Scratchbuild Project - Sperry Detector Car in N Scale

[peteski]

Randy, which specific liquid cement were you using that caused warping?
The Testors MEK-based cement or another brand?  I'm asking because in my experience Methylene Chloride based cements are better when it comes to minimizing warping.  Tenax 7R was one such cement (but it was discontinued).  Micro-Mark sold (and might still do) a clone of Tenax 7R, and there is also similar cement available: Tack-It II cement (https://www.jmhobbysupply.com). This one is available in my local hobby shop.  However I got tired of chasing Methylene Chloride based cements so I just bought a quart of it on amazon, for a price of few bottles of hobby cements, It should last me until I no longer build models.  But Methylene Chloride is aggressive, and evaporates really fast, so you have to make sure that what you're gluing is in perfect alignment.  I think that is also why the warpage is minimized. Residue of slower evaporating MEK lingers inside the glue joint for some time, causing the warpage.

As for Plastruct, I believe it is ABS plastic, not a plain polystyrene that Evergreen uses.  That likely explains the resistance to Testors Orange tube glue (which I abandoned when I was in my mid-teens and never looked back - that stuff is IMO crap).

[BCR 570]

Interesting comments regarding adhesive.  I have used Testor's Liquid Cement exclusively for years with few issues.  I do frequently laminate parts and for this particular build, yes, the parts will be reinforced in behind later on.  The test side piece I assembled some seven months ago now remains straight.  The scratchbuilt woodchip cars I built during the pandemic are holding up very well, and the cook diner for my auxiliary train (for which the 85' sides are completely laminated) is even older.  However I do appreciate and respect your input, and will be watching for any signs of warpage.

One possible solution for me is that I do weight the parts while drying, and that usually yields flat assemblies for me.


Tim

[Chris333]

I have a Testors cement bottle with a brush in the lid. I used it up years ago and keep refilling it with a gallon of MEK. Sometimes it does seem aggressive, but you can blow on it and instantly it will evaporate to stop melting the plastic. I first bought the gallon on MEK because I was a cheap a$$, but it has turned into my favorite plastic glue.

Also when I scribe and sand a sheet of styrene to make it look like wood. I will brush the whole thing with MEK just to get rid of the fuzz.

[BCR 570]

Carbody Sides (cont.)
Now on to the crew lounge compartment.  The sides for this section have a blanked out window on the left followed by two full width windows.  On the right side there is a narrower window (24 inches wide) with a partial blank beside it, and then two full width windows.  On the inside there is a cabinet, table and chairs on the left for dining and other activities, and seating on the right as well as an entertainment cabinet.  The cabinets are up against the forward bulkhead for this compartment which explains the blanked out window and narrower window.

Starting with the left side, I installed a 31 1/2" blank panel (see previous post for fabrication) and used my styrene gauge to nudge it into place:




After installing each part for the window strip, I use my #11 knife blade to skid the blocking pieces to ensure they arent accidentally getting glued in place:




Next comes a vertical window separator, again using the styrene gauge to nudge it into place:




I then leave a width of 31 1/2 inches for a full width window and install the next separator, using my styrene gauges for precise alignment:




Here is the left side of the crew lounge section with one blank panel and two full width windows:




Now over to the right side, and we begin with a thin infill strip for the narrow window.  I used a piece of .020" x .040" styrene for this:




The narrow window was created by using a .156" shim for the 24" width, and then installing a separator to the left of it:




I then proceeded to install the separators for the two large windows in the same manner as for the left side:




Here is the right side for the crew lounge section, with the narrow window and two full width windows:




After installing the window strip parts for each compartment, I match up the two sides to ensure they are both ending exactly across from each other.  This photograph shows the two sides (left side upside down on top, right side below) and you can see that so far the separators at the end of the crew lounge are in the same place, which is good news.  My measuring and cutting seems to be working out okay:




I have now installed the parts for the motor compartment, galley and crew lounge.  The crew bedroom is next.


Tim

[BCR 570]

Carbody Sides (cont.)
The next compartment is the crew bedroom.  It is three window spaces long and the first window of these on each side is blanked out due to large clothes closets up against the compartment's forward bulkhead.  After the closets there is a lower and upper bunk on each side.  The blank panels and window separators were fabricated earlier and installation is identical to those for the earlier compartments.

