To paraphrase Vane Jones, "Knowledge is of little value until shared with others."

Wednesday, February 18, 2015

Finishing a CTM 4000 Baldie Kit Part 2: Drilling Holes, Gluing the Parts Together, and the Brass Skeleton

The prior post should have started with, after contacting Terry Gaskin and getting the instructions, be sure to print them out. I had mentioned to Terry he needed to include the page numbers on the sheets. Having loose sheets of un-numbered pages of paper can be deadly.

If you can print the instructions back-to-back, using both sides of the sheets will help to save on paper.

After seeing the number of pages of instructions you might be scared off getting involved with the kit. But, after you read them over you'll realize half of the instructions involve ordering the parts and then getting them ready to start assembly.

The balance of the pages are filled with assembly instructions and drawings. Most of the pages are drawings. Terry did a great job in illustrating the verbal part of the instructions. While the kit may not be a shake-the-box type of kit, it is moderately easy to assemble.

Back to the assembly - There are dimples where holes for grab irons and handholds are to be attached. The dimples are 0.020" in size. I drilled mine out with a 0.0225" drill. I recommended to Terry the dimples be enlarged to 0.025".

Q-Car used 0.025" brass wire for his CRT 4000 Plushie. I like to use 0.025" brass wire. This size wire is still small enough (scale 1.25") and will hold up to the handling a model will receive during its lifetime.

Eventually the holes will be re-drilled larger than 0.025". Why? When gluing the hand rails etc. in place some of the glue has to be between the brass and the material into which it is inserted.

It's best to drill the holes now by hand since they may be obstructed during the assembly process. Also, you'll find it easier to drill the holes now rather than when the body is assembled.  The 0.020" dimples are small plus it's easy to have the drill slip. Do not use a power drill. The nylon is soft enough for a reasonably sharp drill to go through it when drilled by hand.

There are additional holes to drill for the windshield wipers, whistle air pipe, plus any headlight or route or marker lamps. The holes for route or marker lamps will be drill when needed.

The only holes in question are the sets for the handrails in the ends of the car where the end door is located. It looks like initially these handrails were installed lower then they appear in later photographs. Perhaps the conductors and gatemen complained they were too low to be useful and were subsequently mounted higher.

One last comment about drilling the holes. Some of the holes as you drill them seem to continued to go through the material and not come out the other side. These holes if drilled at a slight angle will come out of the material. It's OK to drill these at a slight angle. When the brass wire is installed, if it is at an incorrect angle, it will be easy to bend it to the correct angle.

Next the 5 parts which make up the sides need to be glued together. To support each glue joint a piece of styrene needs to be glued to the back of the doors to back-up the joint. Butt joints are very weak. Backing-up the joint helps.

If I followed the instructions to the "T", I found the amount of space in which to glue glazing for the window in the door would be too small. For this reason, after each of the styrene backing pieces were cut, a piece of either 0.015" or 0.20" x 0.040" styrene was glued to the backing piece. This pushed the backing piece away from the window leaving more space for gluing in glazing.

The photo shows the center door piece with the 2 pieces of 0.040" styrene backing pieces during the gluing process. Note the 2 cloths pins used as clamps. The red circles are around the additional pieces of styrene attached to the backing piece. Attach these 2 small pieces 1st, then glue the backing pieces to the door pieces.
For the center door attach the backing piece on one side of the door and then on the other side. Remember styrene solvent glue is not "compatible" with CA. Allow the styrene solvent glue to completely cure 1st before using the CA.

Clothes pins, the clamping type, were used to hold all pieces during gluing and afterward. Always allow the CA to cure before going further, A great deal of stress is being placed on the joints even if you do not personally stress a joint.

Once the center door has the backing pieces in place, glue the backing pieces to the back of the end doors. Allow all the pieces to cure overnight before going further.

Be careful of which section with windows is glued to the center door piece. Examine the vertical wows of rivets next to the window in the door.

On the bottom of page 195 of the CERA Bulletin 113, "Chicago Rapid Transit Volume I: Rolling Stock 1892-1947"; is a side photo of a Baldie. Carefully notice the vertical row of rivets to the left of the center door at the window level of the car. There are no vertical rivets to the right of the center door at the same level.

Once the 5 pieces making up the side are glued together, your side will have a slight bow. Do not worry about this. Pieces of brass will be glued to the back which will straighten out and reinforce each side.
This is one side. The center door had been attached 1st. The end doors were attached last.
This is the side after all the CA had cured. Note the bow in the side.

