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| wooden car rot https://www.rypn.org/forums/viewtopic.php?f=1&t=12985 |
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| Author: | Randy Hees [ Sat Apr 30, 2005 12:49 am ] |
| Post subject: | wooden car rot |
I had a conversation with a volunteer from another museum today that was a bit eye opening. Both our organizations restore wooden cars. Both store much or all of our collections outside. We are both located on the left coast, and so both have pretty good weather. Both our museums are now restoring cars that we restored once before. We are currently replacing sills on a 4 wheel flatcar we build in 1994. Several sills rotted (others show no sign of rot.) Two years ago we re-restored a 1907 flatcar that had originally been restored in 1984. That time we replaced one end beam, and treated the sills for rot with various chemicals and epoxies. We now treat all our new work with copper based wood preservative, then prime and paint everything, whether is shows or not. Periodically we treat with a boric acid solution. Its water solvable so is temporary at best, but seems to help. The new system seems to be working, but only time will tell. We have found that the best wood, now identified as “old growth†|
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| Author: | Dave [ Sat Apr 30, 2005 7:36 am ] |
| Post subject: | Re: wooden car rot |
Short story is they don't grow trees like that anymore. Original old growth forests are either gone or preserved as wilderness, which is a fine thing, but it limits the supply of good old growth timber. Managed forests are made up of fast growing light wood that can be harvested frequently, but doesn't have the relaibility of old stuff. In the south, there is an industry of salvaging sunken logs of old growth pine from old rivers and mill ponds. New Heart Pine is milled from these for interior fine woodwork. The best source of old timber is from old structures being demolished, but we as a nation don't value it highly enough to demolish by disassembly for recycling, we just grind it up with dozers and haul it to the landfill. My sister bought an expensive new house a few years ago - he exterior trim was rotting off in two years and hads to be replaced. My little 52 year old house (the new one) has had a large tree fall on it and is still standing. Why would anybody buy a new place in an outer suburb made from junk wood rather than a less expensive well built old house close in and convenient? I assume because we are told to - so we do, and our forest industry is based on growing lumber for these disposable structures now. So Randy, unless you can find some decent old timber, you are doing as well as you can by treating for preservation with the less toxic and not as reliable chemistry available today. dave |
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| Author: | jasonsobczynski [ Sat Apr 30, 2005 8:25 pm ] |
| Post subject: | Re: wooden car rot |
All Dave said is very true. However, there are business....especially in the north east but also in other parts of the country......that take apart old buildings for the old growth timber contained within. I remember about 5 years ago on "This Old House" norm and the boys took a field trip to one such company(in a New England state)and picked out several 14"x20"x35ft or so timber beams made of heart pine that were then milled into small bits to accomadate the material needed for the house. The stuff is about 5 times the cost of conventional timber(atleast it was 5 years ago) which is really not a bad deal in my opinion. The other bit I wanted to point out is that while cars were in service with the railroads the timber stayed drier than it does now sitting in a museum. Think of it like this...sit collect water, wait for drying to take place by way of evaporation......or, get wet then go down the road and get "blow dried". |
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| Author: | David A. Vago [ Sat Apr 30, 2005 10:06 pm ] |
| Post subject: | Re: wooden car rot |
Just to expand on Dave's post, here's how the old vs. new lumber thing works: The older a tree gets, the tighter the grain gets, especially closer to its center. This means that (1) the structure of the wood fiber is sturdier and (2) it consequently retains the resins that help fight off rot and assist structural integrity longer. This is why even big, old logs that have sat in a river for years often reveal fresh, yellow wood when they are harvested and the top few inches are planed or sawed off. Most wooden things built in the U.S. before about 1920, and in some cases for a decade or two later, were built using old, virgin timber. However, after the first few decades of the 20th century, virgin forests became increasingly rare, such that by about (I think) the 1960s the forest-farm industry was gaining a significant chunk of the business. The problem is twofold. First, most harvesters of timber are not willing wait for a