I'm working on converting two Kato HO C44-9Ws to DCC and adding new LED lights since the old ones were on the discarded light board and the front LED lit three outputs (the upper headlight and the lower ditch lghts. So I want to add 3mm LEDs to shortened (making room for the speaker enclosures) front and rear upper headlight tubes and a 0603 SMD LED to each ditch light tube.
I'm interested in what glue to use; e.g., white glue, canopy glue, CA. And whether to glue directly or use a supplemental tube (straw or shrink tubing) to firm up the connection. I've filed the 3mm LEDs flat.
I attached some 0603s to GP-9 upper twin lights lenses directly with white glue (think it dries fairly clear) and that seemed to work ok, but unsure how fragile those connections are. I've currently got two 3mm LEDs gluing to the larger C44-9W headlight tubes but the connection initially seems weak and may need at least some supplemental CA surrounding the joint.
Any advice is most welcome!
Paul
Modeling HO with a transition era UP bent
I did not use any glue but heat shrink tube.
Reinhard
Recently, I have been using Aleene's Tacky Glue for my "light pipe" connections:
It dries clear but flexible and if I need to scrape it off it comes off clean. In many cases I'll also back this up with a sleeve of heat shrink tubing as Reinhard suggests but the clear tacky glue helps transmit the light.
This stuff comes in other varieties and it is handy for gluing details and sticking little people's feet to the ground.
Have Fun! Ed
Sounds like in most cases the shrink tubing is a good choice, as it adds no opaqueness to the interface, plus has some strength. If the two 3mm LEDs started with canopy cement hold, I think I'll try adding shrink tubing (the shapes are not the same, as the light tube is oval). Not sure shrink tubing will adapt to the 0603 SMT LEDs but I'll check that out.
I have some Tacky Glue but think it's not the clear gel. I'll look for that at Hobby Lobby.
A related question. The original, pretty long, Kato light tubes are clear plastic, but of course not fiber optic. How much light is lost along the way? Would painting the outside of the light tubes with silver hobby paint not be a smart approach, or is the light loss throught the walls insignificant? When I add a LED to a cab (like a 5mm) I usually paint the outside cylinder silver to minimize light leakage that can illuminate the walls too much from the inside. (I have yellow UP cabs, maybe I should switch to NYC).
Thanks for the comments!
LION also votes for the heat shrink tubing.
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
Aleene's and canopy glue are very similar. If I had both on hand, I'd try the canopy glue first, as it's designed to dry clear. Aleene's does, too, mostly, but canopy glue is designed more for what you need IMO.
Then shrink tube the connections. This works fine for me and I don't use any glue. It adapts to whatever shape necessary.
I've never done it with SMD LEDs, but that's a case where I think gluing will be of benefit, as you can glue in the exact position you want, then shrink wrap it to protect things.
Silver paint is a good option for light pipes. If you can see them through the cab windows, though, paint that over with black paint and you should be fine.
Mike Lehman
Urbana, IL
Hello All,
Regarding the painting (masking) of the light tubes question.
I suspect that the spill from the tubes are meant to replicate interior cab lights.
I have a Yugoslavian built Model Power RS11 that I converted to DCC and installed LEDs.
The plastic that the shell is made of leaks light like a sieve. I wanted the light spill from the LEDs to illuminate the number boards and simulate interior cab illumination, but not leak through the shell.
Rather than masking the LEDs I painted the interior of the shell flat black. This blacked-out the shell and "focused" the light spill to the number boards and simulated interior cab illumination.
Hope this helps.
"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"
Thanks for the additional comments. Today I found one of the canopy glued 3mm LEDs had a weak joint, so I re-glued both with the Testors liquid cement and then added shrink tubing. That seemed to create a solid assembly, so did that also to the 0603 SMDs, which seems to work ok (tested one with a 9v battery). I shortened the light tubes extensively, for speaker room and/or wiring space. I've silcone glued the speakers in place tonight, so await the decoders in the mail to finish up the first of two Kato's. These will be the most extensive conversions I've tackled, mainly due to the lighting revisions.
I use white glue and/or shrink wrap. Faller Xpert cement has been something I've seen recommended on some install sites - mainly because it doesn't just dry clear like white glue, it dries water clear and forms a better interface between the LED and light pipe. I have some but haven't done any installs since I bought it.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Thanks, Randy. I'll also give that a try. Found on EBay for $8, free shipping. I'm for using the best approach as the amount of time involved justifies any helpful "tools". Edit: I'm a dope, coulda ordered this next MBKlein order for $3. Lazy to not check.
An aside...can't imagine doing this stuff in N scale. Kudos to those that do.