Model Railroading > S.T. BNSF Frostline Reefer (WARP 1) – Great Expectations

This is Part 1 of a series on creating the Weld Warpage on the Scale Trains’ BNSF 72’ Frostline Reefer.
 
NOTE:  ScaleTrains uses the outside length (82’) in their designation, but BNSF uses the interior cargo area (72’) as the “length”.  I will use continue to use 72’ to refer to the length of the BNSF Reefer.   
 
Scale Trains has an ETA Dates web page that I use to keep an eye on the progress of any items that I have preordered.  The normal progression is to have it flagged as In Production, then On the Water, and finally In the Warehouse.  (As of this morning, they are still flagged as In Production.)  Imagine my surprise when I received an email last week asking for payment for my preorder.  I paid, assuming they would ship whenever they arrived on-shore.  It appears they are already In the Warehouse, since I recently received a Tracking Number.  They should arrive in a few days.  Pretty exciting!  :-D
 
This YouTube reviewer lives closer to Tennessee, so he got his order sooner. 
         youtube.com/watch?v=-XEOvcJ5Uyg
(You know the drill.  Need to copy-n-paste that into your browser.)
 
Some of the images on the ST website are taken in flat light, so the white-on-white details are hard to see.  However, I’m confident that the ST folks will do a fine job, as they have done with previous Rivet Counter offerings. 
 
A few of the details that I anticipated would NOT be included are:
 
Underframe Insulation
All BNSF Reefers with a curved roof had foam insulation applied to the underside. 
https://www.trainorders.com/discussion/read.php?3,5597815,5597815#msg-5597815
 
 
Side Panel Weld Warpage
Modern construction methods use robots to weld sheet metal together.  After the weld beads cool, the metal edges shrink, which causes the middle of the sheet metal to “pucker”.  The resulting weld warpage pattern is unique per car, and has never been offered on a production RTR model (to my knowledge). 
 
The addition of the foam insulation is reasonably easy to achieve.  It does take some time, but is definitely possible. 
https://www.trainorders.com/discussion/read.php?3,5600191,5600191#msg-5600191
 
The Weld Warpage is another matter.  If it were part of the CAD geometry, it can be 3D printed.  However, on an RTR model, things are not that simple.  There were several methods considered.
 
Shading
Painting various shades of white could simulate the Weld Warpage, and some folks have done it to good effect.  However, I don’t claim to be an artist, nor have the skill set to pull that off.  Also, the sides would still be flat, so “glint shot at sunset” would not reveal the “texture” of the warpage.

Clear Pools
If clear paint was strategically placed in drops, this could simulate the “bulge” of the Weld Warpage.  However, the metal on the prototype not only extends upwards, it also forms a depression, like a ripple on a lake.  Any areas with lettering (or the huge BNSF Badge), would be beneath the surface, rather than on top of it.  Though it would work fine for the “glint shot at sunset”, normal viewing might be a bit distorted; like looking thru thick glass.

 
 



Edited 4 time(s). Last edit at 02/19/24 19:36 by tmotor.

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3D Print the Side Panels
This would require a major kitbash, where all side panels are entirely removed, and then replaced with 3D printed parts.  Though this is possible, it is a brutal process.  If the first attempts to create Weld Warpage are a total FAIL, then this will be Plan B to the following option (below).
 
Turn Up the Heat
Folks have used heat to soften the sides of gondolas, prior to manually creating bulges and creases.  This works well, since the bulges only go from the inside out.  Could this method be used to create the Weld Warpage on a BNSF Reefer?  One way to find out!  :-0
 
A brief search of the web seems to indicate ABS plastic melts at around 212F.  Since that is the boiling point of water, it seems like a good place to start as a source of heat.  Water is a terrific medium to transfer heat.  One of the pitfalls of heating plastic beyond the melting point, is the risk of “burning” it, leaving permanent damage.  In theory, no matter how hot the water gets, it won’t be hot enough to burn the plastic.
 
