We are getting set up to replace the side sheets on an E8 locomotive, and we need advice as to how to proceed: Is it best to put the Plysteel back or do you simply use steel sheets? If you do, will you have booming problems? What thickness do you use? Can you weld up all the sheets like a coach to stop leakage problems? Will this cause wrinkling or wavy sides? If you don't weld up the sides, how do you seal the sheets to keep the water out? (probably 100 tubes of silicone) How do you replace all the sliding nuts that were damaged when the hardware was removed or do you even mess with them? Anybody just have any good advice or maybe "don't ever do....."Thanks

What locomotive is this? Thanks,Tom Cornillie

Have you considered aluminum treadplate? Makes for an interesting texture, saves weight and if she rolls over you won't slip climbing up. Acually, I wonder if some variety of paintable galvanized or aluminum wouldn't be easy to install, perhaps backed with plywood if necessary? Some lightweight sign boards have a very smooth, hard and dense outer shell over a structural foam interior filler that would be easy to paint and work (and lift).Now contemplating whether to use plymetal or another product for subflooring on a trolley - timely inquiry. dave

Steel and Aluminum do not mix! - which is something that I have learned from researching passenger car histories and restorations. Over time galvanic corrosion can begin, which destroys both the steel and aluminum parts where they contact each other. This is probably why EMD didn't use aluminum to begin with. Tom Cornillie

NO! No no no no! Do not use aluminum, or plymetal made with aluminum sheet over plywood. The problem is you will introduce all the same Galvanic corrosion problems that sent aluminum bodied lightweight cars to scrap early. Not only will the side sheets fail early, but there will be considerable corrosion damage to the steel framing and batten strips.Yes. Attempting to weld steel sheets to the locomotive frame will result in wrinkled sheets; also will require that much more grinding when the next restoration crew wants to put it back as original.As to solid steel vs. plymetal, we've had that discussion on this forum before. Apparently, more than a few E and F units have been done with this substitution, and if the steel sheet is heavy enough gauge, it works well enough. I'll leave it to someone who has done it to suggest the gauge. It appears that plymetal is no longer available in long enough lengths, so you'll have to fabricate your own. There was a web site about the restoration of a Western Pacific F unit where they were doing just that, but we've lost the link when the RYPN message archive dissappeared.I would imagine that the self adhesive rubber sealing strips used by commercial glazing contractors would make a clean alternative to lots of gooey silicone caulk. And, if you really need to do this quick and dirty, check out plastic laminate covered particle board. The Soo Line had reasonably good luck using this, at least for the few additional years they needed to get out of the units. The Milwaukee Road tried using Masonite hardboard, which didn't hold up at all.

Use good old 10 or 7gauge steel(1/8-3/16). You can weld all your seams, just take your time and weld about 4-6 inches at a time. Move frome one end of the seam to the other. Staying several feet apart and letting things cool, that will minimize warpage. if you have ribs or structure to weld to, drill a hole and plug weld it. You are goig to have to grind the seams to make it nice but it will be worth it. Like the other posts above stay away from alum. or compsite material. I replaced a 16 inch by 24 foot long panel on my N5 with little to no warpage. Time wise about 3-4 hours to tack and weld the panel. 3-4 hours to grind and finish for paint. PM me and I can give you my #.Scott

The problem with welding in the panels on an EMD cab unit is the sides are arranged with bolt on battens to clamp separate panels to the frame. So, what do you weld to? Worse yet, when repairs need to be made in the future, you need to cut and grind it all clean again. Using the battens as they were intended might be a better bet, and would certainly be more original.By the way, here is the link I was thinking of:http://www.trainweb.org/wp918d/work_update.htm

There are special paints to create a barrier between the aluminum and the steel, if you need to go this route. Search under antique airplane restoration supplies or try your local body shop paint distributor to find them. Older airplanes mixed both materials successfully for many years. I have used a product that is manufactured by DuPont, but I do not remember the name. Good Luck.Mike