stand of trees to grow long enough to become that well-seasoned on private land (and it's often not economically desirable in the short run). Second, trees on public land that have been around for a little while longer are often much harder to get at on account of protective legislation, red tape, etc. The result is that, as Dave said, they don't make lumber like they used to. Old river timbers, and timbers from old warehouses and such, are easier to get at than live, old growth, and of generally high quality. From a museum conservation point of view, though, they are what you want because they are usually most like the historic material, and they also really do last longer than the new stuff--and are a lot sturdier (i.e. impact resistant) than newer stuff, without a lot of modification or reinforcement. The most expensive option for restoring woodwork is to try and make a composite of original and replacement materials using some of the high-tech resins that are out there, along with some type of reinforcement material such as fiberglass reinforcement bars. This is expensive and labor intensive, it's relatively unproven in the long-term(particularly in application on railroad equipment) and really only works on painted surfaces and components--but if retaining original material wherever possible is one of your org's goals, then it is an option. So, for a non-profit that is stretched for cash, it's a judgment call whether to use, for example, high-quality, reclaimed old-growth timber to replace a beam, or to instead sandwich some pressure-treated in place to get the approximate 'look'. However, that's a synopsis of the state of the field. I hope that it helps. D.A.V. |
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| Author: | Dave Sutter [ Sat Apr 30, 2005 10:21 pm ] |
| Post subject: | Re: wooden car rot |
Has anyone tried tim-bor? I know it is a product used to treat wood for pest prevention in log home construction. |
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| Author: | Dave [ Sun May 01, 2005 6:56 am ] |
| Post subject: | Re: wooden car rot |
Boric Acid treatment - will discourage pests, same stuff as RoachPrufe (the rest of the story). I think Abatron markets a boron product along with their magical wood restoration product line which has expanded to include iron last time I bought. dave |
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| Author: | Dennis Storzek [ Sun May 01, 2005 9:19 pm ] |
| Post subject: | Re: wooden car rot |
[quote="Randy Hees"] We have found that the best wood, now identified as “old growth†|
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| Author: | Ted Miles [ Sun May 01, 2005 11:59 pm ] |
| Post subject: | Re: wooden car rot |
At the Maritime Park in San Francisco we use it in everything we put into our fleet of ships. That is all the soft pine species like douglas fir. Does not work on hardwood like teak, which gets used in our British built ships. We too have seen the problems discussed here and we are paying top dollar for old growth Douglas fir we are using to re-build the C A Thayer. borate preservatives like Tim-Bor can get as much as eight inches into pine but copper naphanate can only get into it for an inch or so, Ted Miles |
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| Author: | Alexander D. Mitchell IV [ Mon May 02, 2005 12:24 pm ] |
| Post subject: | Re: wooden car rot |
I'll suggest a real "you scratch my back, I'll scratch yours" solution. Two places where the old techniques of custom wood cutting for maximum quality have been practiced, in my experience: *Amish sawmills in remote areas of Pennsylvania, Ohio, and West Virginia. The places sometimes use vintage sawing equipment to re-trim barn timbers or cut premium wood for furniture craftsmen. Not every such sawmill is experienced in cutting wood in the old techniques, but many are. Ask about. *Demonstration sawmills at steam thresher shows. At one show in Maryland, I watched the crew spend three long days doing nothing but custom wood-cutting orders for a huge variety of projects--everything from fence posts to a wooden boat restoration. If I were a preservationist looking for wood for my restoration project, I would have no hesitation at paying going rates to a fellow preservation project for my lumber needs. (Of course, one has to check the competence of the mill's operators and the mill's equipment suitability first.) |
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| Author: | Randy Hees [ Mon May 02, 2005 3:13 pm ] |
| Post subject: | Re: wooden car rot |
Sandy, yes, custom cutting is the way to go. We have a couple of "Preserved historic" mills that can do custom work when they run. There is a wonderful synergy when industrial preservation supports railroad preservation. Additionally here in the West we have a couple of "old, historic" commercial mills in operation, plus a couple of commerical operations that do mostly custom cutting. |
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