Aluminum Spot Welding

How to keep the Cessna 170 flying and airworthy.

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DWood
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Re: Aluminum Spot Welding

Post by DWood »

Just wanted to post an update on the aluminum spot welding. Since the last post, I did buy a potable 220 volt spot welder and tried welding aluminum (it probably requires higher voltage/ more amperage). I was not successful in being able to produce a good spot weld and along with potential future questions as to how these welds were certified, I decided to rivet.
I have finished the rudder and it turned out very nice IMO. I only messed up a couple of new skins and Karl Anderson helped me out on the cost of buying more. I probably could have used them but would have kicked myself later if I didn't do it right.
I will update my website soon with pictures.
Dan
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GAHorn
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Re: Aluminum Spot Welding

Post by GAHorn »

The spot-welds visible on the underneath sides of the front door-post ashtray inserts (more properly known as the "Fairing assembly - Ash receiver" PN 0511136 (left) are shown in the accompanying photos. The "tabs" which hold the side panel upholstery are spot welded so nicely ...they appear to be "friction-stir welds"... which I thought was a fairly modern process and not known to be utilized on early Cessna's.
click to ENLARGE
click to ENLARGE
MVC-040S.JPG
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
DWood
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Re: Aluminum Spot Welding

Post by DWood »

George:
It seems as those Cessna used alot of spot welds in not critical applications. I suspect now with plastic that they don't have the need for spot welding as much. I did hear of someone that does alum spot welding but they said their welder was broken and waiting on parts. I didn't push it further. I suspect that they have something in the 440 3 phase range that can really move metal. I was able to just barely get it to stick together with 240V.
Thx,
Dan
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n2582d
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Re: Aluminum Spot Welding

Post by n2582d »

George, Do you have a picture of the other side of that fairing? I found the ash “receiver” below at the salvage yard.
Ash receiver p/n 0413120
Ash receiver p/n 0413120
I have no idea if the knob is the correct style or color. Does anyone know if this knob was rose or “coral” colored like the panel knobs on the ‘52 170B? It’s shown in Fig. 35-15 of the 170B IPC but the same p/n is in exploded view in the straight 170 IPC as shown below.
A29368E0-E2E3-43E7-958E-AB2A746626C0.jpeg
Gary
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Ryan Smith
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Re: Aluminum Spot Welding

Post by Ryan Smith »

n2582d wrote:George, Do you have a picture of the other side of that fairing? I found the ash “receiver” below at the salvage yard.
3F09CB8D-DB9D-49C1-B3C4-C8058AAF7429.jpeg
I have no idea if the knob is the correct style or color. Does anyone know if this knob was rose or “coral” colored like the panel knobs on the ‘52 170B? It’s shown in Fig. 35-15 of the 170B IPC but the same p/n is in exploded view in the straight 170 IPC as shown below.
A29368E0-E2E3-43E7-958E-AB2A746626C0.jpeg
Charlie Beyer's N2320D is as original a 1952 B model as they come. His knobs were light ivory in color. I got a pair of them from http://www.chevsofthe40s.com and installed them in 56D. My airplane is no prize winner, so I'll spare myself the embarrassment of posting pictures, but they do look nice. My dad removed the remnants of the original ones, which were very badly degraded from the sun, at some point in the mid-90s and I remember them to be ivory in color as well. The airplane had a different interior, gold and black vinyl, but the original Lima Tan paint (the best that I can eyeball, anyway) remained, so I have reason to believe that those knobs were not replaced in 1962 when the paint and interior were done.

Also, Charlie's front ash receiver lids were painted. He does not recall them ever having been removed/touched up. His airplane has 90% of the original interior paint and only received new upholstery.
bagarre
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Re: Aluminum Spot Welding

Post by bagarre »

FWIW Both 2481D and 2695D had black knobs and chrome tops for the ash trays.
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n2582d
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Re: Aluminum Spot Welding

Post by n2582d »

Thanks David and Ryan. I ask an unambiguous, black and white question ... and the answer is ambiguous — black and white. :lol: I scoured this website for a picture of one and came up empty-handed. It seems every C-170 YouTube video had the ashtray covered with a portable GPS so I didn’t have any luck there either. :roll:
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Bruce Fenstermacher
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Re: Aluminum Spot Welding

Post by Bruce Fenstermacher »

I do not know all the colors than may have been used in the 170, white and brown I think I've seen. These ash trays also came from the car industry but I have not yet identified what car they came from. I have seen the same ash tray used in a couch of the same era. In fact this particular couch is/was at John Hess's home airport or maybe it was Gettysburg, I forget now which one I saw it.

As for spot welding aluminum, after seeing a video on Youtube: https://www.youtube.com/watch?v=gcgC3V3mkcw, I tried it. However I did not have available to me the type of spot welder that clamps w2 spots together between the electrodes. I had a type that you held both electrodes, one in each hand and pressed them together aligned by hand. We aren't quite sure the amperage adjustment was working on this machine, a 240v '60s era car body repair model either. It could have been full amperage.

