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Consensus on Rust Proofing?

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dave9118
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Joined: Mon Feb 17, 2014 1:11 pm
Location: Devon UK

Consensus on Rust Proofing?

Post by dave9118 » Tue Jan 08, 2019 12:44 pm

Hi all, I've taken the plunge and bought brand new wings for my '81 635 rebuild, as the ones on the car you can put your fist through. Now, being as these were like a second mortgage as you're all aware, I was wondering what the group opinion is on rustproofing the undersides? Obviously I want to protect my investment, and not have to do repairs in two years time, so considered etch primer and underbody seal (hammerite).

I just wondered if there was a tried and tested 'go to' method I'd be better off doing?

Thanks in advance!
"The explanation you are about to give, needs to be.... PHENOMENALLY good"!

Edmond Blackadder

Pod
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Re: Consensus on Rust Proofing?

Post by Pod » Tue Jan 08, 2019 3:27 pm

I always use zinc spray which you can get at Screwfix. You could lay some other rustproofing over this - perhaps some stonechip/body schutz. Its much cheaper and easier to put on a decent thickness if you use a gun rather than aerosol cans.

olympia57
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Re: Consensus on Rust Proofing?

Post by olympia57 » Tue Jan 08, 2019 4:59 pm

The wings on my '81 turned out to be new when I bought the car .
Whilst I had them off to do repairs to the inner wings during the restoration I removed all the traces of the poorly applied underseal from them . I used an angle grinder with brush attachment for this but found that the heat generated burned the paint on the outside of the wings so be aware of that .
Once happy with the internal finish I applied several brushed coats of Zinc 182 primer . On top of this I applied a couple of coats of metal protection paint purchased from Aldi stores which is in effect Smoothrite paint , I've used this on all my cars and it really is a quality paint . Once dry three coats of 3M stonechip applied with a schutz gun and compressor .
Once the wings were refitted two or three applications of Waxoyl then followed getting right into all the dark corners.
Lastly I fitted a pair of Lokari liners which seal off the inner wings preventing chipping and any build up of salt and road dirt .
I cannot stress how valuable these Lokari liners are on the E24 and I believe every owner should fit them . It easily is the best money you will spend on these cars if you live in a cold wet and salty location.
If you look at my project write up you will see all the ledges , nooks and crannies that will allow muck to settle and slowly rust those expensive wings away again.
Don
1981 635 series 1

dave9118
Posts: 62
Joined: Mon Feb 17, 2014 1:11 pm
Location: Devon UK

Re: Consensus on Rust Proofing?

Post by dave9118 » Tue Jan 08, 2019 5:38 pm

Thanks, I'll definitely look into those liners, I don't want to have to replace the wings again!

Also good to see that some of what you're all using isn't overly expensive commercial stuff. Interesting to see as well that you're using zinc primer, and paint, AND stonechip followed by waxoil. You really don't want those wings to rust do you!

I'll check out you thread, thanks for the info everyone.
"The explanation you are about to give, needs to be.... PHENOMENALLY good"!

Edmond Blackadder

dave9118
Posts: 62
Joined: Mon Feb 17, 2014 1:11 pm
Location: Devon UK

Re: Consensus on Rust Proofing?

Post by dave9118 » Tue Jan 08, 2019 6:05 pm

Also, I've had my running gear powder coated. What can I use to keep the moisture off of it without caking it in schutz?
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"The explanation you are about to give, needs to be.... PHENOMENALLY good"!

Edmond Blackadder

olympia57
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Re: Consensus on Rust Proofing?

Post by olympia57 » Tue Jan 08, 2019 7:10 pm

Powder coating is very tough finish if applied properly .
I was looking at my old car recently that I had suspension and engine components powder coated in 1991 the surface finish was still intact and although less glossy the coating was still protecting the components underneath .
I didn't get any powder coating done on the E24 as there was no company locally offering the service .
I wouldn't worry about applying any additional top finish to the coated components .
Just make sure you don't chip it when assembling as once water gets under the coat it will lift and then flake .
1981 635 series 1

dave9118
Posts: 62
Joined: Mon Feb 17, 2014 1:11 pm
Location: Devon UK

Re: Consensus on Rust Proofing?

