Tonawanda Foundry

[bergy]

Several members of this site have asked me over the years to explain the automotive casting process. Since most of my GM experience was at Tonawanda - I thought that I'd start with the overall plant layout - then drill down into how the processes worked in each department. I was blessed to have been superintendent of production in each of the production departments at Tonawanda. The foundry was shuttered in about 1983 and torn down in the 1986 through 1998 period. I couldn't find any composite plant layouts in my files, so over the weekend I placed the foundry outline as accurately as I could on a later drawing of the Tonawanda complex. The combined length of the motor plant and attached foundry was more than 2,000ft! Is this kind of stuff of interest to any of you?

[Plowman]

I am interested in this stuff,sound's cool.

[SCMProf]

I'd like to know more about the process and which parts were made there. I interviewed for a GMI position in 1980 at that plant, and can still remember the plant tour a little. I was fortunate to have taken a position in Lockport at the Harrison Radiator Div.
-Jim

[Steve Shauger]

Yes Bruce that would be an interesting topic. The more insight and understanding of the production process the more accurately we can restore and preserve our cars.

[SS427]

Absolutely interested. <<GRAEMLIN_URL>>/biggthumpup.gif

[bergy]

http://www.yenko.net/ubbthreads/pics/usergals/2013/06/full-2170-5250-scan0335.jpg


You're gonna need to make the layout bigger to read it. The Tonawanda complex was (is) massive!

[YENKO DEUCE REGISTRY]

I'm all in, let's hear it! <<GRAEMLIN_URL>>/biggthumpup.gif

[mockingbird812]

Bring it! <<GRAEMLIN_URL>>/laugh.gif

[Material_Boy]

X2

[njsteve]

No I dont wanna hear it.

(Just kidding. Bring it on. <<GRAEMLIN_URL>>/grin.gif)

[olredalert]

----I have often thought that I would have loved to be a fly on the wall in a plant like this. This stuff fascinates me to no end.......Bill S

[bergy]

The original scan of the drawing was a lot larger file, but it was also a lot clearer when blown up. I attached the original to an email for Rick and he said that he could open it. If anyone else wants the larger file - just PM me with your email address. In the future, as I describe each production department, I'll try to include more detailed sketches of the equipment layout.
I'll try to just keep my departmental text focused on the processes, equipment, and parts. The &quot;people&quot; part would take a volume all by itself. There were soooo many great, hard working people at GM. People who dedicated themselves to doing their best every day. It always aggravates me when the focus is on the negative - union problem, etc. Just like today's labor force, we had our problems. I was the manufacturing management representative on our contract negotiating team - lived through strikes, crossed picket lines as all management did (if confronted, we were instructed to turn around). The foundry, by nature of the activity, was a very dangerous place - I witnessed a fatality the second week of my first Chevrolet supervisory job (second shift melt supervisor). A &quot;king pin&quot; broke on a hot metal delivery car - 2 tons of 2,700 degree iron spilled in the driver's lap. I can still see it and smell it to this day. An experience like that will cause plant safety to be #1 on your &quot;to do&quot; list for life. I'm proud to say that our Pennsylvania foundry worked a million man hours without a lost time accident several times - a record that most foundries have never accomplished.

[Keith Seymore]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bergy</div><div class="ubbcode-body"> Since most of my GM experience was at Tonawanda - </div></div>

As an aside, did you (or do you) know Emmett Moynihan?

He was a high level manager at Tonawanda and eventually rose to a director position (over both the Milford and Desert Proving Grounds) before retiring.

Thanks -

K

[bergy]

Name doesn't ring a bell Keith. Do you know which plant he worked at? When he worked there? - there were 5 plants on the property.

[bergy]

I do have a draft of the core department verbiage. I tried to post a word file - no go. Then scanned the document - again no go. I can attach the file to an email if anyone wants to volunteer to try to post it. I'd just like to get comments on whether folks would like more detail, less detail, different detail, etc. Thanks

[mockingbird812]

Bergy - Sent it to Bruce for posting.

[bergy]

K - Thanks

[Xplantdad]

Bruce-sent you a return email....