Lots of sparks and flying hot molten metal. Of course Leroy and I where properly equipped with all the necessary PPD so we didn't get hurt. :roll: About 6 attempts and out of the 6 one spot stuck and showed me promise that the process might actually work. But Leroy and I needed a lot of work to perfect it. And at least some PPD to protect us before we got hurt.

Search Youtube for spot weld aluminum and you will get several videos with people demonstrating the art.

After my folly with Leroy and his spot welder I thought about it. I did not clean the aluminum. The secret to Oxy/Acetylene welding aluminum is clean clean aluminum. I'm sure spot welding would be the same.
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MoonlightVFR
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Re: Aluminum Spot Welding

Post by MoonlightVFR »

Aluminum welding exhibitor at OSHGOSH.

Aluminum welding of empty beer cans .
Making budweiser model airplanes.

I observed his craftsmanship.I made a comment that all 10M+ airplanes on the field are riveted together, so why the welding display. He had a good verbal spiel which DID NOT impress me.

Assume he was there every year. I observed over a period of 12 year span.

Welding with a simple propane torch and special aluminum welding rods. So simple.

Bless his heart , regular vendor/exhibitor . must have made a profit to keep coming back yearly.

I have not been to OSHGOSH in over a decade. Is he still there?
gradyb, '54 B N2890C
hilltop170
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Re: Aluminum Spot Welding

Post by hilltop170 »

Grady-
If you're asking if he is still there because you have depleted your supply of aluminum welding rods, I have some I'll give you that I bought from that guy in 2003 and have never even played with.
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Bruce Fenstermacher
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Re: Aluminum Spot Welding

Post by Bruce Fenstermacher »

The guy with the special aluminum rods soldering aluminum cans is like Santa. He's every where at every car show, tractor show, mechanical show of any sort. How does he get to so many shows? How does he do 4 shows across the land in one day?

The Oxy/Acetylene welding of aluminum I referred to does not use special rod. It is a art to be sure. A lost art of days gone by which was used to build some airplane parts. But the magic thing is if you know the art, it still works today. Besides a torch with very very little pressure, cleaning the aluminum is essential. Mentioned before go to https://www.tinmantech.com/html/oxy-acetylene_torch.php.
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Re: Aluminum Spot Welding

Post by Bruce Fenstermacher »

On the ash tray knobs I believe some where painted to match the rest of the knobs in the AC.
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n2582d
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Re: Aluminum Spot Welding

Post by n2582d »

Sounds like the debate over rocker box cover color ... silver? ... black? ... who knows. It was probably whatever Fred found in the parts bin that day, never realizing someone would care about such arcane trivia 66 years later. I guess I’ll go with coral colored knobs as I’m painting the rest that color. I found NOS knobs for my Narco VHT-3 that are ivory. For uniformity I’ll be painting those coral as well. I also found a gray - soon to be coral - knobbed control cable at the salvage yard. Cut the shaft off about 1/2” from the end so I could thread the stub and use it on the cigar lighter which had the wrong style knob. Of course the thread size for the lighter was an almost impossible to find 12-28. Can’t figure out why this project is taking forever. :lol:

I went to one of Kent White’s metalworking workshops last year. By the end of the aluminum welding portion of the class I was able to lay down some beads that looked like bird s*#t all lined up. Birds might take offense at the comparison as what they produce is arguably better looking than my welding. So in addition to super clean aluminum and the right equipment it takes a whole lot of practice. It seems to me there is about a 2°F spread between too cold to melt the rod and a hole melted through the metal. What was really humbling was when Kent’s grandson, about 10 years old, comes in and gives it a try. He laid down some beautiful beads.
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GAHorn
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Re: Aluminum Spot Welding

Post by GAHorn »

n2582d wrote:...I went to one of Kent White’s metalworking workshops last year. By the end of the aluminum welding portion of the class I was able to lay down some beads that looked like bird s*#t all lined up. Birds might take offense at the comparison as what they produce is arguably better looking than my welding. ....
:lol: :lol: :lol: :lol: :lol:

As for ash-tray knob color and other such trivia... I think it'd be a good thing to recall that the period of time in which Cessna (and others) were producing these relateively cheap airplanes ... was at a time that had predicted every returning serviceman from WW-II would be buying their own personal airplanes and operating them like "family cars of the air".

The sheer number of small parts and left-overs from the "big war" were sitting in bins and sold at less than scrap-prices, and that's why AN gyros from military stocks ended up in these airplanes... They were CHEAP! and plentiful.
Same thing with door knobs, ash trays, and car-parts that would fit airplane interiors.... so the actual color of ash tray knobs likely were decided by what arrived at Cessna on the pallet.

I do have an original ash-tray fairing and an ashtray in the junk box I'll go fetch and post a pic.
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
bagarre
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Re: Aluminum Spot Welding

Post by bagarre »

n2582d wrote:Thanks David and Ryan. I ask an unambiguous, black and white question ... and the answer is ambiguous — black and white. :lol: I scoured this website for a picture of one and came up empty-handed. It seems every C-170 YouTube video had the ashtray covered with a portable GPS so I didn’t have any luck there either. :roll:
https://photos.app.goo.gl/zHIFv321Scw1KLwz1

Those are a few photos of the black knobs.
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