Ive been making a modified sump to fit on my Fiat 2.0 Twincam, its been chopped fairly radically to fit in the confines of my Lada.
(Yes Lada )
Whats the advice to ensure oil leak free welds ?
Ive reduced some of the leaks with extra weld runs, but its still leaking.
Someone has suggested over brazing to fill the welds up.
Any suggestions ??
PS Lada / Rust & Oil Leak jokes have already been thought of ....
Amps up and wire feed down and look closely at what you are doing. I have a pair of +1.50 reading glasses for when I want to get in really close, a gold EW9 filter will help as it reflects the light back onto the workpiece.
Practice................loads of practice 
A big problem with welding sumps (I believe) is that as they are a deep-drawn pressing , they are made from steel with a high lead content (like EN1A)
, so so not weld very well .
I dont think I have ever welded a sump and had it totally leak free 
quote:
Originally posted by clairetoo
Practice................loads of practice
A big problem with welding sumps (I believe) is that as they are a deep-drawn pressing , they are made from steel with a high lead content (like EN1A) , so so not weld very well .
I dont think I have ever welded a sump and had it totally leak free
The original TC sump is like you suggest a pressing...
But most of it has been chopped away leaving the flange, and new metal put in.
Putting the volume to the front of the sump, so it clears the Lada diff.
Like this...
http://www.ladaniva.co.uk/baxter/cloggy/fiva4.html
I will have another go, on my days off.
quote:
Originally posted by clairetoo
Practice................loads of practice
A big problem with welding sumps (I believe) is that as they are a deep-drawn pressing , they are made from steel with a high lead content (like EN1A) , so so not weld very well .
I dont think I have ever welded a sump and had it totally leak free
Well a nice and clean surface helps alot. You want a nice even consistant weld. So minimize your stops and anything (like dirt) to intervere with your
welding.
If you have miniature spots still leaking, then try giving it another peck just next to the actual leak. It will often cover it. While if you try to
close it of with welding right on top of it then what caused the original hole will most likely create another.
That's a tip I got from a guy at work who has been a pro welder for years. And seen him do it with a T piece for the cooling system of his banger
racer. Worked a dream.
We do a lot of welding at work, but usually try to avoid having to weld things that need to hold (presurised) oil etc. Really labor intensive.
It really must be the material that causes problems as Claire says... I'd describe myself as an average MIG welder and had no probs fabricating an airtight and petroltight fuel tank.
When I did mine I had a few leaks but found it best to dress the weld back hard with the angry grinder in suspect areas. Wipe with cellulose thinners to clean and put a spot more weld on the holes. Just welding layer after layer without dressing back didn't work.
Mig suffers cold start, this means that the initial start of the weld is porus, when yiu strike the arc the work is cold so the globules of weld do
not stick.
The trick is to start the wrong way, go half an inch then back over where you started carrying on and do the whole thing in one continous weld to
avoid another start.
Alternative is to start the weld on a piece of scrap held against the work then work forward, as you start over the work quickly lift the scrap off,
again a continuous weld back to where you started.
As always, get it clean!