A bit of background first.
For decades I tried to care for a displayed steam engine. I no longer live in the area and so the care or lack of it has been done by others. There is a new group hoping to restore the engine--ON DISPLAY ONLY. One thing they are debating is the removal of the protective fence because it is now "an eyesore." (because they are proposing to fix it up, I won't add that the engine itself is falling into that category ). I have advised against that idea, but it is still to be seen what will happen. Right now they want to take down the fence to make it easier to work on the engine and then perhaps replace it later with something more attractive--it is presently chain link with three strands of barbed wire on top.
So now to the "fixing up." They want to sandblast the engine. I have advised against doing so because it will pretty much render the axle and rod bearings unfit. Presently they are not too bad, and in the 1970s I even borrowed an Alemite gun and filled the rod bearings with fresh grease (grease donated by the 4449 crew when the engine was here overnight). All the other accessory bearings have been lubed too (dynamo, air pump, etc.) and back in the 1970s all this stuff was actually still functional. I don't know what shape it is in now.
I was always taught that in preservation one should "do no harm" and I consider sandblasting "doing harm." Their stand is that the engine is a monument display and will never be moved, so it's not an issue. I did mention that the underlying insulation material will likely be disturbed by the process, but they claim the contractor is familiar with engines and there will be no problem.
What is this group's opinion on this?

Greetings:
A few comments...

In my opinion, sandblasting a locomotive still insulated with asbestos is inviting problems. There is no way to prevent high pressure air from disturbing the asbestos. In it's dry state, asbestos is "friable" that is it can become air born if disturbed. To the best of my knowledge, asbestos is dangerous when it is air born and therefore can be breathed into the respiratory system.
I think that it would be advisable to have the asbestos removed by a licensed contractor prior to any restoration work that might disturb the asbestos.
Now, since most removal contractors have no experience with steam locomotives, it is also advisable to hire someone who IS familiar with steam locomotives to show them how to properly remove handrails and piping, etc. as well as properly removing the boiler jacket.

By properly, I mean carefully, so those items can be re-installed or used for patterns.
I would note that even as I write this, Gary Bensman is performing these duties at Steamtown National Historic Site in conjunction with the work being done on "Big Boy" No. 4012 as he did previously with several other steam locomotives in that collection.

As far as sandblasting is concerned, think about it: if the side rod bearings have just been greased, how will sand get in between the bearings and the crankpins, especially if they are greased again after sandblasting? What I have always done is to mask around crankpins, axles and such with plastic wrap and duct tape and avoid blasting those areas. Clean them by hand, there aren't that many of them. I have had several steam locomotives sandblasted which were later moved without damage/incident.

A lot of issues can be avoided with a bit of knowledge about steam locomotives and taking care to avoid getting sand in critical areas in the first place.

By the way, I have found that areas which are really heavily rusted (like the tops of boilers & wrapper sheets) are best dealt with using a scaler/needle chipper or such prior to sand blasting. The idea is to get down to bare metal and then coat the surfaces with a good primer. For locomotives that are going to be outside, I use an epoxy coating made by Sherwin-Williams that when dry is difficult to remove with a scaler/needle gun (note: I hold no stock in that company).

Good luck!
J.David

It's real simple. Follow faithfully what J.David says above and all will be well.

IMHO-Ross Rowland

It is critical to have a person on hand who is familiar with the locomotive, the piping and the appliances. Contractors are famous for cutting off "useless things, 'cause, hey, it's never gonna run again". Some items, such a brass gauges, very pretty when polished, disappear during the "fixing up" process. The abatement will be expensive and for gosh sake, don't reapply something else like fiber glass to try and make it look authentic!

If the boiler still has its lagging, you can be sure that it is collecting water which will most likely rot out the boiler jacket.

Both of the engines that I worked on were sandblasted, and on the one that does get switched around, we dropped all the rods, cleaned and lubed everything. I don't recall finding any sand in any of the bearings.

Prior to sandblasting, both engines were stripped down to the bare boiler, (including the removal of all machinery) in both cases to facilitate the asbestos abatement. At that point, they were sandblasted, painted, and then the reassembly process started.

I know of another engine that was sandblasted without being disassembled and it seemed to turn out so-so, as the painters did not do a thorough enough job in cleaning up the sand, prior to painting.

The biggest problem seems to be paint jobs. Tragically both engines have now received absolute failures of paint jobs. On one engine, the paint did not even stick to the metal, on the other the painter just butchered everything. In both cases huge amounts of money were mercilessly wasted on botched work.

Please, please, please build a fence.

There is no reason that the public should have completely unsupervised 24-hr access to such things. There are an infinite number of opportunities for blunt object injuries around a steam locomotive. People tend to walk next to them looking down, and not noticing for example the blow-off cocks just waiting to split their skulls open, or the fall hazard for children and drunken young adults climbing on them. Razor wire is your friend.

As well, in the age of portable sawzalls, valuable brass and copper parts can be chopped off in a few moments. Once they are gone, you're never getting them back.

