Kurust to treat pitting

[M@tt]

Hi

I'm prepping my old 205 CTI for its respray I've been working my way round the front of the car removing the rust with various wire brushes, sanding discs and flap wheels etc.

however there are certain areas which have pin prick style rust pitting but because the panels are so thin i don't want to go too aggressive with the grinding and risk going through the metal. Therefore I'm thinking i probably need to use some kurust or the like on these affected areas.

Is it best to apply the kurust over and around the area, let it work for the required period then sand/grind back to bare metal leaving only the small pitted sections covered in kurust before applying my U-POL acid etch primer(or etch weld primer in the areas where i need to spot weld the new front panel on)

Cheers

Matt

 

[Coo]

I'd recommend Bilt Hamber Deox Gel

http://www.bilthamber.com/deoxgelhowto.html

I got some of the powder deox stuff yesterday and it works a treat.

 

[jaykay]

if you have pinholes right through,you'll have trouble of paint bubbling up.

 

[M@tt]

my description wasn't brilliant, the pitting isn't all the way through, its just that i's quite fine and probably about half the thickness of the material but i riisk taking too much good material away with the grinder.

I've ordered some of that deox-gel anyway so i'll give that a whirl and see how i get on

 

[Antsuno2]

i use hydrate 80 to paint over scabs, very good it forms a barrier the rust cant break through, the gel is for removing rust , Ant!

 

[GeorgeB]

i don't want to go too aggressive with the grinding and risk going through the metal. Therefore I'm thinking i probably need to use some kurust or the like on these affected areas.

I've recently been de-rusting various metal parts and panels and have had a chance to reconsider what I see as the best methods. I've been using electrolysis for years' and this remains my favourite. In time (2 or 3 days), it will get rid of every last grain of rust without removing a single molecule of steel. From what you say, you won't be able to do much better than that! It's also far and away the cheapest method, as it happens.

Some other members on this forum said they prefer citric acid, Kurust or whatever, so I gave those another chance. My test batch of chemicals included vinegar. They all work, after a fashion, but they're not as good as electrolysis and the cost of these chemicals (even vinegar) is a lot higher than the electricity and a teaspoon of soda used for electrolysis.

Best of the chemicals in my experience (but still not as good as electrolysis) was Swarfega metal restorer which I bought in B&Q. It cost about £8 for 5 litres but it's diluted with water to at least 3:1 so it's very good value compared to some of the other products mentioned here.

I take metal back to bright steel before I apply primer. I would NEVER leave a coating of Kurust or anything else below the primer. Kurust and other rust treatments simply cannot form as good a bond as primer. It's not a case of leaving Kurust to seal in, or keep out, the rust. There shouldn't be any rust there!

 

[jaykay]

jk

at times,i have used solder on pinholes.

 

[M@tt]

The problem i have with the car is that its parts like chassis rails and panels that have the rust so i't's not really possible to dunk them in a bath of fluid so i'm stuck with paint on liquids/gel.

With the swarfega metal restorer is it paint-on-abale or is it designed to be used as a bath to dunk items into?

I've tried the vinegar solution as well and found it worked fairly well (tescos value 1 litre vingegar 13p , the tesco's home delivery man thought i must be bomb making when i ordered 20l in our weekly shop one week!), but it did appear to stain the items once you took them out even when washed and dried and they got a surface coating of rust very quickly indeed i found.

 

[GeorgeB]

The problem i have with the car is that its parts like chassis rails and panels that have the rust so i't's not really possible to dunk them in a bath of fluid so i'm stuck with paint on liquids/gel.

You're right - that's more of a challenge but I've even successfully used electrolysis on a large vertical panel, like a car wing, so anything is possible!

>With the swarfega metal restorer is it paint-on-abale
>or is it designed to be used as a bath to dunk items into?

It's liquid, rather than gel, so it doesn't 'stick' as such but if you just keep re-painting the area to keep it wet, it does still work.

>(vinegar) did appear to stain the items once you took them out

Yes, I find that's a problem with all the chemicals, which is one further disadvantage, compared to electrolysis. It's best not to let them dry out.

