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Treating rust

Posted: Wed Nov 06, 2019 5:48 pm
by parahandy 15
My '64 traveller restoration is progressing. Lots of replacement panels,and fabrication required . No surprise.!
I am cleaning off the surface rust with grinder/wire brush/ flapwheel and then treating with Phosphoric acid, and the results are very good.
I checked up the price of proprietary rust treatment and was a bit taken aback at the cost, so 5 litres of H3PO4 is under £20, which makes sense on every level. Brush it on, rub with stainless steel scourer ,wash off with dilute bicarb to neutralise. Leaves the metal clean and ready for priming. Stinks a bit though. Use with care, Gloves and full protection at all times.

Re: Treating rust

Posted: Wed Nov 06, 2019 7:01 pm
by jagnut66
Gloves and full protection at all times.
I don't think you can stress that enough using acid. Watch your eyes.
Best wishes,
Mike.

Re: Treating rust

Posted: Wed Nov 06, 2019 8:16 pm
by parahandy 15
Absolutely Mike. I also have a bucket of clean water nearby just in case of accidents .

After I rinse the metal off ,I use a hot air gun to dry it quickly before priming.

Re: Treating rust

Posted: Wed Nov 06, 2019 10:56 pm
by panky
I've use Bilt Hamber Deox gel with good results. Not as quick as acid but a lot less hazardous, washes off with water and, if the instructions are followed closely. it does a great job

Re: Treating rust

Posted: Thu Nov 07, 2019 8:46 am
by parahandy 15
Morning Panky, thanks for the reply. I know that there are many products on the market which do the job. However the reason for my original post was that plain Phosphoric acid is a very cheap method. At the risk of repeating myself, do be careful using any chemicals.
On the same(ish) subject, paint stripper ain't what it used to be . Nitromors is practically useless nowadays ,because the active ingredient was linked with health problems. It is still possible to buy old style dichloromethane stripper though, the main type is called Paramose,but is only obtainable through the trade,but any friendly decorator/furniture restorer should be able to help you .
Perhaps I should have put this post in the "Useful Tips" section. Just a thought. Hope this is useful to somebody. Have a good day ... off to do more welding.

Re: Treating rust

Posted: Thu Nov 07, 2019 2:27 pm
by Owlsman
Interesting to read about the formulaic change of Nitromors. Nothing to do with Moggies or even cars but I bought some recently (not having used for many a year) and my instant impression was that it was not as efficient as I remembered it. Now I know why.

It did the job, eventually, but it was pretty much one paint layer at a time whereas the 'original' stuff was taking 3 or 4 layers off just with one application.

Re: Treating rust

Posted: Thu Nov 07, 2019 3:08 pm
by geoberni
parahandy 15 wrote: Thu Nov 07, 2019 8:46 am
On the same(ish) subject, paint stripper ain't what it used to be . Nitromors is practically useless nowadays ,because the active ingredient was linked with health problems. It is still possible to buy old style dichloromethane stripper though, the main type is called Paramose,but is only obtainable through the trade,but any friendly decorator/furniture restorer should be able to help you .
From the Paramose website:
Paramose paint and varnish remover contains Dichloromethane which is now restricted under European regulation 455/2009/EC. From the 6th December 2011 restrictions are in place to limit the sale of this product to INDUSTRIAL USE - which means a facility for paint stripping activities. Orders can not be dispatched until the attached industrial declaration form has been signed and checked.

Other products containing Dichloromethane sold and used for other purposes (e.g. degreasing, adhesive removal, DCM gel cleaning), are not banned and can continue to be sold and used (for uses other than stripping paint). Those products are as follows

Paramose ARC Thin - Adhesive remover and cleaner • Paramose ARC thick - Adhesive remover and cleaner • AS1 Industrial strength Adhesive stripper • AS10 Industrial strength Adhesive stripper!
Dichloromethane is under increasing restrictions globally, not just in the EU. The USA banned it this year from use as a paint remover in non industrial premises.

See here and scroll to the section on Toxicity. https://en.wikipedia.org/wiki/Dichloromethane

Re: Treating rust

Posted: Thu Nov 07, 2019 5:11 pm
by parahandy 15
As I said you can obtain it via a professional contact, and it is better to use it either in a very well ventilated space, or outside.
The old original Nitromors was easily obtainable , contained dichloromethane and was around for years before it was reformulated.
The new stuff is worse than useless.

Re: Treating rust

Posted: Thu Nov 07, 2019 7:32 pm
by SteveClem
It’s the old problem, a balance between stuff that works and stuff that is ‘safe’ under current rules.
Years ago I stripped down a 3 story Victorian staircase that had been stained in thick,old,original varnish. The sort that was made out of dead animals. Modern varnish strippers just turned it into sticky porridge. Ammonia solution melted it away to a thin liquid that washed away with water.
The problem,of course, was that the smell was horrendous. Although it did clear the nose very effectively.
Anyway, I survived..

Re: Treating rust

Posted: Fri Nov 08, 2019 8:12 am
by GavinL
i had the same issues with paint stripper available in the shops, and bought 5L of "industrial" paint stripper in eBay, comes with the usual ' only to be used by professionals' warning. Found this was much more effective, and just like Nitromors used to be.

for larger items i prefer the electrolysis approach - large dustbin of washing soda, scrap metal as the anode and a battery charger. Works a treat https://www.instructables.com/id/Electr ... aka-Magic/

Re: Treating rust

Posted: Sat Nov 09, 2019 9:32 am
by parahandy 15
Back to the rusty stuff again,, here's one I did earlier This was 3 rounds of Phosphoric acid followed by neutralising with bicarb solution. I am not planning to reuse this panel!
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