Corrosion!

[Jon Weywadt]

Good point with the phosphoric acid/rust converter, Jon!
--------------
If reinforcement should be needed anyway, I'd prefer to have it done from the engine room side as I need to have to engine taken out anyway to fix a water leak.

/Anders

That does not sound good with the water leak 
Are you going to send the engine to Roy, or is that your spare engine going that way?

[Anders Dinsen]

That does not sound good with the water leak 
Are you going to send the engine to Roy, or is that your spare engine going that way?

I'll be doing that one myself. It's the sealing between the engine block and the cam cover that will need to be redone. A good cleaning of the engine will be done at the same time.

http://gallery.dinsen.net/v/biler/Matra/technical/water/DSC_4035_02S.JPG.html

My plan is to send the spare to Roy for a complete rebuild.

/Anders

[Anders Dinsen]

Ready for sand blasting...

[klumzer]

Have you checked the metal plate which is under the fender? It looked like this in my car. The chassis was not corroded there, but the plate was totally and the rivets too. I changed them to stainless steel plates.
Unfortunately they cannot be replaced without removing the fenders and you can only see the bottom of them.

[Anders Dinsen]

Have you checked the metal plate which is under the fender? It looked like this in my car.

It's looking bad. Worse than yours, actually
However, I'm not going to do it this time. The car will get a complete paintjob, and then I'll do those two plates (why did they not use galvanised steel there! )

By the way: How did you get the fenders off? Heat gun?

/Anders

[klumzer]

Here is a description how I did it:

http://www.matrasport.dk/forum/index.php/topic,2311.0.html

Do not laugh at the funny pictures...

It is easier to remove if the glue is warm. I did not use heat gun, because it was a sunny day. About 30C and the car was standing outside so it was quite warm. After removal the inner side of the fenders were reinforced by some epoxy resin. I also had to change the foil on the sides of the boot underneath the fenders.

If you have any question just ask me and I try to answer.

[Oetker]

Inspected my 1.6 at that point.


Some corrosion found.



Gonna brush most of.
Then put on rust converter and some layers of paint.
It isn't to bad but not as good as my 2.2 that is like new there.

Greetings Herman

[klumzer]

After 30 years it is not so much rust.
Have you removed the rust on the A-pillar? It looks much worse and the trailing arms also look rusty outside...
I hope you can prolonge the life of the car.

What is your plan with this car? You will sell it after repairing or keep it? 

[Oetker]

After 30 years it is not so much rust.
Have you removed the rust on the A-pillar? It looks much worse and the trailing arms also look rusty outside...
I hope you can prolonge the life of the car.

What is your plan with this car? You will sell it after repairing or keep it? 

I have a friend that is specialist in painting and welding the more difficult things.
I asked him to repair this without removing the front screen.

Before


Sanding down we saw there has been worked before on that spot.


He removed al the bad rust and the foam.
It is clear that the galvanisation had a airtrap at that point.


He welded a plate in and sprayed it with some Motip spraycan I had provided.




The A-stile wil have some rustprevention inside this week.

I am busy preparing the car to be my daily driver.
The engine is good.
The rest sucks, but I am busy fixing everything the car needs me to fix.
Already planted €1200.- parts in the car wich is far more then I payed for it.

Greeets Herman

[klumzer]

Nice job.

I think you will not be bored during the winter. 
But it is worth working a lot because another Murena will be saved. If I had more space for cars and more money...

[Anders Dinsen]

Almost there  

[klumzer]

Problem solved. Nice job.

[Oetker]

Same here.
Solved for the next decade

[Anders Dinsen]

Old, but not less relevant topic.

I've done some research on cold-galvanisation and has found some interesting resources.

My research lead me to Zinga who are makers of a professional grade 96% zinc cold-galvanisation product: https://www.zinga.eu/zingaspray/
The product is also available for professional spray painting and is intended to protect unprotected iron and repair damaged galvanized iron. According to their website it is used in various different environments, including off shore and wind mill industries.

Now, in the subject of this thread, the question is how we can protect already rusty surfaces. Zinga's faq addresses this question, but the marketing language is unclear about the outcome of spraying rusty surfaces:

"The performance of ZINGA is, like any coating or paint, highly dependent on the degree of surface preparation before application. Therefore, ZINGA can be applied on a slightly rusted surface, but due to the barrier of rust between ZINGA and steel, the galvanic protection is affected and therefore the performance of ZINGA is reduced. Since ZINGA can offer a sustainable, longlasting protection of steel surfaces, it is profitable to invest in a thorough surface preparation which prevents premature failure of the coating."

However, their section on surface preparation is a bit more helpful https://www.zinga.eu/application/surface-preparation/ as it instructs the surface to be rough by blasting to SA 2.5. This designation is according to an ISO stanard and is explained on the web site, but I've included a picture from the site below and a PDF showing even more details too (link to the attachment: http://www.matrasport.dk/forum/index.php?action=dlattach;topic=2502.0;attach=6662 )

Now, if sand blasting is not possible, Zinga SA 2 level clearnliness can be obtained by wire brush, and will also work, though not give quite the same level of protection:

"substrate should be grit blasted or slurry blasted to SA 2.5 (cleanliness) – or treated with a steel brush for small, non-critical applications. If the surface already has adequate roughness (due to weathering or previous blasting), the surface can also be cleaned to SA 2.5 by using UHP washing."

Now, in the past, I've applied a product similar to Zinga to areas where I only obtained SA 2 cleanliness, and I find that the zinc binds very well to the metal, even to the level that when I brush clean it using a rotating brush, the zinc paint still sticks to the metal in a way paint cannot do.

I'm going to use zinga on all areas of my chassis that either has salty surfaces and therefore needs fresh protection, or are rusty. In both cases, I'll clean down to SA 2, spray the area, and leave it there, inspecting it regularly. The world is not perfect, but in my dreasm, I'm going to strip my chassis completely down, grit blast everything that's not perfect to SA 2.5, and paint it all over in Zinga, repeating that process every 20 years

[JV]

Thanks!