>even when washed and dried and they got a
>surface coating of rust very quickly indeed i found.

I fear that's just a reflection of the rapid oxidation of a fresh steel surface, if not painted quite quickly. At least this new surface rust does brush off quite easily.

 

[grandads_shed]

You're right - that's more of a challenge but I've even successfully used electrolysis .

any more advise on the electrolysis method?
like how to make the setup. and cemicals and quantitys etc?
whats the voltage? A/C or D/C- I assume you use electric hence the name.

 

[GeorgeB]

any more advise on the electrolysis method?
like how to make the setup. and cemicals and quantitys etc?
whats the voltage? A/C or D/C- I assume you use electric hence the name.

cathode (rusted part to be cleaned) = 12v- negative
anode (scrap ferrous metal) = 12v+ postive
Use 1 tbls washing soda per gallon of tap water
or less than 1tsp washing soda per litre

That's 12v - and + from a normal little 5 amp car battery charger in my case. The meter reads about 0.5-1amp when charging, with the charger set on low. High amperages are less desirable.

I find steel sheet best for the anode because there's a greater surface area, but you can use a bar.

Position the anode and cathode quite closely together, without touching (shorting). Leave overnight, or as long as needed. Also reposition from time to time, if needed. The red rust will turn black and with a bit of effort can then be brushed off. I use a glass jug, plastic bucket or other non-metallic container.

 

[MajorPayne]

Been doing some of this today and using the Kurust product,

I've got a spare cordless battery drill charger hanging around and it's output was 24v@2.5amps works awesomely to be honest it's DC by the way but I have tried an AC 240v which converted the AC again into 9v@300ma and I have to say that did not do so well. I can't work out if it's because it's a lower setting of voltage but anyway I'd stick with DC because it's constant rated current rather then an off/on motion and after all we want to repel the rust and that's prolly best done with a DC supply..

I've a few links you could use but really they have been nicked from another thread.
So I'll give you the link and you can have a lok yourself

The Kurust product is okey, I've used it for getting to harder to reach places or things like you've mentioned thin areas on a car and places like that. it's alright but I'm honestly finding using the electrolysis a better bet because it takes the harder scrubbing work out of the equation but takes allota time.

Today along the part I've been cleaning has been in a good 8 hours and I would like to leave it for another 24 hours if I can, but about every 4~5 hours I take it out of the bath give it a good clean, and place it back in the bath and give it another whirl

Basically get yourself a plastic bucket in my case a 50L storage container, an AC/DC power supply, rig up the + to a few bit's of metal and lay them around the part your wishing to clean and connect the - to the part you would like cleaned of rust. Stick the power on an just wait, ohh forgot to mention when you fill up with water add in some washing powder or baking soda you don't need too much just enough to raise the conductivity of the water a little I guess

I'm honestly no expert though and could not guide anyone on much about the subject.

Kind regards,
MajorPayne

http://www.mig-welding.co.uk/forum/showthread.php?t=8143
http://www.mig-welding.co.uk/forum/showthread.php?t=12686

 

[keni010]

Kurust...

... try Vactan rust treatment, apparently the U.S. navy use it!

 

[paultheg33k]

... try Vactan rust treatment, apparently the U.S. navy use it!

I'd vote for Vactan too.

Much discussed on the CanalWorld forums, searchable like so:

http://www.greenferret.net/cwfsearc...i&cof=FORID:9&ie=UTF-8&q=vactan&sa=Search#926

In the following pic, my better half, Creamcheese, has treated the large now-black areas with Vactan, and is overpainting with red oxide primer.

The vactan contains an acrylic primer and dries to a hard shiny, black finish, suitable for overcoating or leaving as a holding coat by itself. No need to rinse it off, like Fertan and the rest.

PC

 

[droopsnoot]

any more advise on the electrolysis method?
like how to make the setup. and cemicals and quantitys etc?
whats the voltage? A/C or D/C- I assume you use electric hence the name.

Check out this thread: http://www.mig-welding.co.uk/forum/showthread.php?t=12686