The N&W SD50S: The Atlas/Bearden secret now revealed

[nsbob]

   
     Sorry I'm late to this thread, but I have used a rosin cured with ultraviolet light to weld broken handrails and other similar plastics.  I have used it with great results, just make sure you have the parts properly aligned before you use the UV light to cure them.  The product has several names but the last tube I bought at Ace Hardware is called BONDIC.  To indicate its strength, my dentist used a different version of the same product to reattach my crown.

[peteski]

That's interesting Bob.  In my experience Bondic UV-cure resin makes a very poor glue for any smooth surfaces. It can be easily peeled off.

The UV-cure resin dentist use to make temporary crowns or cement them is quite different than Bondic, and the surfaces they cement are not smooth, so those surfaces result in strong bond.

[nsbob]

   Interesting.  All I know is I used it to repair a couple of broken walkway rails on a Micro Trains tank car and it has held up for three years.  I recommended it to Scott Teague and he used it to piece together handrails for a SD70 ACU project he built.  He made one of his videos about the results and also recommended it.

[peteski]

   Interesting.  All I know is I used it to repair a couple of broken walkway rails on a Micro Trains tank car and it has held up for three years.  I recommended it to Scott Teague and he used it to piece together handrails for a SD70 ACU project he built.  He made one of his videos about the results and also recommended it.

Any chance you could take a close-up photo of the repair?  I'm just curious what the glue joint looks like.  Was the railing exposed to any flexing after being glued?  We might just have different ideas about what a good glue joint is supposed to be.

[Mark5]

I created a tool for this process.    I split a 3/16" K&S brass tube.   This is actually too large but it was all I had.   A tube with a smaller diameter hole would be better.   The handrails measure at about .5 mm.    The tube is soldered onto a handle.   I then cut a groove for a stanchion.

Ron, may I ask how you cut the brass tube in half? I have a moto tool with cutting disks - I am thinking that I would cut the tube with that (very carefully!  ).

Thanks,

Mark

[u18b]

Ron, may I ask how you cut the brass tube in half? I have a moto tool with cutting disks - I am thinking that I would cut the tube with that (very carefully!  ).

Thanks,

Mark

Good question.  Safety is important. 
Whole tube…..  half the last inch or so.  So I’m holding 5 or 6 inches when I use the motor tool.
Flatten a handle. 
THEN solder the two pieces together. 
Trim as needed.

[peteski]

Did you actually use a cutoff disk to slice into  the tube or did you just grid off half of the tube's diameter?

[u18b]

Did you actually use a cutoff disk to slice into  the tube or did you just grid off half of the tube's diameter?

Cut off disc.
I wasn't precise as far as measuring.
I cut "about" half away.

[u18b]

I should also add that fusing is obviously not perfect.

Kato quality Delryn works best.

The Atlas plastic .... when you cook it too long it gets brittle.
I did have one troublesome spot on the U18B that broke off.  And then I had to back up a stanchion and do it again (using another set of handrails).

Bottom line.   If you do this, you should consider the handrails to be very fragile.

I have my back up SD50 walkway coming in soon and then I'll install the replacement jacking pads on the SD50S.
Next will be correcting the sidesill slope.

When I'm finished manipulating and handling the shell and walkway, then I'll fuse the handrails.
In my case, I happen to have extras of SD50 handrails, so I can adapt if the first try doesn't work our well.

[nsbob]

Any chance you could take a close-up photo of the repair?  I'm just curious what the glue joint looks like.  Was the railing exposed to any flexing after being glued?  We might just have different ideas about what a good glue joint is supposed to be.

Scott Teague at NSSCOTTTEAGUE VIDEOS made two videos on this.  If you go to his videos on youtube he shows the results of his work.  I feel Ron's melting method will give a better appearance but if I have to repair a handrail that is no longer available as a part, I am going to be hesitant to try it.  However the tool he made to align the parts is a great idea and I intend to make one.  (I know Scott uses the words glue and black light in his videos which are incorrect.)

VIDEO 1:  9 years ago;  SD 70ACU N-scale Project 2
VIDEO 2:  7 years ago;  How to fix Fox Vally N-scale ES44 handrails to NS and CSX style.

[u18b]

By the way....
It may be important to note that plastic handrails come in various thicknesses.

The B30-7 handrails are VERY thin and delicate (and I broke mine    .
Atlas must have had some complaints because the U23B handrails are much thicker.

[peteski]

Scott Teague at NSSCOTTTEAGUE VIDEOS made two videos on this.  If you go to his videos on youtube he shows the results of his work.  I feel Ron's melting method will give a better appearance but if I have to repair a handrail that is no longer available as a part, I am going to be hesitant to try it.  However the tool he made to align the parts is a great idea and I intend to make one.  (I know Scott uses the words glue and black light in his videos which are incorrect.)

VIDEO 1:  9 years ago;  SD 70ACU N-scale Project 2
VIDEO 2:  7 years ago;  How to fix Fox Vally N-scale ES44 handrails to NS and CSX style.

Thanks for the links. As I expected, we all  have different sets of standards. He basically created a clear "muff" or sleeve around the handrails from the UV cured resin.  It results in a bit of a blob at he joint area.  From my experience with multiple brands of UV-cured resins, that "muff" could be easily scraped off the slick plastic handrail.  It is more of a mechanical fix than a bond.

[u18b]

The SD50 walkway arrived and I thought I'd take photos before I cut it up.

In the photo below, the top walkway is a stock SD50 production.
The one below is my shortened pre-production walkway.

You can see that the pre-production walkway (phase 1) is fatter and the regular production walkway (phase 2)  is thinner.   So if you want to build an SD50S, you need to add a strip of styrene along the edges of the walkway to make it fatter.




The last two photos show how I spliced the walkway to shorten it.






My next step this week will be to cut off the rear jacking pads from the walkway I just received and add them to the SD50S walkway.

[Mark5]

The SD50 walkway arrived and I thought I'd take photos before I cut it up.

In the photo below, the top walkway is a stock SD50 production.
The one below is my shortened pre-production walkway.

You can see that the pre-production walkway (phase 1) is fatter and the regular production walkway (phase 2)  is thinner.   So if you want to build an SD50S, you need to add a strip of styrene along the edges of the walkway to make it fatter.

To be accurate, I am not so convinced that you want to make the production walkway thicker:


https://www.nwhs.org/archivesdb/detail.php?ID=33838

I think compromise is unavoidable here.

Mark

[u18b]

So the photo above is what the U18B rails looks like with the 3 foot view (normal viewing distance).   The joints look good.

But here are some brutal macro shots.   There were three joints.   Two in the rear and one near the cab.
One joint looks really good.
One does not.    The one that does not is because I placed my tool on the inside and fused the outside.   

I then had to repair the ugliness I created.

Well, this was good practice.    The SD50S should be better having practiced on the U18B.

(Note to self..... Protect the outside curvature of the rail.  Tool goes on the outside.  Tool goes on the outside!!!!  Weld on the inside.)