Anyhow, it helps to keep things lubricated because, while it may be a monument today, it may be in the way tomorrow, and the guys that have to work on it to get it ready to move will thank you if they find that every last single thing is not rusted in place.

Thank you for your thoughtful responses so far. I must point out that I will have little to no input nor control over what happens to the locomotive and its display-despite the fact that for some 30+ years I was its primary caretaker.
In the past few years the vandalism, even inside the fence, has been increasing. One evening some persons sawed off the whistle, stole the air powered bell ringer mechanism and one sight glass. This seems to me to be more than souvenir hunting. More recently the Pyle-National headlight unit was stolen off the tender, and I don't know what else may be missing from the cab. Last I knew, the one intact boiler gauge has a home-made face and dial (by me) and it did still function. I don't know if it is still there. Areas of the boiler jacket have been patched over the years, mostly at the bottom of the boiler where the jacket was completely rusted away. In the 1980s a group of us (steam locomotive nuts) offered to remove the asbestos and re-apply the jacketing, but we were turned down--long story on small town politics and a guy running for county supervisor needing public attention. This was before the licensing regulations for such an activity (asbestos removal) were put in place.
I will pass on your comments and recommendations in hopes that they have some influence. There is, as far as I know, no one left in the community that "knows" steam locomotives. It is a small town, some 3,500 souls, and I really don't know where they think they will find the funding for all this. The group, last I knew, was fewer than ten people. They have applied for IRS non-profit status though.
There are at least two museums who would like to have the engine to restore to operation, but not being local to the area, they have been turned down. Being a small engine originally designed for passenger operations it would be ideal for such a use.

What about using dry ice instead of sand as the media for blasting? It's way less mess and might be kinder to the fixtures and appliances you're concerned about.

In 2004 or 2005, we tried dry ice blasting on S.P. 2472's boiler (outside surfaces). The boiler was in good external condition, with light surface rust where the non-high-temp paint (applied the the 1980s) had cooked off. Dry ice blasting didn't accomplish much. It's OK to remove a failed paint layer, but it doesn't take off a noticeable amount of rust.

Result: We wirebrushed and needle-gunned the boiler exterior, and then applied high-temp rust-converting aluminum paint.

- Doug Debs

Looks like the locomotive in question is WP 164? I think the other ex-Jerome loco is at Portola? Maybe?
I agree that sandblasting in general is not a good solution for steam engines or even other mechanical things where the bearings may get damaged.
Kudos to you for trying to fix things right.
Ned

If you want to see a real first-class mess, do it to an F-unit without sealing off the grilles and contaminate EVERYTHING inside the carbody (including the electrical cabinet) with carbide grit..stuck to virtually every interior grimy surface.. Freshy-painted, now completely inoperative, F-unit, later sold at scrap price... That was a memorable inspection.

As far as for steam, J. David rules on this one.

Ned,
Not WP 164, although for a while I was officially in charge of that one as the city's curator. I'm really trying to keep somewhat Mum about it, but there aren't that many displayed locomotives here in Northern California. Maybe it doesn't matter; SP1727.

I'm certain that it's very frustrating David. Good for you for trying. BTW, we sandblasted and almost ruined 2 ex-N&W GP-9's in a vain attempt by our inexperienced crew to get some cheap power. They were neat and tough, but never worked out quite right. The grit gets everywhere.
Ned

EMH,
One of the issues with those two GP-9's was the time on a coal loadout. The low voltage wiring was so fragile it would break if disturbed. I ran a work train with #4 and everything worked, including the dynamic brakes. I understand they're a parts supply for whatever is still running down on the ELKR.
SCW

Sand blasting is pretty harsh on thin sheet metal. One of the things not mentioned in sand blasting is it will blow holes in rusty thin sheet metal. Depending on the thickness and corrosion of the sheet metal you may be spending a lot of time patching or replacing the sheet metal. I have found this is likely along both sides of the bottom cab and along the outer bottom of the tender. I would not worry too much about grit getting into bearings, rods, etc. As someone already said they are packed with grease and clearance is minimal.

I would not recommend sandblasting with asbestos insulation at all! When that nozzle hits a gap in that sheet metal (or blows a hole in it) asbestos is going to go everywhere. A much better option if you need to blast metal, is the dustless blasting process which uses high pressure water mixed with grit shown here https://www.youtube.com/watch?v=TezbPALbVw8 . At least that will keep the asbestos dust to a minimum.

Tom F is correct: sandblasting quickly finds any thin spots in sheet metal and cabsides etc.
I would however be careful of water/abrasive blasting (been there, done that). The problem is that whatever nasty stuff is disturbed (lead based paint, asbestos, etc.) will be in with the grit and has to be dealt with. Trust me, it is far easier to dispose of grit without lead with it. What happens when the wet grit drys?
However, it is a great way to deal with rust or non-lead based paint in a controlled environment.
Hint: don't do it inside a building even with tarps covering the walls. The wet stuff becomes airborne and goes everywhere and is very difficult to clean up (a word from the now wiser!)
Be well,
J.David