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Help, mounting caboose hobby ground throws on foam based layout

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Help, mounting caboose hobby ground throws on foam based layout
Posted by IDRick on Sunday, August 13, 2023 3:32 PM

My layout has 1" extruded foam board glued to 3/8" plywood.  Track is mounted on cork roadbed.  I attached wood strips (3/16" thick by 1/2" wide by 1" long) to the foam board at the appropriate CHGT mount locations with wood glue.  The CHGT bases were wood glued to the wood strips plus attached with small wood screws.

Today, I had a catastrophic failure.  A ground throw + wood strip + big chunk of foam ripped away from the foam board.  I can move the turnout to a different location and want to make sure a future catastrophic failure is prevented.  Any advice on how to mount the caboose ground throw?  My old mount method worked too well, the foam base failed...

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Posted by tstage on Sunday, August 13, 2023 4:08 PM

IDRick,

I mounted my Caboose Industry (CI) 220S ground throws on top of a 1/2 piece of inverted cork roadbed so that the beveled side mated with the track roadbed.  I secured the 1/2 piece to the foam with DAP Alex Plus acrylic latex caulk.  Railroad spikes secured the CI ground throw to the 1/2 piece of cork.  Worked great for me.

Tom

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Time...It marches on...without ever turning around to see if anyone is even keeping in step.

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Posted by dknelson on Sunday, August 13, 2023 6:15 PM

In addition to Tom's advice, perhaps consider what people mounting Tortoise switch motors to foam have done -- rout out to a depth of 1/4 inch and secure a piece of masonite on which to mount the Tortoise (or Caboose Industries ground throw)

Dave Nelson

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Posted by Pruitt on Monday, August 14, 2023 8:59 AM

I had similar problems in my Casper yard when I first built that area. I used N Scale cork roadbed chunks under my ground throws (glued down with caulk), and at first I couldn't get the throws to stay securely in place.

I solved the problem by using 1" ring-shank (panel) nails to secure the throws. The rings on the nail grip the cork and foam tightly. I can pull them out pretty easily if I need to, but I have to handle the ground throw pretty roughly to loosen it. Best part of all is it's really easy to install the throws! I did need to ream out the mounting holes slightly so the nail shanks would pass through.

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Posted by IDRick on Monday, August 14, 2023 10:15 AM

Pruitt

I had similar problems in my Casper yard when I first built that area. I used N Scale cork roadbed chunks under my ground throws (glued down with caulk), and at first I couldn't get the throws to stay securely in place.

I solved the problem by using 1" ring-shank (panel) nails to secure the throws. The rings on the nail grip the cork and foam tightly. I can pull them out pretty easily if I need to, but I have to handle the ground throw pretty roughly to loosen it. Best part of all is it's really easy to install the throws! I did need to ream out the mounting holes slightly so the nail shanks would pass through.

Mark, how thick is your foamboard?  Do you have a plywood sub-base?  If so, did the nails reach or penetrate the plywood sub-base? 

In my case, I would need to order 1-1/2" ring shank nails to penetrate 1/4" into my plywood sub-base.  One-inch nails are available today but would only penetrate 3/4" in the foam board.  Which would you recommend 1 or 1-1/2 inch?  Thanks.

I have dremel tool + attachment to create a trench for a mounting pad (ie 1/4 inch thick wood).  Will give that a try as well on some scrape material.  Your idea sounds much quicker and less of a cleanup issue...

 

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Posted by Pruitt on Monday, August 14, 2023 12:22 PM

Rick,

My foamboard is 1 1/2" thick. It's affixed to a ladder-style grid using Pliobond PL300(? - that was a few years ago). There is no plywood underlayment. Nails penetrate only the thin cork on top, then the foam. 

The panel nails I use are brown, 1" long. I checked - that's 1" from the top of the head to the point.

If you use 1 1/2" on a 1" foamboard you'll have the points going into the plywood. That will make installation more difficult, but they should hold even more securely - probably to the point that you'd have to destroy the ground throw to remove it. Ring shank nails do not like to be pulled out!

The 1" nails work great. You can push them all the way in using pliers, with no need to hammer them. They grab and hold very well. The ringed shank is the key to that, I'm sure. Plain nails will simply pull back out (I know because I tried them).

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Posted by IDRick on Monday, August 14, 2023 1:57 PM

Thanks Mark!  One inchers will be picked up this afternoon!