A few of the potential issues are:
 
How hot does the plastic need to be before it becomes pliable, but not disfigure or collapse?
How long will the “work time” be before the plastic begins to cool and harden?
How will small details (like ladders) fare?  (I assume they will have to be removed BEFORE applying any heat.)
How will the lettering fare?  Hopefully it will flex enough to follow the Warpage. 
Will the shell remain true (square) during the process?  (Probably will use a brace, just to be safe.)
How deep of a depression is needed to have it show up on the model's panels?  (The prototype has shallow depressions.) 
 
At this point I don’t have a BNSF Reefer in-hand, so I’m not sure how it comes apart.  However, the brief snapshot of the exploded diagram (in the YouTube video) implies the roof is attached to the sides, and the floor is removable.  The trick is to apply heat to just the side panels, and NOT trashing the rest of the shell.
 
Only a nut-job like me would purposely disfigure a perfectly good, brand new, $80, ST Rivet Counter model.  I’m beginning to feel the angst of those that weather new locomotives.  At least with weathering, it can mostly be reversed if the results are less than desired.  However, when it comes to melting plastic, there isn’t much of a “back-space key” to reverse the effects.  Things can be fine-tuned later, but generally I’m going to have one shot at getting it right.  The 4 Reefers I have coming are all equipped with sound.  All of the non-sound models have sold-out at ST, so I will have to use some other models for R&D purposes.  When I’m reasonably sure the process works, I will then disassemble one of the BNSF Reefers, gulp hard, and give it a try.
 
Dave
 
 



Edited 8 time(s). Last edit at 02/21/24 03:02 by tmotor.

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One issue with trying to use boiling water to soften the plastic is you will need to remove the body shell from the water, which means using tools which could leave a mark. I suppose you could use a piece of fabric as a sling the suspend the shell in the water and then remove it without applying pressure to the shell.

Ted Curphey
Ontario, OR

Yarmouth offers a few boxcar kits with this feature. Not sure if I like it or not. Maybe a little "too much."

Greetings Ted!

> One issue with trying to use boiling water to
> soften the plastic is you will need to remove the
> body shell from the water, which means using tools
> which could leave a mark. I suppose you could use
> a piece of fabric as a sling the suspend the shell
> in the water and then remove it without applying
> pressure to the shell.

Agreed
I'm thinking about trying to circulate hot water thru a heat exchanger that will be underneath just one half of one side of the shell.  That way the heat is more localized, and I'm working on just 1/4 of the shell at at time.  We'll see what happens.  :-D

Take care and God bless!
Dave



Edited 1 time(s). Last edit at 02/20/24 07:32 by tmotor.

Greetings CPR_4000:

> Yarmouth offers a few boxcar kits with this
> feature. Not sure if I like it or not. Maybe
> a little "too much."

Thanks for the heads-up on their kits.
Looks like they are headed in the right direction.
Execution is everything.  If done right, it can really enhance the model.  Done wrong, well, not so much...  :-0

Take care and God bless!
Dave

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I hate to see suggestions from folks who have not actually successfully done a deed. lol but what about shooting steam through a small nozzle impinging on the plastic? Like the Stewart-Macdonald neck joint steamer used in guitar repair. Looks like something a careful and thoughtful tech could make at home.

Regards,
Jeff Oliver

Greetings Jeff!

> I hate to see suggestions from folks who have not
> actually successfully done a deed. lol but what
> about shooting steam through a small nozzle
> impinging on the plastic? Like the
> Stewart-Macdonald neck joint steamer used in
> guitar repair. Looks like something a careful and
> thoughtful tech could make at home.

A jet of steam coming out of a narrow tube would work if it went into a manifold to evenly distribute the heat over a wide area.  I'm thinking that heating the panels to the left of the door (on a single side of the shell) would be possible.  Once it is up to temp, then pressing that area of the shell between a "negative" and "positive" of the Warpage-shape, hold it until it cools, then release.  That is the theory anyway.  :-D  

Take care and God bless!
Dave
 



Edited 2 time(s). Last edit at 02/21/24 03:08 by tmotor.

