Team-BHP - Underbody Rust - Is it permanently fixable?
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I was recently told that my Indica has rust on the underbody - where the engine is mounted. I saw the rust when the car was jacked up - there are holes in the metal, so I assume it will get bad. The service tech said that it can be fixed for 20K.

My question is, apart from the amount, can this be fixed permanently? I've heard most people sell off their cars when rust shows up. Though my car is a little over 6 years old, I would like to keep it for a little longer, but if this rust is unfixable, I don't want to invest too much in it.

What to do ?

20K seems too much for this job. I would suggest to get a quote from FNG and you might get it done for 2K and you will be able to keep this car for 2 - 3 more years without any sign of rusting. Nothing is permanent, once these metal starts getting rusted no matter how good is the job done it will start rusting again. Do get underbody rubber paint done.

If the corrosion and holes are on one face of a box section, rather than just a plate of steel which you can access from the other side, make sure the repaired box section is injected (internally) with a corrosion protection wax to prevent the exposed steel from continuing to corroding, out of sight. Have the rest of the underbody checked for corrosion also. It would make sense to have the other vulnerable areas treated with a preventative - sills and other exposed box sections are vulnerable. Ask your garage for advice if you trust them, they will know what suffers in your locality. A garage specialising in old cars will be the most knowledgeable for this problem.

Living in a mild, damp climate with winter roads often covered in salt to melt snow and ice, corrosion can be a big issue especially when cars aren't galvanised. I nip any corrosion in the bud, before it has chance to eat its way through my cars!

edit - in reply to Hashim, a repair properly done will last as long as the rest of the car. The critical thing is to cut out the corroded steel, not just patch over it, or the rust spreads like cancer. But on modern cars which are to end up as scrap before they are 20 years old, few workshops bother to do a proper job - the customer may look for a cheaper quote on a car which is on a one-stop trip to the scrapyard (as most are, from the moment they leave the showroom). What is important is that the job returns the car to it soriginal strength.

Also, if the rust is in the chassis rails either side of the engine, this is a critical area for strength. In a collision, a poorly-repaired job could cost you your life.

Quote:

Originally Posted by greenhorn (Post 3165594)
can this be fixed permanently?

No.


Quote:

Originally Posted by greenhorn (Post 3165594)
What to do ?

Sell the car. Using an Indica for more than 6 years is pushing your luck a bit too far.

Quote:

Originally Posted by VeyronSuperSprt (Post 3165873)
No.

Sell the car. Using an Indica for more than 6 years is pushing your luck a bit too far.

Im sorry but your answer is not very helpful and plainly misleading and I would assume contrary to the rules of the forum.

As in the previous post which I can only assume you had not read, as explained rust can be very easily repaired and if done professionally and carefully it can sometimes be better than the original car.

I have a car that is from 1974 that has been restored and then coated with waxoyl and PU sealer and it has as much rust today as it was when it was new, ie none so please do not mislead people into throwing away perfectly usable cars.

Hi,

can anybody suggest me what to do for these kind of rust? do we need to replace the the entire unit or a patch-up welding work should solve the issue?

Quote:

Originally Posted by VeyronSuperSprt (Post 3165873)
Quote:

Originally Posted by greenhorn
can this be fixed permanently?
No.
Sell the car. Using an Indica for more than 6 years is pushing your luck a bit too far.

Technically this is correct, but more than a little misleading, in the sense that nothing lasts forever. But, if a repair is carried out correctly, removing all old corroded metal and letting in new and maintaining the same structure and strength then it will by definition last as long as or longer than the rest of the car if it is properly protected.

Quote:

Originally Posted by technic (Post 3195422)
Hi,

can anybody suggest me what to do for these kind of rust? do we need to replace the the entire unit or a patch-up welding work should solve the issue?

It looks like a suspension member is bolted through in the vicintity, or other mount. In which case, remove the mounting, cut away all corroded metal, fabricate a new section to replace the old (it looks as if there may be a box section above part of the pictured area, so this will have to be rebuilt also where it is affected by any rust) and weld in. Protect with etch primer, stonechip and underbody schutz, in that order, allowing time for each layer to dry. Drill holes for the mount and bolt back.

Be aware there may be other strengthening steel sections around a mount, make sure the new metal is as similar as the original as possible - or if a repair section is available, use that. In a situation where a floor pan is rusty in more than one place, it makes sense to buy a ready-made floor section if possible, there may appear to be more cutting out and then welding in, but once underway it is surprising how little time fitting new complete sections of floor can take compared with cutting away and remaking more than one area of corroded metal.