Full width blank panel for the left side, again using my gauge to nudge it into place:




Separators for the two full width windows:




Blank panel for the right side:




Separators for the two full width windows:




Here are the two sides after installation of the window strip components for the crew bedroom, with another check to ensure that the last separator on each side are in line with each other:




We are now about halfway along the carbody sides; the washroom is next.


Tim

[Dwight in Toronto]

Coming along, step by baby step.

Hey Tim - I looked into the NWSL tools that you’re using, but had not yet made the purchase leap.  Fortuitously, I was at the Hamilton/Ancaster train show earlier today and picked up this well-seasoned Chopper for $5.00 !   Haven’t tried it yet, but at that price I didn’t think I could go wrong … it’s listed at $60 Cdn on the NWSL web site. 

[BCR 570]

Hi Dwight:

That is a good pick-up; the Chopper is an essential tool for this kind of work.  If it is a used one you just want to verify that it is still cutting square (there is an adjustment knob at the base of the chopping arm) and that the blade is still sufficiently sharp.  (I recently came across a second NWSL Dupli-Cutter here so if you need one of those let me know.)


Tim
 

[randgust]

Looking at my solvent cement collection, what I'd experimented with was the Micro-Mark solvent optimistically labelled 'Same Stuff', which I felt was supposed to be the same stuff as maybe Tenax.  Certainly smelled like it.

And evaporated rapidly.  And at least for me, was difficult to use and control (even with a pipette/glass applicator) and had pretty much the same warping issues as the Testors Orange.   Which is OK once you learn how to control the stuff, it is a strong bond, but once is thickens up from any prolonged air exposure, time to toss it.

What's bugged me about the solvent laminations is how long it takes to show up for warping.   Usually over a year, maybe longer.  Certainly not while you are working on it.  Certainly not when it was solid dry.   Much, much longer before it would appear.

Then there's the dissimilar materials thing.  I just did (and some of you may be seen it at Altoona) the tannery complex on my West Hickory T-track module.  All scratchbuilt from photos.   I had a stash of old H&R styrene brick material, about .015 thick, in sheets.  I'd used it on my 1974 Flagstaff depot, and discovered then that solvent cements would hardly touch the stuff unless the back surfaces were scraped.   Lots of repairs.   I don't know what plastic that is, but it's solvent resistant compared to styrene.   I'd fallen back on 5-minute expoxy for parts of it.

But this new tannery project had thick brick walls; the H&R had to be laminated to .030 styrene to get a nice thick brick wall with windows coming in from the back, also cornices, pilasters, etc.   I used ACC for all of it, it's held really solid - I can't pick it apart, and no warping at all. And no odor, although the outgassing has it's own issues and it naturally wants to glue fingers to it.   Too long around solvents and yes, I feel it.

I also had to laminate up a ton of Campbells Aluminum to styrene sheet for the roofs, same thing - dissimilar materials.   ACC there too, and it's solid.  I used to use 5-minute epoxy for the same job.   I'm just finding that ACC has it's own merits in some situations.

[BCR 570]

Carbody Sides (cont.)
We now come to the smallest compartment on this car, which is the crew shower and water closet.  It is only one window space long and on each side there is a small horizontal window measuring 12" high x 24" wide.  These are identical to the small horizontal window built earlier for the galley section (left side).  This compartment comprises a shower stall on the left and a water closet on the right.

The area above and below the window is to be filled in with lengths of #120 .020" x .020" and #125 .020" x .100" styrene respectively, cut to a length of 31 1/2 inches.  The parts for both sides were cut at the same time on the Chopper using a piece of .156" as a stop block for offsetting the square and another as an alignment guide for the pieces to be cut.  (Small parts like this can disappear into the crack between the cutting mat and the metal frame.)  This photograph illustrates the method I use for cutting small parts like this:




The same method was used to cut four short lengths of #120 .020" x .020" for the infill either side of the windows.  These tiny parts are about 15 scale inches tall:




Here are the parts for filling in around the two windows after cutting:




The top piece goes in first:




followed by the bottom piece:




I then added the vertical separator on the other side of this panel:




The two side pieces went in next:




The resulting window opening was a little taller than desired, so I installed a piece of #100 .010" x .020" at the bottom to reduce the height by .010" which looked better.  Also, a few of these pieces were slightly different in thickness with each other but hopefully I can fix that with a little sanding.  Here is the completed window surround for the left side:




And here is the opposite panel completed for the right side:




Again, after the completion of each section, I compare the two sides to ensure that they are ending at the same point on each side:




Like the left side galley window, these will be framed in with pieces of #100 .010" x .020" styrene a little later, and the full size windows will be framed in with pieces of Plastruct #90709 .010" x .010" strip.