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Posted by IDRick on Monday, August 14, 2023 4:38 PM

I purchased these nails   Only 1-inch ring shank panel nails in stock.  Sadly, my experience is much different Mark's, these nails pull right out of the Owen Corningware pink foam.  Similar to minimal effort when removing smooth track nails.  The rings feel prominent so I think the nail is similar to what Mark purchased.

I think I will try my Dremel + 565 attachment to create a narrow, shallow trench for a wood base mount.  Hat tip to Ed (gmpullman).

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Posted by Pruitt on Monday, August 14, 2023 6:15 PM

IDRick
I purchased these nails   Only 1-inch ring shank panel nails in stock.  Sadly, my experience is much different Mark's, these nails pull right out of the Owen Corningware pink foam.  Similar to minimal effort when removing smooth track nails.  The rings feel prominent so I think the nail is similar to what Mark purchased.

I think I will try my Dremel + 565 attachment to create a narrow, shallow trench for a wood base mount.  Hat tip to Ed (gmpullman).

They look just like what I use. Interesting that we have such different results. I also used Owens Corning foam. Do you have a cork overlay on top fo the foam? Maybe that's where most of the grip is coming from on mine. I use either 1/4" or 1/8" cork, depending on whether it's a mainline turnout or secondary track. Both work just fine.

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Posted by wrench567 on Monday, August 14, 2023 6:36 PM

   When I built the gantlet scale track for my modules. I used PC ties for the head stock ties. I actually double thickness them for additional strength and stiffness. Mounting the ground throw with a phosfor wire soldered through the head ties and folded over the ground throw. Have worked nicely for over a decade.

    Pete.

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Posted by IDRick on Monday, August 14, 2023 10:31 PM

Mark, I tested with 3/16 inch cork roadbed.  I drilled a 1/16 inch pilot hole in the cork and pushed the nails through the pilot.  The nails provided great side-to-side stability but the cork + nails could easily be lifted vertically away from the foam board.  A light application of adhesive would provide some vertical stability but still allow easy removal of the ground throw (if needed).  Very strange that our experiences are so different with the holding power of the panel nails, shrug, a life mystery!

I tried using a small piece of 1/4 in deep by 1-1/2 inch wide lath as a mount for the cork + ground throw.  The cork adheres well to wood with conventional wood glue.  The nails readily hold the ground throw in position but I don't have the right diameter bit for a pilot hole through the lath (1/8 is too large 1/16 is too small).  Small wood screws would probably work better to attach the ground throw to the cork + wood lath.

Tomorrow I will try creating a 1/16" deep trench in the foam for the wood mount with my dremel.  I will apply wood glue to the wood mount and the cork and attach the ground throw with wood screws to cork + wood mount.  Maybe I am over thinking this...  LOL!  shouldnt be this challenging!

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Posted by IDRick on Monday, August 14, 2023 11:29 PM

tstage

IDRick,

I mounted my Caboose Industry (CI) 220S ground throws on top of a 1/2 piece of inverted cork roadbed so that the beveled side mated with the track roadbed.  I secured the 1/2 piece to the foam with DAP Alex Plus acrylic latex caulk.  Railroad spikes secured the CI ground throw to the 1/2 piece of cork.  Worked great for me.

Tom 

I'm going to try your method Tom.  I grabbed a tube of DAP All purpose acrylic latex caulk plus silicone.  Oops, it is not the same as the one you recommended.  Should I bring it back and replace with your version?  

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Posted by rrebell on Tuesday, August 15, 2023 8:16 AM

I only have 2" foam with cork roadbed. I use the same roadbed for the throw landings and use screws to mount the throws, no problems. Used to use ply for the landings but it was a pain to run screws into them so tried the cork, no problems.

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Posted by rrebell on Tuesday, August 15, 2023 8:18 AM

IDRick

 

 
tstage

IDRick,

I mounted my Caboose Industry (CI) 220S ground throws on top of a 1/2 piece of inverted cork roadbed so that the beveled side mated with the track roadbed.  I secured the 1/2 piece to the foam with DAP Alex Plus acrylic latex caulk.  Railroad spikes secured the CI ground throw to the 1/2 piece of cork.  Worked great for me.

Tom 

 

I'm going to try your method Tom.  I grabbed a tube of DAP All purpose acrylic latex caulk plus silicone.  Oops, it is not the same as the one you recommended.  Should I bring it back and replace with your version?  

 

Your type is what I use, less brittle than those that don't have the silicone.

