Brian

What about double-sided tape?  You should be able to find various thicknesses.

Blair

Double Back Tape

Do you think that would be permanent enough? Some of them in that back corner are going to be pretty inaccessible once the helix circular tracks are installed,...back corner..
 

Oh, and I just through about it, that would leave a sticky side up that would attract all sorts of dirt and debris over time.

I'm thinking one of those rubber-based adhesives like Pliobond?

Lay track, then bond

I likely need to be able to lay some of the unusual curves in some of those tracks, THEN bond it down. I'm thinking I could hot-melt glue tack it down, then use some sort of 'flowing' glue to complete the bond?

DAP

I used DAP Alex Plus Acrylic Caulking to lay all my track.

I also used it to secure my Sheet Metal backdrop corners to painted drywall.

3+ years and still solid. I would suggest that this product will work great for securing track to your aluminum pieces too. A thin layer is all you need. It gives a reasonable working time and is easy to remove with a putty knife later.

Just Weighted in Place?

Bill,
Did you just weight your track into place until the caulk dried? What about curves??

This is one particular curve

This is one particular curve I need to lay upon this joined alum bridge for the very top loop of my helix. It kind of snakes around those upright post that join the circular alum ring at the top & bottom of my helix.

 

Its very fortunate that my alum upright post of the helix can be removed (and shaved) while constructing this monster. 
 

Looking at the last photo above....

That's very close with little to no clearance to get your fingers in there. I would make sure your trackwork in there is 'Bullet Proof'. That's too close for comfort Brian.

Neal

Adhesive & Caulk

I ran the DAP idea by my general contractor friend here in town, and he offered what he considers one better caulk,....Loctite Polyseamseal Adhesive Caulk
http://www.loctiteproducts.com/p/pss_seal_ap/overview/Loctite-Polyseamseal-All-Purpose-Adhesive-Caulk.htm

• Loctite Polyseamseal All-Purpose was designed to be a multiple use adhesive and caulk. It can be used for almost any household or remodeling project.
• Bonds to almost any surface including wood, concrete, metal, ceramic, drywall, plaster, tiles and much more.

...and I like the idea that it is water clean up

Adhesive caulk

Might be overkill.  You will have a devil of a time separating the track from the caulk if you ever change your mind. I used adhesive caulk once and paid the price.  I believe that regular caulk should be fine.

John C

Just Weighted in Place?

Yes. I used small steel weights and soup cans.

Also any wood blocks I stuck to the metal are still firmly in place. It's amazing - and yet, if I slip the steel putty knife into it, it will come right apart.

Caulking on Cork Roadbed?

Bill, you said all your track.

Do you use some cork roadbed as well? Do you use that DAP product on that as well??

DAP

Yes, I use clear DAP to secure track to cork, have on previous layout as well.  Goes on white and dries clear.  Hold track in desired alignment while it dries and good to go.

Brown

caulk is also available, at a slight premium (actually, it just doesn't end up on sale as often).  While white will do the job under cork, because it's easy to hide, I find the brown is better when fixing track - means I don't have to ballast to hide the white.  I may just leave the brown caulk in place, forgoing ballast for a year or two, until I'm sure the track is where I want it.  One thing you will find - any opaque caulk will obscure the lines you're trying to establish for the track.  Methods vary, but we've resorted to leaving a caulkless gap occasionally so we can find the centerline, or making the caulk layer thin enough that the centerline can be seen due to the discontinuity between the two sides of the cork.  That's usually enough to center the track. 

Using a handful of map pins to hold the track in place while the caulk sets also works well; adding weight will work, but I just use a small roller (I think it was a seam roller for hanging wallpaper, not sure) to roll down the track as we go.  If you've put down too much caulk, you'll know it because it will crown between the ties, leaving you with caulk ridges; when they appear, you'll want to lift the track immediately and scrape out some of the caulk, then lay the track again.  Sounds difficult, but you'll get the hang of it quickly.

Blair

+1 for Alex caulk

I used it on all track on my layout which fills half a California garage. My experience is consistent with Bill’s.

It will adhere the cork roadbed as well. After laying that, sand the cork to remove crumbs on the edges and get a dead flat surface, then paint with any flat spray paint, with overspray onto the aluminum base. Let it dry for 2 days and you should not have any moisture problems.

Bonding to Aluminum

Bill, was that sheet metal you spoke of steel or galvanized steel?

I've had a problem with some adhesives bonding to aluminum lately. I'll document that in a few days.

Use some grit before gluing the track

If possible use paper grit or a grit sponge with heavy grain and grit the metal surface.

This will give some grip to the glue, because metal does'nt have any porous area.

Even if you use any acrilyc or vinyl glue, in the time, the glue didn't glue anymore on these kind of surface.

Second contraction and expand of the metal with temperature will be problematic for anything glued on this surface.

As an iron worker I really know the problems.

If you have had the place it would be better to bolt a piece of wood Inside your metalic rails and fix the track on this piece of wood.

Don't know if you have the Heinkel glue stuff in the US but they made a special flex glue for metalic purpose.

I have use it a lot and it seems to stay in time.

For sure, I will ask a professionnal in this case and not use a current glue, but a specialized one.

