Steering Column Work: Powder Coating & Shrink Tubing Install Trick

One of my regular avocations is custom powder coating.  I keep quite busy doing mainly custom motorcycle, bicycle and hot rod work and on occasion, I get to do some of my own parts as well.  Recently, I was doing a poop-load of black powder work in the exact color I have chosen to do several critical pieces of my Boss in.  This allowed me the opportunity to coat my steering column shell and dash bracket and to show a little trick I developed to duplicate the factory shrink tubing used to encase the lower collapsible section of the Mustang steering column.

I started by stripping all of the factory finish off of the column and bracket and passing them through my blast cabinet to remove the rust scale that had accumulated over the years.  Then I applied a urethane matte black powder coating to both parts to ensure years of trouble-free service and great appearance.  And now for the “trick”:

Almost everyone I talked to that has ever restored a Mustang has stumbled a bit when it came to restoring the shrink tube encasement at the bottom of the steering column.  I’ve seen lots of Mustangs that have nasty looking original shrink tube sleeve still intact on otherwise nicely restored columns or, on the flip side, the owner has cut off the offending tube and left it off complete because they could not duplicate the process.

I was part of the “unlucky” group where this shrink tubing was concerns in that all manner of rodent had chewed up my original shrink tube jacket on my original column.  After months of scouring the internet for hints on how to repair this area, I came up with almost nothing helpful.  So, I started to think about a way I could recreate this detail on my own, and what I came up with worked better than I expected.  So much so, that I thought it only prudent to pass it along here.

In my research, I came across some very large heat shrink tubing for large industrial electrical cable that I thought might do the job.  Unfortunately, most of these products didn’t have the proper shrink factor I would need to do the job.  Then I stumbled upon some high shrink factor tube that would fit the bill from a company called Parts Express.  The shrink tube I found is referred to as 3” high-shrink rate tube.  It shrinks with a diametric factor of 2:1 and a linear factor of 1.07:1.  The stuff is a bit expensive, but I decided to order enough material to do a few columns just in case I blew it on the first try.

I measure my original shrink tube that I cut off my column and determined the finished length I required.  After taking the shrink factors into consideration, I cut a length of shrink tube  and slipped it over the collapsible section of my refinished column tube and began gently warming it with my heat gun while rolling the column tube slowly, making sure to evenly shrink the tubing from end to end.  After a few short minutes, I had a nicely finished detail that (I think anyway) replicates the original shrink tube nicely.  Hope this might be useful!

Steering column tube and dash bracket in the powder booth and ready to coat.

A nice coat of urethane matte black powder looks really nice.

My original shrink tube jacket was chewed up by rodents after years in storage and generally looked like crap.  Believe it or not, this is the "good" side.  There is very little information available on how to duplicate this detail so I set about figuring this out.

I found some industrial, high-shrink rate tubing material and started to experiment.  I found the 2:1 diametric shrink rate was spot on and determined the linear shrink rate was only 1.07:1.  This proved to be a perfect match for the requirements of this job.

I measured off a 10.75" section of shrink tube and cut it squarely with my razor knife.

Here is the new shrink tube placed on the collapsible column section before shrinking.  The nasty original is shown next to it for reference.

Being a single fella, I can get away with a lot of restoration "stuff" in my kitchen that many "spoken for" fellas don't get to do!  Using my heat gun on low heat, I started to slowly shrink the tubing by heating along the entire shrink tube sleeve by rotating the tube and heating it along it's length.  In this shot you can see the tube has just started to shrink around the ribs of the column tube.

about 30 seconds later, and the tube is pretty well secure on the column an shrinking nicely.  Note the ends are not quite tight to the column yet.

Almost there.  I have been heating the shrink tube about 90 seconds at this point.

And there it is.  The tubing has shrunk to its maximum and the ends are nice and snug against the column tube.

Compared to the original shrink tube jacket, I think this will work just fine.

With the dash bracket in place, this restoration detail really sets off the column well.