HO Scale GP39V Build

[packers#1]

One of the main reasons I switched to HO Scale was a realization that, while I wanted to build locomotive and freight car models, I hadn't done much of it because I was so frustrated just trying to build buildings in N scale. And so without further ado, this will be my thread to document the physical detailing on my first of up to 3 GP35 rebuilds. I also want to get a GP30u to do up for Greenville and Western, and would want to do one of these GP39E/M/Vs in the whiteface with white stripe scheme, and could see doing a second of the standard BN scheme to replace or pair with this one. I also am starting with an Athearn Yellow Box GP35 for this build and didn't want to take on replacing the steps with the Cannon & Co brass ones designed for Kato's GP35 just yet, so we shall see. There's also the Lamoille Valley/NSHR's ex Canadian American GP35Es that were initially SP GP35Rs that I'd like to give a shot which would require a bit more extensive modification for the Canadian American rebuilds (removed the single stack exhaust for an angled filter box and added two exhaust stacks amongst other things) so I don't really know how many of these units I'm going to end up building because I really like the rebuilt GP35's. 

This first one will draw inspiration from BN 2975 / WAMX 3906 and will be a GP39V. BN rebuilt GP30's and GP35's at three different contractors to what they dubbed a GP39, with the last letter corresponding to the contractor: GP39E's came from EMD, GP39M's from Morrison-Knudsen, and GP39V's from VMV inc. I had found a great little write-up of the conversion process out on the inter webs but managed to close all my tabs open on my phone a couple days ago so now I have to remind it. But regardless, the main points are the locomotives kept their single exhaust stack and lost the middle fan; that's going to be the most difficult bit to figure out for this build, and will be the subject of my first questions shortly. Now, onto prototype photos:

We'll be using BN 2975 (BNSF same number, then WAMX 3906). Some links to prototype photos:

http://www.rrpicturearchives.net/showPicture.aspx?id=1276132
http://www.rrpicturearchives.net/showPicture.aspx?id=2989756
http://www.rrpicturearchives.net/showPicture.aspx?id=1354050
http://www.rrpicturearchives.net/showPicture.aspx?id=1725341

Adding this rear view photo 8/5
http://www.rrpicturearchives.net/showPicture.aspx?id=2302150

Of particular note for this build is the middle radiator fan was not simply plated over, it appears as though it was filled in and made to be a flush, smooth surface, as this shot showing the roof of 2975 and another of WAMX 3901, another GP39V, shows.
http://www.rrpicturearchives.net/showPicture.aspx?id=1276128
https://www.railpictures.net/photo/857200/

And it's this feature which is currently giving me the most pause. I've found a Details West kit for the P2K GP30's for BN which is going to give me most of what I need for the Athearn shell (train line and MU hoses, horn and horn stand, firecracker antenna etc) and I'll need to also add lift rings, cut levers, and ditch lights from what I can see. I also want to try to make brass handrails and may need to also bend some brass for the air line to the horn, but all this seems relatively straightforward (although I'm sure there will be some questions) but I'd love to hear how anyone here would approach filling in the middle radiator fan hole and making it appear clean. My first though is either get some thick styrene rod, if I can find the correct diameter, and cut it and fill it, but I'm not sure how easy that would be. I could also take some sheet styrene and try tracing, cutting, and filing it to fit the hole. However, I'm not sure if I should get some green putty or some other body filler for the edges, or if there's a trick anyone knows with styrene cement to melt it together. The shell and chassis are below, and a second photo with the shell on the chassis and the cab put on. I'll also need to fill the mounting hole for the stock horn.




As far as the unit goes, I've thus far repainted the frame black and am currently waiting on wire so I can wire up the trucks to move electric pickup to that method only. I'll use Kapton tape to ensure the motor stay isolated from the frame along with the paint and rubber mounting pad. I'll mostly follow Keith Robinson's Athearn Blue Box upgrades from his Jan 2019 article in RMC, but I'll be using a larger speaker and installing a keep alive along with using an ECU decoder unlike Keith's article. I'll most likely create a second thread documenting that in the DCC forum. But in the meantime, follow along as I build this locomotive!

[packers#1]

Well I went ahead and just went for it. I tried cutting a few plugs to size and it didn’t work, so I slowly sanded one down and was able to get it to fit. I then used a couple slivers to plug the two areas that weren’t round and had been hidden by the fan and used the styrene cement I had to get them to melt and bond. We’ll see how rough it is once the paint is stripped, but I’m hopeful that it’s going to look alright as is. If not we’ll just have to sand it smooth

[packers#1]

Detail pets have started coming in and I have a question for those of you who have worked with some of the details west and gold medal models parts. For stuff like lift rings etc I’ll be drilling mounting holes, but some of the thicker pieces like the snow plows I’m wondering if I need to drill mounting holes for the large pins, or if I should cut them off, square the face and glue the plow to the pilot. Further reasoning for this is the pilot of the GP35 has two holes which are slightly wider and will make drilling the holes a bit tougher. What advice does the  collective have for this?

[peteski]

I like to pin all the add-on details which can be easily knock off.  Without a pin and a hole the glued areas are rather small and with metal to plastic joint, the glue joint will not have much strength.

[mcjaco]

Back in my HO days, I went both routes.  Preferred to drill holes for those pins.  More surface area for the glue. 

[NorthWestGN]

I've always preferred to drill holes when possible, like you said more surface area... it also adds physical strength in a different direction. If you're using CA to bond two smooth surfaces without a post or lug to anchor it, it's very easy to knock the part off as CA has very little shear strength unlike a plastic to plastic solvent bonded or welded joint.

I did have problems when mounting metal details parts in N scale to plastic bodies and that was the difficulty and amount of time to clean up the castings bottom or mating surface while keeping the pin. A friend showed me the trick of very gently heating the brass or white metal detail part with a soldering iron with it in final position to seat it into the plastic until the bottom of the part was flush with the surface of the body. Not for the faint of heart but saved a lot of time in clean up and the joint often didn't need glue at all. Oh and have a container of cold water and a brush handy to cool the part quickly so it doesn't sink in too far...

Brent

[packers#1]

No phoyy try is yet but I did finally make a little progress by stripping the shell and putting putty in to smooth over the styrene plug I filled the fan in with. Fall is when I spend a ton of time outside so I anticipate this will be a slow pace for the near future.

On another note, I found this build chronicle posted by a guy in the BN Modeler’s group on Facebook and wanted to preserve the link for my own reference as well as for others

https://milepost15.com/2024/09/28/burlington-northern-gp39m-2885/?fbclid=IwZXh0bgNhZW0CMTEAAR1cDZitP3-EzZrfawdkuX1-q4TYpOukW87d06SvfRr6EJF_OF-n4Upyb1o_aem_JRRxTYLPcVFwc2iSBozcLg