[bergy]

OK - let me know if you find it interesting -

Chevrolet Tonawanda Metal casting Plant

1. Core Department
By far the most labor intensive area of the Tonawanda metal casting Plant was the core department. We employed in excess of 1,000 hourly workers in the department when I served as superintendent. Except for bearing caps and brake drums, every casting required at least one core. There were about 60 core producing machines in the department, each requiring one operator per production shift. Many support employees were required to prepare the cores for use in the casting process.
Cores are used in the sand foundry process to form internal passages and re-entrant pockets in the castings. These cores are quite literally castings themselves; made of sand that is mixed with a binding agent and blown under high pressure into a metal form referred to as a “core box”. The two core binding agents used at Tonawanda were a derivative of linseed oil (“oil sand cores”) which had to be cured, or cooked, in large tower ovens, and furan resin (later replaced by phenolic resin) which was catalyzed by heat right in the core cavity during the machine cycle “hot box cores”). It is interesting to note that each core cavity required many small vents (often small screens) to help the high volume of air escape the cavity during filling while keeping the sand/binder material entrapped in the core cavity. These screens eventually manifest themselves as small, round “bumps” on the cored areas of the casting surface. The simplest casting utilizing a core at Tonawanda was the v-8 exhaust manifold. The 4 internal exhaust passages that merge into a common collector passage were formed in the casting process by a single, one piece sand core. This care was set in place in the bottom half of the foundry mold (drag mold) prior to “closing” the mold cavity (lowering the top half of the foundry mold onto the bottom half). Gray iron at 2,600 degrees ferinheit was then poured into the mold through a hole called a sprue – it flowed through a runner system in the mold and entered the casting cavity through small rectangular openings called gates. If you examine the “parting line” (joint where the upper and lower halves of the molds meet) of a casting, you will notice these small rectangular “gate” impression. When the liquid iron enters the mold, it flows around core and actually initiates surface solidification or “skins” over at the core surface. If the system is properly engineered, this solidification begins before the hot metal destroys the binder which holds the core together. By the time the casting is removed from the mold (termed “shakeout”), the once solid core (with its’ binder now thermally destroyed) literally pours out of the casting like sand flowing between your fingers at the beach.
More complicated castings like cylinder heads and blocks require commensurately more intricate core assemblies. Small block cylinder heads require 3 separate cores each – a water jacket core to form the cooling passages, an intake core, and an exhaust core. In practice, the small block exhaust core was a “Siamese” design that formed the exhaust ports of two adjacent heads that were cast in pairs - 4 heads to a mold. Cores that were very thin and fragile, as well as cores that formed surfaces that had to be free from sand adherence, were “washed” (coated) with refractory material that would prevent premature core surface breakdown in the casting process. The composition of this refractory wash could be as simple as a mixture of finely graded silica sand mixed into a watery paint like consistency, or, depending on the critical purpose of the core, could be made of fine zircon sand with graphite powder added (to chill the iron and provide a layer gas protection). The water jackets of small block cylinder heads have thin passages that completely encircle the spark holes – the core that creates these thin passages had to be protected with a high quality core wash. Both big block and small block case castings utilized 2 separate cores to form the fuel pump area as well as the oil filter bowl. Owners of 1969 Norwood built Camaros will note with aggravation that the filter bowl core had several small, round, raised areas about the diameter of a pencil eraser located right at the otherwise flat surface where the VIN was stamped. These raised “bumps” are actually made by the small screens in the core box (previously mentioned). It is also interesting to note that, had the foundry known that the filter bowl area was going to be used for VIN stamping, the screens could easily have been placed in an alternate location (probably one day’s work for a pattern maker)! The most difficult, and highest scrap castings produced at Tonawanda were the big block MIV heads. A major contributor to this quality problem was that these casting were extremely heavily cored. Also, the water jacket was a 2 piece design that had to be glued together and sent to the molding department as an integral assembly with a large, single perimeter core that formed both the intake and the exhaust ports. If you examine a big block head, you can see evidence of this perimeter core on the cast surface of either end of the head. During pouring and solidification, combustion of core binders in the mold yields “off gas” that has be vented from the mold cavity. The excessive “off gas” from big block head cores created tremendous casting defects referred to as “blows” (large air bubbles literally entrapped during solidification). Big block heads seldom ran below 10% scrap in the foundry.
At the Tonawanda Metal casting Plant, cores destined for the front 4 molding lines were delivered via shelved or fixtured racks which hung from continuously moving monorail delivery conveyor – one monorail system for each of the front mold lines. These monorails would “dip down” to floor level for loading in the core department, and then make their way to the foundry at a mezzanine level of about 25’ above the floor. The trip to the foundry varied slightly on each line, but averaged about 30 minutes.
One final comment about the core department might be of interest to the collector car community. The core tooling required to produce a big block case was as follows:

