Oil Sump Corrosion

[spduffee]

About ready to break on through

Pitting on the inside

Man, one thing after another...I was cleaning the oil sump on my C-145 and noticed a rough spot on the bottom. After cleaning it I noticed it is a good sized pit (about the size of a half embedded b-b pellet) and the other side shows signs of breaking through eventually. Can this be repaired? Can I avoid scouting for a replacement? Thanks in advance for suggestions.

[marathonrunner]

There are some old links on this subject. There used to be a shop in Canada like maybe Kelowna that did epoxy repairs. I do not know of any approved repair stations and I do know you have to control the heat and heat the whole sump to a certain temp then weld it on the outside and then heat it again to normalize it. At least that is what I have been told. I also know that TCM did at least about 5 or 6 years ago have some in stock. I do not know what the price was/is.

I think they are quite expensive no matter what route you go. If you have a lot of time on your engine maybe a 0-360 or IO 360 is the way to go

[blueldr]

I'm pretty sure the oil sumps are made of magesium and at their age they are terminally contaminated when it comes to being welded. Cleaning them to achiece a serviceable bond with apoxy is also very difficult. I have heard of more failed repairs than successful ones. I think replacement is by far the best bet if you can find a serviceable one. I also think that there are two different types concerning the accessory case bolt pattern.
I also know of a case where the owner was able to drill a hole through the bottom of the sump where it was corroded through and installed a gasketed bolt and nut so stop a leak. I'm pretty sure this repair was not brought to the attention of the governmental agency that is dedicated to helping us, but it worked in this case.

[spduffee]

Thanks for the replies. Yes, they are made of Mg and very hard to find. I will ask local shops this week if they think they can repair it. If not, who knows? If anyone has a spare lying around please let me know. I probably won't go the IO-360 route, but it is a nice thought - and those are still free, even for aircraft owners....

[marathonrunner]

I'm pretty sure the oil sumps are made of magesium and at their age they are terminally contaminated when it comes to being welded. Cleaning them to achiece a serviceable bond with apoxy is also very difficult. I have heard of more failed repairs than successful ones. I think replacement is by far the best bet if you can find a serviceable one. I also think that there are two different types concerning the accessory case bolt pattern


I agree, they are magnesium and at this stage very difficult to attempt to successfully repair. I would at least call TCM and see if they have any. Looks like these 0-300's are sort of becoming orphaned engines for some parts.

[Bruce Fenstermacher]

If I were you I'd explore the epoxy repair option with Okanagan Aero Engine, Kelowna, BC, Canada 250-765-9718.. Once someone welds on it the epoxy repair option is gone.

And should you think the welding is a permanent repair you think incorrectly by reputation that repair has on these sumps no matter who does it it seems. Welding wold be my last resort.

[SteveF]

This topic had a fair amount of input 3-4 years ago. I can not search and find the topic though.
I had this problem and found the sump is made of magnesium. There are two model sumps, a five
bolt hole and a three bolt hole.

As a price point there had been one of each, used, on eBay a year or so ago and they were selling
for 400 dollars each.

The way the plane sits does not allow all the water to drain when the oil is changed and that is
the main cause of the corrosion.

Could not find new ones, sent to Canada to epoxy and part was sent back as not repairable by
them. They have very tight standards as to porosity but are very fair about returning and not
charging a large amount to look at the part.

Found there are very few welders who handle magnesium as marathonrunner points out it needs to
be heated and welded then slowly cooled. I think the total process is done in an oven. Anyway
there is a place in Wichita Kansas that is authorized to do this so I sent it to them and they did a
nice job welding it and documenting the work.

I have sold the great 170 and and am having fun as a Sport Pilot. I gave all the paperwork to the
new owner so I don't have the name of the shop handy but I think the welding cost was between
300 and 400 dollars but not positive. If you need to contact the shop then PM (private message) me
and I will get the information for you. It was online in my older post but again I can not find it with
the search function.

[bagarre]

Why were these made from magnesium instead of aluminum?

[spduffee]

I'll have to look into the epoxy fix right away. Thanks for the contact info. There are currently two for sale on eBay, both 3-bolts. One looks decent, the other has some light surface corrosion (looks like aluminum corrosion, white-ish deposits), the cheaper of the two.

[blueldr]

I have been trying for a couple of years to sell a firewall forward power package from a C-170B, with a core engine, for $2,500. The lack of interest makes me more and more think of complete disassembly and sale of the individual parts. Of course, I wouldn't know about things like sump corossion until disassembly, but I'm beginning to think it's worth the gamble.

[marathonrunner]

You can always get more for parts than the whole unit...hence Wentworth, Global...etc...maybe not in a divorce though, in that case hide the body

[SteveF]

DivCo is the company that welded my sump. They did a great job and their service and turn around time were good also.

[T. C. Downey]

These mag sumps can be welded with good results, I have a 5 bolt with a weld repair for sale exchange.
Tungsten Inert Gas welding was invented to weld Mag during WWII, temp control is important during cool down they will crack during this period.

[spduffee]

I have a 5 bolt with a weld repair for sale exchange.

Mine is a three-bolt.

I'm going to send my oil sump to DivCo. I just hope they can fix it; it's in a tough spot to weld and it appears extensive.

Bluldr - Pull the trigger and sell your engine for parts. I think you've stated in two threads you were thinking of parting the engine out. I also think you'll make more on the individual parts than on the whole. It will take longer to sell them off, of course, but....

[hilltop170]

Shawn-

I posted the following when I got my oil sump repaired back in 2006, good luck with your's.



I just got off the phone with Fred at Okanagan Aero Engines (O.A.E.) about their sump repair. It is an epoxy repair, not a fusion weld. According to O.A.E., they have been doing them for 5 or 6 years now and some have already gone to TBO and come back for overhaul again. The sump repairs have lasted and did not have to be redone. The only times the repairs have had problems is when it has looked like sombody, maybe the mechanic, has picked at the repair with some sort of tool to see what is in there. Even then they can be re-repaired. Otherwise they last, according to O.A.E.

They start by water/bead blasting the corroded/leak area to clean it up. No grinding tools or chemicals are used which could contaminate the repair area. The epoxy is applied and cured. Then a special paint is applied over the whole area where the repair was made and where future corrosion could occur. This paint is not affected by engine oil. The engines which have had the pan repair and have already come back at TBO still have the paint intact.

I asked if O.A.E. would clean and apply the paint to a good oil pan to inhibit corrosion. He said they do that but he has never seen one without some corrosion and no matter how little, their repair stops the corrosion and protects the metal all around the area.

The other pan I had was sent out for weld repair to a shop in Anchorage that does weld repairs on Magnesium pans. They have not been able to weld mine without having the repair area show small cracks under dye penetrant inspection. O.A.E. will not work on a pan that has been welded on because of the cracks that are there. I don't know of any other repair that might work, so it looks to me that O.A.E. is the only approved method left out there. We'll see how long their repair lasts. I'm betting it will.