Dealing with rust!!

[mgbroadster]

Merry Christmas All
The picture below is from the top of the wheel arch from my MGB project. The paint has been stripped back and the rust exposed. Without cutting and replacing what is the best way of dealing with it and which is the most effective brand of rust curer. Any help greatly appreciated. Mike

 

[georgetheforge]

i'd be tempted to try and get it shot blasted-

will take it back to bear metal, and 'remove' anything that's too thin/ rusted out so you can see the total damage

i've used a mini one from machine mart before was fine for patch type repairs,

best of luck, and have a good christmas

George

 

[mm289]

Whether it can be "treated" or needs replacing will depend on how bad the damage is, but as you have said without cutting and replacing i am assuming you are confident there is enough metal to still be structurally OK.

There are a number of rust converters available including Vactan and Hydrate 80, mostly based on phosphoric acid which converts the rust and stabilises the corrosion.

I use Hydrate 80 from Bilt Hamber and find it pretty good, I particularly like it cause it provides a paintable base even on clean metal. Some converters only "bind" when put on oxidised (rusty) metal and dont bite on clean steel. this means you have to clean up the "clean" steel before overpainting.

One caveat on the converters is they are not a cure all for heavy rust as they only convert the top surface. So if you have deep/flakey rust they will convert the top layer, you will paint then x months later be very dissapointed to see new rust bubbling through.

It is essential you get through the flakey/heavy rust first by abrasion of one sort or another before applying the converter.

If you have the time and facilities the best prep for a rusty panel is media blasting in my experience as this is the only method that will get rust out of pitted areas (sandpaper and even wire brushes only have limited effectiveness in my experience). The risk with media blasting is if you have heavy rust it can blow through and leave holes, but TBH if this is the case you are better knowing that now as you should be replacing or pathing the panel anyway

Hope that helps as a starter for 10, others will no doubt add from their experiences as well

MM

 

[mgbroadster]

That was very useful MM, thank you. The photo makes the panel look worse than it actually is in reality. I stripped the paint back with a polycarbide disc, very effective but a bit pricey given that each disc is c.£4. Any other opinions would still be appreciated!!

 

[awemawson]

Best rust remover I know is citric acid. It not viscous though so you have to soak items in a container of some sort. If your wing unbolts it'll be fine, but if it's welded you'd need a darn great bath! A 24 hour soak usually does it.

The advantage of citric acid is that the rust converts to iron citrate which is water soluble, so if you have a rusted up thread for instance, as the rust is disolved it comes out into the body of the liquid and eventually the solution will get into every nook and cranny. With phosphoric acid, iron phosphate is formed, and this is not soluble, so stays where it forms leaving threads still frozen.

At this very moment I have a plastic cattle trough of citric acid in my workshop cleaning up the mechanical bits of a very large planer / thicknesser.

 

[chunkolini]

The citric acid thing not being viscous.
I have used the Bilthamber version, DeoxyC good stuff.
To work on vertical surfaces soak kitchen towels in it then use cling film to wrap that onto the workpiece. Simples. Messy but worth the effort
Alternatively you can buy the gel version but I can steal kitchen towels from wifey.
I have cleaned some quite large awkward shaped workpieces like this.

 

[the artfull-codger]

Everyone seems to have their favourite treatment,if it's a small item I soak in vinegar, for larger jobs I sand[oops figure of speech!!] grit blast or if it's not convenient my preferred treatment is ''jelonite'' which incidently is approved for the MOD.

slan go fol

 

[Chipper]

I'd wire brush that and Jenolite it, or buy some phosphoric acid in bulk (same thing but cheaper by volume). Save the strip discs for paint, they do too much wallet damage otherwise...
Citric's ace if you can soak things in a bath of it.

A nice primer like Jotamastic or Epoxy mastic, it doesn't need spotless shiney bare metal. Lots of posts about these two on here.

 

[dannyp]

intresting stuff.

been wondering about rust converters myself muchly today, i have a vw golf that has some well established surface rust underneath, been trying to work out the best way to deal with it.

i was thinking of sandbalsting it then spraying with a rust eater but was wondering if it would work/ bind on the clean bits.

sensible course of action be, blast> rust eater > zinc phosphate primer > stonechip
> paint ?

any recomended products as id rather use stuff that works as i would prefer not to have to do it again

 

[kelsham]

I am fascinated by rust converters. I have tried most of them. I have come to the conclusion that mechanical cleaning is a major part of the answer. I have just been cleaning off a rear wing for a 1931 BSA car. Very rusty.

