underside rusting

[birch]

my 1993 8v got a couple of comments on the mot advisory about rust starting underneath the car. 'corrosion around rubber grommets in the floor' ive tried a couple of rust stopping products in the past with little success, can anyone tell me the best method and product to try and stop or at least slow down the corrosion. thanks.

[Seanl]

Cut it out, and weld in new. You will only slow the spreading down by treating it, and I wont make any difference to the areas that are already affected. Shouldnt cost massive amounts and you will just keep spending money on kurust or the like, paint, underseal etc etc anyway.

[Wayne]

If it is only surface rust, wire brush back and treat with underseal.

[Len]

It wont be surface rust for an MOT advisory!

Those grommet things are an absolute pain!

As Seanl says get it cut out and welded is best solution and a good underseal.

[Wayne]

It wont be surface rust for an MOT advisory!

If it was major rust it would have failed 

It says rust starting underneath the car so if caught in time might not need plating.

[AudiA8Quattro]

Stop flirting you two 

[Gti_Jamo]

Will need to cut it out to do it right. Rust is like a cancer and will spread if not dealt with. Those floor gromets are easy to sort out.

[Len]

It wont be surface rust for an MOT advisory!

If it was major rust it would have failed 

It says rust starting underneath the car so if caught in time might not need plating.

Try and read what I said numpty!

[Wayne]

It wont be surface rust for an MOT advisory!

If it was major rust it would have failed 

It says rust starting underneath the car so if caught in time might not need plating.

Try and read what I said numpty!

I did  , and as I said if it was too bad it would have failed the mot so if it is caught in time what is the point of cutting it out, when cleaning it back, treating it and undersealing it would do the job.

My god I never missed you once when you went on holiday 

[Gti_Jamo]

I'm sure corrosion will only fail if its within 12 inches of a structural area like suspension mountings, seatbelt mounting etc. Or if its exposed with jagged edges. Those grommets could be a rusty gaping hole and still pass if outside the prescribed areas.