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Posted by IDRick on Tuesday, August 15, 2023 11:06 AM

rrebell

I only have 2" foam with cork roadbed. I use the same roadbed for the throw landings and use screws to mount the throws, no problems. Used to use ply for the landings but it was a pain to run screws into them so tried the cork, no problems.

 

 
Thank you for your comments rrbell!  I'm searching for small screws locally, best I can come up with #2 at 1/2" long.  Will give these a try.
 
Thanks also for your comment relative to the DAP caulk with silicone.
 
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Posted by tstage on Tuesday, August 15, 2023 6:49 PM

IDRick
tstage

IDRick,

I mounted my Caboose Industry (CI) 220S ground throws on top of a 1/2 piece of inverted cork roadbed so that the beveled side mated with the track roadbed.  I secured the 1/2 piece to the foam with DAP Alex Plus acrylic latex caulk.  Railroad spikes secured the CI ground throw to the 1/2 piece of cork.  Worked great for me.

Tom

I'm going to try your method Tom.  I grabbed a tube of DAP All purpose acrylic latex caulk plus silicone.  Oops, it is not the same as the one you recommended.  Should I bring it back and replace with your version?

Rick,

This is the version that I was describing before...

https://www.dap.com/products-projects/product-categories/caulks-sealants/latex/alex-plus/

I use it to adhere the cork to the extruded foam and the CI ground throw to the cork.  I also reinforce the ground throw to the cork with track spikes.  Ringed brads is even better.  It will help the nail lock into the cork - i.e. if you use the inverted 1/2 cork piece underneath the ground throw idea I mentioned in my earlier post.

The DAP Alex Plus will begin the cure in about 30-45 min.  I let it cure overnight and often 24 hours before doing anything further

Maybe try it on a spare piece of extrude foam to see if it works for you?

Tom

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Posted by IDRick on Tuesday, August 15, 2023 9:48 PM

Thanks Tom, that is the one I purchased as well!

Yes, I have been playing around with foamboard glued to plywood, cork on top, inverted cork for the ground throw, and two sacrificial ground throws.  Trying different nails and screws.  The 1" ring shank nails are just a shade under 1/8th of an inch in diameter which leaves very little material between the mount hole and the outer edge of the throw.  I'm thinking I will use conventional track nails on the ground throw and ring shank nails on the cork to provide additional lateral support.  My catastrophic GT fail occurred laterally rather than vertically.

 

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Posted by rrebell on Wednesday, August 16, 2023 8:12 AM

You can find very small round headed brass wood screws.

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Posted by Pruitt on Wednesday, August 16, 2023 10:27 AM

IDRick
Mark, I tested with 3/16 inch cork roadbed.  I drilled a 1/16 inch pilot hole in the cork and pushed the nails through the pilot.  

Maybe that's the difference. I don't drill a pilot hole. Maybe the additional compression of the cork around the nail gives it better grip.

Anyway, good luck with whichever method you settle on!

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Posted by IDRick on Wednesday, August 16, 2023 3:33 PM

Pruitt

 IDRick

Mark, I tested with 3/16 inch cork roadbed.  I drilled a 1/16 inch pilot hole in the cork and pushed the nails through the pilot.  

Maybe that's the difference. I don't drill a pilot hole. Maybe the additional compression of the cork around the nail gives it better grip.

Mark,

You have given me excellent advice in the past and I realized that if your advice didn't work, I must have done something wrong.  I found the "problem".  I had only run partial tests.  A 1/16th inch pilot hole did slightly reduce the friction between the cork roadbed and the nail but nails were still easily removed in either situation.  No friction at all pulling a ring shank nail from the foamboard.  But, I hadn't tried the three together (roadbed with adhesive, drilled out CI to accept the nail, hand push nails through CI + roadbed).  Works very well!  I did not adhesive to the underside of the CI.

I did a have problem with CI clip for the groundthrow (218S).  I have Atlas Code 100 Custom Line III turnouts (#4 and #6's) and I used the G shaped clip to attach to the throwbar.  The clip was properly mounted to the CI and throwbar but separates at that juncture when after throwing the turnout several times.  This problem may go away with a permanent installation but not there yet.  Any suggestions?

UPDATE:  I was able to reposition and CI now works correctly...  typed too soon...  Will stay with the easier method.

I'm tempted to throw out the atlas clip and go with this more prototypic approach: http://madisonrails.railfan.net/eci/ground_throw.html

 

 

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