Remember to internally treat any box sections, even if they are on the inside of the vehicle. And to paint the interior bits as well. Check for any leaks and seal as necessary.

The temptation is to take a short cut with rust, which in this case would be dangerous if the mounting is for suspension or anything else which is load-bearing. The short cut is simply to plate over the damaged area, trapping the rust under a new layer of metal, to which it would quickly spread. This is the way to drastically reduce the life of a vehicle body or chassis and sadly is seen all too often.

Hope this is of some help.

Quote:

Originally Posted by FlatOut (Post 3195555)

if a repair is carried out correctly,

Part of the reason why the answer to the OP would be a No. Add to this the budget constraint mentioned and the fact that for such repairs to be carried out properly, the owner would have to know at least as much if not more than the tinkerer considering the shoddy quality of workmanship in most workshops, and you have the practical answer to the question in the OP.

Quote:

Originally Posted by VeyronSuperSprt (Post 3195686)
Part of the reason why the answer to the OP would be a No. Add to this the budget constraint mentioned and the fact that for such repairs to be carried out properly, the owner would have to know at least as much if not more than the tinkerer considering the shoddy quality of workmanship in most workshops, and you have the practical answer to the question in the OP.

So would you trust the average workshop to do any repair, then? Or just scrap a car the moment it needs work? As for the owner's knowledge to check on the quality of repair, isn't that what this forum is here for, in part?

Quote:

Originally Posted by technic (Post 3195422)
Hi,

can anybody suggest me what to do for these kind of rust? do we need to replace the the entire unit or a patch-up welding work should solve the issue?

That panel is a load bearing surface on the car and definately needs replacement. Ask your service guy to use 3M Underseal for a long time fix.:thumbs up

Quote:

Originally Posted by FlatOut (Post 3195702)
So would you trust the average workshop

Standard repairs and maintenance, maybe. But of this sort, not unless I know their skills personally or through a reference. And even then I would have to be present there all the time to ensure this is done right.


Quote:

Originally Posted by FlatOut (Post 3195702)
Or just scrap a car the moment it needs work?

I have a 13 year old car (bought new by me in 2000) that does not have rust even in the water drain holes in the doors. Prevention is better, always.

Quote:

Originally Posted by FlatOut (Post 3195702)
As for the owner's knowledge to check on the quality of repair, isn't that what this forum is here for, in part?

In part yes, but the repair indicated in the OP needs hands on knowledge too.

Quote:

Originally Posted by Hashim (Post 3165793)
Do get underbody rubber paint done.

I have asked this before - but what kind of shops do underbody rubber paint job? The only underbody coats I have seen are the expensive ones like 3M etc.

Quote:

Originally Posted by carboy (Post 3195733)
I have asked this before - but what kind of shops do underbody rubber paint job? The only underbody coats I have seen are the expensive ones like 3M etc.

You can get this done at any local garage. What they do is take the car for the wash to nearby wash centre and wash the underbody. Then they apply the rubber paint using either paint brush or cloth. I got this done on my M1000 long time back. I bought that rubber paint from ordinary paint shop. I have mentioned the name of this brand somewhere in this forum in other thread (again long time back) and don't remember it now but this paint did work and also reduced road noise quite a lot. Regarding cost, at that time it was Rupees 175/litre and 2 litre was enough for a thick coat.

Quote:

Originally Posted by VeyronSuperSprt (Post 3195719)
Standard repairs and maintenance, maybe. But of this sort, not unless I know their skills personally or through a reference. And even then I would have to be present there all the time to ensure this is done right.

I have a 13 year old car (bought new by me in 2000) that does not have rust even in the water drain holes in the doors. Prevention is better, always.

In part yes, but the repair indicated in the OP needs hands on knowledge too.


I think we actually agree on everything here - certainly more people need to understand the prevention better than cure approach, in many aspects of life!

Quote:

Originally Posted by Hashim (Post 3195763)
You can get this done at any local garage. What they do is take the car for the wash to nearby wash centre and wash the underbody. Then they apply the rubber paint using either paint brush or cloth. I got this done on my M1000 long time back. I bought that rubber paint from ordinary paint shop. I have mentioned the name of this brand somewhere in this forum in other thread (again long time back) and don't remember it now but this paint did work and also reduced road noise quite a lot. Regarding cost, at that time it was Rupees 175/litre and 2 litre was enough for a thick coat.

Found your post - http://www.team-bhp.com/forum/techni...ml#post1057096

Quote:

I have used Jackson (JK is the company name) in my esteem and found it good, no chipping or flakes etc and really feels like a reall rubber after drying. It cost Rs.75 per litre.


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