1993 Mercruiser v6 4.3 oil pan repair

[dlogvine]

While installing rebuilt engine into the boat the engine was dropped from the stand and landed on the oil pan causing it to leak. I replaced the oil pan, however was interested in fixing the old one. First i managed to straighten the
dent around the plug. But there was a significant leak in this area, and the plug and it's thread were also damaged so i decided to weld a nut over the hole and use a new oil plug. When welding I discovered that the steel on the oil pan is too thin and if I used shorter welding time, the weld was was spotty and leaving plenty of crevices and holes, but if I raised the temperature higher, the weld was going smooth but it was in some places burning through the pan. After several hours of welding, grinding and rewriting again, there were still micro cracks left and i gave up. At least for the day. Now, im thinking about putting some kind of sealing glueing compound in this cracks, and my question is, what should I
use? Bondo, automotive epoxy or anything that could withstand the hot oil. Thx

 

[Scott Danforth]

you used a mig didnt you?

you do realize the pan from GM is just around $100. not even worth firing up the welder

and no, none of those band-aid fixes would ever last with bondo pealing off in about an hour.

the best you can do is pull the pan, cut out the bad, use a sand-bag and mallet along with the english wheel and planishing hammer and beat yourself another pan corner from 20 gauge. Then tig weld (not mig) the new corner in. then fire up the gas torch with a small head and braze over your tig welds on both sides......then paint 10 hours later you have repaired the pan

as i stated, the low cost of the pan is not worth the effort. buy a new one, paint it, go boating

 

[dlogvine]

Yes Scott, I used MIG welder. And i know how much a used oil pan costs, since I already bought and used the replacement in the rebuild engine. The reason why I tried to fix the old pan was out of curiosity and to see if it is possible. That is something I'm interested in and is my hobby, learning how to fix engine and boat related pieces. Will try to use tig welder next time, since I'm learning how to weld it will be a good exercise.

 

[dlogvine]

I was thinking about something like this:
http://alvinproducts.com/Product-Line/aT/View/ProductID/3/Lab-metal

 

[Bondo]

Yes Scott, I used MIG welder.

Ayuh,..... Yer choices for such a repair is ole school, Brazin',....
Or,... New tech, Tig weldin',....

I'm an ole life long Welder, 'n wouldn't even consider Mig, nor stick weldin' it,....

 

[Scott Danforth]

I used to buy the oil pan bump-outs and modify pans to get an extra 2-3 quarts in them on the hotrods I tinkered around with. especially when running oddball motors that had little aftermarket support. you can do it with a mig..... if you run 0.023 wire and take a month of sundays placing spot welds. you also need a copper backing bar so you fuse vs burning thru.

Tig is so much easier to weld paper-thin sheetmetal

 

[dlogvine]

Im just learning how to TIG weld, will be my first TIG welding project, will talk to my instructor about using it. MIG was something I am more familiar with, but appears that it is very difficult to keep it from burning through the thin pan walls. Thank you guys. I know now what is my next step - learning TIG welding.