Good question. Unfortunately, the answer ain't...black n' white.First of all, consider the fact that the structure of a carbody-type locomotive is somewhat flexible. In fact, the underframe is built with a slight camber to account for the weight of the machinery. When the engine, generator, etc is applied to the body, the underframe 'levels out.' So that will put the entire truss structure under tension. Also consider the fact that there can be some large temperature differentials between the engine room and outside ambient.With that being said, the first thing you DON"T want to do is weld the sides to the structure. ICG did this on a bunch of E and F units they remanufactured for MBTA and NJT among others-and over time, the sides loooked anything but smooth. As the frame deflects and distorts over time, so will large metal sheets that are welded to it. The temperature induced stresses don't help either. And...The other issue is VIBRATION. Without getting into periodic vibration, natural frquency and all of that-the lighter the panels-the better. So....You want the panels to float as EMD designed them.Choice of materials ? There is a supplier of metal-faced plywood located in Poughkeepsie, NY. Google 'Plymetal' and you'll find them. Recall that everything is made-to-order and there are choices as to overall thickness,metal facings ( AL,steel, galvanized). Think that the limit on length is 12'-having nothing to do with the metal because...the upper limit on the length of a sheet of plywood is 12' these days. BTW, I would choose galvanized as I'm sure (based upon the use of galvanized steel in autos) that one of the automotive paint houses has an etching primer for that material. One of the virtues of metal-faced plywood is that the sheets are 'relatively' light based on square footage. So, if you choose to use steel-I wouldn't go any thicker than 10 gauge. Even those are going to be heavy. You can pick up some rigidity by plug welding some flatbar around the edges and along one of the diagonals. I would get some automotive type non-hardening body sealer (try 3M) and carefull seal the seam between the flat bar and the panel edges.Make your own plymetal ? I made a small sample (looked good) just like the WP F-unit crew did-but one has to wonder how many volunteers will left to assemble the locomotive after the boys make enough material for 60-odd feet of E-unit.The rubber channel to set the panels in can be sourced from McMaster Carr or one of the antique car restoration suppliers. If you want to seal the external clamping strips against the panels, once again I would check the 3M autobody materials line and see what they have to offer. The same material I mentioned before might just do the trick, as it is both non-hardening and paintable...supplied in caulking tubes. Personally, I'm not really sure that sealing this interface is such a good idea. The captive nuts might also be available from McMaster....if not, go to the Thomas Register website and do a search. As for the screws, I would check with RSI (EMD's small end-user distributor) in order to determine if EMD still has any. They did-before a good part of the plant was smashed to bits.

Southern 6914

Thanks to all for their interest and replies.DLO

There is a company that makes a sandwhich of thin aluminum and polethylene for buildings and signs. It's prepainted and you can get it in any size according to the manufacturer. I'm planning on installing this material to replace the plywood that was in the roof of a 20 ton Davenport. As for price, I don't know. I bought my 2 sheets from an employee that was getting scrap and selling it. But still it is aluminum, but it might be utilized in other applications.Stuarthttp://www.alucobondusa.com/defau ... /home.html

Recently restored a Cincinnatti curveside car that had aluminum and steel in close contact for a few decades. There was some limited corrosion, but no more where they met than anywhere else on the carbody (plentiful). Not sure just how critical an issue it really is? Has anybody else joined the two metals for many years with ill effects?dave

What we are worried about, glavanic action, is basically an electro-chemical process. The two dissimilar materials, aluminum and steel, provide the chemistry. But we can manage and cope with that if we interrupt the electrical path with barriers, films, coatings, or even use of a membrane. And more importantly eliminate moisture from the joint or contact.Builders constantly experimented and innovated such as the aluminum body on our Indaina RR highspeed which must be nearing or at its 70th birthday. But not all work was so successful. Ask anybody who has tried to disassemble an aluminum window frame held together with steel threaded fasteners such as on a PCC car!!!But if we are talking preservation, why would we want to modify and re-invent a design for convenience? That convenience requiring us to manage a new problem, and outsmart ourselves?Bob Kutella

