Underseal and rust protection-need some advice

[cebul]

Hi, try to search some information here but can not find anyghing (maybee because Im on the phone now), but anyway, my daily Mazda 3 is a great car, really happy witht that apart one thing- rust protection= no rust protection.

Just looked under a car and is really drama. Whole flor.has rusty spots, also all suspensions arms as well.

So plan is instead of get rid of the car-get rid of the whole rust.

Suspension will be removed to get more acces to floor areas.

I will see what Im going to do with all arms- shot balsting or wire brush/some gels to remove rust.

Underfloor will be cleaned by wirebrush.

But Im stuck with underseal stuff, so need your advice guys- what would you or what did you use to remove rust and protect you underfloor on yours cars??

What stuf and what make did you use??

Maybe you have some write-up or photos-that would be helpfull.

Me and missues really like the car especially it has LPG so we do not want te get rid of it, and if I do not do all job with rust, I belive in next year car will need to go for floor welding.

[RattyMcClelland]

Check out my profile thread on the type s. Near the beginning.

[nick_s]

I've always used Dinitrol to good effect

[Vtecmec]

There's a bit of info in my build thread, but basically:

Remove rust.
Paint with a zinc primer - Bilt Hamber's zinc primer is excellent.
Paint with a 2k epoxy mastic - I've used Bilt hamber's which is very good.
Seam seal.
Paint with a stone chip - 3M is very good.
Cavity wax the box sections.

Additinally you can use a semi liquid covering as well such as Bilt Hambers Dynax Underbody.

[cebul]

@Vtecmec, @RattyMcClelland, just check your threads, many thanks very helpfull

One more question, could anybody explain me a diferences between that:

and that:

Which one would be better to use ??

[Thebusofwoe]

I also have used Dinitrol on the rear of my track car, in build thread again chap. I have used other stuff before, but dinitrol is the best stuff i have used. Get it warm, spray on with gun

[Vtecmec]

.

One more question, could anybody explain me a diferences between that:

The stuff on the left is for spraying into the box sections with a lance where you cannot reach, it creeps into the seams and then semi sets to help stop corrosion from the inside out.

The stuff on the right is for applying to the underside of the car with a brush, similar to the stonechip that's (or should be already be) on the underside of the car. It also has some waxoyl mixed in to help prevent rust and creates a surface that never quite sets solid, the theory is that it will self heal when damaged by stones etc.

Personally I use dynax S50 firstly in the box section, as it is quite thin and creeps really well, then follow up with Waxoyl which is a little thicker and more robust.

For the underbody I'm not personally a fan of the semi liquid coatings and use 3M underbody rubberised stonechip

[cebul]

I do not have a compressor so will ise brush or spray or if it is avilable -that little pump

[wurlycorner]

Again, another one for Dinitrol.
http://www.dinitrol.co.uk/rust_preventi ... _oils.aspx

I haven't used Bilt Hamber stuff, so I'm not saying don't use that - and plenty do seem to recommend it, but... I have had many prior years experience of Waxoyl and honestly, it's just is no-where near as good as Dinitrol. It's not just me that says that either, that's also what the classic car mags find when they do product tests.
Really, buy Dinitrol and use that instead of Waxoyl!

Waxoyl cavity wax just doesn't run into the cavities anything like as well as the Dinitrol stuff. To get Waxoyl to run at all, you have to properly heat it up and then it still doesn't run very far at all. The Dinitrol cavity wax runs into all the seams like buggery

Waxoyl underseal doesn't adhere as well, doesn't coat very easily if sprayed on (it clumps) and takes absolutely bloody ages to dry. Dinitrol underseal adheres nicely, sprays on evenly and dries really quite quickly.

Dinitrol 3125 is the cavity wax;


Dinitrol 4941 is the underseal (in black);


You can buy it direct from the merchant either on their ebay shop, or direct from their website http://www.rejel.com/rejel-store/rust-proofing.aspx

I've ordered via both in the past.
Check on both, because dependant on the quantity you're ordering, once you've taken into account delivery it can sometimes be cheaper off their ebay shop and sometimes cheaper off their direct shop.

[cebul]

Thank you very much for your help and recomendagions, so it is look a like I know what Im gonna do over an Easter breakedown