the track. it's done as he talks about in the video to access and rearrange track issues without using dynamite. I use Elmer's yellow or white and that's it.

[dangerboy81]

I use matte medium as well. Before that I used watered down white glue with isopropyl alcohol as a wetting agent. They both work well for me, and they both allow you to lift your track or turnouts if you ever want to change or repair anything.

[TinyTurner]

Do cork and foam play well together?

I got several tubs of cork adhesive years ago on sale, I should go check that's still good (and foam friendly) 
It not might matter to much, I forgot that I planned to sandwich the foam with thin ply

The CA glue Idea to tack track down I like.  It holds model aircraft together so I know it's strong, and now it's inexpensive. 
So white glue/PVA can also dissolve, is that in IPA or water?

Ballasting with IPA seems fairly new here, and to most folk, is a type of English beer 
It easy enough to get online now, even in large quantity's.     

I see an industrial order in the near future.

[robert3985]

I used to be a big proponent of using artist's matte medium, but I started getting a white, powdery residue on several applications.  I thought initially it was because my matte medium was old, but after having the same problem with newly purchased matte medium, I decided it was the medium itself.  I don't know exactly what the problem was, or why it started, but the residue was bad enough on my last application that I pulled the scenery off of that small section because it was ruined...intending to use white glue instead, and never again taking the chance that artist's matte medium might ruin my work again.

I used white glue (Elmers) for a while, but I didn't like the slight gloss it has, which isn't all that evident, but showed up in several close-up photos I took...and I take a lot of photos. So, I wasn't happy with white glue either, but for a different reason.

I was looking around at my local Michaels, picking up some gloss medium and gel medium for my river project when I stumbled across Mod Podge Matte, and decided to give it a try.

I mixed it 2parts distilled water to 1part Mod Podge with a couple of drops of Dawn dishwashing liquid and I was (and am) totally happy with the results, after thoroughly wetting my ballast with distilled water with a couple of drops of Dawn in my atomizer.  No gloss, no white powdery residue, and it's a lot cheaper than quality artist's matte medium.

I highly recommend using Mod Podge Matte because it doesn't have the disadvantages of both white glue and artist's matte medium.

As to your cork.  Although I use sheet cork for my yards (with drainage ditches cut into it before applying ground cover and ballast), and for everywhere else, I use both HO-scale and N-scale Midwest Cork Products Cork Roadbed, which is split down the middle so the long, flat sections of it bend easily to whatever radii you're laying down.

I glue it down with Titebond II Premium Wood Glue, which forms a "water resistant" bond because I don't want it coming de-bonded when I flood it with both wet water and ballast glue when gluing my ballast, or ground cover adjacent to my trackage.  Having built one 8-foot long display "module" out of 2" extruded Styrofoam, I never had any de-bonding of my cork roadbed happen, even after the "module" warped and the track popped up (before ballasting), so it works okay laying cork directly on extruded Styrofoam.

I purchased a small "hardwood roller" (1 1/4") for around fifteen bucks...with a flat roller...to squash down my cork roadbed when I'm gluing it to my splined Masonite subroadbed.  I also pin the cork strips so they don't shift laterally until the wood glued dries enough shortly afterwards.

One good reason to purchase Midwest Cork Products Cork N-scale Roadbed is because of its split-down-the-middle feature.  I want my track to be laid as exactly as I can do it, so I transfer track centerlines to my subroadbed by printing full-sized CAD plans then "pouncing" them, after perforating the printed centerlines on my plans with a "pounce wheel".  Since with Midwest Cork Products N-scale Roadbed, you lay one side of your roadbed at a time, I lay the first side of the roadbed so the flat side of it (the center) follows the centerline I've transferred to my subroadbed.  I lay the other half to the already laid-down previous half, butting its flat side up against the already laid half while the wood glue is still wet.

What this does, is gives me a centerline to lay my track to...both hand-laid and commercial flex...flex being easier to lay than individual ties of hand-laid track. 