A 3/32" square brass tubing is about the smallest size square brass tubing which will resist moderate bending. Yes, this size can be bent and for this reason when shopping for this and the other pieces of brass; inspect them for bends. It is almost impossible to straighten these small sizes of brass into their original unbent shape!

The 3/32" square brass tubing will be glued at the top of the wall while a 3/32" x 3/16" rectangular brass tubing will be glued directly under the interior bottom of the doors. To tell the truth, a 3/32" square brass tubing could probably be used under the doors.

This is one of my sides after both pieces of brass had been glued in place. All the filler pieces have been added to make the interior of the side one flat plane. Notice the green body filler added and sanded.
To hold the brass against the nylon during the curing of the CA adhesive, place as many clamps along the top or bottom as needed. I used so many there was less than an inch between them!

As to the length of the tubing, I cut mine a little short of the length of the side. If I were to make another Baldie, I would cut each piece of brass tubing the length of the side. The top piece would have each end tapered at a 45 degree angle to clear the glazing of the end windows.

To assemble the body into a square piece, some years ago I discovered if a car side and end were glued together square and the other side and end were glued together square; then when the 2 side/end assemblies were glued together, the body was square. Make sense?

Only one corner of a side and end can be assembled square with the model. On the ends the dash below the motorman's window is not square with the side. The other side, I'll call the passenger side, is square with the side.

The assembly will be done up-side-down on the glass plate I use. To prevent the CA from adhering to the plate glass, a large "ZipLoc" type of bag will be opened up and laid over the glass.

Using as many machinists' squares as possible the side and end are glued together and held squarely in place. The same is done with the other side and end. Allow the CA to cure over night.

These are views from both sides of the side/end gluing process.

While the curing is taking place, cut out the floor and/or make the floor if it has not been done already. A drawing of the floor is included in the instructions. I had a piece of 3/23" thick basswood on hand. It turned out to be exactly the correct thickness required.

To glue the 2 side/end pieces together squarely, again up-side-down, on the piece of plastic bag glue the 2 assemblies together and insert the floor in place. Check the entire assembly for squareness and allow to cure overnight.

The next day a piece of styrene, wood, or brass can be glued inside of the end doors to serve as a tab to which the floor will be screwed. Be careful! the sides and ends assembly is extremely fragile. The floor was taken out. then the pieces were glued to the interior of the doors and after a couple of minutes the floor was placed back in place.
A  green arrow points to the styrene tab.
The roof is glued onto the body next. Place the body with the floor in place right-side-up on the opened plastic bag. Place the roof on the body. My body did not have any tabs to locate the roof. I had to locate the roof on the body as best I could.
If there are no problems, apply CA to the top of the walls of the body. Place the roof back on the body. Apply pressure on the roof if required. As mentioned before my roof had a slight bow. It was high in the center. Machinist weights were added to the roof. Allow the CA to cure over night.
If you find gaps after the CA has cured, like I did, apply more CA through the windows and use the large wide rubber bands the USPS uses for the mail to secure the roof to the body. Be sure to have the floor in the body during this process. Again allow the CA to cure over night.
I found it best to lay the body on its side during the curing process. This allows the CA to flow into the top of the body side and roof contact areas. This should take care of the attaching the roof to the body.
If everything is square, add pieces of styrene into the 4 corners of contact between the sides and the ends. I used 0.188" x 0.125" styrene. My pieces were just short of the windows down to the top of the brass piece at the bottom of the sides. Allow the CA holding the pieces in place to completely cure.
For the side of the end where the motorman is located. This end is bumped out for additional room for the motorman. You need to add some stripes of styrene to fill in and support the added pieces.
This process is to support the joint between the ends and the sides of the body. These 4 joints may be the weakest of all the joints making up the body.
These pieces can be seem through the end windows. I used a Dremel Tool with a small round end mill to shave off the corner of the pieces of styrene not attached to any nylon of the body. This is the one corner which can be seen inside the body. Since I did not want to weaken the joint being supported, my cuts were tapered. The top of the added styrene piece was cut off the most with the bottom cut off the least.
Unfortunately I did not take photos of this and my drawings were too poor to be used! I apologize for not taking any photos.
To get this post into the blog and out on the web, let's cut the material off here. We'll pick it up from here with the next post.

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