Doing it properly vs doing it at all

Post by **Pyoor_Kate** » Tue May 13, 2008 12:35 pm

Okay; so this possibly could go in the OT section, but I reckon it's valid for mog owners too (although in this case it relates to a Variomatic DAF 44).

Let's say that you've only got a limited period of ownership of a car (in this case, roughly a year). It's rusty in the conventional MOT failure places, has been patched once before in a couple of the spots, but otherwise is fairly solid.

If, say, you had the choice between patching it up MOTstylee, or giving it away and sourcing another more solid one (potentially more than the cost of patching it up), do you reckon patching (as a temporary return it to the road) measure is worth it?

And do those seam welded patches return any of the structural strength of the car (as the mobile welder claimed). I've always thought patches cause the metal underneath to rust out more quickly (although it's not sound metal anyway, so I'm not too worried about that) and don't actually give you back a significant amount of structural strength...

I know they're not a long term solution, but in the short-term, are they any use?

And as a side point - a patched car - better or worse than a non-MOT-unpatched one?

Post by **superchargedfool** » Tue May 13, 2008 12:42 pm

my opinion is that a patched car on the road has to be better than a laid up car.

If patches are done neatly and sensibly then they can always be removed in the future when restoring properly, cos what the patches are attached to usually will be going in the skip anyway when restoring properly.

If patching is all that can be afforded then it has to be better than nothing doesn't it?

Patching doesn't necessarily mean bodging anyway. If the rotten bit is cut out and the patch replaces the rotten bit only overlapping by say 5mm and is welded properly then in my eyes that is a propper repair that will last a long time.

BUT badly welded nasty patches applied by a bodger can cause harm in the long term.

Personally, patch away and get that mot.

Post by **chickenjohn** » Tue May 13, 2008 1:57 pm

If all the rust is cut out, then its a repair and not a bodge. Especially if zinc weld thru primer is used under the small overlap and the repair is seam sealed and painted rather than just undersealed. Or better still cut the rust out and butt weld in patches and paint both sides. Then its a proper repair.

Post by **Stig** » Tue May 13, 2008 4:14 pm

I'm so glad you said that as that's the sort of repairs I do, though not always butt welded.

I did get a cheap MOT patch done a couple of years ago when I didn't have time to do it myself and it lasted another MOT before I had to cut out and do it 'properly' this year. The patch was seam welded (MOT rules) so yes, that's strong enough but if the rust isn't cut out and the metal protected you just end up with rusting of the patch as well.

my opinion is that a patched car on the road has to be better than a laid up car.

Inclined to agree, aside from road salt etc. cars deteriorate more quickly if they're not used.

Post by **rayofleamington** » Tue May 13, 2008 4:48 pm

my opinion is that a patched car on the road has to be better than a laid up car.

Same opinion here! i'm not sure I've ever had a Minor without patches!
If they are done well as per previous posts then they should last many years. If the area being patched is not going to last another year then it's not worth patching, (unless that's the only way tyo get back on the road)

Post by **MGFmad** » Tue May 13, 2008 10:00 pm

I remember getting told about welding many years ago by an old neighbour that had worked in a steel fabricators, they tested welds and found that if done properly, the weld was stronger than the metal - don't know if its true though.

As said above, patches are fine if done properly, most MOT style repairs are just a patch slapped over the rust and seam welded, the rust is still there, eating away at the metal.

I have been replacing the drivers sill of my Traveller this week, it looks like its had a repair section fitted in the past, then a patch welded over this - the whole thing looks a mes but it was stong - I had a lot of cutting to get it off.

Post by **les** » Tue May 13, 2008 10:28 pm

As above, a well made patch welded properly is sound if surrounded by good metal, you could say a completely replaced panel, welded in place, is just a big patch!

Post by **8009STEVE** » Tue May 13, 2008 10:46 pm

Possidly something to do with the heat generated as this can make the metal hardened.

Post by **chickenjohn** » Wed May 14, 2008 7:00 am

"I have been replacing the drivers sill of my Traveller this week, it looks like its had a repair section fitted in the past, then a patch welded over this - the whole thing looks a mes but it was stong - I had a lot of cutting to get it off."

Yes, good point, this is a bug bear of mine. On my Traveller when I did the LHS sills a few years ago, I came across FOUR layers of patches welded one over the other. Its a pain as you often have to cut into good metal as its hard work cutting through the old welds and multiple layers of rust sandwich.

I cut it all out and replaced with a nice new LMC Hadrian panel (1.2mm thick).

Post by **MGFmad** » Wed May 14, 2008 9:52 pm

chickenjohn wrote:"I have been replacing the drivers sill of my Traveller this week, it looks like its had a repair section fitted in the past, then a patch welded over this - the whole thing looks a mes but it was stong - I had a lot of cutting to get it off."

Yes, good point, this is a bug bear of mine. On my Traveller when I did the LHS sills a few years ago, I came across FOUR layers of patches welded one over the other. Its a pain as you often have to cut into good metal as its hard work cutting through the old welds and multiple layers of rust sandwich.

I cut it all out and replaced with a nice new LMC Hadrian panel (1.2mm thick).

Yes, New Hadrian panels for me as well, just finished the drivers sill tonight

- now its over to the passenger side for the same again.