I have used Gojo only on steam locomotives and tenders where a dull finish is desirable.  Once the undesired lettering is removed you can detect some residual smudge. When applying decals I use micro set and then micro sol, in that order (alphabetical).   After the decals have dried I spray Testors dulcote and there is no sign of any smudge and there is no tell tale skin of a decal visible.

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Gojo comes in an orange bottle, it's a pumice, I apply it with my finger.  It works,just requires a little patience.  You can get it at a big box hardware store.

Great information.  Thanks.

One question, the speaker goes in the place formerly occupied by the PCB.  How did you reattach the PCB after you installed the speaker? 

Thanks.  I have rewired several vintage locomotives for DCC but have never tried to convert factory DCC without sound to sound.  I would appreciate confirmation of my proposed methodology. 

I have a GS4 4-8-4 model no. 50201, DCC on board.  To add sound, I assume I can do so by (a) opening the tender and removing the 8 pin male plug and the attached factory decoder from the circuit board, (b) replacing it with an 8 pin to 9 pin converter which then attaches to a motor and sound decoder and (c) placing the speaker under the existing circuit board.  Also, I assume the magnet side of the speaker is up and cone down.  Am I missing something?

Thanks.

I recently purchased a 4-8-2 light Mountain, DCC ready, on eBay.   It came with a DH120 decoder installed although the description said no DCC.  It ran slow and noisy but after lubricating it is up to speed and less noisy. The firebox is illuminated constantly, independently of the headlight.  Is there a way to make it flicker or turn it off?

After decals have dried (overnight) I spray dulcote over the entire engine or car, of course, over the decals too.  It protects them from damage when handled.  And greatly improves the overall appearance.

I would say flat black for a passenger steam locomotive but you can use gloss black and then kill the gloss by spraying with Testor's dulcote.  But, wait until after the decals are affixed to apply dulcote.
Re decals, get a bottle of micro set and  a bottle of micro sol.   Use them in alphabetical order, one when applying the decal and one afterwards.  I found that using the micro sol too soon causes the decals to float and shift.  Let the decal dry for awhile and then apply microsol.  I use an eye dropper and absorb excess with Kleenex.  The microsol works quickly to harden the surface of the decal.  Apply dulcote after decal is dry and you will be amazed at how the all evidence of any film associated with the transparent part of the decal simply disappears.  Apply dulcote sparingly, opt for separate thin layers if you want more dullness after a first spraying.  it goes on looking very glossy but dries quickly to a dull finish. Putting it on too thick makes the finish milky. 

Thank you, Jonathan.

In this DDC on board Consolidation, what is the status of the tender re adding sound?  Are their holes for a speaker?  What sound unit is recommended.