Just my opinion.

plywood not cork

Where you have vertical clearance for it, you could lay thin plywood in your aluminum trough, cutting the plywood for the full width of the trough so it can't move side to side. Then you can nail or glue down your track to the plywood. You can probably cut and bend up a little tab on the ends of the trough near the edges to keep the plywood from sliding lengthwise or just rely on the angles where the aluminum 'turns' to stop the wood from sliding. If you're worried about moisture and the plywood, apply some sealant after cutting it to shape.

I think I opened up a can of

I think I opened up a can of worms on this subject,...maybe another analysis paralysis situation as I have been labeled at times....ha...ha

Some of these alum channel bridges of mine are going to be very difficult to access once all of the helix trackage is in place, particularly those over in the back corner, as they will be 'outside' the circumference of the helix tracks and the vertical support rods. SO I was looking to be sure to get the trackage on those channel bridges CORRECT in all aspects, …..can't be redone/fixed at a later date without BIG disruptive work.

First thoughts were how to best glue the tracks to the alum channels. As some of you have noted why not glue some plywood into those channels, then glue the track to the plywood. Problem here,...I am working with tight tolerances again, and just don't have the extra height available for anything thicker than about a 1/8” or preferably 1/16”.
 

I next started considering vinyl flooring materials,...lots of selections, and a number of them in thin dimensions. And many of them with adhesive already applied to their backside. I went to my local flooring place, to Home Depot, to Lowes, and looked thru their selections. I also gather up sample pieces (many about a foot long) that were offered.

The sticky backsides of these samples were sure inviting. I lined 2 long channel bridges with this stuff,...photos here..
 

I burnished this material onto the alum that I had cleaned with acetone. Surely this would work. NADA !!,....after a day sitting unmolested I decided to just turn those channel upside down unloaded in any way. To my surprise the darker one of these samples simply feel off overnight! The lighter tone sample fared much better, but I was NOT convinced of its long term viability. I re-burnished both channels, and still the material came loose over night.

From my boating days I recall the difficulty we had getting paint to adhere to alum long term. We had to pre-etch it. I was not up for this idea on a simple train project. I decided to run a few sample test with trying to adhere some of this flooring vinyl to my alum channel...

I was NOT that impressed with the caulks, including those 'adhesive ones'. Rather than continue down this path I thought again about my boating days when we utilized a polyurethane caulk 3M 5200. That stuff would stick tenuously to everything and hold on forever. I got a moderate Loctite version of polyurethane and it seems to be doing the job,...even re-glueing that stubborn self-adhesive floor vinyl.
 

Before I continued on with the floor vinyl interconnecting idea I needed to decide how I might best glue the track to that vinyl flooring. This appears to be settled quite easily with the use of PVC cement,...the type used to joint PVC piping.
PHOTO (oops don't seem to have those photos?)

But here is an interesting one,...glueing track and a scrap piece of plastic rain spout material to alum channel with PVC cement.
 

Sikaflex

Don't know if this brand exist in US but Sikaflex is a mono composant polyurethane caulk.

It's used in ship construction to glue wood deck and especialy Teck.

I have used it also on metalic surface with good results and durability; this caulk stay elastic all the time.

It's also UV protected

Specifications say it hold 25kg by cm² of glue, most you need for your purpose.

This is a Professional brand.

Sikaflex

Yes its available in boat building areas. Don't recall the last time I've looked for it.

I've used it, and it is good,...probably over kill for for what I need,...like the 5200. And both of them are likely 4 to 5 times more expensive than the Loctite product.

Caulk

IMHO. I am not familiar with Alum. But: I used DAP Alex/$2.84 for 10 oz tube caulk in a standard caulking gun. It works with pink foam and cork and other stuff. And plastic track. I see an above comment where he used it on metal. In my situation: I had caulked track to roadbed and caulk to the foam. When I needed to make changes, it pried up real easy. No mess. What there was, I used fingers to roll it off. I also used it to hold other stuff. And it seems to be pretty good. Have no idea on long term. But you could try it on a portion of the exposed part of the layout and see how it works. A couple weeks should be enough to be sure. But I also tried other caulks. And like above, some caulks are a disaster. A cheap brand I used and an expensive one. Maybe they weren't caulk like DAP, and more of an adhesive. But as I say: This "Alex" seems to be ideal. Morgan Bilbo

I am working on the

I am working on the assumption that you will have solid mounting on both ends. You can use sectional track and solder the joints creating a rigid piece of track. Or for the straight track you can get a 3’ piece of Bachmann Ez track, removing the plastic roadbed portion if you want it to be thinner. 

I used two different

I used two different materials on some of these alum bridges,....thin cork on some, and sample pieces of vinyl flooring material I obtained at the local HD. I glued those two items onto the alum bridge material with both Titebond glue and polyurethane sealant.

I then screwed by track down to the combination of alum/facing material with #6 x 3/8" truss headed screws. I also used those screws to attach my track to the very hard surface of the helix roadbed I had made of double thickness Masonite.

If I were doing it anew I would likely make the roadbed of plywood, generously coated with paint to try and seal it against moisture/humidity. I'm quite happen with screwing the track down as it has been a much cleaner operation than using glue, and it has allowed me to 'tune it up'.

See 'laying track in my helix',...

btw - Not gluing to aluminum

What you are gluing to is paint or some other kind of coating. This does not substantially change what you use to glue stuff down.