Best rust preventer for inside car doors

[marlinspike]

Pressing on with the rust repairs on my car doors, cutting out the rust and welding in new metal. What's the best stuff to protect the inside of the doors? There is bound to be some water ingress, and the car will not be used every day, so I need something quite heavy duty.

I have some Bilt Hamber Hydrate 80, which you can prime and top coat, but wondered what others use on here.

 

[Burdekin]

First thing is surface prep, remove all the rust, sand the surfaces (blasting is best) and then thoroughly clean. Paint with a good quality epoxy paint like Jotamastic 80 or 87 then I use Dinitrol classic cavity wax. Make sure you get 100% coverage of the epoxy and the cavity wax.

 

[chevy2]

I've used good old waxoyl on a few cars over the years and seems to hold the rust at bay but they have been weekend type classic cars,

Did the front and rear doors on an anglia van but once must have put a bit too much in as it was running out of the drain holes in the hot sun the first few times i used it

 

[marlinspike]

Thanks for the suggestions. I have some Waxoyl left, though I get the impression it isn't as well thought of as it used to be. I do like the Bilt Hamber stuff but it's not cheap and postage adds a lot.

 

[steveo3002]

dintrol is way way better stuff that waxoil

 

[chevy2]

dintrol is way way better stuff that waxoil

I wouldn't be surprised at all by that as a lot of products like this that were once good have had the formulation changed due to cost or legislation and are now just diluted versions.

 

[Dave3066]

Classics Monthly 3 year anti-rust test

Actually this might be a better link

Cavity waxes

Dave

 

[jordan1]

Wayoyl used to be very good, but then it was made by Finnigans IIRC.

 

[marlinspike]

I had forgotten about that issue of CCM, Dave. Dug it out, results were:

1st (best): Rustbuster Epoxy Mastic 121
2. Carprotex rx10
3. Rust Seal
4. Rust Bullet Six Shooter
5. Bilt Hamber Electrox
6. Eastwood Rust Encapsulator
7. Por 15

I am always a bit sceptical of mag tests as I sometimes think they are influenced by who is the biggest advertiser. Visually, to me anyway, there wasn't a huge amount of difference between most of the panels.

I will have a good read this week. The 121 certainly looks good value on a price per litre basis.

 

[marlinspike]

Cavity Wax results were:

1. Noxudol 700
2. Waxoyl
3. Mil Spec 3215 and BH Dynax S50

5. Korrosion Schutzfett
6. Carprotech RX7

 

[outofthefire]

My logic says the best thing is good drain holes and sealer in the bottom seam so any water is fed straight into them

 

[lshigham]

Personally I etch prime, PU seam sealer, normal primer, 2k top coat and a thorough coating of cavity wax to finish. I use this PU sealer all the time, much cheaper than tigerseal etc. http://www.ebay.co.uk/itm/4-X-HIGH-...booking_Glue_Tape_EH&var=&hash=item2a2ad95891

 

[gulf]

cant go wrong with waxoil in, around and behind every nook and crannie,used it for years on stuff i cared about.I heat it up on an old stove and spray it while its hot and watery,not thinning it down like ive seen other use.

 

[normspanners]

IMO-- Greece----------- and no I havnt spelt it wrong thats what I was going to do to stop my truck rusting !!

 

[Brad93]

Bilt Hamber Hydrate-80 is worth a look. Has kept the rust on my fiesta at bay

 

[marlinspike]

I have some Hydrate 80. I had planned to use that, then epoxy primer, then top coat. I was wondering if there was something I could put on top of that.

Thanks for the suggestions so far. Looked at my old tin of Waxoyl - it's Underbody coating, so I'm thinking it will be the stuff that never quite sets and stays a bit sticky. Probably not suitable for inside of the doors.

 

[andeep]

1. Cut any rust out and replace any metal as needed.
2. Get the metal completely clean through media blasting or other mechanical methods
3. Epoxy prime
4. 2K Top coat
5. Cavity wax

If theres any metal that you cannot prime after welding in (i.e. the back of patches), make sure you coat them with a weld through primer before welding them in.

 

[Daz2012]

I would have thought these cavity waxes would work best over bare metal,no ?
If you're applying primers first won't the rust inhibiting properties of these waxes only come into play once the rust has broken thru the paint in which case you're dealing with a problem rather than preventing it in the 1st place

 

[Burdekin]

The areas where painting is not always good and fails is in seams and knooks and crannies so you're right in what you say. The cavity waxes are good at protecting those areas where paint might not get into properly and there's those types of areas in doors, especially if you remove the old paint and try and get all new paint in to everywhere. The cavity waxes arethen a good barrier as they creep into the areas where the paint coating may not be that good.

 

[aaran]

I would have thought these cavity waxes would work best over bare metal,no ?
If you're applying primers first won't the rust inhibiting properties of these waxes only come into play once the rust has broken thru the paint in which case you're dealing with a problem rather than preventing it in the 1st place

most wont protect bare steel for a long period of time.

a perfect example :

typical body shop bodge (the sort of stuff that i endup fixing for people properly) just welded up a steel plate and folded it into a curve on the inside of a wheel arch and then they BURIED it in waxoyl, no primer, anything other than waxoyl, must have has 1-2 lt in each arch)

the top skin was pig rotten but that new steel under it was also flash rusting under the cavity wax.

cavity waxes as far as im concerned are a Preventative measure only, NOT a cure on existing rust. i hate getting cars in that are rusting and the owners have used a cavity wax in (that example on the car i spent about 10 hours scraping, and using a rag and brake cleaner to get all the wax out so i could butt weld and fix it!)

i use epoxy mastic 121 chassis paint to seal the backs of panels after i have wire wheeled and finished the welds on the rear. zinc primer for seams i am plug or spotting together) then fire cavity wax in there (heat it until it turns to the consistency of tea, you can pour it into a hand held trigger sprayer and if your quick it will come out and run everywhere into every nook and cranny before it cools and thickens up) not has an issue yet with rust coming back through on the inside using that method and most of the cars i started on are a good 3 years old and are used daily throughout the year