When laying hand-laid track, after placing the wood ties in their tie-positioning fixture (which is about 18" long), I draw a centerline on them with a straightedge and a sharp 2B pencil...lightly, and use that drawn centerline to position them over the centerline on my cork roadbed.  I cut a thin strip of masking tape and apply it off to one side of the drawn centerline on my wood ties so I can see both the roadbed centerline and the drawn centerline on the wood ties, then pull the ties out of their fixture.  Before the wood glue dries, I insert my PCB ties into their respective spaces between wood ties every fifth tie after the wood ties are pressed down into the thin layer of wood glue atop the cork roadbed.  I remove the tape after the wood glue is thoroughly dry, then sand the wood ties down so they're the same height as the PCB ties.

After the cork roadbed's glue has thoroughly dried (at least a day on extruded Styrofoam) I sand it to get rid of any humps, lumps or ski-jumps with my home-made 8" sanding block (220 grit emery cloth stapled to an 8" piece of straight premium pine).  Then, I use Micro Engineering Code55 flex (actually I use Rail Craft Code55 from my stash) which is stiff enough to hold whatever curve you bend it to, and after getting it exactly to the curve I want (sighting down it using the M1A Eyeball Method) I glue it down using runny CA, doing "spot welds" every 6" or so, holding it down with a 3" piece of wood (so I don't glue my fingers to the rails), then spraying that glued "spot-weld" with Accelerator...waiting a few seconds for the glue to set up, then removing the piece of wood...sighting down the track to make sure everything is A-OK...correcting any kinks that may have appeared, then, using my old hair-dryer...I blow hot air (medium hot) on to what I've just glued to evaporate any Accelerator that is still there, then I move on down the track, doing the same process at each 1" spot-weld.  After all is securely spot-welded, I go back and apply more runny CA between spot welds...setting it off with Accelerator, and evaporating the Accelerator after the glue has cured with my old hair-dryer on medium heat...I don't want to heat up the rails so much that they expand...so be careful...not too much localized heat, just general hot air overall.

NOTE: The CA method is to temporarily (but fairly securely) hold the track in place before it's ballasted.  The ballast cement is what holds the track permanently (and very securely) in place.

Next, after thoroughly cleaning any errant CA off the tops of the ties and sides of the rails, I solder on my feeders, then test the track so it runs perfectly.

Then, I replace any missing ties, get rid of any globs of solder and inspect my trackage for any other things I need to correct...then test it again so that it's running perfectly.

Then, I paint it...using Krylon Camo Ultra-Flat black and Ultra-Flat Brown...then clean the tops of the rails thoroughly with a clean rag and paint thinner, then polish the railheads with my old Walthers cleaning pad, and test again.

Then, I go over the ties, randomly painting some of them different shades of brown, tan and grey...not a lot of them, but enough to give an "impression" of different colors of wood.  I use photos I've taken of the UP mainline in Weber and Echo Canyons as references for this.

After I'm happy with the paint job, I apply my ballast...which is sifted/graded N-scale real-rock ballast from my stash of Highball Ballast or newly purchased from Arizona Rock & Minerals...graded using screens so that the size of the model ballast rocks are pretty much between .017" (largest) and .013" (smallest)...and most of the dust gets removed in this process also so my ballast doesn't look like concrete.

After getting the correct ballast contour, and getting any ballast rocks off of the tops of ties (if I want that "clean" look), I spray about 18" of track with my atomizer full of wet water (previously described)...making sure the dry ballast is soaked enough so that there's no dry center, but not so much to wash it away.  I use an "atomizer", not a "spray bottle" to do this because a spray bottle produces drops of water big enough to crater the wet ballast...which I do not want.  The atomizer's mist is composed of verrry small droplets, which don't crater anything.