Post by dave9118 » Tue Jan 08, 2019 7:51 pm

olympia57 wrote:
Tue Jan 08, 2019 7:10 pm
Powder coating is very tough finish if applied properly .
I was looking at my old car recently that I had suspension and engine components powder coated in 1991 the surface finish was still intact and although less glossy the coating was still protecting the components underneath .
I didn't get any powder coating done on the E24 as there was no company locally offering the service .
I wouldn't worry about applying any additional top finish to the coated components .
Just make sure you don't chip it when assembling as once water gets under the coat it will lift and then flake .

Thanks, I was wondering about that. I might just use silicone spray and regularly clean it.

My thing is really classic Jap bikes, so this whole car thing is kind of new magic to me. I have two 635's because I like 635's, and I'm learning as I go. Your advice is appreciated! O:)
"The explanation you are about to give, needs to be.... PHENOMENALLY good"!

Edmond Blackadder

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nick88highline
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Re: Consensus on Rust Proofing?

Post by nick88highline » Wed Jan 09, 2019 9:13 am

I've been using Rustbuster Epoxy Mastic 121 recently, which is a two part paint that is incredibly durable. Also try looking at POR15 and "Miracle Paint". For cavities use something like Noxudol 700 and Noxudol 1600UM as an underbody coat.
If I was fitting new wings I'd be tempted to have them e-coated first...but maybe that's just me and my stupid ideas :P
Nick

PS Note that all but the Rustbuster products are hard to come by in the UK, but are available if you hunt around.
BMW 635CSiA (1988)
BMW i3 (2016)
Jeep Grand Cherokee V8 (2000)
Morris Minor 1000 (1968)

NigelC
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Re: Consensus on Rust Proofing?

Post by NigelC » Wed Jan 09, 2019 12:54 pm

I always treat rustproofing in the following way:
after removing as much rust as possible using a coarse wire cup-brush in the
angle grinder, followed by the hard sponge-like disc which actually removes the
hard brown glazed rust, I treat the bare metal with Jenolite rust remover agitated
with a brush. It is excellent on new steel as well as it etches the surface and coats
it with phosphate.
I use Bondaprimer which is a zinc-rich resin primer which is non-porous to stop moisture
getting through to the metal.( most primers are actually porous) I apply 3 coats using
a smooth brush for greater thickness than using aerosols. The primer bonds well to
existing paint and sealers.
I follow this with Hammerite Black (2 coats) by brush to really build up the protection
followed by 1 coat of Hammerite Smooth Satin Black to give the right sort of finish.
I do not just use the Smooth as it does not have the thickness of coating.
I then apply 3M body Schultz Black once the wings etc are refitted.I find that this
system works well for the underside - do not use on topside!
I give my powder-coated suspension an occasional wipe with a rag soaked in 3 in 1 oil.

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Da_Hose
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Re: Consensus on Rust Proofing?

Post by Da_Hose » Wed Jan 09, 2019 8:19 pm

I went kind of simple on my M6, but it's effective. I first hit things with a pressure washer, then used a wire wheel to remove big/loose stuff. Bare metal was sprayed with a zincating solution, or pickled with phosphoric acid. Both seemed to work fine. I gave a final touch with green scrubby pad, and alcohol wipe down. I then used a good quality primer (I like the recommendation to use an epoxy primer nowadays), and finished with a good quality black spray paint. I don't use stone-chip everywhere either. I will take a peek every year or so, to spot-fix. The rear-end and subframe parts I renovated still look great years later. I plan to follow the same approach with my 2002 renovation.

Jose
1987 M6 - My dream car

dave9118
Posts: 62
Joined: Mon Feb 17, 2014 1:11 pm
Location: Devon UK

Re: Consensus on Rust Proofing?

Post by dave9118 » Sat Jan 19, 2019 11:03 pm

All good advice, many thanks for your thoughts. I'm buying a cheap HVLP gun to do the primer, and I'll probably use that to do the whole of the inside too before it gets a lick of paint there too. I think its going to be ok! :-)
"The explanation you are about to give, needs to be.... PHENOMENALLY good"!

Edmond Blackadder

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