Restoring '37 LaSalle Running Board Stainless Caps

[carlhungness]

       The stainless steel end caps on my '37 LaSalle running boards are not entirely made of stainless and that fact presents a pretty significant problem when restoring them. The back-side of the caps have mild steel plates that are encapsulated to the stainless by folding the stainless over the mild steel. The mild steel, which has been punched to hold 8-32 studs rusts.
       Thus if the caps are dented, (and just how they get dented is mysterious as they are located at each end of the board out of the way of shoe traffic) removing the dents means you must cut the mild steel backers out and then hopefully tap-tap the dents out and metal finish them.
         I started the process by cutting out the backers using a dremel and a cut-off wheel, also known in the trade as a ziz wheel for the sound it makes. I was partially successful with my first attempt at cutting out the backers as my wheel did not touch the stainless. I felt like a dentist cutting into a tooth and trying to avoid a nerve.
           Once I had successfully cut out the backer I started the process of trying to tap out the numerous dents and then laboriously sanding the grooves using a piece of tubing wrapped around, first, some 60 grit paper and working my way up to 220, 320, 400, 600 and finally moving to the buffing wheel where I used black, red and white compounds to bring the caps back to original condition.
             I have to admit that my second attempt to cut out the backer saw me going too deep and cutting into the stainless itself. The caps are very thin and welding up my little buzz cuts is going to present a daunting task with a TIG welder.
             Nevertheless I have succeeded in restoring a few of the caps, four needed so I thought I'd post some photos to show progress.
              I can  tell you from experience the stainless is quite different than aluminum when trying to achieve perfection. I was forced to use many different grits of wet or dry sandpaper to remove the minute pits that persisted. One pit the size of the head of a pin on the cap will stick out like a diamond in a goat's butt and you can spend half an hour trying to feather the rounded groove in the cap to perfection.
               Several of the studs were missing so I assumed I could epoxy in replacements using 8-32 studs with a countersunk head (for additional gluing purchase area) but I wasn't happy with the holding power of the J-B Weld I have used for years. It did stick the studs to the caps, but I was able to pop them loose with some thumb pressure so I'll have to try another brand of epoxy. Then too I may have to actually silver solder the studs in place using the largest soldering iron in my tool-box. I won't attempt to use a torch as I fear I'll blow holes or create warpage. I think Hysol may be strong enough to hold the studs but I'll try some over the counter epoxy first.
              Your patience will be tested when tapping on the caps and so will you ingenuity given the sunken shape of the channels on the caps. I found using steel tubing that matches the radius of the grooves will work if one has enough courage to hit the 'ammer when the tubing is in place. I didn't resort to a file for knocking down high spots as the material is just too thin.
           I'm also not in love with using the buffing wheels these days as I've progressed as a violin player and a few of my fingers are already handicapped due to numerous surgeries I've had over the years. I went for 37 years without being able to move my right thumb and have had some tendon issues elsewhere.
             Buffing is another science one will have to study but success can be achieved with some patience. Make sure you use one wheel for each color of compound. Dial up YouTube for some good videos on polishing aluminum-steel and you'll get a good feel for what is required. I thought I had some pretty good looking caps at first, but further inspection revealed numerous scratches that just were not acceptable, so it was back to the sand paper time and again.
               Thus far restoring the stainless hood trim and now the end caps has given me a bachelor's degree in the art and tested my resolve. I'd rather be carving some of the clay I've made several sculptures from, and I thought it was difficult because it is so hard you can barely mark it with your fingernail. It's the same stuff they use in Detroit for new designs called Chavant clay and it too tests your patience.

[Tom Boehm]

I'm impressed. Very difficult problem. If it were possible to unfold the stainless to release the steel, the fact that it is scalloped makes it impossible.

[carlhungness]

       I was perfectly successful in cutting away the first couple of backers on the caps with my Dremel and then must have gotten overconfident on the next one as the cut-off wheel touched the stainless and left minute cuts in it. Thus as mentioned I now have to weld up the stainless cuts and then hope to file them back down and start the finishing process all over again. I DO have 2-3 spares that are untouched but I want to make a couple of sets so I can supply someone else down the road who may need the caps.
         Nevertheless, the caps are easier to work than the ultra-thin stainless strips that go on the hood. Removing dents from those channels is well-nigh impossible because one edge is turned in and there's no way to get a backer in the channel to tap out the dents.

[Tom Boehm]

In some cases, especially where you did not cut away all the steel, could you tack weld on some steel patches to hold the bolts instead of using epoxy? Also I've noticed at auto body supply stores they have epoxy for body repair instead of welding. Maybe that would hold better than JB Weld.

[DaveZ]

Nice work Carl! When and if I ever get the outer molding from Northfeild I will be doing same!

Best wishes,
Dave

[carlhungness]

Your outer moulding, I think you are referring to the running board moulding still hasn't arrived? That's a shame. I DO have one extra piece of running-board side trim..and possibly I'll have spare end caps. In fact I do have spare end caps but they have some Dremel cuts in them which I hope to have fixed, so stay in touch. As I have previously posted, you can make the side trim from '54 Chevy rocker panel trim if you are so inclined. My friend Karl Kinser made some and they look great.