Dave,I'll cite the same Pullman built high speed interurban that Bob just did, Indiana Railroad 65. Built in 1931 with an aluminum body, the car went to the Cedar Rapids and Iowa City when the IRR folded just before WWII, and then it IRM in 1952. While on the CRandIC the car suffered a collision, and in making repairs the CRandIC substituted brass machine screws for the originals, which I believe were zinc plated steel. When the car was being restored in the sixties, just fifteen or twenty years after the repair was made, every brass screw that had been in a damp location had a dime sized hole eaten around the head.Sounds strange, because we normally use brass screws because they are corrosion resistant. However, this is the sort of thing that can sneak up on the unwary when substituting materials without understanding all the ramifications.I'm certainly no metallurgist, but a quick Google search on "Galvanic corrosion" came up with some interesting information. I'll quote from: http://www.ocean.udel.edu/seagrant/publ ... osion.html" Galvanic corrosion, often misnamed "electrolysis," is one common form of corrosion in marine environments. It occurs when two (or more) dissimilar metals are brought into electrical contact under water. When a galvanic couple forms, one of the metals in the couple becomes the anode and corrodes faster than it would all by itself, while the other becomes the cathode and corrodes slower than it would alone. Either (or both) metal in the couple may or may not corrode by itself (themselves) in seawater. When contact with a dissimilar metal is made, however, the self-corrosion rates will change: corrosion of the anode will accelerate; corrosion of the cathode will decelerate or even stop. We can use the seawater Galvanic Series, shown in Table 1, to predict which metal will become the anode and how rapidly it will corrode."" The approximate voltage difference for any two metals can be taken directly from Table 1. It is worth noting that marine slime films composed primarily of microscopic bacteria and diatoms can change the potentials of many of the alloys near the noble end of the Galvanic Series as indicated. The potentials of these alloys become more positive in the presence of slime films, thus increasing the voltage difference when these metals are placed in contact with more anodic alloys. This has been found to increase the corrosion rate of copper, steel, and aluminum anodes by a factor of 2 to 5, but to have no effect on the corrosion rate of zinc anodes. It may also change which metal in the couple becomes the anode."Now, this web site is aimed at ship construction, and assumes seawater as the electrolyte, but our use of strong acidic or alkaline cleaning solutions, such as Muriatic acid or TSP can produce the same conditions if trapped with moisture in a structure. Since most of our restored artifacts run only occasionally, water trapped in the structure may stay here for months without being blown or shaken out.From the table in the paper, it is apparent that the zinc coating on the original screws was meant to be sacrificial to the aluminum body sheets, but the brass screws were considerably more "noble" and caused considerable corrosion to the sheets.On the "Engineer's Edge" web site, http://www.engineersedge.com/galvanic_capatability.htm there is a better chart that rates different metals by their "anodic index". The further apart two metals are on this index, the greater the potential corrosion problems. Their recommendation is that for "harsh environments", high humidity or dampness, that metals be within .15V on the index to avoid problems. Interestingly, their table lists 2000 series aluminum alloys with an index of .75V, but other aluminum alloys are rated at .90V or .95V. Thus it would seem that just specifying generic aluminum without specifying the alloy could lead to problems between the different aluminum components. This chart rates carbon steel as .85V, just about the middle of the aluminum range, but alloy steels go down to .60V, and 18% chromium type corrosion resistant steels (stainless) are rated .50V, very close to the .40V those brass screws were rated.What does all this really mean? It means that without doing a lot of metallurgical engineering ones stands a very good chance of introducing unanticipated corrosion problems when one starts substituting materials. The safest course is to rely on the engineering the original builder already did, and replace materials in kind.