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Discussion Starter #1
I have built a lift out bridge in a radius. I am thinking of using a vinyl flooring glue to hold the Atlas code 100 flex track from moving, by pushing the glue through the ties and then smoothing it tight to the rails. I am looking for any advice to keep the rails in place for proper alignment before I do any gluing.
 

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What is the sub-roadbed material?
 

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I have built a lift out bridge in a radius. I am thinking of using a vinyl flooring glue to hold the Atlas code 100 flex track from moving, by pushing the glue through the ties and then smoothing it tight to the rails. I am looking for any advice to keep the rails in place for proper alignment before I do any gluing.
Can you reach into the bridge? Is it a trestle, open deck girder or what?
Can you pry up on the end of the ties and squeeze some Elmers glue in there?

:ttiwwop:
 

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Discussion Starter #4
The bridge is 3/4 plywood and 1/2 homasote. The trackbed is cork roadbed. I want to be sure once the rails are cut that they stay aligned. Flex track tends to spring back straight somewhat.
 

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What is the sub-roadbed material under the stationary flextrack?
 

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The way to do this is as follows:

With bridge constructed, and the sills or supporting structure in place, place the bridge where it will sit, as it will sit. It should not rock or tilt.

Then, with one or two lengths of correctly connected flex track, lay the track over the bridge so that the ends of the curve extend at least six inches beyond the abutments. This way, you are making the determining factor the bridge's curve, and not making the bridge conform to what's on either side of it.

You use joiners or nails to align the ends of the bridge rail perfectly with the oncoming tracks on either side of the bridge.

Now you'll see what, if anything, you need to do to alter the footing of the bridge. Maybe your radius is going to have to be manhandled a bit somewhere to get it to lie more-or-less centered on the deck. But, if you built the bridge according to a design, with the correct radius for the curve, and you situated the footings and abutments correctly, you should have nothing to do but to remove the joiners, lift the tracks on the bridge, smear some contact cement or wood glue lightly over most of the deck ties, and then relay the tracks. They should fit well, and a light weight over them will press them nicely into the adhesive for a few hours until it's dry.

I'm not clear on what you propose to do, but it sounds complicated, fraught with opportunities to make a mess, and to possibly mess us the appearance, or even to break something.
 

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If you have 1/2" Homasote, use track nails. The Homasote will hold them tightly, but you can remove them if needed. Use a pin vise and a small drill bit to drill some extra holes in the ties if needed. Track nails and Homasote is a pretty firm combination.
 

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Discussion Starter #9
deedub35 I plan to nail it. I did not think the white glue and ballast would hold the flex track. Sure glad I put this out there before doing my Idea. Those hinges where can I get them ? They look like oven door style of a hinge.
 

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I glue all my track. I use white glue. It dries transparent.

I have a number of iron weights slightly wider than the track and six inches long that I use to hold the track in place for a few hours (mostly overnight).

Never have experienced my flex track moving or "springing back slightly" after glue has dried.

Don't know if this is any help to anyone but I often solder two lengths of track together (soldered rail joiners) first and then lay the track (especially if curves involved) second. (If a turnout comes into play, I just cut the track at the appropriate place along the two lengths) ......... then glue it into place and add weights.
 

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You can’t go wrong with track nails and clear Alex Plus caulk for securing your track. Once it is ballasted then pull the track nails.

The hinges are cabinet door hinges often used for medicine cabinets or kitchen cabinets. Check the cabinet hardware aisle at Home Depot.
 

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Discussion Starter #12
Rickie, I do all the things you mentioned. The bridge ends are open gaps that must align to prevent derailment. It's the long term strength of the glue I question. Lifting the bridge in and out the ends getting bumped around...
 

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Discussion Starter #13
Thanx deedub35. That is something I will add later. I was thinking of a caulk also. I have a small amount of henry's floor glue left over from the bathroom remodel. That's why I choose that option to put out here LOL. This bridge is my rough draft version.
 

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on the elevator I built, i held the ends
of the track down with screws allowing them to be adjusted. Anything with wood can shift due to humidity.

while alignment is important, the width of the gap is not. See Train Derailments and Sabotage

if you're confident, why not lay a piece of flex across the gap and cut it in place with a dremel.

 

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I wouldn’t go with the flooring glue. Alex plus clear caulk is a good popular choice as it dries clear so if a little comes up between the ties no big deal. It’s cheap like a few dollars per tube. And it’s latex so cleans up with water.
 

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Discussion Starter #16
Yes, that glue is messy. I have caulk. I can go with that. Greg that elevator is too cool. What a way to conserve space !
 

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Good job, but everytime I see wood or plywood it sends me serious shivers and goose bumps because of the termites eventually devouring my huge layouts despite its treatment. I guess it's because I'm in the tropics, extremely high humidity during the rainy season and around 100 F all year round. I had to do various 2 floor metal constructions with glass on them. But it could be just the climate here. Guys, has anyone had a problem like this, literally devouring wood, plywood by termites wherever you are ? I'd like to know.
 

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...

Never have experienced my flex track moving or "springing back slightly" after glue has dried.
I have had it happen.
If you are careful, you can bend the rails in short 1" sections to lessen the springiness.

Need to be careful using two pliers next to each other.
Bend too much and the plastic tie plates break.
Bend too sharp, you get a kink.

Maybe better to use a 3" sectional piece at beginning of the transition layout-to-bridge.
 

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I forgot a couple of important items in my earlier response.

Once the bridge is in place, and firmly situated as it will always be (even if you have to resort to a cam or shim to keep it wedged firmly in place), you will have to cut the gaps in the rails so that the bridge can swing or lift out. This can be done with a jeweler's saw and a fine filamental blade. Or, if you are skilled, use a cut-off disk.

Then, with the bridge open/removed, use a Dremel and cut-off disk to bevel the inner flange faces of the rails, both on the abutment and on the bridge deck. Try to make them long, not 30 degrees or more. This will help greatly with slight kinking or misalignment of the flange faces, especially during high speed passes over the bridge.
 

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CharterPa

Our members have provided very helpful information
regarding your question.

It isn't clear how your bridge will move. The easiest
construction is a lift bridge, hinged at one end. It
is most important that the construct of the bridge
be exact with no warp and that it easily moves up
and down without friction.

Using the Homosote you can use track nails to
hold your track in place, or simply use temporary
push pins and ordinary Elmer's white glue.

The easy way to align your bridge track with
the base is to use a length of flex track ACROSS
both the Hinge end and 'open' end. Make sure
the track is firmly attached on the bridge and
the base, then, at the point where the bridge
'opens' and at the hinge use a Dremel cutting wheel or other
fine tooth cutter. File the resulting ends.

When you lift and then lower the bridge you
should find the tracks to be properly aligned
vertically and laterally.

One other factor you should consider; a 'safety'
switch that turns off power on the 'open' base
track so that if bridge is up a loco cannot run
off and fall to the floor. This is also easy to do.
First cut a gap in the 'right' rail of the base track
about 2 or 3 feet back from the bridge opening.
Attach a short brass strip to the 'base' and
a matching strip to the bridge. Solder a wire
to the base strip and to the 'right' rail of your
isolated section. Solder another wire to the bridge
strip and to the 'right' rail bus of your layout.
When the bridge is lifted power is cut off to the
iso section and the loco stops before plumbing to
it's death. Since the bridge would act as a
hard barroer no iso section is needed at the hinge end.

Don
 
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