I'm thinking even lower tech than that. One panel or even part of one panel heated at a time, pressed gently with a finger to the subtle shape. The rest of the side protected by wet tissue like a mask. I would be too worried to heat a large area by any heat source, that seems like asking for mishap. Tricky to control.
I have tried this on a gondola, using a pencil soldering iron for heat. Moderate success at best, I got impatient with slow heating, moved hot tip closer and closer, ended with scarred inner panels. Steam may be a more efficient yet more controllable heat source.

Regards,
Jeff Oliver

I've probably missed this, but have  you considered using a blow dryer on the plastic shell?  Perhaps by heating the bodyshell from the inside first with a blow dryer on high?  I have been able to successfully straighten some undesirable warping (warping aused by me) on a resin freight car kit with maybe 10-20 seconds with a hot blow dryer (NOT heat gun).   Of course, this is a resin bodyshell, and not injection molded plastic, that I'd expect requires a higher melting point.  Perhaps a heat gun on at a very low setting might work also, but that seems too much of a "nuclear" solution or just sheer destruction to me to test on some old junk bodyshells first.

Cheers,
Harry

Greetings Jeff!

> I'm thinking even lower tech than that. One panel
> or even part of one panel heated at a time,
> pressed gently with a finger to the subtle shape.
> The rest of the side protected by wet tissue like
> a mask. I would be too worried to heat a large
> area by any heat source, that seems like asking
> for mishap. Tricky to control.
Ah, OK.  A more localized application of heat.
That would be a safer process.  I like the idea of leaving the adjacent panels alone to maintain the integrity of the shell.  It would be a slower process, but could be the ticket.  :-D

> I have tried this on a gondola, using a pencil
> soldering iron for heat. Moderate success at best,
> I got impatient with slow heating, moved hot tip
> closer and closer, ended with scarred inner
> panels.
Though I like the idea of doing an entire 1/4 of the shell at one shot, there is a risk of getting it wrong or warping the shell.

> Steam may be a more efficient yet more
> controllable heat source.
I'm liking the concept.  Assuming the steam is at the melting point of the plastic, it won't burn the plastic (like an open flame could).
Thanks for the suggestion!  

Take care and God bless!
Dave

Greetings Harry!

> I've probably missed this, but have  you
> considered using a blow dryer on the plastic
> shell?  Perhaps by heating the bodyshell from the
> inside first with a blow dryer on high?  I have
> been able to successfully straighten some
> undesirable warping (warping aused by me) on a
> resin freight car kit with maybe 10-20 seconds
> with a hot blow dryer (NOT heat gun).   Of
> course, this is a resin bodyshell, and not
> injection molded plastic, that I'd expect requires
> a higher melting point.  
If the use of localized heat doesn't produce the desired results, then this is worth a look.

> Perhaps a heat gun on at
> a very low setting might work also, but that seems
> too much of a "nuclear" solution or just sheer
> destruction to me to test on some old junk
> bodyshells first.
Indeed!  
Heat guns are not exactly surgical instruments.  The adjacent parts of the shell would need to be shielded from the ricochet of the blast of heat.
It would definitely take some practice to master.

Take care and God bless!
Dave
 

The only practical way is to use thin material for the side sheets, stuff like 10 or even 5 thousands of an inch thick, supported by a framework.
That way you're not trying to control the entire side at the same time. We just had a manufacturer do that for a gondola last year. They used very thin brass.

Greetings PHall!

> The only practical way is to use thin material for
> the side sheets, stuff like 10 or even 5 thousands
> of an inch thick, supported by a framework.
> That way you're not trying to control the entire
> side at the same time. We just had a manufacturer
> do that for a gondola last year. They used very
> thin brass.

Thinner material would be easier to work, require less heat (if any) and yield good results.  It takes some practice to NOT poke-thru the thin material, but it can be worked right up to the edges.
In an ideal world, I could specify the construction of the model.  As it is, I have to work with what is there.

Take care and God bless!
Dave



Edited 1 time(s). Last edit at 02/23/24 12:28 by tmotor.