The International Cessna 170 Association

Rebuilding and reinstalling an engine draws your attention to many details one has left for another day many moons ago. One such detail is what to do about those original United Carr 49166 harness bands holding the wires to the firewall. You see they are working perfectly except the 70 year old insulating rubber is looking pretty sad.

When I pulled the bands off the fire wall, they just snap in, no tools required for removal, I took note the rubber seen to be that of which I've seen somewhere before. Maybe I could refresh or rebuild these bands and keep one more little detail original on this airplane which incredibly still has so many such details remaining. The challenge is on.

Memory was telling me that over the years I've owned several mouse pads with the exact same color and density of rubber foam like material. All I need is a mouse pad. Surely I have one stashed someplace for just this project. 2 weeks later searching the house turned up nothing and even a trip to the local ACE Hardware for a look see did not reveal the suitable material, at least at a price point I was willing to pay. I just couldn't buy a nice new $10 tile float to destroy it. As it is now time to reinstall those wires, we are out of time and in desperation I asked my wife if she ever say mouse pads for sale at the Walmart. Does anyone use mouse pads anymore? A few minutes later she pulls an old pad out of a storage drawer just perfect for my project. Guess I'm not the only one who would keep a old mouse pad for just such a day.

Now all I need is some hollow rivets and a way to set them. The original had brass rivets with a star head on the inside with the star formed into teeth to grip the rubber. I'd already checked the ACE Hardware rivet supply and knew they had nothing like it. I'd just used some aluminum pop rivets to install baffle seal and thought if I removed the nail they might be a perfect substitute. I just needed a tool to set them. Looking in my tool box I saw a 3" C-clamp that I'd modified year before to set nearly the same type of rivet in some brake linings. This would require a minimum amount of modification to use. Just then the wife walks through the garage and so proud of how far I'd come in this challenge I showed her the rivet set tool. She looks right me and says "I have those rivet set tools and maybe some rivets you need". You see my wife is a crafter. She's got lots of cool tools for crafting that every so often come in handy for maintaining airplanes. Sure enough she had a rivet set but no suitable rivets.

Off she goes to the grocery and back to the garage I go but as I do I mention I may have to disassemble her auto rivet set in order to use it with a hammer. In no time I realize the auto rivet set will work as it is but I must shorten the aluminum rivets. I devise a method of holding the rivets against a miniature disk sander I build long ago to sand balsa sticks and the job is done in no time.

I assemble one rebuilt band and decide to take a picture to share with everyone. Just completed the picture and the wife returns from the grocery to say she remembered more rivet sets she had that I won't have to disassemble and even more rivets I might use. Sure enough she did have some brass rivets, even some I could formed into a star head, but as I already had one band assembled and pictures taken I decided aluminum was good enough.
On the left the mouse pad used to salvage just the right rubber material. Top center the 1/8" dia.,1/8" grip aluminum rivets, the right one shortened using a small disk sander while held in the aluminum flat shown top right.

Center left is the rebuilt band, center right is the other band as it came off the firewall. Right bottom is the auto rivet set borrowed from the wife and used to set the rivets.

Challenge completed and I think 100% successful. And my 170 remains just a little bit more original than even that of the original nut.

It is always good to have a CRAFTY wife. Mine is also.

John

And the bands reinstalled.

Bruce, this is great! I've been trying to find those clamps but didn't know what they're called. Now that you told me, I found the one instance in the IPC.

There are a few under the floor of my airplane, and they're really nice for keeping the wires off the bulkhead holes. Any idea what those Tinnerman-like clips are? I don't see them in the IPC. The United Carr clamps and clips save a lot of time compared to fabricating brackets and using Adel clamps (through the inspection holes!)

There are United Carr Harness Bands #49164 and #49165 as well as #49166 that I found in the '48 IPC. I looked but couldn't find exactly the band you pictured. There are all sorts of Tinnerman products listed, just a matter of figuring out which one this one is.

There are United Carr Harness Bands #49164 and #49165 as well as #49166 that I found in the '48 IPC. I looked but couldn't find exactly the band you pictured. There are all sorts of Tinnerman products listed, just a matter of figuring out which one this one is.

Bruce Fenstermacher wrote:... And my 170 remains just a little bit more original than even that of the original nut.

And, you're becoming just as nutty.

gahorn wrote:

Bruce Fenstermacher wrote:... And my 170 remains just a little bit more original than even that of the original nut.

And, you're becoming just as nutty.

That is an excellent observation George.

Reviving an old thread here. Beautiful work Bruce! Thanks for including all the detail in how you did that.

I can't find the thread where someone was asking for the part number of the clamp that holds the overhead fuel vent line in place. It's not listed or shown in any of the 170 series IPCs. The 120-140 IPC however does show those two clamps to be 49165 harness clamps. I have no idea if the 120 or 140 uses the same diameter overhead vent tube as the 170. It's a moot point perhaps as I don't see anybody selling them online.

Earlier in this thread Dave was asking about using harness clamps going through bulkhead lightening holes. I ran across a couple of Cessna Accessory Kits that called for harness clamps. Maybe someone can correlate the dash numbers with diameters for us. KRN and Preferred Air Parts (among others) have these.

I bought a few of the clamps (harness bands). The order from KRN arrived today: S1592-1A, -1B, and -3A.
Size -1A looks like it's for individual wires. -1B is quite a bit larger, and -3A is larger still. I don't understand the numbering, because I'd have thought the number would denote the size and the letter would be some other characteristic. Maybe it's foam padding type, I can't tell. The band closure designs are slightly different, but they're generally the same, with interlocking bends. One significant difference on these is that the the band is riveted to the clip, unlike the two-piece snap-together design that Bruce showed. I'll update when the 49165-21 and 49166-21 clamps arrive from Preferred. Edit: After receiving a batch from Preferred, I'm guessing that what is labeled here as -1B is really -2A. And the A vs B denotes clip size (B larger). See following post.

Got more harness bands, this time from Preferred.
It looks like the S1592-xB bands have longer clips than the -xA bands, and that the -1B that KRN sent is really -2A. The band diameter is larger and the clip is the same size as the -1A.
49165-21 looks like the same thing as S1592-2A.
49166-21 looks like the same thing as S1592-4A.

All units have the band riveted to the clip.

If anyone want more pics or measurements, let me know.

Dave,
Thanks for the excellent write up and pictures. Very helpful!

Thanks, Gary. I admit that those things became an obsession a few years ago when I redid my radios. I really needed a few but didn't know where to find them until you and Bruce broke the secret! I've got a whole lot of them now, so let me know if you need any.

Dave maybe this has been discussed already and covered for the overhead vent center tubing but my plane has two such clamps attaching the tube to the roof skin reinforcing longitudinal stiffeners. The clamp fastens by an expanding metal button formed at the base of the clamp band that just pushes into a hole of the stiffener.
Does your plane have these as well?

Yes, I have those clamps overhead, but these won't work for that. The band is permanently riveted to the clip, not held by the expanding button.