After soaking with wet water, I apply my Mod Podge Matte glue mixture (previously described) with a big dose dropper...applying the glue between the rails, so it flows downward through the already previously wet ballast.  I'm careful here, because I want enough ballast glue to run down through the ballast, wetting it completely, but not so much to wash it away.  Also, I'm careful to not "squirt" it out of the dose dropper as the velocity will also wash ballast away...so, this is a gentle, careful application where you have to pay attention, take three deep breaths and take your time.

After the ballast has dried...usually at least a day...I go over it and if there are any bare spots, I add a bit of ballast, wet and glue...and if there are washouts, I chip them away, re-ballast, wet and glue again.

After I'm happy with the my ballast application, I weather the ties and ballast together by dusting them with my airbrush..just a little...different looks for different types of trackage.  Once again, I use prototype photos to guide me.  Then I add things like grease, sand, weeds, where appropriate.

All this fairly detailed explanation is because laying model track needs to be planned, because it's best done in a specific order, with fairly specific materials, with fairly specific techniques.

Even though Midwest Cork Products Cork Roadbed is probably more expensive than buying a roll of cork, unrolling it, trying to draw your roadbed outlines while the cork is trying to roll back up, cutting it out...gluing it down while it's still trying to roll up, making sure it doesn't pull itself off your extruded Styrofoam subroadbed before the glue dries (you get the picture), Midwest Cork Products Cork Roadbed has many advantages over cutting your own from a roll of cork...including not taking nearly as much time, and being able to lay it much more precisely.

So, if I were you, I'd forget about cutting your own cork, and just buy some Midwest Cork Products Cork Roadbed and be done with it.

After my bad experience with building modules using only 2" extruded Styrofoam as both subroadbed and scenery base, I will now only use a structurally stable and strong subroadbed...either 1/2" (minimum) CDX plywood and/or splined Masonite...with 2" extruded Styrofoam as my surrounding scenery base.  However, for a test diorama, Styrofoam is okay...but, I would never use it again for either layout or module construction.  Yeah yeah, I know that some modelers have never had a problem using it, but...my experience wasn't good, and I'd rather be safe than sorry.

Hope this helps you out a bit.

Cheerio!
Bob Gilmore

[TinyTurner]

I love Bob's reply's.  It's like having the hand of a kindly, wise old mentor, reaching out across the Atlantic to guide distant disciples in the art of model railroading.  They read like journals 

That way of literally laying the road for the rails makes good sense.  I wonder if I can get my ancient giant HP printer ready for a full size plan... 

Midwest Cork Products Cork N-scale Roadbed is going to be trouble to get hold of due to the vast distances involved in shipping.
However, I went through my stuff and found some cork foam strip ordered as a sample back in 2016 from Charles Cantrill.  It just happens to be the same proportions in every way except length.  It appears to be cut differently and is sold 'square' edge, but the chamfer is cut down the middle of the strip so when you lay it down, it is the right way out.  Senendipity!

https://shop.charlescantrill.com/products/chamfered-cork-for-tracklaying

It's quite a bit darker with the black neoprene mixed in.  Not sure if this is something deemed necessary as a design feature, or a stealthy way to recycle old wetsuits 

Also found a sheet each of plain 2mm and 1/8''(3mm) cork.  I suppose the 2mm could be used for really old light lines or narrow gauge.

Specific ballast is also going to be hard to get unless there is an importer, but there are off brands such as Peco and Dcc concepts.  Usual complaint is it's too big.
Think I will give Modpodge a go, a big jug is less than equivalent size matte medium. 
The waterproof wood glue I can do, though I am more familiar with Everbuild 502. 

If foam is going to malfunction, this is the opportunity to test before building anything 'big' that cost real money, and even more importantly, the effort that goes into construction. 

It occurred that the ballast 'wetting' could be done with an airbrush, to control the atomising?

[Scottl]

FWIW I laid my yard on plywood with 1/8" self adhesive cork drink coasters I bought from Amazon.   They work brillianly and are versatile- and inexpensive.   No issues with soaking them with dilute matte medium for ballast or on curves.