The rear engine room is next.


Tim

[BCR 570]

Carbody Sides (cont.)
After the smallest compartment on the car, we now come to the largest.  The rear engine room is five window spaces in length and houses the power source for the testing equipment, car lighting, a secondary air system, heating plant, workbench, and other equipment.  The first window space on the left side is blanked out due to a cabinet against he forward bulkhead on the left side; it is followed by four full width windows.  On the right side the first window space is a full width window and the second is blanked out.  The last three window spaces on the right side feature a large freight door with window, and blank panels on either side.

My work on the window strips for this compartment began with installation of the blank panel and separator on the left side:




The separators for the four remaining windows on the left side were then installed, again using my styrene gauges for alignment and spacing:




Here is the completed let side for the rear engine room, with one blank panel and four windows:




Tim

[BCR 570]

Carbody Sides (cont.)
Moving over to the right side of the rear engine room, I began by installing the separator for the first window:




This was followed by the blank panel for the second window space, and the separator:




The last three window spaces are occupied by the large freight door and blank panels either side.  As the arrangement of components is quite different from the other side, I need to make sure that the two sides for this compartment come out even at the end.  I therefore elected to glue the last separator in place first and then fill in the remaining components.  This photograph shows how I aligned the two sides together and used my square placed against the last separator on the left side to position the last separator for the right side.  In this photograph the left side is upside down on top and the right side is below:




With the last separator glued in place, I used temporary pieces for the blank panels either side of the freight door (marked 25" and 21") and also for the adjacent door posts.  The remaining space between them is exactly four feet which is the width of the freight door:




With this check completed, I could then cut the final pieces for the blank panels either side of the freight door from #127 .020"  x.156" for the left one and #125 .020" x .125" for the right one.  I used my 36" gauge to cut the parts to the correct height for the window strip, and cut the two pieces together at the same time:




Here are the two blank panels installed on the car side:




As soon as they were installed, I checked the remaining dimension one more time to verify that it was four feet wide:




Now to install the door posts and fabricate the freight door.


Tim


Tim

[BCR 570]

Carbody Sides (cont.)
The door posts for the freight door will extend down to the bottom side sill, which requires a termination of the lower side sheet and belt rail at this point.  I can now cut these parts to exact length and install them.  The lower side sheet was cut from #128 .020" x .188" and the belt rail was cut from #131 .030"  x.030" and the two parts were cut together after measuring carefully and marking with a pencil:




This photograph shows a test fit of the lower side sheet and belt rail, and the adjacent door post:




The lower side sheet and belt rail were then glued in, and the parts were weighted until fully set:




The door posts were cut long from #120 .020" x .020" and glued in place.  In this photograph the car side is upside down, and the piece of .010" styrene under the ends of the door posts is there to keep them level while setting:




The door posts were trimmed flush with the bottom of the car side using a #17 blade:




Fabrication of the freight door is next, which will complete this work for the rear engine compartment.


Tim

 

[BCR 570]

Carbody Sides (cont.)
The final step for the rear engine room is fabrication of the large freight door for the right side.  This is too wide to be cut from a strip of styrene, so sheet styrene is required.  I had some practice side sheets left over which were cut from #9010 .010" sheet styrene and sanded square at each end, so I cut my door panel from one of those.  The door measures 48" wide x 60"-63" tall.  I cut out this panel on my NWSL Chopper and then dressed it square using the NWSL True Sander:




After drawing the window opening in the centre of the door panel, I drilled out holes in each corner and then cut between them with a #62 chisel blade:




The window was then opened out to its final dimensions using a number of different files, and smooth jaw pliers to hold the part while filing.  I left a small curve in each corner to try andc apture the look of the modern sealed window.  I found this work challenging but it is easy to start over with a new piece if it doesnt work out.  Fortunately my first attempt went fairly well:




The freight door requires a bottom sill identical in height to that for the cab door, so a strip of #122 .020" x .040" styrene was cut to the exact length.  During its test fit I found that this piece was a little thicker than .020" and was sitting a little higher than the adjacent door posts, so I sanded it down a bit until it appeared to be the same thickness.  (Test fits are good!)  Here is the door sill going in:




Here are the two sides with the rear engine room components finished, including the freight door:




This completes the work on the rear engine room for now.  The recording room at the rear end of the car is next.


