Oil Sump Corrosion

How to keep the Cessna 170 flying and airworthy.

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blueldr
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Re: Oil Sump Corrosion

Post by blueldr »

Gary,
Your mention of GYPTAL or GLYPTAL reminded me of a time in 1962 over on Guam when the flight engineer/mechanic on a FAA or CAA Lockheed Connie came out to Anderson AFB looking for some "Glyptal" to repair a cracked Master Control on one of the engines on their Connie. It was an airplane used for flight testing facilities like VORs and ILSs and was laid up at Agana with a problem precluding their flying it home to wherever.
I had never heard of the stuff until then but found out that it was similar to a shellac and apparently was petroleum proof. Haven't heard of it since, either. Unfortunately, we were unable to help him. To my knowledge, it was never used by the Army Air Forces or Air Force.
BL
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T. C. Downey
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Re: Oil Sump Corrosion

Post by T. C. Downey »

One of the most common protection methods used on these sumps is the aviation grade prematex full harding #1. I have seen several sumps with this in the forward area, the permatex is poured in, and baked until it is fully hardened. oil and gas has no effect on it.
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GAHorn
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Re: Oil Sump Corrosion

Post by GAHorn »

I forgot about Glyptal.

When I worked at Precision Airmotive rebuilding engines and components we painted the old Scintilla magneto coils with the stuff. We also painted starter and generator armatures we had rewound with it, then baked them in ovens.
Although I don't recall the details of it being done, (was it also baked after painting like the armatures?), I believe it was used to seal leaky nose cases and oil tanks for the cropdusters who sent their engines to us.

Here's a product info sheet on the stuff:
Glyptal Sealing Paint.pdf
(114.08 KiB) Downloaded 927 times
'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. ;)
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T. C. Downey
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Re: Oil Sump Corrosion

Post by T. C. Downey »

Picture of a OAE repaired sump.
DSCN2899.JPG
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T. C. Downey
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Re: Oil Sump Corrosion

Post by T. C. Downey »

Pictures of a welded sump
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DSCN2864.jpg
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T. C. Downey
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Re: Oil Sump Corrosion

Post by T. C. Downey »

Pictures of the OAE sump prior to their repair
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GAHorn
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Re: Oil Sump Corrosion

Post by GAHorn »

Tom, ... THANK YOU! There's a prime example of how a picture is worth a thousand words. (Thank You Again, ....for spending the time, effort, and resources to re-join and post them. Welcome home.) :D

I believe that when I rebuild my engine, regardless of it's condition, I'll send the sump to OAE for their treatment.
'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. ;)
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T. C. Downey
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Re: Oil Sump Corrosion

Post by T. C. Downey »

Aryana wrote:Where did you have that sump welded repaired at? My sump that was welded by Divco looked nothing like the one you show above. The OAE coated sump looks nice!
Yes it looks ugly as road kill, but it dye checks fine. and it came out of an engine in for overhaul, no idea who or when it was done.
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T. C. Downey
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Re: Oil Sump Corrosion

Post by T. C. Downey »

gahorn wrote:Tom, ... THANK YOU! There's a prime example of how a picture is worth a thousand words. (Thank You Again, ....for spending the time, effort, and resources to re-join and post them. Welcome home.) :D

I believe that when I rebuild my engine, regardless of it's condition, I'll send the sump to OAE for their treatment.
I believe my last customer paid 450.00 for that treatment.

Your 170 should never have this problem, it is the early 172 that sets a little nose low that will not drain the forward sump that has these problems.
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lowNslow
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Re: Oil Sump Corrosion

Post by lowNslow »

T. C. Downey wrote: Your 170 should never have this problem, it is the early 172 that sets a little nose low that will not drain the forward sump that has these problems.
On the 170 it occurs just forward of the carb.
Karl
'53 170B N3158B SN:25400
ASW-20BL
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T. C. Downey
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Re: Oil Sump Corrosion

Post by T. C. Downey »

P1010026.JPG
lowNslow wrote:
T. C. Downey wrote: Your 170 should never have this problem, it is the early 172 that sets a little nose low that will not drain the forward sump that has these problems.
On the 170 it occurs just forward of the carb.
That is the forward sump.

This is what it looks like when we first see it.
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spduffee
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Re: Oil Sump Corrosion

Post by spduffee »

Well, I'm glad my posting brought about so much good information and comments. It is done, and I am sure the solution I chose may not thrill others, may enforce the view of its proponents, but it is done. I had the pan welded at a specialty shop - not DivCo - (I'm already putting of one their kids through college with the block repair) and below are the results. Fire away....
DSC05845.JPG
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DSC05847.JPG
Once they got into it, it was worse than I suspected. The first pick at the corrosion brought daylight through the body. From then on it was a struggle. I guess I'm happy with it, I mean, it's like the first welded Magnesium oil sump I have ever seen, so....
N5448C -1950 170-A
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blueldr
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Re: Oil Sump Corrosion

Post by blueldr »

It looks like a gas or TIG weld. The gaseous welding shield must keep the magnesium from igniting unless it is done inside some sort of a compartment filled with an inert gas. Magnesium burns like hell, but I suppose it must have to have an oxygen source for combustion.
BL
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Bruce Fenstermacher
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Re: Oil Sump Corrosion

Post by Bruce Fenstermacher »

Nothing to fire away at. You did what you had to do. It is a shame there isn't a coating that could easily be put in over the weld to seal what seems to be the inevitable crack you might get around the outside of the weld. Hoping of course you don't. I'd rather see these repairs be more successful cause they are not making any more sumps and they're all rotting away in some fashion.
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GAHorn
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Re: Oil Sump Corrosion

Post by GAHorn »

Latest information on sump coatings: They don't use red Glyptal because the Green stuff SLOWS down the corrosion activity so much more.
'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. ;)
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