I've never done this type of repair so if anyone can give a little guidance, I'd appreciate it.

We have a Budd diner, ex ACL Baltimore/SCL #5908/AMTK #8008, built 1939. About a 10' section of fluting is starting to come off. It looks to be a "snap-in" kind of configuration but I'm not real sure that there isn't something else to keep it from happening again. Does anyone have any experience reinstalling "delaminated" fluting?

I'll try to get an image taken and post it.

Thanks

This is a not uncommon problem with Budd truss frame cars. The culprit is almost always non-stainless steel fluting fasteners (screws) that have rusted away causing the flutes to come loose.

Re-attaching the fluting with stainless fasteners should correct the problem, but that is easier said than done. There are two problems to deal with here. One is the general difficulty of drilling and tapping holes into 70+ year old stainless steel. The other is making sure you are drilling the holes into one of the "tabs" that were attached to the structural members for the purpose of attaching the fluting. These are difficult to locate because with the fluting in place the tabs can't easily be seen. It becomes somewhat of a seat-of-the-pants deal to locate the tabs. Usually you can drill a new hole next to an existing one and get it in the right spot. Also, sometimes you can knock out the rusty broken fastener stud and re-use the original hole by re-tapping it. These tabs are relatively thin, and thus are much easier to drill into than any of the adjacent structural members which may be 1/8 to 3/16" thick.

Drilling holes into stainless steel is a whole other topic but ask if you run into trouble with that.

This is a quick overview but hopefully it helps to get you started.

Haven't had to drill a Budd car, but from my experience drilling holes in stainless steel ticket booths when I worked for the CTA, the tool of choice is a screw machine length (short) 135 degree split point cobalt steel drill, in a drill motor that will throttle down to 50 RPM or so, and lay on it hard.

Taps should be good quality spiral point "gun" taps, the type that shoot the chip through the hole ahead of the tap. These typically have two flutes, and have more meat than a typical hand tap, so are less likely to break. They also don't need to be reversed every turn to clear the chips, so can be driven by that same variable speed drill.

Hardware store taps don't stand a chance.

Topfuel: Thanks for the info. I'll look down in there to to see if I can find the tabs. There are no exposed fasteners or screw holes easily visible anywhere (that I noticed) so am I correct to assume that the screws are in the narrow strips between the actual wider fluting strips and the fluting "snaps" in? I didn't have my phone or camera on me at the time I was checking it out so I'm going by memory. I'll try to have one of the guys take some images tomorrow. I've never done any repairs to the fluting so this will be a learning experience. All the guys that knew about it are gone.

Dennis: I'm hip to drilling and tapping stainless. I've done quite enough of it working on the insides of these cars. It's indeed a PITA even with the right tools.

re: Drilling Stainless Steel

Drilling Stainless Steel is how a certain ex-CBQ Budd Dome got the nickname of "Silver Toilet" as in "sh*t, I broke another drill bit".

-Hudson

Drilling stainless steel needs the correct tools, speeds and feeds. And they need to be sharp, sharp, sharp.

You can get the best quality drills and taps and do a few hundred holes before your tooling needs resharpening.

Or you can get some "medium" quality drills and taps and resharpen the drills (try a "Drill Doctor" (tm) well worth the money, I have several) after every 50 holes.

Or you can buy "cheap" drills and taps and curse all the while during your first failed hole.

There are times when paying "top dollar" for the right tools is worth it. Drilling lots and lots of holes in Stainless Steel is one of those occasions.

Also, you will want to be very careful putting stainless steel fasteners into tapped holes in stainless steel. Yes, you do prevent rusting in the future, but if the grades of stainless steel have similar hardness you can run into "galling" when the surfaces of two metals of similar hardness will actually "weld" together when "rubbed" (i.e. "twisted") together. Very annoying, sometimes the bolts/screws/pipes won't even thread together all the way before the surfaces weld together.

In some cases you can't even "unscrew" the parts without ruining the threaded surfaces.

Some times you can get away with "Teflon (tm)" pipe sealing tape on stainless steel parts to give enough lubrication to get the bolts/screws/nuts/pipes together/apart without the surfaces galling together.

Cheers, Kevin

I didn't recommend resharpening the drills because I've found the split point grind far superior for stainless, because it reduces the surface area of the drill that doesn't cut and therefore needs to be pushed into the material, which is indeed tough. Not everyone can split the point of a small twist drill by hand, and I don't think the Drill Dr. can be set up for that grind.

There are anti seize compounds made specifically to deal with the galling problems known to exist with stainless threads, but I have no experience with them, as we never had stainless machine screws at CTA. The booths were always indoors or under roof, and cadmium plated fasteners were deemed good enough. Doing a google search on "anti seize for stainless steel" will find a bunch.

Further... I should have mentioned that stainless is notorious for work hardening. Some grades worse than others, but all grades to some extent. If you let the drill spin in the hole without making a chip you have just formed a hard skin in the surface of the hole, and you will drill no further until you force the drill through it and start cutting again. That's why slow speed and lots of pressure are required to drill stainless, and sharp drills ground to require minimum pressure to advance into the work.

We use Permatex nickel anti-seize on larger SS fasteners. It's easy to find at auto parts stores. Galling hasn't been a problem with small machine screws and nylon lock nuts in non-structural applications. No fine threads used. Go easy and don't over-torque.

Also stay away from 316 SS unless corrosion is a huge problem. They gall the easiest. In my previous work life, we used to joke that we should buy them pre-stripped for easier over-torquing.

Quite true about work hardening with SS, if a drill bit "lingers" and heats up the steel locally without cutting you can have problems.

The latest "Drill Doctor" (tm) can regrind the drill bits with a split point, if desired.

Check out the Model 750X, about $140.

You can do 115 to 140 degree point angle. And you can adjust the amount of material removed. You can take just a little off the drill to clean it up, or you can "hog" material off to get rid of big chips out of the cutting face.

Highly recommended, does up to 3/4" bits.

Disclaimer: I don't work for or own any Drill Doctor stock. Just a happy customer, on my third unit (they kept adding features so I upgraded). I put a coarse grinding wheel in my older unit for fixing really bad drill bits and a fine grind wheel in my new unit for "final finishing". I'm sure I've paid for the cost of the unit by saving bits.

Cheers, Kevin.

Couple photos to share. The top one shows what's underneath the buckle (looking up from the bottom), the bottom shows shows the fluting coming off. Any ideas on the best way to fix this?