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Leaking Sump aaaaaargghhhh! Any tips
novicebuilder - 8/6/13 at 05:50 PM

I have cut down and welded up my modified sump for my Haynes roadster and there were few leaks when filled with water. Most I have solved but there a few that I cannot stop. I expect the actual leak is some way from where the water appears. It is driving me mad. I had a nice set of delicate welds but with additional welds to stop leaks, it now looks very ugly..... and it is still leaking.

Any advice from those who have done this themselves? Are there any good tips?
All constructive help appreciated.
thanks

big_wasa - 8/6/13 at 06:02 PM

Tig welding is the way forward here. You can get a good weld pool around the pin hole and add minimal filler.

But a photo up. How bad is it ?

gremlin1234 - 8/6/13 at 07:06 PM

quote:
Originally posted by novicebuilder
few leaks when filled with water. ..
I expect the actual leak is some way from where the water appears...

you could try putting the sump in a bowl of water and seeing where it appears on the inside

jacko - 8/6/13 at 07:39 PM

I always gas weld sumps then mig them inside to find leaks i use thinners
This is on steel sumps And i always screw them to my flat bench to stop it warping
Jacko

loggyboy - 8/6/13 at 08:37 PM

If its hairline/ pinprick holes then paint or powdercoat it.

britishtrident - 8/6/13 at 09:05 PM

Gas Bronze welding (often incorrectly called Brazing which is actually a different process ) is my method of choice when modifying sumps.

However if you clean off any oil residue You should be able to seal the leak with suitable steel-epoxy repair compound (for example JB Weld) or a shellac based sealer.

mark chandler - 8/6/13 at 09:33 PM

Assuming you have mig welded it's caused by cold start, when you first strike an arc the wire drops on to cold metal resulting in pin holes.

You need to weld the sump in a continuous fashion, no stopping and starting do it in one go then where you finish go over the initial weld an inch or so then come back upon yourself and stop.

Also weave in a figure of 8 to keep the heat in the material.

Alternatively butt a piece of scrap metal against you work, start the weld bead on this then advance, again one continouos weld then finish where you started and cut off.

Regards Mark

[Edited on 9/6/13 by mark chandler]

Blackhole - 8/6/13 at 10:35 PM

Or preheat it with a blow torch?

neilp1 - 9/6/13 at 11:53 AM

Grind back the stop/starts an inch or so before re-starting where you have ground back.

Litemoth - 9/6/13 at 12:38 PM

What he said ^^

Grind it back and weld it again. Tarting it up with sealant will just save up trouble and leave oil patches.