Tim

[BCR 570]

Carbody Sides (cont.)
We now come to the rearmost compartment which is the recording room.  This is where the Sperry technicians monitor the testing equipment and record any potential defects in the rails.  The two sides of this compartment are almost identical in composition, with a full width blank panel, a full width window, and a rear entry door.  The one major difference is that the left side features a set of grab irons leading to the roof; these are positioned on the blank panel and the side sheet below.  As with the grab irons on the right side of the car near the front, there is what appears to be a safety cover with a "Danger High Voltage" sign.

This compartment is interesting for several reasons.  Early photographs of this car show rear entry doors with lower recessed panels and a pair of tall narrow windows above, which I suspect were native to the original gas-electric carbody.  By the early 1970s these doors had been replaced by steel doors with single sealed windows.  The same is true for the freight door, galley door and front cab doors.  In 1986 the car underwent a modernization, at which time the location of the rear entry doors and adjacent windows were transposed.  A review of photographs is always necessary to confirm era specific details!

I chose to begin my work on this section with fabrication of the rear entry doors, as they are the most challenging part.  These doors are 30 inches wide and will be 6'-0" tall when cut to their final height.  I cut lengths of #108 .010" x .188" for the door skins to achieve the required 30" width, and cut the top ends square.  I need two doors but elected to make four and choose the best two, as I knew this would be difficult work.  The window openings measure 24" wide x 30" tall and I drew these openings on the pieces with a very sharp pencil:




I then drilled a hole in each corner of the opening to start the process of cutting out the windows:




I used a #62 chisel blade to connect the holes and chop out the window opening:




Now for the fun part - filing out a 24" wide opening on a 30" wide strip of thin styrene  .  The obvious concern are the very thin surrounds on either side.  My first one (one the left) didnt go so well but the following ones got better.  In this photograph the first two are on the left and the second two are on the right:




I left a rounded profile in each corner to simulate the look of the sealed windows.  These are the best two which I will use for now:




Glad to have those done.  The blank panels and windows are next.


Tim

[Dwight in Toronto]

Tim, as I follow your build intently, I am also in the preliminary stages of attempting to construct that N scale theatre car that I posted a pic of earlier (Canadian Pacific CP1 “Sandford Fleming”).  Luckily for me, the prototype is a smooth-side, so I don’t have nearly the detail to contend with as you do in fabricating the car sides!

I used your drill/cut/file technique to rough out the windows, with acceptable results (I’ll probably finish up with some 1200 grit sanding).  However, I’m a bit stumped on how to incorporate a window detail that I think is important. 

As you’ve alluded to above, I believe the coach I’m working on also uses sealed windows.  At least, I assume that’s what they are - obvious aluminum (or stainless steel) channels or bands around the glass panes, clearly evident in this closeup:




I’m perplexed at how best to capture this detail in the model.  Cursory experiments have involved trying to form window inserts using very thin brass wire (I think it’s 0.010”), as shown here:




You can see the jig I formed, using four track spikes, in the upper right corner of the pic.  As a trial, I wound the wire around the spikes to get the basic shape and fit for the first window on the left.  The first attempt is the plain brass frame that is sitting on the car side.  I then tried a quick skim-coat of solder on the brass to simulate the aluminum frame colour (and with hopes of stiffening the wire a little bit).  That second attempt can be seen, nestled into the left-most window. 

The Atlas shell in the photo shows the look I was going for - their injection molding easily replicates a set-back window frame within the car-side window opening.  I used 0.75mm/0.03” styrene for my car sides, and the 0.01” wire has the potential of creating the inset window frame “look”.  However, I’m not satisfied with these first attempts. 

Tim, are you going to strive for a similar window detail on the Sperry car?  If not, I wonder if you or others might be able to provide some hints or direction on how I might tackle this challenge?

I hope this isn’t considered thread drift … my feeling is that it’s related to your build, and it’s not my intention to divert from it in any way.