I would like to offer some thoughts based on the restoration of a Rock island transfer caboose completed between 2006 and 2008 at the Illinois Railway Museum. The first comment is that it appears to me that the roof may be leaking and causing problems at the end of the car as evidenced by the exterior paint failure on the top boards of the siding. We found this to be the case on the caboose we restored and had to make weld repairs to the roof, which stopped the leaks. Second, I most certainly agree that you should not use pine on an exterior restoration. Even a few boards of the well aged fir we used, which we used on an exterior restoration of a Rock island automobile car and the transfer caboose, failed after a few years when the car was left outside. All surfaces of those boards, including the ends had been painted, which is a very important step in restoring a car which will remain outside. We were able to remove many of the square head nuts which were reused; however, some did have to be cut with a grinder or torched off. You should source elevator bolts, which have a flat head that sinks into the wood as the nuts are tightened to secure the exterior siding. Carriage bolts have a head that does not leave a flat surface and your interior siding will not fit properly. It is difficult to determine accurately what all of the interior wood siding is made of from the photo provided. Some of it appears to be barn siding and some looks to be individual tongue and groove siding. Based upon our experience, I would definitely suggest removing the interior wood so that all of the rotten exterior siding car be replaced. Also, as previously noted on another post, I believe that you will find the tarpaper water shield to be in a very degraded condition, which we found. Removal of the interior pieces can usually be completed with little damage to the individual piece, especially as the exterior siding is not in good condition the nails should pull easily. Any minor damage can be repaired with wood filler, as we did. As we removed exterior pieces that were obviously rotten, we found that others that appeared to be good from the exterior were also very structurally deteriorated. From our photos, several other pieces of the exterior appear to be in very questionable condition. If you desire to see the restoration of the caboose which we restored, go to http://www.irm.org and look in Members Photos on the home page. Then go to the photos posted by me and you will find an extensive archive of the restoration of RI-19135.

Kirk: What type of wood would you recommend to use for this project, instead of the fir that you used on the IRM car?

Thank you all for the thoughts so far.

A couple more details;

- I agree that latex paints suck from a preservation standpoint. They seem to hold their color better than oil (at least in the freightcar red department) but they are noting but a death sentence for old wood, even if applied over an oil based primer. I had never thought about the idea that flats are more flexible than glosses. Might have to try an oil based flat paint next time I paint a wood freight car.

- The roof is a rolled asphalt roof installed over a new wood subroof, all done in 1995. It appears to be holding up well, I found no real evidence of current leaks when I looked over the caboose (it was even raining at the time!) I think most of the rot evident in the siding started before the caboose was last worked on 20 years ago. Most of it radiates out from the bolt holes and other seams. Parts of the siding that were patched in 1995 are still holding up.

- Clearly, replacing all of the siding is the best option. That said, and to reiterate the question in the previous post; what wood should be used? Is there anything available any more that won't rot within 4 or 5 years? I can't see recommending the undertaking of all of the work and money to replace the siding if it will just need to be done again in 2020 or so. Patching it every 5-10 years starts to look a lot more prudent use of resources.

- Has anyone ever tried using Trex or a similar "plastic wood" in this type of application? Can anyone think of a reason not to? I have used Trex for trim parts on wood cars before and it has held up very well, even seems to hold onto oil based paint well too.

Thanks again

Jason Midyette

If the car is to remain outside and you cannot obtain fir, I would use reclaimed redwood. It will be very stable and is much harder than cedar.

One of the problems with modern day lumber is no one cuts old growth timber these days. The sapwood of any species has nowhere near the decay resistance of the heartwood of the same species. Years ago the huge trees being cut for lumber were mostly heartwood, and the railroads and car builders had the market horsepower to specify that their lumber contain no sapwood. These days everyone is cutting second growth or timber grown in tree farms, and the resulting lumber has a large percentage of sapwood. I've heard of items made from species once considered impervious to decay, such as cypress, rotting within just a few years of weather exposure. This ain't your Grandpappy's lumber.

The only solution is to find a mill that reclaims timbers from docks, bridges, and mill framed buildings, and cuts them to order. Trestlewood is a big name that comes to mind, but they are aimed at the artsey-fartsey crowd, with pricing to match. There are others.

Trex? Them's fightin' words, pardner. I personally have thought the stuff would be the dream material for restorations that must remain outside, I've had the original material on a deck for twenty years, in a location so wet that I occasionally have to wash it with moss killer. The Trex deck boards are still in perfect condition.

But there are others here who have had bad experiences with Trex; boards with resin starved interiors that delaminated after a few years. I would think that one could inspect the material for this problem by looking at the board ends, and rejecting any that isn't solid.

I've been a proponent of using Trex for roof running boards and the like, which are often left off because they decay so quickly. Also, the fact that Trex doesn't really look like wood is less objectionable up fourteen feet off the ground. So long as something is there, it looks better than nothing being there.

The main problems you will have with Trex is the boards are undersized. The Trex 2x6 is only 1.3" thick, so some shimming will be required. Luckily, the 2x6 is 5.5" wide, while the ARA standard was for a 5.25" face, so they should be able to be ripped to fit, even if slightly oversize boards are needed. But Trex has very round corners, and the 1/4" isn't going to be enough to remove all the round edge. Then again, it is allowable in museum work to make substitutions of modern materials where the original fabric simply no longer exists; using plain white plaster of Paris to hold the remaining shards of an antique pot would be an example. I suppose we can rely on our visitors to be smart enough to realize the original caboose wasn't sheathed in plastic lumber, if they are even observant enough to spot it at all.

I was curious about "reclaimed redwood" and a DuckDuckGo search found this: http://www.oldgrowthtimbers.com/

As a graduate forester with some training in wood technology and experience running hardness and other mechanical tests on wood, I'd suggest a bit of caution about comparing hardness values of wood, especially when using a common name like "cedar" - there are several tree species which are called "cedar", and their hardness values are quite different from one another. Some are harder than old-growth redwood, and some are softer.

From the Wood Handbook (USDA Agriculture Handbook 72, available from the Government Printing Office), some hardness values (12% moisture content, perpendicular to the grain, in pounds) (per ASTM Standard D2555-70):

480 - Redwood (old-growth)

580 - Alaska cedar
350 - Atlantic white cedar
900 - Eastern redcedar
470 - Incense-cedar
320 - Northern white cedar
630 - Port Orford cedar
350 - Western redcedar

Also, these values are averages; the Handbook's table used above does not address variability within these species. It is possible that the difference between redwood and incense-cedar is not statistically significant.

Stay away from glue whenever possible. Let the wood move as it is intended to move.
If you have to use glue, Titebond II exterior is the ONLY way to go.

Since the interior is likely nailed to the exterior, removing both sides will be much less grief than trying to deal with the nail stubs and bolts. And, if you want the effect of the tar paper (or Tyvek) you will want to replace that vapor barrier as a unit, which will be impossible on a piece-at-a-time patching basis.

Just a heads up, the news article recently posted in the discussion of the on going work on the Keokuk, Iowa depot lists this somewhat local source of reclaimed old growth lumber: Eventide Custom Wood and Metal in Keokuk.