There's been a discussion on the steam_tech list regarding the best way to preserve a polished-rod appearance on a locomotive that is on full outdoor display. Options so far have ranged from 'buffable' aluminum paint to Tripeek polish and its purported 'protective layer'.

Who has ideas on the best approach to take?

Polish, wipe clean with suitable solvent, and spray with clear lacquer (or modern paint equivalent)? I've seen some recent variations on "rat rods" (automobiles) that seem to use this approach.

I got this formula from Dan Dandurand at the Milwaukee Railroad Shops Roundhouse Museum in Sioux City.

Even in our desert climate at Campo, the rods on our ex SP 10-wheeler #2353 were starting to show rust, even with the engine stored indoors (unheated building, and dirt floor though). About five years ago I used this formula on the main and side rods, the piston rods and crosshead guides. It is holding up quite well, and the coated surfaces look just like they've been recently oiled. I cut the formula down by a factor of 4, and used a cheap paintbrush to apply.

Of course this is indoors; I don't know what outdoor UV will do to it. But even if you had to renew it every few months, it shouldn't be to hard to do. I have had to do some touch up a few times after we've moved the engine, and it reapplied easily.

From Dan:

Sealer Formula for spray gun:
1 qt. high quality gloss (or semi gloss) outdoor varnish;
1/2 Cup mineral spirits; (if brushing this on - use only 1/4 Cup mineral spirits)
1/4 Cup Penetrol (name brand).
For much faster drying, include 1/8 Cup of Japan Drier, otherwise, leave out.
When adding Japan Drier, what varnish is left, will have to be tossed as it will dry the varnish even in the can with a lid on it.

Stir slowly as to not build up any air bubbles in the mix.
If brushing it on, keep moving along but then once in awhile re-check back where you brushed it on to be sure there are no sags. Lightly brush the sags out (if any) before they set up. Using the Japan Drier, you will have to keep moving along and occasionally check, more often. Just faster pace, unless you are spraying, then you can spray it, let it set up a bit and then give one more spray coat. Done.

The Penetrol is used a lot by the Navy in their paints as it actually makes the paint penetrate surfaces, that without it, the paint would just sit on top of the old paint.

In my experience, clearcoating shiny rods peels more quickly than paint. You can wire wheel them and sand with 320 grit, prime with etching primer and sealer - follow with paint directly for 10' finish or allow to dry and wet sand sealer with 600 grit for a very high finish. I like shooting a single-stage metallic with very little pigment in a Dupont automotive-grade single-stage system - you can walk it on with an HVLP gun with the rods on without a lot of overspray and blow it on the backs of the rods by shutting the pattern air off and using a high air to paint ratio. Paint comes off easily if the rods are going to be re-coned to ever run it. If you are interested, email me mjanssen@vaporlocomotive.com for a paint recipe.

The good NMSL&RHS folks restoring ATSF #2926 had its rods clearcoated and recently had to have them re-done because the initial application failed. It might be a good idea to contact them for suggestions on what to do, or what not to do.

http://nmslrhs.org/

Interesting info about the clearcoat peeling- I had read that and forgotten it.

Matt- is it FRA-legal to paint side rods with opaque paint (for an operable steamer)? I'm just thinking this could hide surface cracks that would be found during normal operating inspections.

The other possibility is to do what NS did when N&W 611 was restored- chrome plate them. IIRC, N&W originally cadmium-plated their rods. Of course practically all metal plating involves pretty nasty chemicals and has gotten very expensive in recent history.

Greetings:
Valley Railroad has been using "ProtectaClear" www.EverbriteCoatings.com with good results for several years. It cost a about $75.00 per quart (enough for several coats on a set of rods).
We have found it is important to put on three or four coats, especially if the rods are wiped on a daily basis and steam cleaned periodicly.
The rods on 3025 were polished with emery cloth and coated in 2010. In January 2014 they were wire brushed and re-coated.
Over the years we have tried any number of clear lacquers and such, thus far, this is the best we have found for our service.
Good luck,
J.David

Hugh, My recommendation was for static displays only. I cannot provide an interpretation of FRA rules, but believe the less paint and powder something has, the easier it is to see what you have. For an operating locomotive, a coat of white kerosene will get it through the day until the next inspection. Sincerely, Matt

It's hard to tell from the photo if they're chrome plated in that shot, but when the locomotive was restored in ~1982 the rods were chrome plated according to Preston Claytor who was on the crew at the time. Preston told me he had personally assisted in polishing the rods with abrasive rubber disks (?) prior to chroming, as every scratch and nick had to be polished out or at least radiused to eliminate stress risers prior to chroming.

The SP units still in original paint testify to the durability of LPU. You can also get LPU varnish. Awlgrip has several options with different properties, although they're made for brightwork (varnished wood).

Spar varnish is for spars, which is not what you want. It trades away properties you want for properties you don't want (the ability to flex and not crack.)

LPU = linear polyurethane.

In case anyone is interested in a primer on various epoxy systems, there's a fairly good one from the System Three people, available as a .pdf download here:

http://www.systemthree.com/reslibrary/l ... y_Book.pdf

The AkzoNobel Awlgrip technical assistance section (more interactive) is here:

http://www.awlgrip.com/support-and-advi ... dance.aspx

And I suppose we might include some Imron (now Axalta, spun off from duPont) technical material while on the general subject -- I believe the 'clear coat' system most nearly applicable would be EL 600:

http://www.google.com/url?sa=t&rct=j&q= ... Wc&cad=rja

The 611's rods were initially plated...... it was then removed as there were concerns of cracking which may develop as a result of the plating process. Today there are methods of plating which do not require the noxious acids that lead to issues on the surface of base metals. No where does it say in part 230 that rods cannot be plated AND the N&W's practice of doing so does make it a "railroad practice".

Cheers, Jason

Jeff- While it was definitely chrome, I don't think it was a full "triple plating" job as is normally used on car parts. For that process, the base metal is highly polished. Then thick copper plating is applied (maybe more than once) and polished. That will fill VERY minor imperfections. That's followed by nickel and then finally chromium. That's what gives the mirror-like chrome finish you see on a restored classic car.

From what I heard (and saw) with 611 they polished the rods with fine abrasive disks and had them chromed. The finished rods had a shiny finish, but imperfections in the base metal were pretty apparent.