Advice please - treating rust underneath car

[Austin09]

Hi Guys,

I have some rust on the underside of my car, and with Winter fast approaching I wanted to get it sorted. I've found a place where I can rent a ramp and get underneath it to get rid of all the flakey rust etc and clean it up.

What is the best solution? Any suggestions on some anti-rust stuff I can apply and then paint over?
Also, which paint should I use after the anti-rust stuff has been applied?

Cost wise I'm not too bothered, I'd rather get the job done properly.

Thanks

 

[s130]

Appart from removing as much loose rust as you can and a good clean/polish with a drill and wire brush ......

I have no problem at all in recommending Bonda Rust Primer. (google as required)

I've quite a few of these types of products over the years and this one has worked every time for me. It is not the cheapest of stuff but worth every pound.

 

[Ziggy122]

Wire Brush attachement in a drill

scrub the Rust away - Seal the Exposed paint work up - And then Seal the paintwork in with something like Waxoyl - there is a similar product that does same

Either spray it on - or paint it on again

Dont just do the rusty bits - give the whole underside a clean and seal Including the Sills

Ziggy

 

[Andy Monty]

I'd contact Bilt hamber and see what they suggest

http://www.bilthamber.com/

(they have customer service which i recently found is second to none)

 

[fingers99]

Epoxy mastic generally comes out best in tests. Available in several colours.

 

[bluejohn125]

Depending on the age and model of the car, you will probably find that the flexible underseal is failing and letting water gather and rot underneath. Expect to have a very good scrape around and clean-up, then apply some liquid rustkiller to transform the rust, then paint with Zinc182 or hammerite, then underseal, possibly mixed with Waxoyl....

Front mudflaps stop a lot of water and salt attacking brake pipes and the underside in general.

 

[jimboy]

Aye the dreaded rust. Lots of stuff on the market right enough, but with a lot of these, preparation is the key. I'm afraid once it has a hold, the paints anyway, just stave off for another day. The stuff with additives do work to point. A well known remedy back in the day works very well indeed.

Spent engine oil & melted grease mixed & sprayed on. This will sink into the metal & remain there dispelling moisture, as metal will retain this, even so on older cars. Even the small bits of rust that you can clean off, this will work on.

 

[J.R Racing]

I think everyone has their tried and true method for this.

I gained this experience from a man who restores classic cars for a hobby / living.


Thorough Prep, not just a quick clean. But thoroughly wire brushed and then sanded with an abrasive sand paper (60 grit works well).

Anti Rust Primer, Hammerite Anti-Rust Primer or Eastwoods Rust Encapsulating Primer. (FYI most dedicated Zinc Primers these days have reduced Zinc content so are no where near as good as they used to be)

Top Coat - Eastwoods Extreme Chassis Black - this is a rubberised style coating which is a different approach to those such as Waxoyl but works in our climate far more effectively. It is far more likely to bounce debris off than chip through like Waxoyl.

For those who haven't heard of Eastwood a little research will do wonders, an American based product but available over here from people like Frost Autos.

 

[jimboy]

As said, everyone will have a tried method. Certainly all work to a degree. When you start using paint this traps moisture. Cleaning an underside of a car is very difficult to eradicate all signs of rust. The spent oil & grease method will work on the bits that can't be cleaned properly, although messy the oil mixture can be sprayed over other parts without fear of damage, easily cleaned off if need be.

At the end of the day, how long do you keep a car when things get like this?

 

[fingers99]

At the end of the day, how long do you keep a car when things get like this?

If you do it properly, with the right materials, there's no reason the chassis should need attention for 15 years or so.