I started off with a mixture of wire brushes and polycarbide discs on an electric drill ,I then applied Jenolite, and using a hand held wire brush I rubbed away at the surface.
This lifted the rust deep down in the pitted areas.
Did this several times. Eventually the Jenolite surface remained clear and stopped turning red with rust. Final wipe with Jenolite.

Not a procedure for the faint hearted.

I have used Hydrate 80 in the past and Loctite rust remedy, Trustan, no longer on the market. and Fertran. As stated earlier if you test by applying the product to a rusty surface and then when dry, scrape the surface you will find rust still lurks beneath the coating.

I once did a dashboard and thoroughly cleaned the surface, it had deep pits I used Trustan and then primer and topcoat. 35 years on it still is rust free. Of course it is not in the wet.

I used to favour Jenolite and then Bonda primer. Bonda primer is not easy to obtain these days, I have a large can I am slowly using.

Don't forget to get a coating on as soon as possible after treating and bear in mind most primers are porous. So you will need a topcoat.

 

[stuvy]

Don't forget to get a coating on as soon as possible after treating and bear in mind most primers are porous. So you will need a topcoat.

Apart from brands, techniques used, this last part is the most important IMO

 

[mike 109444]

There was a test being run in "Practicl Classic" earler this year where they were painting stripes of different types of rust treatment on the bonnet of a Ford Siera. I did not get the followup mag to see the outcome of the test ..Doh... They were even trying a stripe of engin oil. Anybody know the outcome? If the part to be de rusted is removable try the washing soda and battery charger methord, it works a treat.... now I just need to find a tub big enough to drop the whole car in and jobs a good'un..... spare hot tub anyone?

 

[mgbroadster]

I think what you are looking for can be found at :

http://rust.co.uk/filestore/Practical_Classics_Rust_Converter_Test.pdf

Interesting article.

 

[Chipper]

Porous primers is why I use the marine epoxies (rated below waterline), or automotive 2k epoxy.

 

[awemawson]

It's not as hard as you may think to make a tank big enough for a car body and total immersion. Make up a suitably braced timber structure, lay a sheet of heavy duty polythene over it, pressing down into the corners, then carefully lower your item in. Wooden bearers to take the weight are a good idea to prevent tearing the polythene. There are many examples on the web of people doing just this, mainly in America. Google electrolytic rust removal, you'd be amazed what people are dunking !!!!

 

[Windy Miller]

There was a test being run in "Practicl Classic" earler this year where they were painting stripes of different types of rust treatment on the bonnet of a Ford Siera. I did not get the followup mag to see the outcome of the test ..Doh... They were even trying a stripe of engin oil. Anybody know the outcome? If the part to be de rusted is removable try the washing soda and battery charger methord, it works a treat.... now I just need to find a tub big enough to drop the whole car in and jobs a good'un..... spare hot tub anyone?

I heard on the radio yesterday that someone 'round here came home to find their hot tub had been stolen - was it you that done it?

 

[mike 109444]

Ahhhh thoses lovely bubbles.... eh what who's knocking at the door with there big red key..... cripes it's the rozzers scarper and don't forget me frount wings

 

[Lawnmowerboy]

dont switch the lights on either theres tons of hydrogen coming off them electro soda baths i learned that the hard wat

 

[bigbird76]

phosphoric acid 75% is awesome stuff

I had 25Ltr from a brewery and it is great for small parts or hard to reach areas of the car. just make up a solution it can be diluted with water, Yes water...

It eats away the rust but leaves the good steel alone. any rust that is actually eaten into the steel can be removed with this stuff.

I made some up in a bucket and threw in some suspension parts and left them 24hrs, Was very suprised at the results.

Leigh

 

[jordan1]

I used to favour Jenolite and then Bonda primer. Bonda primer is not easy to obtain these days, I have a large can I am slowly using.

That's going back a bit, happy memories with my dad , he used it a lot.