Thread topic change: Stripping paint Arnold U25C from the 2015 run

[delamaize]

Hey guys, going through my parts box I discovered I have enough pieces to build a Arnold u28c, with the exception of a light board. I know you guys are tired of hearing about my Skookumchuck beltline, but I think that's the plan with this locomotive is to repaint it for my line. I have two boards, they both are bad though. One board I have one LED in one direction, and it's missing several of the resistors in the center of the board, two of the resistor pads have been lifted. The Other Board is completely fried it has no life whatsoever and actually causes a short when put power to it. So what are you guys got? Anybody have one of these boards in their part box they be willing to part with?

[peteski]

Did you try ordering new one from Arnold?  I believe the parts diagram included with the loco shows the part number for that board.

That board has a decoder socket along with all the interconnecting traces, resistors, and other components for lights and track/motor power on it so I doubt anybody would have discarded it to for example hardwire a decoder.

[k27463]

I doubt anybody would have discarded it to for example hardwire a decoder.

Both of mine short with a decoder installed, so I ended up gutting/hardwiring...we are still out here 

I'd just hardwire and attach LEDs to the shell if you can, I suspect it'll be easier in the long run.

[delamaize]

Okay a couple of interesting developments. To begin with it wasn't resistors that were missing, it was actually diodes. I managed to scavenge two from the board that does nothing but shorts and was able to get all of the lights working for One Direction, and one light for the other direction. I did not have any more of the same type of diodes, but I did have some old Atlas loco directional lighting incandescent bulb boards. I scavenged one of the glass diodes, and installed it for the one that was still missing, lo and behold everything is working now. Now I just got to buy a decoder.

[peteski]

Okay a couple of interesting developments. To begin with it wasn't resistors that were missing, it was actually diodes. I managed to scavenge two from the board that does nothing but shorts and was able to get all of the lights working for One Direction, and one light for the other direction. I did not have any more of the same type of diodes, but I did have some old Atlas loco directional lighting incandescent bulb boards. I scavenged one of the glass diodes, and installed it for the one that was still missing, lo and behold everything is working now. Now I just got to buy a decoder.

While I have  not done any detail examinations of this loco's PC board, going by what I saw in Arnold SW1 board, those diodes are basically there to supply the "blue" common positive voltage for the headlights.  Any silicone diode (which is pretty much all you can easily find nowadays) with reverse voltage of 20V and forward current of 0.1A  or more will work.  Basically it is this:



They do this because the 6-pin decoder connector does not provide the "blue" output and connecting positive lead of an LED-based headlight directly to the track DCC signal might not work as well as it did with incandescent bulbs.

[peteski]

Both of mine short with a decoder installed, so I ended up gutting/hardwiring...we are still out here 

That short seems strange, but then again  . . .

[delamaize]

Hey guys, since I was able to get this junkyard dog running, I'm going to Repaint it into Skookumchuck Beltline (Big surprize right).
Is there a best method/chemical to strip these shells without damaging them? Luckily, I have 2 good shells, so if one accidently gets trashed its not the end of the world, but I only have one shot really. If I trash one shell, im going to just renumber the other NP shell, and run it with the other 2 NP units I have already

[peteski]

There are many official and unofficial plastic-safe paint strippers out there. Some might not be safe on all plastics and various types of paints used by various model companies can also be unaffected by certain strippers.

There have been many paint stripping discussions on TRW. Here are some references: https://www.therailwire.net/forum/index.php?topic=59957.msg826499#msg826499

Unless someone actually stripped that particular model and tells you what they used you might have do some experimentation.

[peaks]

Is there a best method/chemical to strip these shells without damaging them?

I successfully stripped paint from plastic shells soaking them in 99% isopropyl alcohol. A few hours is enough.
Then use a soft toothbrush to remove the residue. Clean with water and soap, then paint.

[delamaize]

Thank you guys. I have 99% isopropyl alcohol already, I may start with that. If it don't touch it,  I think I'll try to find some Purple Power like Peteski mentioned in the thread he posted.

Stay Tuned! I may start a new thread on it eventually.

[delamaize]

Update: 99% isopropyl alcohol did the job, Took a short soak, toothbrush and a paper towel to take off 99% of the paint. Ill get some pictures of the repaint soon.

Edit: here are some pictures. Paint job isn't perfect, but I'm pretty happy with it overall. And had some issue with paint on the cab and needed to repaint it. I will say it's a good 3-ft job. I forgot how much of a pain in the handrails are on these Arnold U -Boats!!
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[peaks]

Nice! Glad to hear 99% IPA worked