International oil sand core machine
Core boxes for front barrel cores (2 cavities per box)
Core boxes for center 2 barrel cores (common – 2 cavities per box)
Core boxes for rear barrel cores (2 cavities per box)
Core box for front end housing core
Core box for rear end housing core.
“Dryers” specially made for each type of core
Core box for fuel pump core (6 cavities per box)
Core equipment for filter bowl core (6 cavities per box)
Osborne hot box machine (massive hydraulically operated machine)
Core equipment for left hand water jacket cores (6 cavities per box)
Core equipment for right hand water jacket (6 cavities per box)
Ejector system to remove cured cores from boxes.
Special water cooled sand magazine to fill bore box
Gas fired heating manifold with temperature controllers

All of this equipment (without machines – which only automotive foundries had) weighed conservatively 10,000 pounds. Because of the massive logistics and set-up required to run this equipment, cores for use by outside vendors (i.e. Winters or Lockport Castings) were produced on the Tonawanda machines and shipped along with the molding patterns &amp; fixtures to the vendors. I do specifically recall shipping out cores and molding patterns on our company truck, but never recall lending out core making equipment.

[bergy]

Please excuse the typos - just a draft!

[bergy]

2. Molding Department

http://www.yenko.net/ubbthreads/pics/usergals/2013/08/full-2170-6331-ton_mold_dept_1.jpg
http://www.yenko.net/ubbthreads/pics/usergals/2013/08/full-2170-6332-ton_mold_dept_2.jpg
http://www.yenko.net/ubbthreads/pics/usergals/2013/08/full-2170-6333-ton_mold_dept_3.jpg
http://www.yenko.net/ubbthreads/pics/usergals/2013/08/full-2170-6334-ton_mold_dept_4.jpg

[Xplantdad]

Bruce, this is really cool! Keep it up!

[m22mike]

Interesting read, thanks Bruce... <<GRAEMLIN_URL>>/biggthumpup.gif

Mike

[70 copo]

Bruce,

If you get that book ready let me know. A book like this covering this information is long overdue, also if you have questions on getting it published I can help there too. <<GRAEMLIN_URL>>/flag.gif

[bergy]

I tried to post this a few minutes ago and it doesn't look like it posted correctly - here it is again. It's a description of the Tonawanda Foundry Melting Department. Gets a little technical - PM me if you have questions. http://www.yenko.net/ubbthreads/pics/usergals/2013/09/full-2170-6656-tonawanda_melting_1.jpg
http://www.yenko.net/ubbthreads/pics/usergals/2013/09/full-2170-6657-tonawanda_melting_2.jpg
http://www.yenko.net/ubbthreads/pics/usergals/2013/09/full-2170-6658-tonawanda_melting_3.jpg

[YENKO DEUCE REGISTRY]

Fascinating! <<GRAEMLIN_URL>>/biggthumpup.gif

[Dicky]

What a GREAT read, thanks for all the interesting data Bruce.

I hope you can turn this info into a book.

Dicky <<GRAEMLIN_URL>>/flag.gif

[mockingbird812]

What a treasure of historical gems by someone who was there!! Thanks Bruce!

[Verne_Frantz]

Yes, very very interesting. Thank you so much. When did you start at Tonawanda?

Verne <<GRAEMLIN_URL>>/biggthumpup.gif

[bergy]

Summer of 1968

[Keith Seymore]

The Pontiac Michigan plant had its own foundry for casting Pontiac engines; here is some footage of the Pontiac process but it will give the reader some perspective perhaps on what Tonawanda looked like:

http://www.youtube.com/watch?v=y2413Nkhj_8

K