SP 3301 Combine (Part 2) - Daylight Confetti

In SP 3300 & SP 3301 (Part 1), I covered the history of the two prototype cars and made my cuts into the body of the MTH 79-CB-1 to shorten it by about 24" to make the 77-CB-1.  In this post I will be covering the splicing, splicing the underframe, and cleaning up the various joints in the shell.

SP 3301 after 1st coat of paint priming over the patched splice areas.

Rough Body Shortening and Gluing Up

I stopped in SP 3301 (Part 1) just before I glued the body shell back together.  This is the next step, make sure that the end is square and will line up with the strips and fluting at this point.  If the fluting is not indexed properly, it will be VERY hard to fix later.  It is MUCH better to get this right now.

Liquid Tamiya Plastic Glue used to 'weld' the body back together.

I worked my way around the car body checking alignments.  Do this before finishing this joint up and really putting enough glue that you can't make adjustments.  Make sure that the sides are good and tight joints.  Pressing the body in from the end will insure a tight joint with the Tamiya glue.  I left a slight gap in the roof of the car, as this joint is between panel joints in the roof, sanding and filling will be much easier here than in the fluting!

Right side and roof joint.

Close-up of right side baggage elevator opening.

Here's the roof joint filled and sanded down.

Don't forget to finish the roof joint before starting to work on the sides.  The body needs the strength of the roof being solid for the strain the filing and plugging of the elevator openings will require.

Donor Fluting Parts

Unfortunately there's no good way to do this without sacrificing a MTH carbody to get more fluting to replace the baggage elevators.  The SP 3002 and 3003 Parlor cars were strictly assigned to the Coast Daylights and Morning Daylight (1938-1942 and 1946-1949) and have no use when modeling the San Joaquin Daylight.

Here's the cut ends of the SP 3301 car (Left) and the sacrifice SP 3003 Parlor body (Right).

Here's a photo showing the SP 3003 Parlor car body that I decided to cut up to get all of my replacement fluting from.  Pencil marks are made on the parlor body to show where I will be making the cuts.

Here's the Left Side Plug before whittling it down to fit the hole.

These two photos (above and below) show the body parts and plugs before I glued the body shell together.

Here's the Right Side Plug before trimming it down to fit in the baggage elevator opening.

Notice that I keep the vestibule side of the baggage elevator molding.  This will provide the material that I need to sand and file the body down to the exact length that I want.

Installing the Elevator Plugs

I decided that instead of doing square cuts to insert the fluting plugs, I would make the cuts at an angle.  This will allow me to make very small changes in the size and change the depth that the plug will fit into the opening.

Here's the plug and the opening with a bevel angle filed into them.

This makes it very easy to slowly file the plug or the body to make a perfect fit both in depth and size.  If the part gets too small it will 'sink' into the opening.  If the part's still too large, it will stay high and not be flush in the opening.

Here's the body with the plug sitting hight.

In the photo above, the plug is still slightly proud of the body.  I know the Tamiya glue will melt the plastic a bit and cause the plug to sink into the opening.

Here's the plug glued in before sanding.

Here's the plug after it was glued in.  I use my carbide scribe at a low angle to 'burnish' the fluting back to shape through the joints.

A small amount of filling with Squadron Green putty.

I also used some light sanding from 600-grit to smooth the tops of the fluting so that the plug doesn't bump out from the rest of the carside. - I thought the plug would 'sink' a bit more into the opening I guess.

After the light sanding.

Once the sanding and burnishing of the fluting is complete the car's ready for touch up painting.

Here's the carbody once the basic Daylight Red and Orange have been 'patched' over the work area

Now that the body's been mostly finished, it's time to catch up with what I was doing with the underframe.

Underframe Shortening

I started by cutting the body in the previous post, and I then decided to cut down the underframe to help the reassembling of the body, as this will become the new structural foundation of the car.  The floor was cut inboard of the rear truck.

Here's the underframe cut apart

The underframe sills were cut about 3/8" of an inch offset from the floor.  The interior was shortened in the baggage elevator compartment area.  This way all of the joints do not line up to cause a weak point in the car.

Another overview of the underframe.  The rear of the car is to the right.

Here's the floor with the 24" removed just inside the first cross beams.  Also 24" of centersill is removed about 3/8" over.

Make sure the floors are cut square and a little light filing makes sure that they fit together true.

A top view of the underframe cuts.  Notice that the weights have been removed for modification.

However don't forget that we're moving the bolster screw inboard in the process here.  A new relief hole will have to be cut into the inboard side of the two weights.

Here I'm checking the fit of the weights, interior and the shortened rear underframe section.

Here's the floor of the car with the weights cut.  I used a Dremal cutoff wheel to grind the new relief's in the weights.

Here's the marked weights so I'm sure to keep them on the correct sides after reinstallation.

A detailed view of the modified weights.  Note the two notches to to the left for the ribs in the underframe floor.

Next, the ends of the weights are check to see if I need to cut them off to fit within the shortened end of car.  (Note: at this point the interior was already removed and shortened.)

Here's the modified weights mated to the forward underframe and interior.

With the offset in the floor and underframe cuts lining up now, I test fit the parts to be sure the plan will work.

Test fitting the floor splice joint

Here I double check that the sides of the spliced floor will line up within the body.

Double checking everything will go together and be correct length.

Here's the shortened underframe and shortened body together.  The underframe splice was 'welded' together with Tamiya brand liquid plastic glue.  I made sure to flow enough glue into the joint and ad pressure until I could see a small amount of liquefied plastic squeeze out from the joints.  Also make sure that the parts are still straight and true before the glue totally sets.

Here's the completed underframe with the modified body.

If I were to do this again, I would probably do this kitbash in the same way that I've done here in that the body work needs to be done first, and then the underframe done to match it.  For clarity of process I'm splitting this up so that the progression is clear.  Just realize that I was actually doing the body slightly ahead of where the underframe was at.

Interior Shortening

Stepping back a moment to check on the interior of the car, basically we need to shorten the elevator space in the car.  The 77-CB-1s have a luggage rack much like the 77-C-1/2/3s have.

Here's the 79-CB-1 starting point for the interior.

Here's where the cuts were made in the floor to shorten the Interior.

Notice that two of the underframe retaining clips are being sacrificed in this modification.  These MTH cars hold together pretty well, so I'm not too worried about loosing these clips because of the other ones forward in the car will still be able to hold the car together.

Styrene shims added to keep the interior square

The last step with the interior is to add styrene shim blocks to the luggage rack spaces.  This will keep the interior of the car square and true.  Ideally the joint in the floor will also be able to be reglued, but that joint is now secondary to the shim blocks which do most of the structural work holding the vestibule interior in place.

In Closing

This pretty much covers what work has happened in the interior and underframe of the SP 3301.  In SP 3301 (Part 3) I'll be covering the rest of the body shell modifications and changes to the skirting to clear the truck in the shortened wheelbase configuration.

Jason Hill

Addition Related Links:
MTH's 1939/1941 Daylight Cars Upgrades & Mechanicals - Basic modifications to MTH passenger cars

SP 2424 (Part 1) - Truck Conversion - Modifying Athearn-Genesis 77-C-3 for CoSF Pool in 1954.